Department of Environment, Food and Rural...

Department of Environment, Food and Rural Affairs

Rapid Evidence Assessment

Cement Kiln Dust and By-Pass Dust from Cement Kilns

April 2015

Amec Foster Wheeler Environment

& Infrastructure UK Limited

3 © Amec Foster Wheeler Environment & Infrastructure UK Limited

April 2015 Doc Ref. 36656 Final Report 15150i3

Executive summary

Purpose of this report

The Environment Agency (“the Agency”) regulates the spreading of waste to agricultural land in England

under the Environmental Permitting Regulations (EPR) 2010. Under EPR the operator is required to obtain a

standard rules or bespoke permit, and make a separate deployment application for waste to be spread on a

specific area of land. Upon receipt of the deployment application, the staff in the National Permitting Service

(NPS) must consider the potential adverse impacts on human health and the environment. This requires a

clear understanding of the physical, biological and chemical hazards presented by a specific waste type,

particularly in an agricultural context. The purpose of this report is to identify the primary hazards associated

with Cement Kiln Dust (CKD) (part of Waste Code 10 13 12), Cement By-pass Dust (BPD) (Waste Code 10

13 13), including conditioned waste (Waste Code 19 02 03 and 19 02 04) to support NPS officers in their

deployment review.

This Rapid Evidence Assessment (REA) has been undertaken in accordance with the REA Methodology

(Environment Agency, 2014); in the present report the data search strategy and inclusion and exclusion

criteria are summarised in Section 3 and presented within Appendix B.

The REA addresses the overarching primary question “What key hazards are associated with cement kiln

dust and by-pass dust which could present a risk to critical receptors1 during or after landspreading on

agricultural land”. A series of secondary questions are also asked to provide more detailed evidence to

identify the relevant pathways and receptors for particular waste streams and identify key hazards which may

impact upon these. The responses to these questions are provided in an Evidence Extraction spreadsheet

(Appendix B).

Amec Foster Wheeler has identified numerous sources of evidence which have been used to provide

answers to the primary and associated secondary questions. These include both literature sources, which

range from peer reviewed journal articles and reports to unpublished documents and information provided by

industry (see Appendix B). The main findings of the evidence extraction process are summarised below.

UK Cement Industry

All existing cement works in the UK comprise either dry process or semi-dry process kilns, which produce

either CKD or BPD. A total of eleven cement manufacturing facilities are currently in operation within the UK,

which are operated by four producers: CEMEX UK, Hanson Cement, Lafarge Tarmac, and Hope

Construction Materials. CKD or BPD is produced depending on the infrastructure in place at each facility.

Waste Production and Form

Dusts from cement kilns comprise fine particulate material, which is generated from cement kilns during the

process of cement clinker manufacture (the product). CKD comprises a mixture of partially calcined2 and

unreacted raw feed, clinker dust and ash, enriched with alkali sulphates, halides and other volatiles. The

CKD composition (both chemical and in particle size terms) can vary over time and between facilities, and

typically comprises particles representing the raw feed mix at various stages of burning, particles of clinker,

and a limited number of particles eroded from the kiln interior and associated apparatus.

Cement BPD comprises fully calcined dusts collected from the by-pass system de-dusting apparatus of

certain kiln designs (suspension preheater, precalciner, and grate preheater). The by-pass system extracts

process gases high in chlorine, sulphur and alkalis, therefore BPD tends to contain higher concentrations of

these substances than CKD. Similarly to CKD, BPD composition can vary significantly between facilities and

over time.

1 Critical receptors is the collective term for humans, controlled waters and dependant ecosystems, wildlife, soil (quality), air quality and

property in the form of livestock and crops. The critical receptors will be dependent on the type of waste and site specific information for

each deployment application.

2 Heating to cause oxidation, reduction and loss of water/volatile matter.



Factors affecting dust composition are as follows:

Variations in kiln design / process;

Dust collection systems in place, including whether a by-pass system is in place;

Changes in kiln temperature;

Raw material inputs (including co-processing of wastes); and

Fuel source (including substitute fuels such as refuse derived fuel).

Both CKD and BPD can be present in either ‘conditioned’ or ‘unconditioned’ form, dependent on whether the

dust has been treated with water. Conditioning is traditionally undertaken for ease of handling in order to

minimise dust transportation and deposition issues.

Benefits and Land Application

CKD and BPD application to agricultural land can take place for a range of purposes, primarily as a means of

stabilising and raising soil pH in acidic soils (i.e. as an agricultural liming substitute), and as a fertilising agent

due to the presence of typically high concentrations of potassium and sulphur.

A UK landspreading operator has provided two example deployment forms which demonstrate the

concentrations of nutrients that can applied to land from BPD. It appears that generally these dusts contain

a higher proportion of nutrients than other liming materials, but have a lower neutralising value. However,

evidence in the literature suggests that, due to the smaller particle size of these dusts in comparison to liming

materials, they can be as effective as lime at altering soil pH, as they are easily incorporated into soils.

The UK landspreading operator has indicated that generally this material is applied to land at a rate of up to

4.5 tonnes per hectare, at intervals of 3 years. This material is generally applied to arable land in autumn

and grasslands in the spring.

Chemical Hazards

CKD and BPD are alkaline in nature, with a typical pH of around 12.5 pH units.

Concentrations of metals within CKD/BPD vary widely between producers, with a smaller variability being

identified between samples at individual facilities. The concentrations of semi-volatile metals, such as lead,

appear to be particularly susceptible to variation.

A comparison has been undertaken between metal concentrations within CKD and BPD samples collected

from the UK and the USA, which demonstrates that differences in the chemical composition of raw materials

used can significantly influence the chemical composition of the resultant CKD and BPD.

Low concentrations of organic contaminants, including dioxins, furans and PCBs have been identified within

samples of CKD and BPD from UK producers. The chemical results support the findings of the literature

review and are considered unlikely to present a significant risk to relevant receptors.

Samples of CKD and BPD from the UK have not been analysed for the potential presence of pesticides and

radionuclides. However, previous investigation of CKD composition by the USEPA has indicated that these

substances are unlikely to be present at significant concentrations, or to be artificially enhanced to a

significant degree, within CKD (and by extension BPD) as a result of the cement production process.

Leachate generated by CKD and BPD has been found by analysis to be alkaline, with pH values typically in

excess of 12.

The concentrations of many metal contaminants within leachate vary widely between samples, with

occasional high concentrations recorded for metals, in particular lead, barium and chromium in BPD and

molybdenum and lead in CKD.

A review of UK specific data for unconditioned and conditioned BPD suggests that leachable metal

concentrations are lower within conditioned BPD to those within unconditioned BPD. However, this is based

on a limited dataset and the reasons for this are uncertain.



Leachable concentrations of metals within CKD/BPD as reported within the literature are typically low, with

only occasional individual samples being found to exceed the adopted screening criteria in the literature.

No significant leachable concentrations of dioxins and dibenzofurans were identified in CKD leachate in a

published USEPA study.

Highly soluble salts have been identified within CKD leachate as part of the literature review. These can

influence the dissolution or stability of other elements within the dust. One literature source (Peters, 1998)

indicates that high concentrations of soluble salts can result in high total dissolved solids (TDS) within

leachate if CKD is improperly managed3.

Concentrations of a selection of contaminants identified in BPD and CKD have been compared to those

reported for UK rural soils and other fertilisers and liming materials. The results have shown:

Concentrations of arsenic, beryllium, manganese and boron in CKD and BPD are broadly

comparable to those reported in UK rural soils;

Concentrations of antimony, cadmium, copper, mercury, lead, molybdenum, cobalt, chromium,

thallium, silver, selenium, barium, vanadium and zinc have been reported in CKD and / or BPD

at concentrations above that reported in UK rural soils;

Concentrations of benzo(a)pyrene and dioxins in BPD have been identified at comparable

concentrations to UK rural soils;

A comparison of contaminant concentrations identified within BPD / CKD and other fertilisers

and liming materials has been made, with varying results being noted; and

Generally concentrations of metals are higher in BPD / CKD in comparison to other liming

materials.

Plant and Animal Pathogens

Plant and animal pathogens are considered to be unlikely to be present within CKD and BPD, given the high

temperatures at which the dusts are produced and their high pH.

Invasive Weeds

Invasive weeds are considered to be unlikely to be present within CKD and BPD, given the high

temperatures at which the dusts are produced and their high pH.

Physical Contaminants

Due to the physical nature of the CKD/BPD produced by the cement manufacture facilities (i.e. a fine dust,

subsequently conditioned or left unconditioned), notable physical contaminants are unlikely to be present.

Due to the very high kiln operational temperatures and long residence times within the kiln, any physical

contaminants entering the kiln are likely to be destroyed or exit the process in the clinker.

Nuisance

CKD/BPD is described as odourless, and due to the temperature at which these dusts are produced, any

significant quantity of organic matter which might attract pests or produce odour by decomposition would be

destroyed.

The potential for dust to pose a nuisance is considered to be a hazard for CKD and BPD. However, the

potential for dust generation is reduced by the application of CKD and BPD in conditioned rather than

unconditioned form to agricultural land.

Hazard Evaluation

Based on the above findings, a Master List of hazards for BPD and CKD have been determined as follows:

3 No further information is provide in terms of what improper management relates to



Master List of Hazards for BPD

Hazards Relevant Receptor

Chemical Hazards

Metals and metalloids – antimony, cadmium, chromium, copper, lead, thallium, zinc, silver, molybdenum, selenium, barium*, mercury

Soil quality, human, livestock / ecology and crops, surface water and groundwater

Soluble salts, principally potassium, fluoride and chloride Soil quality, livestock, crops, groundwater and surface water

Nuisance

Dust Air quality and humans

* CKD appears to contain concentrations of barium above background rural UK soils, but no testing results have been

provided for barium in BPD so this is considered as a possible hazard

Master List of Hazards for CKD


Chemical Hazards

Metals and metalloids – antimony, cadmium, chromium, copper, lead, thallium, zinc, molybdenum, silver, vanadium, nickel, barium, selenium**, mercury**, cobalt


Soluble salts, principally potassium, fluoride and chloride Soil quality, Livestock, crops, groundwater and surface water

Dioxins and furans Soil quality, humans and livestock / ecology

Nuisance


** Selenium and mercury have been identified as master hazard for BPD, but no testing results have been provided for

selenium or mercury in CKD so these are considered as a possible hazard

This Master List of hazards was then screened to determine which hazards have the potential to represent a

significant risk to identified receptors under generic conditions. Note that due to the limited chemical data

provided for CKD it has not been possible to refine the Master List of hazards specified above. The resulting

Principal List of hazards for BPD are:

Principal List of Hazards for BPD


Chemical Hazards

Metals and metalloids – cadmium, lead, thallium, selenium, barium*

Human, livestock, soil quality, surface water and groundwater

Soluble salts, principally potassium, fluoride and chloride Groundwater and surface water

Nuisance

Dust (from unconditioned BPD) Air quality and humans


provided for barium in BPD so this is considered as a possible hazard.

The risks from these master and principal hazards are considered likely to be successfully mitigated through

the use of good practice during the transport, storage and application of these dusts to land and through the



use of appropriate management practices and compliance with the restrictions on application rates and set-

off distances under a standard rules permit. These factors should be considered by the operator and evident

on the deployment application.

Amec Foster Wheeler has identified a number of limitations with the REA and data obtained, which are

detailed in full in Section 5.2. The primary limitations relate to issues presented due to the time constraints of

the project, limitations of the data provided by industry and that identified within the literature.

Amec Foster Wheeler has recommended that further investigation should be undertaken to refine and

confirm the findings of this REA, as follows:

To collate further quantitative data to fill in data gaps within the currently available UK industry

dataset, particularly to address the lack of UK data for CKD; and

Undertake further investigation and assessment, comprising pot and field trials and bench scale

column tests to provide further evidence on the risks potentially posed to livestock, human

health and to controlled waters from metals contamination.



Contents

1. Introduction 10

1.1 Background 10

1.2 Terms of Reference 10

1.3 Structure of this Document 10

2. Summary and REA Roadmap 11

2.1 Summary Table 11

2.2 Range of Typical Contaminant Concentrations 12

2.3 Individual Waste Stream Roadmap 18

3. REA Scope, Approach and Methodology 20

3.1 Research Questions and Scope 20

3.2 Approach and Methodology 22 3.2.1 Initial Literature Review 22

4. Evaluation of Evidence 26

4.1 Introduction 26

4.2 Quality of the Evidence Collected 26

4.3 Synthesis of Data 26

4.4 REA Findings 27 4.4.1 Cement Manufacturing in the UK 27 4.4.2 Waste Production and Form 30 4.4.3 Benefits from landspreading 30 4.4.4 Land Application 34 4.4.5 Reasons for Variability in Composition 35 4.4.6 Chemical Hazards 48 4.4.7 Concentrations relative to comparators 55 4.4.8 Plant and Animal Pathogens 62 4.4.9 Invasive Weeds 62 4.4.10 Physical Contaminants 62 4.4.11 Nuisance 62 4.4.12 Other Environmental Hazards 63

4.5 Hazard Evaluation and Screening 63 4.5.1 Master List of Hazards 63 4.5.2 Principal List of Hazards 65

4.6 Refined Generic Conceptual Model 78

5. Conclusions and Recommendations 80

5.1 Conclusions 80

5.2 Limitations and constraints 80

5.3 Recommendations 83

6. References 84



7. Abbreviations 87

8. Glossary 88

Table 2.1 Range of Contaminant Concentrations for CKD (unconditioned)4 13 Table 2.2 Range of Contaminant Concentrations for BPD (unconditioned) 14 Table 2.3 Range of Contaminant Concentrations for BPD (conditioned)4 16 Table 3.1 Secondary Questions 20 Table 3.2 Databases and Organisations 22 Table 3.3 Keywords 23 Table 4.1 Quality Indicators for the REA 26 Table 4.2 Concentrations of beneficial elements found in BPD and other fertilisers / soil conditioners 32 Table 4.3 Concentrations of beneficial elements found in conditioned BPD and other liming materials 33 Table 4.4 Example of total nutrients supplied (kg/ha) 34 Table 4.5 Example of available nutrients year after application (kg/ha) 35 Table 4.6 Sources of selected potential contaminants in raw materials and fuels 42 Table 4.7 Typical concentrations from raw materials in the UK (mg/kg) 44 Table 4.8 Typical concentrations from fuels in the UK (mg/kg) 46 Table 4.9 Typical inorganic composition of BPD 49 Table 4.10 Metal concentrations compared to typical background concentrations in the rural UK soils 55 Table 4.11 Selected chemical properties of CKD and Lime 57 Table 4.12 A Comparison of metals and other elements in CKD/BPD with other fertilisers / soil improvers 59 Table 4.13 Justification for Choice of Master List of Hazards for BPD 63 Table 4.14 Justification for Choice of Master List of Hazards for CKD 64 Table 4.15 Master List of Hazards for BPD 65 Table 4.16 Master List of Hazards for CKD 65 Table 4.17 Concentrations of potentially toxic elements (PTE) in BPD compared with maximum permissible concentrations 67 Table 4.18 Estimated rate of PTE addition based on an application rate of BPD at 4.5 t/ha 68 Table 4.19 Estimated Potential Enrichment of median UK rural soils following one 4.5 t/ha application 69 Table 4.20 Justification for Choice of Principal List of Hazards for BPD 77 Table 4.21 Principal List of Hazards for BPD 78 Table 4.22 Summary Generic Conceptual Model for Landspreading CKD and BPD to Agricultural Land 79 Table A1 Summary Generic Conceptual Model for Landspreading to Agricultural Land

Figure 2.1 Individual Waste Stream REA Roadmap 19 Figure 4.1 Map Showing Location of Cement Works 29 Figure 4.2 Typical Semi-Dry Process (taken from Environment Agency et al., 2001) 37 Figure 4.3 Typical Pre-Calcinator Dry Kiln (taken from Environment Agency et al., 2001) 38

Appendix A Generic Conceptual Model Appendix B Search Strategy and Evidence Extracted



1. Introduction

1.1 Background

The Environment Agency (“the Agency”) regulates the spreading of waste to agricultural land in England

under the Environmental Permitting Regulations (EPR) 2010. Under EPR the operator is required to obtain a

standard rules or bespoke permit, and make a separate deployment application for waste to be spread on a

specific area of land. Upon receipt of the deployment application, the staff in the National Permitting Service

(NPS) must consider the potential adverse impacts on human health and the environment4. This requires a

clear understanding of the physical, biological and chemical hazards presented by a specific waste type,

particularly in an agricultural context. The purpose of this Rapid Evidence Assessment (REA) is to identify

the primary hazards associated with Cement Kiln Dust (CKD) Cement By-pass Dust (BPD) (Waste Code 10

13 12 and 10 13 13), including conditioned waste (Waste Code 19 02 03 and 19 02 04) to support NPS

officers in their deployment review.

1.2 Terms of Reference

This project has been carried out by Amec Foster Wheeler Environment & Infrastructure UK Limited (Amec

Foster Wheeler) in accordance with Defra’s instruction (reference LM0107) dated 11 December 2014, under

Contract RM830. This document is the third example aimed at trialling the REA methodology developed

under the Environment Agency Contract (reference. HOEV121302/66) and reported in “Hazards from

Landspreading (SR2010 No. 4 wastes) – Methodology for Rapid Evidence Assessment” (dated March 2014).

1.3 Structure of this Document

This REA report is structured as follows:

Section 1 provides the background and structure of the document.

Section 2 presents an REA summary and roadmap, which can be used for rapid referencing by

Agency staff.

Section 3 describes the REA Scope (with primary and secondary research questions), approach

and methodology. This is further supported by information presented within the Evidence

Extraction spreadsheet (Appendix B).

Section 4 discusses the evidence collected as part of this REA under the defined headings of

the secondary questions. This information has been used to compile a Master List of hazards in

Section 4.5.1 with the Principal List of hazards and refined conceptual model presented in

Sections 4.5.2 and 4.6, respectively. The answers to individual secondary questions and all

quantitative data obtained as part of the REA are presented within the Evidence Extraction

spreadsheet (Appendix B).

Section 5 presents the conclusions and recommendations based on the information obtained.

4 The operator must also demonstrate (and permitting staff must evaluate) the agricultural benefit from applying the wastes

under a specific deployment but this is not the focus of this REA.



2. Summary and REA Roadmap

This Section provides a summary of key information relating to CKD and BPD, including the Master and

Principal List of hazards (Section 2.1), a range of typical contaminant concentrations identified within CKD

and BPD (Section 2.2) and an individual waste stream roadmap (Section 3.3).

2.1 Summary Table

Waste type: Cement Kiln Dust and By-Pass Dust from Cement Kilns

Waste Codes: 10 13 12, 10 13 13, 19 02 03 and 19 02 04

SR2010 No. 4 permitted waste type? : Yes- Table 2.2B List B Waste

Waste Description:

Cement kiln dust (CKD) – fine particulate material generated from cement clinker, comprising a mixture of partly calcined and unreacted raw feed, clinker and ash

By-Pass dust (BPD) – highly calcined fine particulate material collected from cement kiln by-pass systems

Date: March 2015 Version: 1.1

Assessment team : Amec Foster Wheeler (compiled by Becky Whiteley and Tom Sheen, reviewed by Tony Marsland)

Methodology: Hazards from Landspreading (SR2010 No. 4 wastes) – Methodology for Rapid Evidence Assessment (Amec Foster Wheeler for Environment Agency, March 2014)

Primary question: “What key hazards are associated with cement kiln dust and by-pass dust from cement kilns which could present a risk to critical receptors during or after landspreading on agricultural land”.

Master List of Hazards for BPD

Chemical Hazards Relevant Receptor



Soluble salts, principally potassium, fluoride and chloride

Groundwater, surface waters, crops, livestock, soil quality

Nuisance


Principal List of Hazards for BPD

Chemical Hazards

Metals and metalloids – cadmium, lead, thallium, selenium, barium



Groundwater and surface water

Nuisance




Master List of Hazards CKD

Chemical Hazards Relevant Receptor

Metals and metalloids – Metals and metalloids – antimony, cadmium, chromium, copper, lead, thallium, zinc, molybdenum, silver, vanadium, nickel, barium, selenium, mercury, cobalt


Dioxins and Furans Soil quality, humans and livestock / ecology


Groundwater, surface waters, crops, livestock, soil quality

Nuisance


Items to consider on Deployment Application

Concentration of contaminants in receiving soils – especially substances on the Principal List of hazards

Consideration of potential contaminant loading

Proposed use of land to receive deployment – crop/livestock type(s)

Confirmation of conditioning of waste. If unconditioned waste is to be used a dust management plan is required.

2.2 Range of Typical Contaminant Concentrations

The range of typical contaminant concentrations, identified during this REA for CKD (unconditioned) and

BPD (conditioned and unconditioned) in the data supplied by industry, is presented below in Table 2.1, Table

2.2 and Table 2.3. The arithmetic means, median concentrations and 95% percentile values for these data

are also presented for those determinands which have more than 10 samples. The calculation of these

statistics is not considered appropriate for those determinands which have less than 10 samples.

Analytical data has been provided for a limited number of samples for unconditioned CKD and conditioned

BPD. As a result, it was not considered appropriate to present median and 95% percentile concentrations

for these wastes types. Note that there is currently only one cement works in the UK that produces CKD

waste. The data presented below in Table 2.1 therefore only characterises the CKD produced from this one

location. The data for BPD is representative of samples collected and analysed from four cement works

across the UK. On this basis, it is likely that CKD will represent a small proportion of the total quantity of

cement dusts that are available and may be put forward for spreading to land.

The range of concentrations for BPD (unconditioned) is based on UK industry provided data only, with the

CKD (unconditioned) data being augmented with that provided by the Environment Agency. The leachate

data summarised for both unconditioned CKD and BPD is based on that provided by UK industry only.

The conditioned BPD data are representative of that provided by a UK landspreading operator and have

been supplemented with one result from a conditioned BPD sample provided by UK cement industry. No

chemical data representative of conditioned CKD have been provided by industry or others to inform this

REA. The synthesis of data for this REA is discussed further in Section 4.3.

Note that these ranges are provided to identify waste material which may lie outside of the norm and are not

intended to be used as threshold concentrations for risk assessment purposes. A more detailed list of

contaminants, including basic statistics is presented in Appendix B.

It is recognised that there is likely to be some variation in concentrations of contaminants analysed by

different laboratories, using different methodologies etc. However, for the purpose of this REA, the data are

considered to be comparable and representative of contaminant concentrations present within CKD and

BPD.



Table 2.1 Range of Contaminant Concentrations for CKD (unconditioned)4

Determinand No. of samples range

based on Minimum Maximum

Solid Data (mg/kg)1

pH (units) 1 12.8 -

Antimony 2 10 18

Arsenic 4 4 14

Cadmium 2 5 28

Chromium 4 45 104

Cobalt 2 10 13

Copper 4 13 140

Lead 4 250 580

Manganese 4 >250 910

Molybdenum 2 8 12

Nickel 4 125 192

Vanadium 2 450 600

Zinc 2 >250 -

Thallium 1 18 -

Silver 2 3 4

Silicon 2 >250 -

Aluminium 2 >250 -

Iron 2 >250 -

Calcium 2 >250 -

Free lime as Ca(OH)2 4 24300 78000

Magnesium 2 >250 -

Potassium 2 >250 -

Sulphur 2 >250 -

Total organic carbon (%) 1 0.25 -

Total petroleum hydrocarbons >EC10-40 1 126 -

Total polycyclic aromatic hydrocarbons 1 <1.28 -

PCBs (µg/kg)3 1 <5 -

Leachate2 (mg/l)

pH (units) 4 13 13.1

Antimony 4 0.001 -

Arsenic 4 0.002 0.003

Barium 4 0.475 0.616

Cadmium 4 0.0032 0.0104

Chromium 4 0.504 1.41



Determinand No. of samples range

based on Minimum Maximum

Copper 4 0.009 0.107

Lead 4 0.214 2.71

Mercury 4 0.0001 0.0002

Molybdenum 4 1.3 4.64

Nickel 4 0.017 0.023

Selenium 4 0.21 1.17

Zinc 4 0.358 1.48

Chloride 4 281 2760

Fluoride 4 3.1 8.0

Electrical conductivity (µS/cm) 4 33200 57200

Sulphate 4 6220 17400

1 – Assumed to be dry weight, although some of the evidence sources do not specify.

2 – Based on the results for prEN12457-3 L/S = 2 analysis

3 - Based on 7 PCB congeners (118, 101, 138, 153, 180, 28, 52)

4 - Insufficient results have been provided to present statistical data for this waste type

- No data provided for this contaminant

Table 2.2 Range of Contaminant Concentrations for BPD (unconditioned)

Determinand

No. of samples

range based on

Minimum Maximum Arithmetic

mean6 Median6

95 percentile

value6

Solid Data (mg/kg)1

pH (units) 22 12.4 12.8 12.6 12.6 12.8

Antimony 44 0.8 10 5.4 3.8 10

Arsenic 57 0.6 19 7.8 12.2 3.3

Beryllium 1 <1 - - - -

Water soluble boron 1 0.9 -

- - -

Cadmium 57 0.9 78 17.8 12.0 44.2

Chromium 37 14 40 28.5 26.0 40.0

Hexavalent chromium 21 0.4 31

16.4 18.0 26.0

Cobalt 56 0.4 25 6.6 5.6 12.5

Copper 57 10 1200 258.4 195.0 592.0

Lead 57 25 9400 (190003) 1345.5 775.0 1731.0

Mercury 57 <0.06 1.3 (413) 3.0 0.23 10.0

Manganese 56 18 445 227.5 210.0 440.0

Nickel 57 2 35 16.8 17.0 30.0



Determinand

No. of samples

range based on


mean6 Median6

95 percentile

value6

Selenium9 1 5.2 - - - -

Vanadium 57 12 870 56.2 29.0 45.2

Zinc 57 1.9 690 219.4 220.0 555.0

Thallium 56 <10 120 (6500 and

72003&5) 19.5 10.5 49.8

Silver9 2 3 5 - - -

Silicon dioxide4 30 129100 160800 147700 148000 157000

Aluminium oxide4 30 37900 48100 42700 43000 45000

Iron (III) oxide4 30 21200 25700 23400 23000 25000

Calcium oxide4 30 389500 578300 467900 460000 550000

Magnesium oxide4 30 9400 11000

10300 10000 11000

Potassium oxide4 30 23300 57300 41800 43000 55000

Sodium oxide4 30 3600 10500 6600 7000 9000

Sulphur trioxide4 30 21700 126200 71200 71000 110000

Sodium oxide equivalent4 30 1.91 4.83

34100 35000 45000

Total organic carbon (%)9 1 0.76 -

- - -

Total petroleum hydrocarbons >EC6-409 2 47 590

- - -

Total polycyclic aromatic hydrocarbons9 3 <1 2.7

- - -

Dioxin I-TEQ (ng/kg)8 51 0.004 67.000 6.151 0.940 20.250

PCBs TEQ humans (ng/kg)8, 9 7 0.0017 1.1629

- - -

Leachate2 (mg/l) 9

pH (units) 2 12.74 12.87 - - -

Antimony 5 <0.006 0.017 - - -

Arsenic 5 <0.005 0.089 - - -

Barium 5 1.3 8.6 - - -

Cadmium 5 <0.0001 0.0016 - - -

Chromium 5 0.097 1.100 - - -

Copper 5 <0.01 0.029 - - -

Lead 5 0.036 1.500 - - -

Mercury 5 <0.0005 - - - -

Molybdenum 5 0.073 0.3 - - -

Nickel 5 <0.02 - - - -



Determinand

No. of samples

range based on


mean6 Median6

95 percentile

value6

Selenium 4 1.3 3.3 - - -

Zinc 5 <0.025 0.37 - - -

Chloride 5 7120 22000 - - -

Fluoride 5 0.8 1.7 - - -

Electrical conductivity (µS/cm) 2 9150 48700

- - -

Sulphate 5 32.1 5200 - - -

Total dissolved solids 5 19200 53000

- - -

Phenol index 4 <0.15 - - - -

1 – Assumed to be dry weight, although some of the evidence sources do not specify

2 – Based on worst-case results (WAC 2:1 dilution)

3 – Isolated high concentration(s)

4 – Converted to mg/kg from assumed % values as units not specified

5 – Possible reporting error for thallium for two BPD samples provided in an excel spreadsheet for one facility by

industry. The concentrations for these two samples are substantially greater than those identified in the remaining 54

samples, which suggests a possible unit error with these concentrations potentially representing concentrations in

µg/kg rather than mg/kg

6 – Reported concentrations represent the arithmetic mean, median and 95%ile of measurable concentrations reported

by industry, excluding isolated high concentrations. Where the concentration is reported as the laboratory limit of

detection, the laboratory limit of detection has been assumed as the concentration.

7 – Based on results for 12 PCBs congeners (77, 167, 169, 189, 81, 105, 114, 118, 123, 126, 156, 157)

8 – The toxic equivalent factor (TEF) is a value expressing the toxicity of a particular dioxin, furan and PCB congener in

terms of the most toxic form of dioxin (2,3,7,8-TCDD). The TEQ (toxic equivalency) is a single figure resulting from

the product of the concentration and individual TEF values of each congener. The International Toxic Equivalents for

dioxins and furans only is shown as I-TEQ. The PCB TEQ is based on the WHO approach for TEF, which also

includes dioxin-like PCBs.

9 – Insufficient number of samples to undertake statistics

Table 2.3 Range of Contaminant Concentrations for BPD (conditioned)4

Contaminant No. of samples range based on

Minimum Maximum

Solid Data (mg/kg)1

pH (units) 8 7.64 12.8

Arsenic 4 <3 10.3

Cadmium 6 4.35 51.2

Chromium 6 13 326

Copper 7 119 384

Lead 6 271 4626

Mercury 6 <0.05 0.442



Contaminant No. of samples range based on

Minimum Maximum


Nickel 6 5.04 26.2

Selenium 4 96.1 543

Zinc 7 55.6 526

Potassium 7 59667 245000

Sodium 7 4253 20050

Sulphur 7 9219 86500

Total organic carbon (%) 5 1.48 7.14

Total petroleum hydrocarbons >EC10-40 1 32.0 -

Total polycyclic aromatic hydrocarbons 1 <1.0 -

PCBs (µg/kg)3 1 <1.0 -

Leachate2 (mg/l)

pH (units) 1 12.79 -

Antimony 2 <0.006 -

Arsenic 2 0.031 0.079

Barium 2 1.7 2.2

Cadmium 2 0.001 -

Chromium 2 1.6 1.8

Copper 2 0.016 0.022

Lead 2 0.16 0.7

Mercury 2 <0.0005 0.00081


Nickel 2 <0.02 -

Selenium 1 4.9 -

Zinc 2 0.34 0.47

Chloride 2 18600 21300

Fluoride 2 1 1.1

Electrical conductivity (µS/cm) 1 83700 -

Sulphate 2 4370 4830

Total dissolved solids 2 49900 55300

Phenol index 1 <1.5 -

1 – Assumed to be dry weight, although some of the evidence sources do not specify.

2 – Based on worst-case results (WAC 2:1 dilution)

3 – Based on 7 PCB congeners (118, 101, 138, 153, 180, 28, 52)

4 - Insufficient results have been provided to present statistical data for this waste type

- No data provided for this contaminant



2.3 Individual Waste Stream Roadmap

A roadmap demonstrating the REA process and location of specific information for CKD and BPD within this

document is presented within Figure 2.1 below.

Figure 2.1 INDIVIDUAL WASTE STREAM REA ROADMAP

Generic Conceptual model

Appendix A

Define Scope/Approach

Section 3

Evaluate Evidence

Section 4.1,4.2, 4.3

Hazard Screening

Section 4.4

Search strategy

Appendix BREA METHODOLOGY

(Environment Agency,

2014)

REA Evidence spreadsheets

(Appendix B for CKD & BPD)

A – Data sources

B – Evidence extraction

C – Quantitative data

D – Supporting informationMaster List of hazards (Table 4.15 & 4.16)

Principal List of hazards (Table 4.21)

Refined Conceptual Model (Table 4.22)

Summary REA (Section 2.1)

DEPLOYMENT ASSESSMENT

Italics refer to individual

waste stream report

Conclusions and recommendations

(Section 5)

19

© Amec Foster Wheeler Environment & Infrastructure UK Limited



3. REA Scope, Approach and Methodology

3.1 Research Questions and Scope

The REA will address the overarching primary question “What key hazards are associated with cement kiln

dust and by-pass dust from cement kilns which could present a risk to critical receptors5 during6 or after

landspreading on agricultural land”.

A series of secondary questions are asked to provide more detailed evidence to identify the relevant

pathways and receptors for particular waste streams and the identification of key hazards which may impact

upon these (see Table 3.1). These are based on the generic conceptual understanding of the landspreading

process to agricultural land, which is presented within Appendix A.

Table 3.1 Secondary Questions

No. Question


1 How many producers are there for this waste within the UK?

2 Is the waste from a single producer or as a result of a collection of waste from a number of producers?

3 Are there different production processes for this waste and how long have these been in place?

4 Is the waste produced as part of a treatment process e.g. effluent treatment

5 If yes, please provide details for the primary treatment process, particularly whether this has the potential to introduce contaminants such as disinfectants etc.

6 Is there any information on the primary product for this waste e.g. material safety data sheets?

7 How variable is the waste between batches and what factors influence this variability?

8 How variable is the waste between producers and what factors influence this variability?

9 Is the waste to be applied as a solid, sludge or liquid?

10 What is the method of application of this waste to land?

11 Why is this material to be spread to land?

Chemical Hazards

12 Are there any analytical data available for this waste?

Groundwater assessment

13 Does the waste contain any hazardous substances (as defined by JAGDAG7)?

14 Does the waste contain any non-hazardous pollutants in concentrations substantially above (> x 2) typical natural background for shallow groundwater/drinking water standards?

Surface water assessment

15 Does the waste contain any Priority or Priority Hazardous substances?

16 Does the waste contain any Specific Pollutants?

5 ‘Critical receptors’ is the collective term for humans, controlled waters and dependant ecosystems, wildlife, soil (quality), air quality and

property in the form of livestock and crops. The critical receptors will be dependent on the type of waste and site specific information for

each deployment application.

6 This relates to potential nuisance or direct harm issues arising during the land spreading of the waste in question, as well as any potential

hazards associated with storage prior to spreading and drift during the landspreading activity. Potential health & safety requirements do

not form part of the REA.

7 Joint Agencies Groundwater Directive Advisory Group - http://www.wfduk.org/stakeholders/jagdag-work-area-0

http://www.wfduk.org/stakeholders/jagdag-work-area-0



No. Question

Soil etc. assessment

17 Does the waste contain potentially toxic elements (PTEs) or other contaminants?

18 What substances does the waste contain that could benefit the soil?

General assessment

19 Does the waste contain any contaminants which are considered to be toxic to human health (i.e. have proven or suspected carcinogenic, mutagenic, reproductive toxic effects etc.)?

20 Does the waste contain any contaminants with a high bioaccumulation potential?

21 Are there any contaminants present within the waste that are proven or suspected to be persistent in the environment?

22 Does the waste contain any contaminants which are proven or suspected of being endocrine disrupting?

23 Describe any speciation or the form of contaminants identified within the waste, which could influence the hazards associated with these.

24 Are pesticides, herbicides or fungicides likely to be present within the waste?

25 Are there any breakdown products or metabolites associated with these contaminants, which could present a significant hazard?

26 Does the waste contain any contaminants which could potentially have cumulative / additive effects?

27 Does the waste contain any contaminants which could present a significant hazard due to their volatility?

28 Does the waste have a biological oxygen demand (BOD) of >6 mg/l?

29 Does the waste have a pH of <5.0?

30 Does the waste have the potential to contain any emerging contaminants of concern?

Plant and animal pathogens and toxic compounds

31 Are Salmonella, Listeria monocytogenes, Escherichia coli, Clostridium botulinum and / or Bacillus Cereus, or other bacteria / pathogens or diseases such as BSE and scrapie, likely to be present in the waste, post spreading?

32 Are plant pathogens, fungus and / or soil borne diseases likely to be present in the waste, post spreading?

33 Are toxic or injurious plants likely to be present within the waste, post spreading?

Invasive Weeds

34 Is there potential for invasive weeds to be present within the waste, post spreading?

35 Is there potential for exotic species to be present within the waste, post spreading?


36 Is non-biodegradable material, such as plastics, metal, brick, concrete and / or glass etc., likely to be present in the waste, post spreading?

Nuisance

37 Are unpleasant odours likely to be associated with the waste?

38 Is dust likely to arise from this waste?

39 Is the waste likely to attract pests, such as flies or scavenging animals?

Other Environmental Hazards

40 Does the waste have a high fat or oil content i.e. >4%?

41 Is the waste likely to cause anoxic soil conditions?

42 Is there the potential for the stability of the waste to come into question?

43 Provide any further details on hazards identified within this waste which are not covered in the questions above.



3.2 Approach and Methodology

A comprehensive search has been undertaken using multiple information sources in order to provide a

variety of evidence sources and to minimise potential bias in answering the Secondary Questions above.

The data search took into account the hierarchy of information sources listed under Table 4.1 of the REA

Methodology (Environment Agency, 2014)i and summarised below (starting from the most preferred

sources):

Producer – specific waste stream data (upstream producer liaison – see below);

Representative case-specific / compliance data (not relevant to this REA as this is not being

undertaken as part of a deployment application);

Environment Agency / Defra database;

European Commission database;

Generic producer data (UK based), including material safety data sheets;

UK published literature, grey literature, expert knowledge and UK academic research; and

European and overseas data.

3.2.1 Initial Literature Review

An initial literature review has been undertaken which focuses on identifying the answers to the secondary

questions and identifies data gaps, conflicts of opinion / data or uncertainty which require further

consideration during the upstream producer liaison.

The databases and websites noted in Table 3.2 below have been reviewed as part of the data search, in

addition to a key word search on Google and Google Scholar. The keywords used for this REA are

summarised in Table 3.3.

Table 3.2 Databases and Organisations

Databases Institutions / Organisations Waste Producers

World Wide Science Mineral Products Association (MPA) Hanson Cement part of Heidelberg Cement & Castle Cement

Scopus British Cement Association (now part of MPA) Cemex UK

Science Direct European Cement Association (CEMBUREAU) Hope Construction Materials

BioOne European Aggregates Association Lafarge Tarmac

OpenSIGLE Internationalcement.com Kerneos Aluminate Technologies

Worldcement.com

The concretecentre.com

Public Health England

Institute of Occupational Medicine

National Farmers Union

Food Standards Agency

Environment Agency (England)

Natural Resources Wales

Scottish Environmental Protection Agency

Northern Ireland Environment Agency



Databases Institutions / Organisations Waste Producers

European Food Safety Authority

Irish Agriculture and Food Development Authority

United States Department of Agriculture

Table 3.3 Keywords

Waste type Activity / Process Hazard identification

Dust UK Material data sheet

By-pass (and by-pass) dust Cement Environmental risks

CKD Cement kiln Hazards

Clinker Incineration Human Health

Waste Waste derived fuels Groundwater

Waste code 10 13 12 Producers Soil

Waste code 10 13 13 Uses Soil Quality

Waste code 19 02 03 Agriculture Livestock

Flue dust Landspreading

Application to land

Fertiliser

Conditioning with water

Generally, the first 50 hits from the search were screened by Amec Foster Wheeler. However, where it was

obvious that unrelated or inappropriate hits were being brought up the number of hits reviewed was reduced.

It became apparent during the search that there was a large amount of research and information available

for one of the primary waste materials, CKD, in particular with respect to its use in land stabilisation, mixing

with biosolids to produce a fertilizing agent, and as a component of other structural materials, in particular

asphalt. Less information was identified with respect to the characterisation or uses of cement BPD, with

some sources apparently not differentiating between the two. Information with respect to the direct

application to land of CKD and BPD as a lime substitute was notably sparse.

With the above in mind, the keyword searches on the journal databases, such as Scopus, were restricted

using the NOT phrase, where appropriate, or filtered using the filtering system provided by the database

itself.

Further details of the keyword searches undertaken, number of hits per search etc. can be found in Appendix

B.

The evidence collected comprised a mixture of peer reviewed, grey literature and unpublished information.

This evidence was screened against the inclusion and exclusion criteria specified below to identify key

evidence for review. This was done by reviewing the title and / or abstract / executive summary for each

piece of potential evidence. Note that documents relevant to the UK were considered to be a higher priority

for review than those referencing the use of CKD in other countries.

Inclusion Criteria for the REA are as follows:

The keywords chosen forms at least part of the subject of the evidence;

In addition to the above, at least one of the following inclusion criteria will also apply – the chosen evidence

will:



Provide information on the production and treatment processes;

Provide information on the types of fuels and raw materials that are used within the kilns,

particularly alternative fuel types and potential impact this could have on the resultant dust

produced;

Provide qualitative or quantitative information about the chemical composition of CKD and/or

BPD;

Provide evidence on the physical hazards associated with CKD and/or BPD;

Consider the spreading of CKD and/or BPD to agricultural land; and/or

Provide a comparison between different types of dusts, non-waste comparators such as lime,

and/or application to different land types.

Exclusion criteria for the REA are as follows:

The evidence is not published in English;

Full text version of evidence is not available;

Full text version is considered to be overly expensive given the perceived potential benefit

based on the abstract / executive summary8;

The evidence does not identify or focus on keyword chosen; and

The evidence does not relate to current waste production processes, such as the use of long

rotary wet kilns.

The reference for the literature evidence obtained and used in the REA and brief description of the content is

provided within Appendix B.

Upstream Producer Liaison

A combination of the following has been used to obtain information directly from upstream producers of this

waste stream:

Questionnaires;

Site visit; and

Face-to-face expert meetings/interviews with selected producers.

Questionnaire

A questionnaire was prepared and distributed to the Minerals Products Association (MPA) to obtain general

information about processes, waste streams etc. and obtain basic data such as product and materials

properties/safety information from a wide range of producers. The questionnaire was based around the

Secondary Questions, with a particular focus on obtaining information relating to questions 1-12 in Table 3.1.

The questionnaire was discussed at a meeting with the MPA and other industry representatives in early

January 2015. This allowed for clarification to be provided on what sort of information was required for the

study and what the information would be used for in the REA and hazard evaluation. The questionnaire was

then issued to the MPA for distribution to their members. In the interest of confidentially, the individual

member responses were received by the MPA and consolidated to provide a combined industry response to

the questionnaire.

In addition to the questionnaire response, the MPA also forwarded on analytical data that had been provided

by individual producers and facilities to inform the REA. This data was collated by Amec Foster Wheeler,

where appropriate to provide a range in contaminant concentrations for CKD and BPD currently produced in

the UK. The synthesis of this data is discussed in more detail in Section 4.3.

8 No information was excluded from this REA for this reason



Site Visit and Expert Interviews

As discussed above, the purpose of the REA and information requirements were discussed at a meeting with

Industry in early January 2015. In addition to this, Amec Foster Wheeler undertook telephone discussions

with a landspreading operator and attended a meeting and site visit at Padeswood Cement Works on the 9

February 2015. This allowed more detailed information to be obtained in key areas, particularly with regard

to the application of this waste to land, and allowed for clarification on any areas of uncertainty identified in

the questionnaire response and during the initial literature review. The transcripts from these discussions

and the site meeting have been approved by all attendees and have been included in the evidence review.



4. Evaluation of Evidence

4.1 Introduction

Amec Foster Wheeler has identified numerous sources of evidence, which have been used to provide

answers to the primary and associated secondary questions. These sources range from peer reviewed

journal articles and reports to unpublished documents and upstream information. The quality of the evidence

obtained has been determined in Section 4.2 and the approach to synthesising the evidence is discussed in

Section 4.3 below.

The answers to the secondary questions are discussed in Section 4.4 below. These findings have been

subsequently used to answer the primary question and identify a Master List of hazards which could

potentially be associated with CKD and/or BPD. These hazards have been further screened to identify a

Principal List of hazards which could potentially present a significant risk to identified receptors. The Master

and Principal Lists of hazards are discussed and presented within Section 4.5. A refinement of the generic

conceptual model for landspreading of waste, for CKD and BPD and based on the Master List of hazards, is

presented within Section 4.6.

4.2 Quality of the Evidence Collected

For each secondary question answered, Amec Foster Wheeler has assigned an evidence confidence rating

using the matrix presented in Table 4.1. This is based on the robustness of the information provided, the

number of evidence sources which gave similar findings and the type of evidence source(s) identified. The

rating for each secondary question answer can be seen in Appendix B. A statement is also provided on the

quality of evidence to support the discussion in each sub-section in Section 4.4.

Table 4.1 Quality Indicators for the REA

Quality Ranking

Robustness of Evidence Primary Evidence Category Objectivity

High Strong evidence with multiple references

Most authors / experts coming to the same opinion/ conclusion(s)

Supporting quantitative data

Peer reviewed No discernible bias

Medium Evidence provided in a small number of references

Authors / experts vary in their opinion / conclusion(s)

Sparse supporting quantitative data

Grey Literature Weak to moderate bias

Low Scarce or no evidence

Authors / experts opinions / conclusions vary considerably

No supporting quantitative evidence

Unpublished Strong bias

4.3 Synthesis of Data

Where appropriate, evidence has been synthesised using the guidance from the REA methodology, both

within the secondary question responses and in the detailed discussion below (see Section 4.4). Where

possible, Amec Foster Wheeler has attempted to characterise the nature of CKD and BPD separately to



identify any significant differences which could impact on their associated hazards. However, this has been

constrained by the fact that the majority of literature sources do not distinguish between CKD and BPD.

The presentation and discussion of analytical data has been divided by waste type where possible i.e. CKD

and BPD, unconditioned and conditioned. Analytical data for CKD and BPD have been provided by industry,

a landspreading operator and the Agency, with further data being obtained from several literature sources.

The discussion on the chemical composition of CKD and BPD has focused on the data provided by industry

as this is UK specific, current and therefore representative of those wastes produced by existing UK

producers and the associated raw materials and fuels. The analytical data provided by UK sources have

also generally been undertaken to accredited standards i.e. UKAS and MCERTs. Due to the potential for

duplication of data provided by industry and that provided by the Agency, the datasets provided for BPD

have been kept separate but compared against each other to identify any significant differences. A limited

dataset for CKD has been provided by industry. This has been combined with that provided by the Agency,

as there is no obvious duplication of results within the dataset. The chemical data provided by the

landspreading operator has been kept separate as this is indicative of conditioned BPD. One result from a

cement facility for wet nodulised BPD has also been included within this dataset.

With regards to leach testing, several results have been provided for both BPD and CKD by UK industry.

However, many of these have not been undertaken using a consistent and comparable methodology. As a

result, the data have been combined where possible and relevant, and presented separately based on the

dust form (i.e. CKD / BPD, conditioned / unconditioned) and leach test and/or a solid: liquid ratio applied.

The UK industry data have also been benchmarked using the literature based information, although it is

recognised that the latter is generally not UK specific. As discussed above, a further issue is that the

literature based data rarely distinguished between CKD and BPD in its conditioned or unconditioned state. A

lot of the data are also over 10 years old, particularly those presented by the United States Environmental

Protection Agency (USEPA), which refers to industry characterisation work undertaken in the early 1990s.

As such, there is the possibility that some of the literature dataset is reflective of cement kiln technology

which is not currently in operation within the UK. There is also limited or no reference to the sampling or

analytical method or accreditation in many cases.

4.4 REA Findings

Based on the responses to the secondary questions (see Appendix B), the findings with regards to waste

processing, form and the associated hazards of CKD and BPD are summarised and discussed below.

4.4.1 Cement Manufacturing in the UK

The MPA describe the cement making process as comprising of two main stages:

1) The first and most complex stage is to make an intermediate product called cement clinker. In the

UK, the clinker-making process consists of a rotary kiln along with a fixed pre-heater/pre-calciner

tower or a Lepol Grate system.

2) The second, much less complicated stage is to grind this clinker in cement mills along with minor

additions of other materials to make cement otherwise known as the clinker grinding or cement

milling process.

A more detailed description of the cement making process and production of BPD and CKD is provided in

Appendix B.

The following cement works are currently in operation in the UK (also see Figure 4.1). These are operated

by four producers; CEMEX UK, Hanson Cement, Lafarge Tarmac and Hope Construction Materials:

Dunbar Works – 1 No. mid-1980s air separate pre-calciner suspension pre-heater (SP5) kiln of

3300 tonnes/day output with grate clinker cooler;

Hope Works – 2 No. pre-heater SP4 kilns including LP cyclones and enlarged riser ducts;

Cauldon Works – 1 No. pre-calciner AS-SP4 kiln process with grate clinker cooler, 1 No. AS

precalciner suspension pre-heater (SP5) kiln with grate clinker cooler;



Aberthaw Works – 1 No. pre-heater kiln (SP4) with planetary clinker cooler;

Cookstown Works – 1 Lepol kiln process;

South Ferriby Works – 2 No. Lepol process kilns with grate type clinker coolers;

Rugby Works – 1 No. SP2 precalciner kiln with incineration chamber and grate type clinker

cooler;

Ketton Works – 1 No. SP4 preheater kiln with planetary clinker coolers, 1 No. SP4 AS

precalciner kiln with grate type clinker cooler;

Padeswood Works – 1 No. modern SP5 precalciner kiln with separate line calciner, downdraft

calciner and grate type clinker cooler;

Ribblesdale Works – 1 No. SP4 in line calciner pre-calciner kiln with grate type clinker cooler;

and

Tunstead Works – 1 No. SP4 pre-calciner kiln process with multistage incineration and grate

type clinker cooler.

(Updated from Environment Agency, 2008)

It is understood that currently three of the four cement companies operating in the UK produce CKD or BPD,

with BPD being produced at Ribblesdale, Padeswood, Ketton, Rugby and CKD at South Ferriby, Cookstown.

All existing cement works in the UK comprise either dry process or semi-dry process kilns, which can

produce CKD or BPD. The difference between kiln types is discussed further below. Note that information

obtained in the literature relating to CKD as a result of wet or semi-wet process kilns have not been

considered in this REA.

1

2

4

53

6

7

8

9

10

11

DefraRapid Evidence Assessment

Figure 4.1Map showing location of cement works

36656-Bir01.ai pattnFebruary 2015

1) Dunbar2) Cookstown3) Couldon4) Aberthaw5) Tunstead

6) Rugby7) South Ferriby

Key

8) Padeswood9) Ketton10) Ribblesdale

11) Hope Works

Note: Locations are indicative

Not to scale

3

6

9

11



4.4.2 Waste Production and Form

Dusts from cement kilns comprises of fine particulate material, which is generated from cement kilns as part

of cement production. The typical processes involved in cement manufacturing are shown in Figures 4.2 and

4.3 below. The two categories of dust considered in this REA are cement kiln dust (CKD) and by-pass dust

(BPD).

CKD is caught in the bag filters from the raw materials mills and is a mixture of partially calcined and

unreacted raw feed, clinker dust and ash, enriched with alkali sulphates, halides and other volatiles (Peters,

1998). Kunal et al. (2012) describe CKD as “a very heterogeneous mix both in chemistry and particle size”.

The composition of CKD can vary over time even from a single kiln line, but includes particulates

representing the raw mix at various stages of burning, particles of clinker, and particles eroded from the

refractory brick or monolithic surfaces of the kiln interior and associated apparatus. The particulates are

captured by kiln exhaust gases and collected in particulate material control systems such as cyclones, bag

houses and electrostatic precipitators.

In order to minimise or avoid dust disposal, most modern cement kilns are operated with a system to return

the majority of CKD to the kiln feed or cement clinker grinder. The removal of some dust from the system is

still required periodically in order to prevent excessive concentrations of alkali, chloride and sulphur

compounds, which may impact the quality of the clinker product. The MPA (2015a) has indicated that alkali

levels of more than 0.6% in the cement can have a deleterious impact on the performance of the finished

concrete. Volatile inorganic components, such as alkali chlorides and sulphates, can also be an issue in the

kiln system, impacting on pre-heater cyclones through blockages and / or forming rings in the rotary kiln inlet

(Environment Agency et al., 2001 and ERAtech Environmental Limited, undated).

BPD is dust collected from the by-pass system de-dusting unit of the suspension preheater, precalciner and

grate preheater kilns. This can comprise a mixture of calcined meal and condensed alkali chlorides and

sulphates (MPA, 2015b and ERAtech Environmental Limited, undated). The by-pass system is used to

extract process gases high in chlorine, sulphur and alkalis and therefore BPD tends to contain relatively

higher concentrations of these chemicals than CKD. BPD can have similar properties to cement, as this

comes from the hottest part of the kiln, although it tends to contain higher quantities of sodium, chloride and

potassium compounds. BPD can be used to enhance the qualities of some grades of cement by leading to a

reduced setting time. However, the sodium, chloride and potassium content of BPD can be a limiting factor

in the use of this material (MPA, 2015a).

CKD and BPD can be unconditioned or conditioned (treated with water). The conditioning of the waste can

be undertaken at the cement works itself or by the landspreading operator. The material is generally placed

into a container, such as a silo, and a small volume of water is added to the dust and mixed. The addition of

water results in a chemical reaction with calcium oxide converting to calcium hydroxide. This chemical

reaction also produces heat. No water is lost out of this process, through drainage etc. and therefore there is

no potential for leaching of contaminants, such as metals, out of the dusts.

The conditioning of the waste has traditionally been undertaken for ease of handling to prevent issues with

dust when transporting the dusts off site to landfill. However, CKD and BPD can be supplied either dry or

conditioned depending on the end use, recipient site and the available handling facilities.

4.4.3 Benefits from landspreading

No UK specific evidence to demonstrate the benefits and effectiveness of applying these dusts to agricultural

land have been identified as part of this REA. During the expert interview (2015a & b), the landspreading

operator confirmed that his clients (i.e. farmers that had used this waste) were happy with the results, with

many making repeat orders. Further evidence was provided to Amec Foster Wheeler by the landspreading

operator in the form of benefit statements from two example deployments. Note that both example

deployment forms were for the spreading of BPD to agricultural land. In the absence of information relating

specifically to CKD, the information provided by the landspreading operator has been assumed to also be

applicable for CKD. This information is discussed below.

There was also limited evidence demonstrating the beneficial properties and effectiveness of spreading

these materials to agricultural land in the literature reviewed as part of this REA. As noted above in Section



3.2, a lot of the most recent studies have focused on the use of these dusts in stabilising biosolids to produce

a fertilising agent, which is then spread to land. As the mixing of these dusts with biosolids is likely to result

in a substantial change in the physical and chemical characteristics of these wastes, this information is not

considered relevant for this REA. Those articles / studies that have been identified within the literature

generally refer to the spreading of CKD only, with many of the studies being quite old (dated back to 1980s

and 1990s). Due to the age of these studies, the dust is likely to have originated from wet process kilns,

which are no longer operated in the UK. Whilst useful as general background, limited reliance can be placed

on the specific information presented.

Optimising the soil chemistry is an important aspect of agriculture. Acidic soils can inhibit the uptake of

essential nutrients and stunt seed germination and root development. The application of CKD to agricultural

land can increase the pH of the soils, reduce pH fluctuations, and hence decrease plant and root stress

(Rahman et al. 2011). CKD and BPD can be used as a substitute to the application of agricultural lime,

which the Environment Agency (2014b) has indicated can increase the availability of major nutrients

nitrogen, phosphate and potassium and minor nutrients such as sulphur, calcium and magnesium.

Rahman et al. (2011) has noted that due to CKD’s ability to hold water (from 40%-50% of its weight) this

material can assist in drought resistance. Discussion with industry has indicated that water will tend to be

bound within the mineral structure following conditioning of the waste, which suggests that Rahman et al

(2011) may be referring to the application of unconditioned CKD/BPD to land. Prior conditioning of the dust

is likely to reduce any holding capacity of this waste for water. Furthermore, water bound within the mineral

structure of the dust is considered unlikely to be readily available to plants under drought conditions.

The beneficial properties and nutrient value of CKD / BPD will depend on its chemical and physical

properties, which can vary between cement works (Rahman et al., 2011, IEEE/PCA, 2008). In addition to

the lime substitute applications, the dusts can also provide valuable plant nutrients, due to their enriched

potassium and sulphur content (Preston, 1993).

The IEEE/PCA (2008) refers to a published study in Australia in 1989 which found that CKD increased crop

yield equally as well as crushed limestone. This document also refers to a study by Fraiman et al. (1991)

which recommended the use of BPD as a fertiliser due to the high concentrations of potassium oxide,

sulphur trioxide and chloride typically present. The IEEE/PCA go on to state that “CKD with high potassium

content could be adequately utilised as a fertiliser...[but that] nutrients such as nitrogen and phosphorus are

still required from other sources regardless of whether limestone or CKD is used on agricultural soils”.

Rodd et al. (2010) indicated that reports on the effects of CKD on plant yield have provided inconsistent

results. The application of CKD to land has increased yields in some studies (with reference being made to

Dann et al.,1989 [pasture] and Lafond and Simard, 1999 [potato]). Lafond and Simard (1999) indicated that

potato tuber yields increased due to the application of CKD, at rates similar to that experienced with

commercial fertilisers, but fell following the application of lime9 The authors also indicated that heavy metal

soil content and plant uptake of metals were not impacted by the application of CKD to land. The increased

yields were noted to be positively correlated with soil extractable potassium and to a lesser degree

extractable magnesium.

Rodd et al. (2010) reported that no significant effects were found in a study undertaken by Gelderman et al.

in 1992, but reduced plant yields were encountered in two studies (Dann et al. 1989 and Gelderman et al.

1992). The reasons for the reduced yields were ‘not immediately apparent’. The study undertaken by Rodd

et al. (2010) looked at the differences in forage yield and accumulation of nutrients due to the application of

CKD and lime9 to soil. They found that forage yield increased, along with the accumulation of potassium,

calcium, manganese, zinc, copper and boron in the forage. However, the accumulation of magnesium was

found to decrease. Furthermore, as the accumulation of potassium increased a reduction in the

accumulation of nitrogen, phosphorus and magnesium was observed in year one, although by year two (a

year after first application) the accumulation of nitrogen, and phosphorus were found to increase. Rodd et al.

indicated that the higher yields from the spreading of CKD to land were probably due to a combination of the

greater effect of CKD initially to soil pH and a response to the added potassium, which was higher in CKD

than lime (1.5 g/kg in CKD compared to 0.07 g/kg in lime).

9 Type of limestone unspecified so assumed to be agricultural lime



Rodd et al. (2004) reported that CKD generally has a lower apparent neutralising value than limestone9.

Despite this, a study by Carroll et al. in the 1960s found that CKD increased soil pH to a greater extent than

coarse limestone. However, when the limestone was pulverised the results were found to be similar to that

reported for CKD. The study undertaken by Rodd et al. (2004) looked at the differences in soil pH response

due to the application of CKD and lime9 to soil. They found that CKD increased soil pH to a greater extent at

soil depths to 6cm in comparison to lime. This difference was thought to be due to the fineness of the

material in comparison to lime, which allowed a quicker reaction to take place following application. The

authors also noted that CKD contained more appreciable quantities of calcium oxide (CaO) than lime, which

is a more reactive material than calcium carbonate. Note that this suggests that the CKD in this study was

applied in unconditioned form as the calcium oxide converts to calcium hydroxide during the conditioning

process.

Analytical data for beneficial elements in UK BPD has been provided by the UK landspreading operator

(Expert interview, 2015a). The range of concentrations identified in UK BPD from three cement works is

provided below in Table 4.2 and 4.3. Concentrations of these elements found in a selection of other

fertilisers / soil conditioners are provided for comparison purposes.

Table 4.2 Concentrations of beneficial elements found in BPD and other fertilisers / soil conditioners

Fertiliser Dry matter (%)

Concentration as received (kg/t)

Total Nitrogen (as N)

Total Phosphate (as P205)

Potassium (as K2O)

Magnesium (as MgO)

Sulphur (as SO3)

UK BPD1 79.2-97.7 ND2-1.2 ND2-2.2 66.3-279.6 3.7-20.9 21.3-204.8

Thermally dried biosolids

95 40.0 70.0 2.0 6.0 23.0

Lime stabilised biosolids

40 8.5 26.0 0.8 2.4 8.5

Broiler / turkey litter 60 30.0 25.0 18.0 4.4 8.0

Green compost 60 7.5 3.0 5.5 3.4 2.6

Paper crumble (chemically / physically treated)

40 2.0 0.4 0.2 1.4 0.6

Source: Expert interview 2015a and Defra, 2010

1 – Range of concentrations presented as there is considered to be an insufficient number of samples to undertake

statistical analysis on the data. Results provide by the landspreading operator have been converted from element to

oxide and units converted from either % or mg/kg to kg/t in accordance with the guidance presented in RB209 (Defra,

2010)

2 – Concentration was below the laboratory detection limit of <0.01% w/w

Table 4.2 further demonstrates the limited nitrogen contained within CKD and BPD in comparison with other

fertilisers. However, the total concentrations of potash, magnesium and sulphur contained within this waste

type appear to be generally higher than organic manures, which support the findings with regards to the

beneficial properties of CKD/BPD identified within the literature above.



Table 4.3 Concentrations of beneficial elements found in conditioned BPD and other liming materials

Fertiliser Dry matter

(%)

Neutralising Value

(as CaO equivalents

%)

Concentration (kg/t)

Total Nitrogen (as N)

Total Phosphate (as P205)

Potassium (as K2O)

Magnesium (as MgO)

Sulphur (as SO3)

UK BPD1 79.2-97.7 7.36-37.3 ND2-1.2 ND2-2.2 66.3-279.6 3.7-20.9 21.3-204.8

Ground chalk / limestone

NR3 50-55 NR3 NR3 NR3 NR3 NR3

Magnesium limestone

NR3 50-55 NR3 NR3 NR3 NR3 154

Hydrated lime NR3 ~70 NR3 NR3 NR3 NR3 NR3

Burnt lime NR3 ~80 NR3 NR3 NR3 NR3 NR3

Sugar beet lime NR3 22-32 NR3 7-10 NR3 5-7 3-5

Liming materials7, 8

96.0 93.6 0.186 2.46 0.96 30.66 1.26

Source: Expert interview 2015a, Defra, 2010, Environment Agency, 2014b

1 – Range of concentrations presented as there is considered to be an insufficient number of samples to undertake

statistical analysis on the data. Results provide by the landspreading operator have been converted from element to

oxide and units converted from either % or mg/kg to kg/t in accordance with the guidance presented in RB209 (Defra,

2010)

2 – Concentration was below the laboratory detection limit of <0.01% w/w

3 – Not reported- assumed to be negligible

4 – Assumed 100% dry matter to convert % to kg/t

5 – Only reported for 4 of the 7 samples

6 – Units converted to kg/t from mg/kg (sulphur as %)

7 – Liming materials are defined as material that contains calcium and magnesium compounds that are capable of

neutralising soil acidity. These include limestone, chalk, quicklime, hydrated lime, marl, shells and by-products such as

slag

8 - Based on median reported concentrations

Table 4.3 shows that the Neutralising Value (NV - the ability of agricultural lime to neutralise acid) in UK

conditioned BPD is lower than that reported in limestone and lime, but comparable to sugar beet lime. The

other elements contained within BPD are generally higher than those reported concentrations in other liming

materials, with the exception of phosphate in sugar beet lime and magnesium reported in liming material.

Note that although the NV of BPD is lower than limestone, there is evidence in the literature to suggest that

due to the finer nature of this material this can be as effective as limestone and lime in adjusting soil pH (as

discussed above).



Main findings (Benefits):

- Evidence has been identified in the literature which indicates that this material can be used as a liming substitute and / or fertiliser;

- Concentrations of nutrients in CKD and BPD are generally higher in comparison to other liming materials, although the NV is lower.

Quality Statement (Benefits): Low to medium – information provided by one UK landspreading operator, with supporting evidence from a small number of international sources.

4.4.4 Land Application

Information relating to the application of BPD to land has been provided by a UK landspreading operator

(Expert interview, 2015a & b). No further information has been obtained from other UK landspreading

operators or from the literature for BPD or CKD. The information contained below therefore represents the

practice of this operator only and should not be assumed to reflect general practice in the UK. Note that

some limited evidence of rates of application of CKD has been identified in the literature and this is provided

for comparison purposes.

Spreading of fine dust (i.e. unconditioned CKD/BPD) on agricultural land is difficult (IEEE/PCA, 2008), which

means that the material is usually conditioned prior to application. This converts the fine dust into larger

particles which helps to minimise the potential for fugitive dust release while transporting, handling and

applying to land. As noted previously the conditioning process also converts oxides to hydroxides, which can

lower the liming potential for the material. Note that the IEEE/PCA has indicated that care must be taken so

the particles are not too hard or rigid that rain and other natural processes cannot dissolve or break them

down. No information relating to the impact on bulk solubility following conditioning of the waste has been

identified. However, the Environment Agency has indicated that poorly managed CKD/BPD can result in the

formation of cementitious material which can have implications for handling and spreading. The

landspreading operator (2015a) has indicated that following conditioning of the dusts, the material is

screened in order to break down any lumps that have formed, minimising the potential for this issue to arise.

According to the expert interview conducted by Amec Foster Wheeler with a landspreading operator (Expert

interview, 2015a & b), the BPD can be provided to the operator in either conditioned or unconditioned form.

Unconditioned BPD is supplied by a powder tanker, which is then conditioned by the operator in a silo, and

then screened to ensure a consistent particle size before spreading to land. The operator confirmed that

production facilities can also provide BPD in conditioned form, with size screening taking place either at the

facility or offsite. Conditioned BPD is then transported to the landspreading operator in covered wagons or

bulk tankers (Expert Interview, 2015a and MPA, 2015b).

Liming frequency and liming rates (including CKD application) are determined by several factors, such as the

desired change in pH and buffering capacity of the soil. This is considered as part of the deployment

application process, with soil chemistry results from the receiving soils being taken into account to ensure

that over-application of nutrients does not occur. Deployment information received from a landspreading

operator in two examples specified a target application rate of 4.5 t/ha in one example (for grassland) and

2.8t/ha in the other (arable land – wheat and barley) for pH adjustment and provision of potassium, once

every 3 years (Expert interview, 2015a). This is comparable with the application rate typically used in the US

of 4.5 t/ha, which is applied once every 3 to 5 years (USEPA, 1998). The total nutrients supplied at these

specified rates (from the two example deployments provided) is presented below in Table 4.4.

Table 4.4 Example of total nutrients supplied (kg/ha)

Application rate Nitrogen Phosphorus Potassium Magnesium

2.8 t/ha <1 4.4 248 6

4.5 t/ha 3 7 245 10

Source: Expert interview (2015a) – based on the results from two deployment examples



The deployment form indicated that this represented the level of nutrients provided in a typical application (Expert

interview, 2015a).

In addition to the above, the benefits statement in the deployment examples also stated that the dusts

contain useful concentrations of sulphur, which can meet the requirements of grass crops, if required, at the

target application rates10. The statement also indicated that these dusts behave similarly to most organic

manures, with nutrients being held in soil fertility reserves and becoming available to plants slowly over time.

Estimates of the nutrients available to plants in the season after application are provided in Table 4.5.

Table 4.5 Example of available nutrients year after application (kg/ha)

Application rate Nitrogen Phosphorus Potassium Magnesium

2.8 t/ha <1 2.2 223 <1

4.5 t/ha <1 3.5 220 1

Source: Expert interview (2015a) – based on the results from two deployment examples

The landspreading operator indicated that due to the high potassium content of BPD, this can result in the

application rate exceeding the receiving soils requirement for this element. This was evident in the two

example deployment forms which show a potash requirement ranging between 85-115 kg/ha for arable land,

but a supply of 223 kg/ha and a requirement of 0-260 kg/ha for grassland and a supply of 245 kg/ha (Expert

interview, 2015a). However, the operator argued that since this material is not spread to land on an annual

basis, it allows the nutrient concentrations in the receiving soils to reach equilibrium over the next 3-5 years.

The operator indicated that due to this over-allowance, the yield from the first crop after application is often

greater than subsequent years (Expert interview, 2015b).

In the UK the spreading is undertaken by standard rear discharge spreaders, which have a moving belt to

discharge the conditioned waste onto spinning discs located at the rear of the spreader. It is understood that

the spreaders have their own weight cells and computer controlled application rates. In addition, all tractors

have GPS and the ability to use uploaded soil maps to allow variable rate spreading. The operator indicated

that the dusts are applied at a maximum bout width11 of 12m to ensure an accurate spread pattern (Expert

Interview, 2015a).

Following spreading, the conditioned waste is incorporated into the soil on arable land, but left as a surface

cover on grassland. The application to arable land tends to take place post-harvest in the autumn, whereas

the application to grassland occurs before the main growing season in spring (USEPA, 1993 and Expert

interview, 2015b).

Main findings (Land Application):

- Information relating to the application of these dusts to land has been provided by a UK landspreading operator;

- Application rates in the UK generally range between 2.8 t/ha to 4.5 t/ha according to the operator;

- The dusts are usually applied to land in conditioned form using standard rear discharge spreaders.

Quality Statement (Land Application): Low - information provided by one UK landspreading operator, with supporting evidence from a small number of international sources.

4.4.5 Reasons for Variability in Composition

The amount of CKD/BPD produced and their characteristics can vary between cement manufacturing

facilities, due to the following:

10 No calculation of sulphur requirement or rates of supply are provided for either the arable or grassland examples.

11 bout width is the distance between adjacent transects of the spreader truck across the field.



Variations in kiln design / process;

Dust collection systems in place, including whether a by-pass system is in place;

Raw material inputs; and

Fuel source.

The UN (2011) has indicated that since the properties of CKD can vary due to the above factors, the physical

and chemical characteristics of these dusts should be evaluated on an individual plant basis. The UN

recommends further testing until sufficient evidence has been collected to ascertain the degree of variability

in the dust.

Each of these influencing factors is discussed briefly below. Note that it is beyond the scope of this REA to

characterise the chemical composition and nature of input materials and fuels used in the cement

manufacturing. However, this has briefly been discussed where this is considered to have the potential to

impact on the chemical composition and nature of CKD and BPD.

Kiln Design / Process

The four main kiln types are as follows (Karstensen, 2006, EC, 2013 & Environment Agency et al., 2001):

Wet Process: The raw slurry is fed either directly into a long rotary kiln equipped with an internal

drying/preheating system (conventional wet process) or to a slurry drier prior to a

preheater/precalciner kiln (modern wet process);

Semi-wet Process: Raw slurry is dewatered within filter presses, with the resulting filter cake

being extruded into pellets and fed to a travelling grate preheater or fed directly into a filter cake

drier for dry meal production prior to entry into a preheater/precalciner kiln;

Semi-dry Process: Dry raw meal is pelletised with water and fed into a travelling grate preheater

prior to feeding into a rotary kiln or long kiln equipped with internal cross preheaters; and

Dry Process: Dry raw meal is fed into a cyclone preheater or precalciner kiln, or to a long dry

kiln with internal chain preheater.

Historically the types of kilns used for cement production have changed over time from ‘wet’ systems to the

more energy efficient ‘dry’ systems, with intermediate stages of ‘semi-wet’ and semi-dry’ processes (Kunal at

al., 2012). Only dry and semi-dry kilns are currently in operation in the UK.

It is understood that the kilns tend to be constructed of magnesia based refractory brick with steel grate

coolers (Moore, 2015 and MPA, 2015a). There is no evidence in the literature with regards to the potential

for the kiln materials themselves to influence the nature of the dusts produced. The MPA (2015a) has

indicated that the erosion of these materials can result in the release of magnesium oxide and some steel to

the cement process. However, this is likely to be minimal in comparison to the quantity of raw material input

and is therefore unlikely to result in significant contamination of the cement dust.

Due to the high temperatures encountered in the kiln and the movement of gases within the kiln system, the

volatilisation and subsequent condensing of particular contaminants can result in the formation of rings on

the kiln surface, which can be eroded, contributing to chemicals present within the system (Gossman et al.,

1990). This is discussed further below.

The typical process of these two kiln types are presented in Figures 4.2 and 4.3.



Figure 4.2 Typical Semi-Dry Process (taken from Environment Agency et al., 2001)



f

Figure 4.3 Typical Pre-Calcinator Dry Kiln (taken from Environment Agency et al., 2001)



The type of kiln used at a site and the presence or absence of a by-pass system will influence whether CKD

or BPD is produced. Differences in the particle size of the dust can have an impact on the chemistry of this

material. Particle size has been demonstrated in the literature to vary between kiln type, with the USEPA

(1993) indicating that median particle size varied substantially between Long Dry kilns (3.0µm) (no longer

used in the UK) and Dry Kilns equipped with precalciners (22.2µm). IEEE/PCA (2008) also compared

particle size distribution with kiln type and found similar results. No particle size information has been

provided by UK industry to allow a comparison with that discussed within the literature and to investigate

potential differences in particle size between UK BPD and CKD.

The potential impact of the particle size of the dust is an important factor to consider, as the concentration of

some chemical substances have been found to be higher in the finer particles of CKD or BPD.

Predominately this has been discussed in the literature with respect to concentrations of free lime, sulphates

and alkalis; hence it could have an impact on the potential benefits presented by CKD or BPD when

considering its application to agricultural land.

Kunal et al. (2012) found that the concentration of free lime, sulphates and alkalis in CKD could be highly

dependent on particle size. The coarser particles of CKD tended to contain a higher content of free lime,

while the finer particles generally contained higher concentrations of sulphates and alkalis and lower lime

content. This has been supported by information provided by the MPA (2015b), which indicated that

concentrations of alkalis will be greater within the finer fraction of dust as these are formed by condensation.

The lower alkali particles can be separated and returned to the kiln system, minimising the proportion of dust

that needs to be rejected. On this basis, the dusts available for spreading to land are likely to contain a high

proportion of fine particles, with relatively higher concentrations of sulphates and alkalis and lower lime

content compared to that returned to the kiln system (MPA, 2015b).

Kiln and Process Temperatures

Both BPD and CKD originate from the same natural raw materials used in cement manufacturing, with the

main difference being the point of production for these two forms of dust. This means that CKD and BPD are

subjected to different temperature ranges, which could potentially influence their chemistry. This is

particularly evident with respect to the amount of free lime present, with the UK industry data showing a

maximum free lime content for BPD of 33% compared to the 4.7% recorded in CKD12 (see Appendix B).

The MPA states that BPD is collected from a point in the production, which is subject to temperatures of

around 1000oC. This results in higher concentrations of calcium oxide (free lime) being present in BPD in

comparison to CKD due to increased calcination levels of the raw materials at the higher temperatures. In

contrast, CKD is collected from a point of production where temperatures only reach up to 200oC. As noted

above, CKD can comprise dusts from various sources, including raw mix at various stages of burning and

particles of clinker. Consequently there is the potential for chemicals associated directly with the raw

materials to be present within CKD that may not be present within the BPD following thermic reactions, as

discussed below.

Due to the high temperatures that are experienced in the burning zone of the kiln, chemicals that would

normally be considered as non-volatile can melt and vaporise. Sodium and potassium can combine within

the kiln with sulphates and chlorides. These salts can volatilise at temperatures around 1400-1480 ºC and

be carried with gases to cooler regions within the kiln process, forming an internal cycle when they are

condensed onto the surface of feed material. As the feedstock moves into the hotter regions of the kiln the

volatile components evaporate again and recirculate within the kiln system. This process can result in the

enrichment of alkali chloride, sulphates and other volatile materials (such as metals as discussed below) in

the kiln materials (EC, 2013 and ERAtech Environmental Limited, undated). Note that Environment Agency

et al. (2001) stated that metal chlorides tend to be more volatile than the elemental form. In cement

production, the majority of chloride in the system is removed in the form of alkali salt in the kiln dusts. High

levels of inorganic volatile components in the system can result in the formation of rings in the rotary kiln inlet

zone (onto the brickwork), which can be eroded over time, re-entering the internal circulation and providing a

periodic flush of contaminants (Gossman et al., 1990).

12 Maximum free lime content of 52.8% and 7.8% in EA provided data for BPD and CKD, respectively



The European Commission (EC) (2013) indicated that non-volatile metals, such as barium, chromium,

arsenic, nickel, copper etc. remain within the clinker and are ultimately almost completely (>99.9%) removed

within the final clinker (EC, 2013).

Semi-volatile metals, such as cadmium, antimony, lead, selenium, zinc, potassium and sodium, can

condense as sulphates and chlorides in the kiln system. These can accumulate temporarily in the kiln

system (condensing in the preheater and being returned to the kiln with the kiln charge) and precipitate onto

either the clinker or kiln dusts. Environment Agency et al. (2001) and Eckert and Guo (1998) have also

indicated that in such instances, there is a greater tendency for the more volatile metals to concentrate more

strongly to the kiln dusts relative to the clinker.

Thallium is a volatile metal which, when not emitted through stack emissions, can condense on dust particles

at temperatures of between 450 and 550 ºC (temperatures which can be experienced in the upper area of

the preheater). Thallium is therefore not captured fully by the clinker but could be present in CKD or BPD

(Eckert and Guo, 1998 and EC, 2013). In contrast, mercury, which is more volatile, tends to pass through

the kiln and preheater in the clinker, only partially adsorbing to the kiln dust (EC, 2013).

Gossman et al. (1990) looked at the fate and transport of trace metals within a wet process kiln. Although,

wet kilns are no longer in use within the UK, due to the similarly high temperatures within the kiln process it is

considered that the observations made by Gossman et al. are worthy of note. The following main findings

were identified in this study:

Antimony – the main source in the kiln process was considered to be from the fuel. An

average of 95% of the antimony entering the system existed within the clinker;

Arsenic – comparable levels were found to enter the system in the kiln feed, coal and

hazardous waste fuel utilised. Significant amounts of the arsenic entering the system remained

in the clinker;

Barium – the main source entering the system appeared to be from the coal and hazardous

waste fuel. Barium was identified in the dust, which was concluded to be from the raw materials

as they enter the kiln without any concentration effect. This observation suggested that

concentrations of barium may be greater in CKD rather than BPD;

Beryllium – this appeared to enter the system from the raw feed and coal. This contaminant

appeared to concentrate in the clinker;

Cadmium – the main source was believed to be the hazardous waste fuel. This contaminant

volatilised and was found in the kiln dust;

Chromium – this entered the system from the kiln feed, coal and hazardous waste fuel. This

contaminant had a strong tendency to concentrate in the clinker, with the only apparent source

of chromium in the dust being from the raw feed. This again suggested that concentrations of

chromium may be higher in CKD rather than BPD;

Lead – the main source of lead entering the system was from the hazardous waste fuel,

although the raw feed and coal also contributed. The study found that 71% of the lead entering

the system was found in the kiln dust. A range of lead concentrations of between <1 to 160

mg/kg were observed in the clinker. The authors suggested that lead was recirculated within

the hotter zones of the kiln and it was periodically flushed out into the clinker, although there

was a strong tendency for it to concentrate in the kiln dust;

Selenium – comparable levels were found to enter the system via the kiln feed, coal and

hazardous waste fuel. The authors noted that the selenium appeared to react in a similarly to

lead in the kiln system, although the evidence was not a clear;

Silver – silver was not found to enter the system in high concentrations from any of the input

sources. The low concentrations that did enter the system, were found to concentrate in the

clinker rather than the dust;

Thallium – low levels were found to enter the system and this was expected to concentrate in

the dusts rather than the clinker;



Vanadium – the main source was found to be from the coal entering the system, although it

was also present within the raw feed and hazardous waste fuel. The authors identified that

vanadium was evenly distributed within the process output materials, although a slight

concentrating effect in the clinker was possible;

Zinc – the main source was noted to be the hazardous waste fuel. The data from this study

showed a clear tendency of zinc to concentrate in the dusts rather than the clinker. The

potential for zinc to be recirculated within the hotter zones of the kiln, similar to lead (see

discussion above),was also identified.

The MPA (2013) investigated the fate of Group 3 metals13 within the kiln system. This study identified a

retention rate of four metals (copper, lead, manganese and chromium) of between 99.63% and 99.99% in

the clinker. This result for lead contrasts to the observations found by Gossman et al. (1990) and discussed

in the literature (EC, 2013, Eckert and Guo, 1998 and Environment Agency et al. 2001) who have found that

lead tends to have a stronger tendency to accumulate in the kiln dusts rather than the clinker.

Slight variations in kiln temperature can also influence how much of a metal is partitioned to the vapour

phase on a daily basis, and hence ultimately end up in the dust (Expert interview, 2015b). However, industry

has indicated that a variation in temperature in the region of 100 ºC would be required for significant

differences in the observed concentrations of metals in the dust (MPA, 2015b).

The high temperatures reached within the kiln mean that organic and volatile contaminants present within the

raw feed are generally volatilised and released as gaseous emissions rather than being present in the

cement clinker or BPD. Organic and volatile contaminants associated with the fuel will also be decomposed

and destroyed during burning. Note that, due to the mixture of sources that make up CKD, there is the

potential for organic and volatile contaminants associated with the raw feed to be present within CKD, if this

has not been exposed to a part of the system where higher temperatures are experienced (EC, 2013).

However, significant concentrations of organic contaminants are not anticipated to be present in the raw

feed. The exception to this could be the potential presence of polycyclic aromatic hydrocarbons within ash

materials used as alternative raw materials (see discussion below).

EC (2013) and Environmental Agency et al. (2001) have indicated that polychlorinated dibenzo-p-dioxins

(PCDD) and dibenzofurans (PCDF) could be formed in/after the preheater section of the kiln system and in

the air pollution control equipment. This requires the simultaneous presence of five factors (“de novo

synthesis”) as follows:

chlorides;

hydrocarbons;

a catalyst;

a temperature window of cooling from 450 to 200 ºC; and

a long retention time in the appropriate temperature window.

In order to minimise the potential for PCDD and PCDF to be formed, the gases leaving the kiln system need

to be cooled rapidly in this temperature range. EC (2013) indicated that this occurs in preheater systems as

the incoming raw materials are preheated by the kiln gases. Environment Agency et al. (2001) commented

that research has shown that trace amounts of chlorinated aromatic compounds can also be formed in the

pre-heater section of the cement kiln. In the event that contaminants are formed, these can adsorbed onto

the kiln feed. However, they are then rapidly decomposed due to the high temperatures experienced within

the preheater (about 1000 ºC). This destruction process is reinforced by the dynamic transfer of material to

the hotter zones, with the transport of gas to the cooler zones. Several studies have demonstrated that well-

designed and operated cement kilns are effective at destroying dioxins (UN, 2011), although EC (2013) has

noted the presence of PCDD and PCDF in CKD and clinker at low concentrations (see discussion under

Chemical Hazards). Note that the EC document does not make reference to the potential presence of these

contaminants within BPD. However, given that BPD is extracted at a point of the kiln system where

13 Group 3 metals includes antimony, arsenic, cobalt, copper, chromium, lead, manganese, nickel and vanadium



temperatures are likely to be around 1000 ºC, it is considered likely that any PCDD and PCDF present will be

negligible (MPA, 2015b).

Raw Materials

BGS (2005) indicated that, in general, limestone and chalk (Cretaceous, Carboniferous and Jurassic) are

used as raw materials for cement works in the UK, although these are supplemented with clay, sand, shale,

and marl. This was confirmed by the MPA (2015a). These materials tend to be sourced locally to the

cement works and vary considerably with regards to their chemistry (Expert interview, 2015b). Thus, they

have the potential to cause variations in dust composition on a site-specific basis, particularly for the less

volatile components. Table 4.6 gives some examples of substances highlighted in this REA that may be

found in the raw materials noted above and also within fuels noted in the following section. A full analysis of

the relationship between raw material/fuel composition and substances present within CKD and BPD would

require more detailed site-specific data and is outside the scope of this REA.

Table 4.6 Sources of selected potential contaminants in raw materials and fuels

Substance Most common occurrence Potential Sources References

Thallium Found in potassium host minerals such as micas and feldspars.

Also a trace element in galena, sphalerite and pyrite

Clays (particularly illitic), shales and some sandstones

Metalliferous veins e.g. in limestones

GTK, 2005

Lead Galena (lead sulphide)

Cerrusite (lead carbonate)

Anglesite (lead sulphate)


(also glass, paint & fuels)

www.mindat.org

Wikipedia

Arsenic Sulphides such as arsenopyrite, pyrite, chalcopyrite, galena and marcasite. Iron oxides*


Clays, shales and some sandstones. Coal

Smedley, 2008

Wikipedia

Vanadium Wide variety of minerals including magnetite and in most fossil fuels


Coal, crude oil and some shales

(also additive in steel)

Vanitec.org

Wikipedia

*various (low evidence quality) sources make passing reference to the presence of arsenic in bone meal in the USA but

we could find no relevant UK references to confirm this.

In addition to the above, ERAtech Environmental Limited (undated) indicated that both raw materials and the

fuels used can introduce chlorine into the kiln process. However, there are restrictions on the percentage of

chlorine present within certain fuel types and alternative raw materials14 specified in the MPA Code of

Practice for the Use of Waste Materials in Cement and Dolomite Lime manufacturing (MPA, 2014). As noted

above, high levels of alkalis, such as chlorine, can influence the quantity of dust that needs to be removed

from the kiln system. The amount of CKD/BPD that requires removal from the kiln system can therefore vary

significantly from one facility to another.

In some facilities, cement manufacture involves co-processing of wastes as part of the kiln feed material (EC,

2013). The MPA (2015a) has confirmed that the following alternative raw materials (ARM) are currently used

in the UK:

Quarry washings;

Lime dust/waste and other calcium waste;

Hydrated Lime;

14 Processed Sewage Pellets (PSP), Solid Recovered Fuels (SRF), Meat and Bone Meal (MBM) and Waste liquid fuels

(WLF) of 2% and blended alternative raw materials (ARM) of 1%

http://www.mindat.org/



Process Spillage;

Filtercake (Ca- based);

Iron Oxide;

Millscale (EWC 10 02 10);

Incinerator Bottom Ash;

Alumina Catalyst;

Alumina Premix;

Fly ash from power generation (PFA) (EWC 10 01 02);

Sodium Carbonate; and

Paper Ash.

These wastes are blended with the raw materials on site, to provide a homogenised feed for the kilns that

achieves the desired chemistry of the final product.

MPA (2013) indicated that as the raw materials provided a much greater volume of material to the kiln feed

than the fuels, this contributed a greater mass of metals into the kiln system. Variations in concentration of

Group 3 metals observed in the MPA study was deemed to be associated to natural variations in metal

concentrations in the raw material. MPA (2013) found that 80% of the input of Group 3 metals (antimony,

arsenic, cobalt, copper, chromium, lead, manganese, nickel and vanadium) was derived from the raw

material input into the kiln, 5% derived from waste derived fuels (WDF) and 15% from fossil fuels.

Typical concentrations of selected metals present within the raw materials used in the UK are reported in the

MPA study (MPA, 2013) and are presented below in Table 4.7.



Table 4.7 Typical concentrations from raw materials in the UK (mg/kg)

Material As Cd Co Cr Cu Hg Mn Ni Pb Sb Tl V Zn Group 12 Group 23 Group 34

Dolomite 1.4 1 2 3.2 2.5 0.1 571.6 2.4 61.2 0.1 0.1 1.7 97.7 - - 646.8

Limestone A 1.3 1.4 3.3 3.8 7.7 0.02 130.5 5.5 8.3 1.3 1.1 6.6 44.0 0.02 2.5 168

Limestone B 1.1 1.8 2.8 3.1 11.1 0.02 134.5 4.3 10.7 2.8 1.0 8.0 35.1 0.02 2.7 178

Shale 10.8 1.8 52.8 33.6 40.2 0.04 476.9 52.4 14.7 6.9 14.8 48.7 76.5 0.04 16.5 737

PFA 103.5 6.6 18.5 66.5 65 0.48 270.5 72.5 49 4 14 201 - 0.48 20.6 851

Alternative Raw Materials (ARM)

0.5 0.7 0.6 0.6 1.6 01 1.9 1.4 1.4 0.7 1.1 01 3.2 0.01 1.8 9

Source: MPA, 2013

1 – Value as shown in source document. Assume this relates to concentrations reported below the laboratory detection limit

2 – Group 1 – not specified but can include lithium, sodium, potassium, rubidium, caesium, and francium.

3 – Group 2 – not specified but can include beryllium, magnesium, calcium, strontium, barium and radium

4 – Group 3 – not specified but assumed to comprise antimony, arsenic, cobalt, copper, chromium, lead, manganese, nickel and vanadium

MPA (2013) found that higher concentrations of Group 3 metals in the raw feed entering the system were associated with dolomite, shale and PFA, with PFA

and shale also shown to contain the highest concentrations of Group 2 metals. The quantity of metals actually entering the system from the raw materials will

vary on a site by site basis and between batches due to natural variations in concentrations of metals present.



Fuel Types

Conventional fuels, such as solid fuels (coal and pet coke), liquid fuel (fuel oil) and gaseous fuels (natural

gas) have traditionally been used for cement kilns. However, the use of alternative fuel sources is becoming

increasingly popular (EC, 2013 and EA, 2008). The MPA (2014) Code of Practice provides a list of the

different categories of waste for recovery by the cement industry as follows:

Processed Sewage Pellets (PSP);

Solid Recovered Fuels (SRF);

Meat and Bone Meal (MBM);

Whole or chipped tyres;

Waste liquid fuels (WLF);

Recovered Fuel Oil (RFO); and

Wood.

Typical concentrations of selected metals present within fuels used in the UK is provided by MPA (2013) and

presented below in Table 4.8.



Table 4.8 Typical concentrations from fuels in the UK (mg/kg)

Material As Cd Co Cr Cu Hg Mn Ni Pb Sb Tl V Zn Group 1 Group 2 Group 3

Coal 6.6 0.08 9.3 18 19.5 0.08 42.5 162.5 20.8 0.2 0.2 587.5 - 0.08 0.3 867

MBM 1.2 0.8 1.7 14.7 28.4 2.1 49.9 5.1 29 1.9 0.7 18.7 130.1 2.06 1.6 151

Tyres 0.9 1.9 120.9 10 72.3 0.1 86.3 8.7 20.6 1.3 0.6 5 4964 0.09 2.5 326

RLF1 5.1 3.1 14.6 34.2 153.4 3.0 22.4 30.7 27.3 31.7 2.7 21.5 - - 5.7 335.7

RLF2 9.9 10.0 11.7 94 80.1 9.9 20.8 41.4 37.8 21.6 9.9 18.0 - - 19.9 325.2

SLF 13 19 22 137 164 3 41 346 43 27 10 28 - - 29 808

SRF1 0.9 2.8 3.0 20.4 170.5 0.15 84.1 12.6 75.9 4.7 3.9 3.5 - - 7.0 375.5

SRF2 10 10 10.1 45 187.3 10 108.5 11.9 46.4 50.8 10 10 - - 30 469.5

SRF3 3.5 2.5 5.7 23.1 45.4 0.59 33.3 10.3 67.6 25.1 1.5 12.6 - - 4.0 226.5

Source: MPA, 2013

It is apparent that some fuels can contain higher concentrations of Group 3 metals in comparison to the raw materials. However, as noted by the MPA (2013),

the proportion of fuels added to the system is substantially lower than that added by way of raw materials. MPA (2013) indicated that between 45 and 55 t/hr

of raw material is added to the kiln system in comparison to between 1.5 and 8 t/hr of fuel. This results overall in a much lower contribution of metals from

fossil fuels and waste derived fuels of around 15% and 5% by weight, respectively to the kiln input.



Substitute fuels can be provided by both local and national suppliers in the UK, who provide fuels to the

specification required by the individual facility (Expert interview, 2015b). EC (2013) indicated that the use of

coal and waste fuels may increase the input of metal contaminants into the process and therefore the

potential for their presence in the dusts produced. However, as noted above, the MPA (2013) has indicated

that the proportion of metals entering the system is minimal for fuels due to the lower input rates in

comparison to the raw materials. Tables 4.7 and 4.8 indicate that coal can contain relatively high

concentrations of nickel and vanadium in comparison to the raw materials used in the UK. Furthermore,

substitute fuels can contain higher concentrations of cadmium, cobalt, chromium, copper, mercury,

manganese, nickel, lead, antimony, thallium and zinc in comparison to the raw materials, although this is

dependent on the type of fuels being used. However, discussions with industry have indicated that in their

view it was rare for substitute fuels to impact upon the chemical composition of CKD or BPD and this has

been demonstrated during technical evaluations undertaken for alternative fuels (Expert witness, 2015b).

The MPA Code of Practice (2014) provides a specification list for several contaminants from waste derived

fuels, including sulphur (2%), chorine (2% for PSP, SRF, MBM and WLF), total fluorine, bromine and iodine

(1.5% for SRF, WLF and wood), mercury (10 mg/kg for PSP, SRF and wood, and 20 mg/kg for WLF and

RFO) and total Group 2 metals comprising cadmium and thallium (30 mg/kg for PSP, SRF and wood and 40

mg/kg for WLF and RFO).

Environment Agency et al. (2001) suggested that conditions within a typical kiln15 should be sufficient to

destroy organics originating from any fuels used in the system.

Environment Agency (2008) reported that although UK companies had increased the number of substitute

fuels used in cement manufacture, there was still further scope to increase both the quantity and the range of

alternative fuel types. It was therefore possible that the composition and range of substitute fuels would

change in the near future. However, this may be constrained by their impact on the composition and

suitability of the cement clinker.

The quality of the final cement product is fundamental to the cement works and processes undertaken. As a

result, the chemical composition of the input materials are considered and monitored by each facility.

Cement works also undertake field trials when a new fuel is under consideration to ensure that this does not

impact on the quality of the cement clinker produced (EC, 2013). As the dusts are influenced by the same

process as the clinker, it is considered unlikely that the waste fuels will have a significant impact on the

chemical composition of CKD or BPD. One notable exception was the introduction of meat and bone meal as

a substitute fuel at the precalciner stage, which was observed to result in a higher phosphorus content of the

BPD produced at one facility (Expert interview, 2015b). Varying concentrations of phosphorus have been

recorded in the waste sample results provided by the UK landspreading operator for conditioned BPD, with

the highest concentration of 1043 mg/kg being recorded in BPD from a facility which used meat and bone

meal as a fuel (Expert interview, 2015a & b). The landspreading operator expressed their view that this

actually strengthened the benefits of spreading this material to agricultural land (Expert Interview, 2015b).

15 Temperatures greater than 1400 ºC and residence times of more than three seconds



Main findings (Reasons for variability):

The chemical composition of CKD and BPD can be influenced by a number of factors, such as:

- Variations in kiln design / process;

- Dust collection systems in place, including whether a by-pass system is in place;

- Changes in kiln temperature;

- Raw material inputs;

- Fuel source.

The main influencing factors appear to be the nature of the raw materials and the kiln type and process used.

Quality Statement (Reasons for variability): High – based on multiple sources of information from UK industry supported by European and international evidence sources.

4.4.6 Chemical Hazards

As discussed in Section 4.3, chemical data for CKD and BPD was obtained from several sources.

Information provided by producers (i.e. cement manufacturing facilities), and by a landspreading operator

from the UK was received as part of this study16. This information was considered to be the most relevant, as

it represented recent data collected from UK producers/operators and therefore directly representative of the

material that was being applied to land.

Additional published sources of chemical characteristic data were also identified from the EU and overseas.

USEPA (1993) was especially useful for characterisation of CKD produced in the USA and Canada due to

the size of the sampled dataset. Chemical data was also collated from the published academic literature.

However, much of the data was considered old, typically relating to non-UK facilities, with very small

datasets.

Summary tables for all quantitative data collected as part of this REA are provided in Appendix B.

Inorganics

Industry data showed that these dusts are inherently alkaline with a pH range of 12.4-12.8 and 12.6-13.3 for

BPD and CKD respectively. This data was comparable with the published literature (Eckert and Guo, 1998

and USEPA, 1993).

As discussed within the benefits section, CKD and BPD can have a high neutralising value (NV), although

Table 4.3 suggests that this is generally not as high as that present within other liming materials. Depending

on the NV, the dust could be treated as caustic.

As discussed above, the concentrations of free lime, sulphates and alkalis can vary depending on whether

the dust is CKD or BPD (conditioned or unconditioned), along with the type of kiln used and the particle size.

This can have implications for the beneficial properties as well as potential hazards associated with the dust

in the context of its application to land (IEEE/PCA, 2008). Literature values for the typical composition of free

lime, sulphates and alkalis in BPD from kilns with alkali by pass compared to that reported by UK industry for

BPD (no data were provided for CKD) are presented in Table 4.9. The typical concentrations reported for

Ordinary Portland Cement are also provided for comparison.

16 Two producers provided data from five UK cement works for the REA. Data for conditioned BPD was provided by

one landspreading operator, with the data relevant for three UK cement works.



Table 4.9 Typical inorganic composition of BPD

Constituent Alkali By Pass (assumed to be BPD)

(% by weight)

UK BPD**

(% by weight)*

Typical CEM 1 Portland Cement

(% by weight)

Silicon dioxide (SiO2) 15.23 14.77 20.5

Aluminium oxide (Al2O3) 3.07 4.27 5.4

Iron III oxide (Fe2O3) 2.00 2.34 2.6

Calcium oxide (CaO) 61.28 46.79 63.9

Magnesium oxide (MgO) 2.13 1.03 2.1

Sulphur trioxide (SO3) 8.67 4.18 3.0

Sodium oxide (Na2O) 0.34 0.66 <1.0

Potassium oxide (K2O) 2.51 7.12 <1.0

Loss on ignition 4.48 8.0 0-3

Free CaO 27.18 20.64 <2

Adapted from: Peters, 1998, Mahmoud and Rimes, 2012, IEE/PCA, 2008 and MPA, 2015a.

*assumed as no units specified

**arithmetic mean of 30 No. sample results provided

Table 4.9 shows fairly comparable concentrations between the two sets of BPD data for silicon dioxide,

aluminium oxide, iron oxide, magnesium oxide and sodium oxide. Concentrations of calcium oxide, sulphur

trioxide and free calcium oxide appear to be lower in UK BPD in comparison to the typical concentrations

presented in the literature, with the concentrations of potassium oxide and loss on ignition higher in UK BPD.

Note that the high concentrations of calcium oxide and free calcium oxide can potentially result in this

material being considered as caustic when introduced to soils17.

Measurable but highly variable concentrations of the majority of metals and metalloids were identified in BPD

and CKD (beryllium was the only metal with concentrations all reported as less than detection limit). For

example, the concentration of lead in BPD ranged from 25 to 19000 mg/kg DW. Similar variability has been

observed in the US and Canada (USEPA 1993).

The most commonly found trace metals in the UK industry data for BPD were lead, copper, manganese,

vanadium and zinc, with minor trace elements including antimony, arsenic, cadmium, chromium, cobalt,

mercury, nickel, selenium and thallium. In contrast the predominant trace metals present in CKD appeared

to be barium, copper, chromium and nickel, with minor trace elements including antimony, arsenic, cadmium,

mercury, selenium, zinc and possibly lead18.

A comparison between the concentrations of elements in BPD and CKD indicated that the maximum19

concentrations in CKD were generally substantially less than those found in BPD, with the only exception

17 http://en.wikipedia.org/wiki/Calcium_oxide

18 It is recognised that this is based on a limited number of CKD samples from the UK (3 No.) in comparison to the BPD

data provided by industry (up to 57 No. for some metals).

19 Ideally this comparison should be undertaken using central tendencies. However, due to the limited analysis results

provided for CKD a comparison using maximum concentrations reported for BPD and CKD is considered to be more

appropriate.

http://en.wikipedia.org/wiki/Calcium_oxide



being nickel. One reason for the difference may be due to the type of raw materials and the kiln processes

from which the dusts are usually extracted.

A greater variability in the concentrations of lead recorded in BPD was noted between facilities, in

comparison to individual samples from the same facility. This again suggests the potential influence of lead

concentrations present within the raw materials, but also the possibility of variations due to the circulation of

lead within the kiln system and slight variations in processing / kiln set up between each facility.

Concentrations of metals, including lead, in conditioned BPD appeared to be lower than that reported for

unconditioned BPD. This observation was based on a much smaller dataset for conditioned BPD (up to 7

Samples per determinand), which did not include data from each of the facilities included within the

unconditioned dataset (up to 57 Samples per determinand). As calcium and potassium in the dust can

result in falsely high results for selenium this result may not be representative (MPA, 2015a20). In principle,

there is no reason why metal concentrations should be reduced following conditioning. The concentrations

of metals identified in conditioned BPD lie within the range reported for unconditioned BPD and hence it is

possible that this is an artefact of the limited dataset for conditioned BPD.

A comparison between the CKD and BPD results obtained from UK industry and the large data set reviewed

by the USEPA (1993) showed distinct differences in the concentrations of several metals, including the

following:

Antimony – significantly higher concentrations identified in US CKD (average of 112.8 mg/kg)

compared to both UK BPD (3.1 mg/kg) and CKD (14.0 mg/kg);

Arsenic – maximum concentrations of arsenic identified in US CKD of 518 mg/kg, is significantly

higher than that identified in UK (19 mg/kg) and CKD (9 mg/kg); and

Copper – higher concentrations identified in UK CKD (average of 89.5 mg/kg) and BPD

(average of 258.4 mg/kg) than in the US CKD (average of 30.1 mg/kg).

This could be due to differences in the chemical composition of raw input materials used within the UK and

the USA.

Organics

Few analytical results have been provided for organic contaminants in CKD and BPD in the UK. From

discussions with industry it appears that organic contaminants are not routinely determined as they are

considered unlikely to be present at significant concentrations in the dusts. There is a consensus in the

literature that any organics present within the fuels are mostly destroyed in the kiln and hence concentrations

of organics in BPD are anticipated to be very low (EC, 2013). Although there is the potential for organics

within the raw feed to be present in CKD, it is considered unlikely that this would be in significant

concentrations, given the nature of the raw and substitute raw materials used.

In 2 samples of BPD provided by industry, the concentrations of benzene, toluene, ethylbenzene and total

xylenes were below the laboratory limit of detection (<0.1 mg/kg in BPD).

In 3 samples of BPD, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were also low, with

many of the US EPA 16 reported below the laboratory limit of detection (<0.1 mg/kg) and measurable

concentrations below 1 mg/kg. Quantifiable PAH compounds tended to be those with a greater number of

aromatic rings such as benzo[a]pyrene. These compounds are expected to have the greater thermal stability

and persistence and are also the most persistent and toxic. Concentrations of benzo(a)pyrene ranged

between 0.049 and 0.1 mg/kg. Volatile PAHs, such as naphthalene were unsurprisingly reported at less

than the laboratory detection (<0.1 mgkg in BPD and <0.08 in CKD).

Total petroleum hydrocarbons (TPH) was reported at less than the limit of detection (< 10m/kg) in a single

sample of BPD.

Organics data was provided by industry for only a single sample of CKD, from which it is difficult to draw

conclusions. Whilst the data were similar to BPD for PAHs and BTEX, much higher TPH was recorded

(7060 mg/kg), although only 126 mg/kg was identified within the carbon ranges of C10-C40. This is

20 Statement provided on an analytical certificate as reason why selenium concentrations were not reported.



important as the lighter carbon fractions present a greater risk to receptors in terms of their toxicity, volatility

and solubility.

The industry data is similar to results in the wider published literature, with concentrations for BTEX below

the laboratory limit of detection (LOD) and PAHs below or marginally over the LOD. For example, Palmer

(2000) found that concentrations of PAHs and BTEX measured in a single sample of CKD from Australia

were also all below their respective LODs21.

No analytical results for other volatile organic compounds (VOC) were provided by UK industry. USEPA

(1993) reported the results of VOC testing undertaken on CKD in the USA. They suggested that measurable

concentrations of individual VOCs were identified in CKD from several facilities. However, they concluded

that these levels were insignificant, based on the fact that the observed levels were very close to the LODs

and were not apparent in CKD on an industry-wide basis. USEPA (1993) also analysed for semi-volatile

organic compounds (SVOCs) and found no measurable concentrations in CKD samples taken from six

facilities.

Concentrations for dioxins (PCDD) were available in the BPD results provided by UK industry, but similar

data was not provided for CKD. A summary of the individual congener concentrations for BPD is provided in

Appendix B. The higher concentrations are present as octachlorodibenzodioxin (OCDD) and 1,2,3,4, 6, 7, 8-

heptachlorodibenzo-p-dioxin (HpCDD), with median concentrations in unconditioned BPD of 3.1 ng/kg and

1.4 ng/kg, respectively. The median concentrations for other congeners are generally <0.5 ng/kg (see

Appendix B for further information).

An average concentration of 6.2 ng I-TEQ/kg for the sum of PCDD and PCDF was recorded in UK BPD

(based on 51 No. samples), with a maximum concentration of 67 ng I-TEQ/kg. Note that this maximum

concentration appears to lie outside of the normal range, with the majority of reported samples with less than

15 ng I-TEQ/kg (44 of 51 No. samples – 86%). These observations were consistent with those reported by

SINTEF for CKD (Karstensen, 2006), with an average concentration of 6.7 ng I-TEQ/kg for PCDDs/PCDFs in

CKD and a maximum of 96 ng I-TEQ/kg. This was noted by the authors to be comparable to concentrations

within food stuffs such as fish, butter and also with levels in breast milk. UN (2011) noted that this level was

also lower than the maximum permitted concentration of 100 ng TEQ/kg in sewage sludge to be used on

agricultural land22 (UN, 2011). SINTEF also refer to a range of concentrations of PCDD/Fs which have been

reporting in CKD in UK cement kilns at 0.001-30 ng TEQ/kg (Karstensen, 2006).

Measurable concentrations of PCBs23 have also been recorded in UK BPD. Levels of dioxin-like PCBs were

reported in the range between 0.0017 and 1.1629 ng WHO TEQ/kg (humans)24. In general, concentrations

for individual congeners were below the laboratory limit of detection, with occasional measurable

concentrations in individual samples. USEPA (1993) indicated that no measurable concentrations of target

PCB compounds were detected in CKD during their assessment; however, this may have been due to the

use of higher LODs in the earlier US study25.

Industry provided analytical data for only a single CKD sample, which showed no detectable PCB

concentrations (LOD <5 µg/kg26).

Pesticides

21 The LOD is not reported.

22 This maximum permissible limit does not apply to the UK and it is not clear in the report which country this is applicable

to.

23 PCB analysis was for 12 dioxin-like PCB congeners (77, 167, 169, 189, 81, 105, 114, 118, 123, 126, 156, 157).

24 Note that these are not directly comparable to the I-TEQ concentrations due to the reporting to different TEF schemes.

25 Unfortunately the LOD obtained by the USEPA is not detailed in order to confirm this.

26 PCB analysis was for 7 PCB congeners (118, 101, 138, 153, 180, 28, 52)



No UK data was available. This was not unexpected, as pesticides are excluded from the waste derived

fuels (MPA, 2015b) and given the nature of the production process of these dusts, pesticides were not

considered to be a possible hazard of concern.

USEPA (1993) analysed for the presence of 13 target pesticides in CKD at eleven facilities in the US and

Canada. Three of the target pesticides were detected in CKD at two facilities. Endrin and heptachlor were

identified at one facility, with endosulfan being detected at another facility. On the basis of these results the

USEPA (1993) concluded that no further investigation of pesticides in CKD was warranted.

Radionuclides

The raw materials used for cement production could be a major source of common, naturally occurring

radionuclides, which in turn could lead to these radionuclides being present in CKD and BPD. It is

understood through discussions with industry that CKD and BPD are not routinely tested for the presence of

natural radionuclides. However, USEPA (1993) has identified measurable concentrations of radionuclides in

CKD, including isotopes of lead, radium, uranium, thorium and potassium, but these were considered to be

similar to those found in environmental samples of comparable composition. The notable exception was

uranium, where slightly higher than average concentrations (compared to natural soils and rocks) were

identified in CKD. USEPA (1993) speculated that this was due to the potential for greater variability in

uranium isotopes in soils and rocks and that the incineration process could be expected to slightly increase

the concentration of uranium isotopes. This increase was due to the substantial reduction in volume of the

raw material and fuels during the kiln process. However, USEPA (1993) concluded that this was not

considered significant as the equilibrium state of the isotopes was consistent with levels expected for

environmental samples containing natural uranium. There was no evidence of any isotopic separation,

enhancement or depletion process.

Main findings (Chemical composition):

- CKD and BPD is alkaline in nature with a typical pH of around 12.5;

- Concentrations of metals vary widely between producers and less so between samples at individual facilities. This is particularly the case for semi-volatile metals, such as lead;

- A comparison of results for metals obtained for CKD and BPD in the UK and the USA highlights the influence that differences in the chemical composition of the raw materials can have on the dusts produced;

- Low concentrations of organic contaminants, including dioxins and PCBs have been identified in UK BPD and CKD, which supports the findings discussed in the literature;

- No analytical results have been provided for pesticides and radionuclides in the UK. The USEPA (1993) has previously investigated their presence in CKD and has confirmed that they are unlikely to be significant or artificially enhanced as a result of the cement production processes.

Quality Statement (Chemical composition): High – multiple sources of information, with supporting information obtained from literature. Some chemical data has also been identified within the literature for contaminants not normally tested for in the UK. Limitations of the data provided by industry have been noted.

Leachability

The pH of BPD and CKD leachate data provided by UK industry ranged between 12.4-12.9 and 12.8-13.3

respectively. This was consistent with the published literature. Kunal et al. (2012) reported that CKD

leachate was typically in excess of pH 12 and could be considered potentially caustic.

As discussed in Section 4.3, a few leach test results were provided for both UK CKD and BPD samples,

although these were undertaken using several different methods and solid: liquid ratios (MPA, 2015a). They

generally showed a low chemical leaching potential for both unconditioned and conditioned BPD and

unconditioned CKD, although occasional peaks for several metal contaminants were recorded. This



supported the conclusions drawn by Rahman et al. (2011), who reported that CKD had a relatively low

leaching potential for heavy metals. Eckert and Guo (1998) identified detectable leachable concentrations of

a range of metals and metalloids within CKD, although with the exception of rubidium, these are typically in

the order of µg/l.

It should be noted that the leachability of metals present within the UK dust appears to vary between

samples, similar to that identified within the solid results. Large variations were evident for the following

contaminants:

Unconditioned BPD

Lead (concentration range of 0.036-1.5 mg/l in 5 samples);

Chromium (concentration range of 0.097-1.1 mg/l in 5 samples); and

Barium (concentration range of 1.3-8.6 mg/l in 5 samples).

Unconditioned CKD

Lead (concentration range of 0.21-2.71 mg/l in 4 samples); and

Molybdenum (concentration range of 1.3-4.64 mg/l in 4 samples).

The reason for this variation is unknown, but could relate to the variable solubility of matrix mineralogy and

corresponding higher concentrations of these contaminants being present within the solid phase dust

samples.

Based on the two leachate results provided for conditioned BPD, it appears that the leaching potential of

lead and barium was reduced by the conditioning of the waste, though this is based on a very limited

dataset. This may be due to the fact that the conditioned dust has previously been exposed to water,

reducing its water capacity and leaching potential and / or changes in mineralogy as a result of the

conditioning of the dust.

The results of leach testing of CKD/BPD were also reported in the published literature with most tests

conducted using the US EPA toxicity characteristics leaching procedure (TCLP). The TCLP approach is

designed to simulate the effect of material deposited in a landfill for a number of years and uses an acidic

leachant (Eckert and Guo, 1998). Eckert and Guo indicated that this is likely to overestimate the potential

risk from leaching contaminants arising from landspreading for agricultural purposes as the leachate is

unlikely to be representative of ‘real world’ conditions. However, they further noted that these methods can

be insufficiently aggressive toward leaching heavy metals from alkaline soils, resulting in an underestimate of

leaching potential.

Several studies also provided leach test results using the synthetic precipitation leaching procedure (SPLP).

The SPLP is designed for material sitting in-situ (in or on top of the ground) which is exposed to rainfall, and

hence is more relevant for the activity under consideration in this REA (Eckert and Guo, 1998). A brief

discussion of the main findings in the literature with respect to the leachability of CKD and BPD is provided

below.

USEPA (1993) analysed a number of CKD samples using the TCLP and SPLP. Measurable concentrations

were identified for most target metals. However, in general, the concentrations of trace metals were well

below the US screening criteria adopted27, with many recorded concentrations up to an order of magnitude

below these criteria. Individual exceedances of the criteria were only observed for lead (2 from 244 samples

analysed, with a maximum concentration of 16.5 mg/l), and for selenium (2 from 129 samples, with a

maximum concentration of 1.711 mg/l).

Consistent with the low solubility of dioxins (PCDD) and furans (PCDF), the USEPA (1993) reported no

measurable concentrations in CKD leachate for almost all congeners. The exception to this was

octachlorodibenzodioxin (OCDD), which was observed in two samples with a maximum concentration of

27 These may or may not be relevant to the UK



0.00017 µg/l. Based on these results, the USEPA did not consider that the leaching of PCDD and PCDF

required further risk assessment.

Peters (1998) compared leach test results (using the SPLP) for unconditioned and conditioned CKD. He

found that significantly lower concentrations of similar contaminants, such as aluminium, barium, chromium,

lead, selenium, zinc, and sulphate were present in leachate from the conditioned CKD in comparison to the

unconditioned CKD. Concentrations in leachate for arsenic, cadmium, copper, mercury and silver were

reported below the LOD for both conditioned and unconditioned CKD. This supported the findings from the

limited dataset obtained from UK industry for BPD (as discussed above). Peters (1998) concluded that

conditioned and appropriately managed CKD would have minimal impact on the environment.

Leach testing undertaken by Palmer (2000) on a sample of Australian CKD using the TCLP method showed

generally low concentrations of metals in the leachate. These concentrations were compared against local

landfill leachate limits, with the author concluding that heavy metals and non-metals leached from the CKD

were likely to have little or no impact on groundwater, even in highly acidic environments.

Eckert and Guo (1998) referred to a study in which the potential effects of dissolved carbonate on lead

solubility were investigated. They suggested that in very high pH solutions, typical of CKD, the dissolution of

lead could be enhanced. However, as the pH dropped, such as through neutralising it with other leachates,

lead solubility decreased as a result of chemical precipitation. Mahmoud and Rimes (2012) drew similar

conclusions from the results of leach tests on CKD from a Canadian cement works. Their results showed

measurable concentrations of cadmium, lead, manganese, molybdenum, nickel, selenium, thallium and zinc.

Based on these results, the authors indicated that the CKD analysed “had the potential to leach albeit small.”

Lead, selenium and manganese concentrations were identified above the Canadian drinking water quality

guidelines. However, the authors did note that these exceedances related to the testing of ‘pure’ CKD and

stated that “it is likely that CKD-amended soil samples might demonstrate little or no exceedance, particularly

in the case of lead concentrations…previous research has shown that addition of CKD leads to increasing

pH which in turn results in less potential for heavy metals to leach.”

Kunal et al. (2012) indicated that some constituent elements in CKD, such as lime, arcanite (potassium

sulphate) and sylvite (potassium chloride) are highly soluble and unstable mineral phases when they come

into contact with water. The concentrations of other elements may therefore be controlled by their availability

to the leachate solutions and / or their diffusive flux into solution from the leaching of the primary phases over

time.

Kunal et al. (2012) also discussed the results from a series of batch leaching experiments by Duchesne and

Reardon (1998), which found that CKD leachate contained extremely high concentrations of leachable

potassium, sulphate, caustic alkalinity, chromium, and molybdenum. Even at high water to solid ratios (20:1)

the tests produced concentrations of chromium over 40 times greater than the USEPA Maximum

Contaminant Level of 0.05mg/l (Kunal et al. 2012).

Peters (1998) commented on the presence of soluble salts such as potassium in CKD at high quantities.

The author indicated that if CKD is improperly managed28, these soluble salts resulted in leachates with a

high total dissolved solid content.

No analytical data has been provided for leachable concentrations of potassium in either BPD or CKD in the

UK industry data (MPA, 2015a). However, concentrations of other soluble salts, such as chloride, sulphate

and to a lesser degree fluoride, have been reported at high concentrations in both BPD and CKD. Chloride

concentrations ranges of 7120 - 22000 mg/l were recorded in unconditioned BPD leachate and 281 –

2760 mg/l in unconditioned CKD. Similarly high concentrations of sulphate have also been reported in BPD

and CKD (maximum of 5200 mg/l in BPD and 4830 mg/l in CKD), with concentrations of fluoride of 0.8 to

1.7 mg/l in unconditioned BPD and 3.1 to 8.0 mg/l in CKD (MPA, 2015a - see Appendix B).

28 No further information is provided in terms of what improper management might relate to.



Main findings (Leachability):

- CKD and BPD leachate is alkaline and typically in excess of pH 12.

- As with the solid data, the concentrations of many metals in leachate vary widely between samples, with occasional high concentrations recorded for metals, such as lead and chromium.

- The limited UK results show an apparent reduction in concentrations of metals, such as lead and barium, for conditioned BPD in comparison to the unconditioned BPD results. This is supported by similar findings identified in the literature.

- Little or no UK industry data was available on the leachability of contaminants in CKD/BPD under field conditions. Generally low concentrations of metal contaminants in leachates were reported in the literature, with only occasional individual samples recording concentrations above national / local criteria adopted for screening.

- A USEPA study analysed for dioxins and furans in CKD leachate and identified no significant concentrations.

- The presence of highly soluble salts in CKD was reported in the published literature. It was suggested that this could influence the subsequent dissolution or stability of other minerals and elements, and result in leachates with high total dissolved solids.

Quality Statement (Leachability): Low on the basis that there is evidence to suggest that this may not be representative of true conditions in the context of this material being spread to land. Multiple sources of information, with supporting information obtained from literature.

4.4.7 Concentrations relative to comparators

UK background

In order to give a perspective on the levels of metals in CKD and BPD and the potential for soil enrichment

when applied to land, a comparison of contaminant concentrations present within the dust and UK

background soil has been undertaken. Contaminant concentrations representative of median levels for UK

rural topsoil have been obtained from a number of sources29 and are presented in Table 4.10. Where

sufficient sample results are available, median concentrations have been presented; for the rest, including

CKD (unconditioned), BPD (conditioned) and for some contaminants for BPD (unconditioned), the range of

reported concentrations has been presented for comparison purposes.

Table 4.10 Metal concentrations compared to typical background concentrations in the rural UK soils

Contaminant Median or Range of concentration (mg/kg)

CKD (unconditioned)1,

4

BPD (unconditioned)2

BPD (conditioned)3, 4

UK rural soils6

Antimony 10-18 3.75 - 0.8

Arsenic 4-14 7.8 <3-10 7.1

Beryllium - <14,5 - 1.0

Cobalt 10-13 5.6 - 8.9

Cadmium 5-28 12 4.4-51 0.29

Copper 13-140 195 119-384 17.3

29 This does not take into account the potential for enrichment from repeated application of dusts to land over a number

of decades.



Contaminant Median or Range of concentration (mg/kg)

CKD (unconditioned)1,

4

BPD (unconditioned)2

BPD (conditioned)3, 4

UK rural soils6

Chromium 45-104 26 13-326 29.2

Lead 250-580 775 271-4626 37.4

Mercury - 0.23 <0.05-0.442 0.1

Nickel 125-192 17 5.0-26 15.8

Manganese >250 210 - 420

Molybdenum 8-12 - 2.9-5.0 0.9

Thallium 185 10.5 - 0.5

Silver 3-4 3-54 - 0.3

Barium 158-250 - - 60.5

Boron - 0.94,5 - 34

Selenium - 5.24,5 96-543 0.5

Vanadium 450-600 29 - 39.2

Zinc >250 220 56-526 65.9

Benzo(a)pyrene <0.085 <0.1-0.05 - 0.05

Dioxins – I-TEQ ng/kg - 0.94 - 2.06

PCB component WHO-TEQ ng/kg

0.0017-1.1629 - 2.55

PCBs – sum of 7 congeners7

(µg/kg) <5 <1 <15 0.66

Source: MPA, 2015a, Environment Agency, 2015, Expert interview, 2015a, Environment Agency 2007a, b & c, Salminen

et al., 2005 and Archer and Hodgson, 1987

1 - Based on up to 4 No. samples from MPA, 2015a and Environment Agency, 2015

2 - Based on up to 57 No. samples from MPA, 2015a

3 - Based on up to 7 No. samples from Expert interview, 2015a

4 - Insufficient data to calculate a representative median concentration

5 - Based on 1 sample result

6 – Sourced from Environment Agency et al., 2006a & b, Salminen et al., 2005 and Hodgson, 1987

7 - PCB analysis was for 7 PCB congeners (118, 101, 138, 153, 180, 28, 52)

The main observations with regards to Table 4.10, noting the limited data for some contaminants, can be

summarised as follows:

Concentrations of arsenic, beryllium, manganese and boron in CKD and BPD are broadly

comparable to those reported in UK rural soils;

Concentrations of antimony, cadmium, copper, mercury, lead, molybdenum and zinc in both

CKD and BPD are higher than those reported in UK rural soils;

Concentrations of cobalt recorded in unconditioned CKD are slightly higher than that identified

in UK rural soils. However, the median level of cobalt in unconditioned BPD is less than the

median concentration for UK rural soils;



The maximum concentrations of chromium identified in unconditioned CKD and conditioned

BPD are higher than the median concentration reported for UK rural soils. However, the

median concentration of chromium for unconditioned BPD is similar to UK rural soils;

Few results have been provided for thallium and silver in CKD and BPD but the concentrations

recorded are above the median concentration for UK rural soils;

Few results have been provided for selenium in BPD, with these suggest that concentrations

could be higher in BPD than in UK rural soils;

Barium concentrations have only been provided for a few samples of CKD, with the results

showing a concentration range in excess of the median for barium in UK rural soils;

Few results have been provided for vanadium in CKD, but these suggest that vanadium may be

higher in CKD than in UK rural soils. Note that the median concentration of vanadium in

unconditioned BPD is lower than that reported for UK rural soils;

Concentrations of benzo(a)pyrene in unconditioned CKD and BPD are comparable to that

identified in UK rural soils;

Dioxin concentrations in unconditioned BPD are lower than the median in UK rural soils; and

Concentrations of PCBs appear to be comparable to the median for UK rural soils, although the

LOD reported for CKD is over 5 times this median.

Fertilisers and Liming Materials

Little information has been identified in the literature with regards to comparison of concentrations of

contaminants within CKD / BPD and other materials. IEEE/PCA (2008) referred to a study by Kanare (1999),

which looked at the differences in metal concentrations in CKD, agricultural limestone (aglime) and sewage

sludge applied to soil. Kanare found that sludges generally contained higher concentrations of chromium,

lead, mercury, nickel and silver compared to CKD, aglime or North American soils. However, the highest

concentrations of thallium and selenium were reported to be present within CKD30. All other elements of

interest were reported at less than the LOD (not specified) or comparable between the different materials.

Table 4.11 shows the concentrations of some determinands, including some metals, in CKD and lime

(assumed to be agricultural) that are provided by Rodd et al. (2010). Note that these relate to CKD and

limestone from Canada and hence are necessarily representative of concentrations present in either UK

CKD or limestone. However, this information is considered useful to demonstrate the potential differences in

concentrations between CKD / BPD and lime.

Table 4.11 Selected chemical properties of CKD and Lime

Determinand Concentration

CKD Lime

Dry matter (g/kg) 994 + 20 962 + 30

Calcium (g/kg) 300 + 1.3 209.4 + 0.9

Magnesium (g/kg) 5.0 + 0.1 94.2 + 6.74

Phosphorus (g/kg) 25 + 0.9 0.8 + 0.36

Potassium (g/kg) 1.5 + 0.02 0.07 + 0.02

30 Samples were tested for antimony, arsenic, barium, beryllium, cadmium, chromium, lead, mercury, nickel, selenium,

silver, and thallium. No concentrations of metals were provided in this document. Original source document appeared

be no longer available for purchase / review.



Determinand Concentration

CKD Lime

Manganese (g/kg) 0.3 + 0.03 7 + 0.4

Copper (mg/kg) 7.8 + 0.4 8.6 + 0.8

Zinc (mg/kg) 31 + 3.0 19 + 9.7

Boron (mg/kg) 360 + 355 360 + 174

Source: Rodd et al. 2010

Table 4.11 indicates that CKD and lime are likely to contain similar concentrations of calcium, copper and

boron. CKD can potentially contain higher concentrations of phosphorus, potassium and zinc in comparison

to lime, with concentrations of magnesium and manganese likely to be higher in agricultural lime.

In addition to the literature based information, Amec Foster Wheeler has compared the concentrations of a

selection of metals and other elements reported by industry for CKD and BPD with typical concentrations

identified in other fertilisers and soil improvers. This information is presented below in Table 4.12. Where

sufficient sample results are available, median concentrations have been presented; for the rest, including

CKD (unconditioned), BPD (conditioned) and for some contaminants for BPD (unconditioned), the range of

reported concentrations has been presented for comparison purposes.



Table 4.12 A Comparison of metals and other elements in CKD/BPD with other fertilisers / soil improvers

Material Type Concentration (%)

Median or Range of Concentrations (mg/kg)

N P K S As Cd Co Cr Cu Mo Ni Pb Se Tl V Zn F Cl

CKD (unconditioned)

- -4 -4 -4 4-14 5-28 10-13

45-104 13-140

8-12 125-192

250-580

- 181 - -4 - -

BPD (unconditioned)

- - 3.6 2.8 7.8 12 5.6 26 195 - 17 775 5.21 10.5 29 220 <100-600

46000

BPD (conditioned)

<0.01-0.13

0.02-0.10

6.0-24.5

0.9-8.7

<3-10.3

4.4-51.2

- 13-326 119-384

2.93-4.95

5.04-26.2

271-4626

96.1-543

- - 55.6-526

51.9-1351

-

Triple superphosphate fertiliser (TSP)

0 46-472 0 - 7.5 17.9 0.4 160.9 28.2 12.7 21.4 4.0 - - 281 281.5 546 -

Other straight phosphate fertilisers

01 181 01 211 5 9.2 0.4 82.5 17.2 17.8 17.3 3.8 - - - 170.15 510 -

Phosphate potassium (PK) fertilisers

0 7-252 25-302

- 4 10 0.6 55 8 - 7 1 - - - 90 - -

Nitrate phosphate (NP) fertilisers

10-182 20-592 0 - 13.2 4.1 1.2 74.4 15.2 8.3 12.9 3.6 - - 113.6 45.6 6461 -

Low N fertilisers 13 15+ 12 - 5.8 4.5 1 54.3 16.4 3.2 11.7 1.6 3 - 29 115.1 - -

High N fertilisers 24 2 5 5 8.6 1.3 0.6 5.2 9.5 - 2.8 2.7 - - - 10.8 - -



Material Type Concentration (%)

Median or Range of Concentrations (mg/kg)

N P K S As Cd Co Cr Cu Mo Ni Pb Se Tl V Zn F Cl

Liming materials 0.0003 0.03 0.1 0.05 2.3 1.0 1.1 5.1 4.0 2.0 3.1 9.4 1.0 3.0 5.02 34.1 48.6 30

Sources: MPA, 2015, Environment Agency, 2013, Environment Agency, 2014b

- No data reported

Note that the application rates for CKD / BPD and liming agents are typically several tonnes per hectare, while fertilisers are generally applied at much lower rates (typically no

more than 500 kg/ha)

1 – Based on one result only

2 – Median has not been calculated in the evidence source so the range is presented for comparison purposes

3 – Is noted to comprise of limestone, chalk, quicklime, hydrated lime, marl, shells and by products, such as slag

4 – Reported concentrations are >250 mg/kg for industry data



Table 4.12 can be summarised as follows:

Concentrations of phosphorus in conditioned BPD are comparable to that reported in liming

materials, but lower than typically present in fertilisers;

The concentrations of potassium in conditioned and unconditioned BPD varies, but is generally

higher than that identified within liming materials and comparable at the higher end (for

conditioned BPD) to that in fertilisers;

The concentration of sulphur in BPD is higher than that in liming materials;

Concentrations of arsenic and zinc are broadly comparable to that identified within fertilisers

and liming materials;

The median concentrations of cadmium and molybdenum in unconditioned BPD are

comparable to those in phosphate fertilisers, but higher than in other fertilisers and liming

materials;

The concentrations of cobalt, copper, lead, selenium reported for BPD are high in comparison to

those in fertilisers and liming materials. The concentration of copper and cobalt in CKD is also

high in comparison to fertilisers and liming materials;

The median concentration of chromium in unconditioned BPD is comparable to that in fertilisers,

but higher than that in liming materials. The range of chromium concentrations for CKD is lower

than the median concentration for TSP, but higher than concentrations in other fertilisers and

liming materials;

The concentrations of nickel identified in BPD are comparable to those in fertilisers and liming

materials, but the concentrations in CKD are all higher than the median concentrations in both

fertilisers and liming materials;

The concentrations of thallium reported for BPD and CKD (only 1 sample) are high (3-6 times)

in comparison to the median concentration in liming materials;

The median concentration of vanadium in unconditioned BPD is lower than that in fertilisers, but

higher than that identified within liming materials;

The concentrations of fluoride in BPD are comparable with that identified in TSP and other

straight phosphate fertilisers, but substantially lower than that in NP fertilisers. The

concentrations of fluoride in BPD are higher than that in liming materials; and

The median concentration of chloride identified in unconditioned BPD is substantially greater

than that reported for liming material.



Main findings (Comparison to comparators):

- Concentrations of arsenic, beryllium, manganese and boron in CKD and BPD are broadly comparable to those reported in UK rural soils;

- Concentrations of antimony, cadmium, copper, mercury, lead, molybdenum, cobalt, chromium, thallium, silver, selenium, barium, vanadium and zinc have been reported in CKD and / or BPD at concentrations above those in UK rural soils;

- Concentrations of benzo(a)pyrene and dioxins in BPD have been identified at comparable concentrations to UK rural soils;

- A comparison of contaminant concentrations identified within BPD / CKD and other fertilisers and liming materials has been made, with varying results. Generally, concentrations of metals are higher in BPD / CKD in comparison to other liming materials.

Quality Statement (Comparison to comparators): Medium – Limited information has been identified in the literature with regards to the composition of CKD / BPD in comparison to other materials. However, a comparison has been undertaken using UK based information for other materials and UK background soil concentrations.

4.4.8 Plant and Animal Pathogens

MPA (2015b) confirmed that pathogens are unlikely to be present within the input materials into the kiln. In

the event that these were inadvertently introduced into the system, the high temperatures experienced in the

kiln process would result in them being destroyed. As a result, this is considered unlikely to be a hazard for

this waste type.

4.4.9 Invasive Weeds

CKD and BPD are produced in high temperature kilns, which are likely to destroy the viability of any seeds or

plant materials present. No studies were identified, but it is considered unlikely to be a hazard for this waste

type.

4.4.10 Physical Contaminants

As discussed within Section 3.2.1, some cement kilns make use of co-processing of waste, and use waste-

derived fuel. MPA (2013) reported that the base material for alternative waste-derived fuels is processed

and segregated to remove glass, ferrous and non-ferrous material prior to use in the kilns. As such, the

potential for physical contaminants within the fuels burnt in the kilns is considered to be low, although there is

still the possibility for a small proportion of physical contaminants (e.g. wood, plastic) to be introduced into

the process. Given the very high operating temperature of cement kilns (>1200 ˚C) (UN, 2011) and long

residence time in the kiln, it is likely that any such materials will be mostly destroyed, with any material

surviving the incineration process likely to fall into the clinker. Only fine dust particles from physical

contaminants may be present within the CKD or BPD. As a result, this hazard is considered to be negligible.

4.4.11 Nuisance

According to Material Safety Data Sheets (MSDS) for CKD and BPD, these materials are odourless.

Due to the temperatures at which cement kilns operate (>1200 ˚C) (UN, 2011), it is considered unlikely that

any significant quantity of organic matter will be present in the product which could attract pests. This was

also the opinion expressed during discussions with a UK landspreading operator (Expert interview, 2015b).

Given its physical properties, the potential for nuisance from dust is considered to be a hazard. However, the

potential for dust generation would be expected to be reduced by the application of CKD and BPD in

conditioned rather than unconditioned form (Expert interview, 2015a). It is also notable that application of

CKD in the USA (USEPA, 1993), which was not reported to employ conditioned dusts, resulted in little dust

becoming airborne even on windy days. IEEE/PCA (2008) also referred to a testimonial that CKD is not

extremely dusty and is easily handled.



Note that the example deployment applications provided by the UK landspreading operator took into account

the need to manage the potential for fugitive dusts releases. Spreading was not to be undertaken near

sensitive receptors such as residential housing and watercourses. It also referenced the need to comply with

the Code of Good Agricultural Practice for the Protection of Water, Air and Soil (Expert interview, 2015a).

4.4.12 Other Environmental Hazards

No other potential hazards were identified for CKD or BPD.

4.5 Hazard Evaluation and Screening

4.5.1 Master List of Hazards

Based on the information provided above, a number of hazards have been identified for BPD and CKD, in

the context of landspreading to agricultural land. The Master List of hazards has been informed by their

presence or absence in CKD / BPD as reported in compositional data and relative to their concentrations in

UK rural soils and other comparators.

Justification for the selection of Master List hazards is presented in Tables 4.13 and 4.14.

Table 4.13 Justification for Choice of Master List of Hazards for BPD

Hazards Comments Master Hazard

Chemical Hazards

Metals and metalloids – antimony, cadmium, chromium, copper, lead, thallium, zinc, silver, molybdenum, selenium, barium, mercury

Concentrations of antimony, cadmium, copper, mercury, chromium, molybdenum, selenium, thallium, silver and zinc have been identified at concentrations above those reported in UK rural soils.

No analytical results have been provided for barium in BPD. However, concentrations above those identified in UK background have been recorded in CKD.

Yes

Metals and metalloids – arsenic, nickel, cobalt, beryllium, manganese, boron, vanadium

Concentrations of arsenic, manganese, beryllium, vanadium and nickel are broadly comparable to that identified within UK rural soils and other fertilisers and liming materials.

Concentrations of cobalt reported for BPD are less than that identified in UK rural soils.

No


High concentrations of contaminants have been reported in both unconditioned and conditioned BPD.

Concentrations of potassium are high relative to other liming materials, but comparable to some other fertilisers. However, there is evidence in the literature to suggest that high concentrations of potassium in BPD could present a risk to controlled waters under certain conditions.

Concentrations of chloride and sulphur are high in comparison to other fertilisers and liming materials. High concentrations have also been recorded in BPD and CKD leachate.

Concentrations of fluoride have been identified at comparable concentrations in other fertilisers, but are higher than that in other liming materials. High concentrations of fluoride have been identified in BPD leachate.

Yes

Dioxins, furans and PCBs Median concentrations in BPD are less than that reported for UK rural soils.

There appears to be a consensus in the literature that the kiln process is effective at removing dioxins and furans from the system. The high temperatures experienced by the BPD in particular should remove the majority of these congeners.

No

PAHs Concentrations of PAHs reported in BPD are low, although it is recognised that this is based on a limited number of samples. There is a consensus in the literature that organic contaminants are not considered to be a significant hazard in CKD or BPD.

Concentrations of benzo(a)pyrene reported in BPD are less than the median concentration in UK rural soils.

No

Pesticides Considered unlikely to be present due to the nature of the kiln process and input / waste materials.

No




Radionuclides No UK information. However, a USEPA study in 1993 indicated that the kiln process was unlikely to enhance the quantity of radionuclides present in the CKD and BPD.

No

Nuisance

Dust Small particle sizes for CKD have been reported in the literature. Due to the nature of this waste material there is considered to be the potential for dusts, although this risk can be mitigated by conditioning of the waste.

Yes

Table 4.14 Justification for Choice of Master List of Hazards for CKD


Chemical Hazards

Metals and metalloids – antimony, cadmium, chromium, copper, lead, thallium, zinc, molybdenum, silver, vanadium, nickel, barium, selenium, mercury, cobalt

Concentrations of antimony, cobalt, cadmium, copper, chromium, molybdenum, selenium, thallium, silver and zinc in unconditioned CKD have been identified at concentrations above those reported in UK rural soils.

Higher concentrations of nickel and vanadium have been reported in CKD in comparison to BPD, which are above the UK median for rural soils.

No analytical results have been provided for selenium or mercury in CKD. However, concentrations above those identified in UK rural soils have been recorded in BPD.

Yes

Metals and metalloids – arsenic, beryllium, manganese, boron

Concentrations of arsenic, manganese and beryllium are broadly comparable to that identified within UK background and other fertilisers and liming materials.

No concentrations of boron have been provided for CKD. However, concentration of boron identified in BPD are well below that reported for UK rural soil and hence this is considered unlikely to be a hazard.

No


High concentrations of sulphate, chloride and fluoride have been reported in unconditioned CKD leachate.

Yes

Dioxins, furans and PCBs Analytical data for one sample for PCBs (7 congeners) has been provided, which shows concentrations to be less than detection limit (<5 µg/kg).

No dioxin and furan data has been provided by UK industry or the Environment Agency for CKD. Based on the BPD data risks from measured concentrations of dioxins and furans are considered to be low. However, there is evidence in the literature that concentrations of these congeners may be higher in CKD due to the dusts point of production in comparison to BPD. Literature evidence does indicate that although measurable concentrations of dioxins and furans have been reported in CKD, these concentrations tend to be low. However, in the absence of UK specific data this cannot be confirmed at this time.

USEPA (1993) indicated that potential risks from dioxins and PCBs to controlled waters will be minimal due to their low solubility.

Yes

PAHs Concentrations of PAHs reported in CKD are low, although it is recognised that this is based on a limited number of samples there is a consensus in the literature that organic contaminants are not considered to be a significant hazard in CKD or BPD.

Concentrations of benzo(a)pyrene reported in CKD are less than the median concentration in UK rural soils.

No

Pesticides Considered unlikely to be present due to the nature of the kiln process and input / waste materials.

No

Radionuclides No UK information. However, a USEPA study in 1993 indicated that the kiln process was unlikely to enhance the quantity of radionuclides present in the CKD and BPD.

No

Nuisance

Dust Due to the nature of the dust there is considered to be the potential for dusts, although these can be mitigated by conditioning the waste

Yes



Based on the above information, a Master List of hazards has been determined for BPD and CKD

respectively (Tables 4.15 and 4.16).

Table 4.15 Master List of Hazards for BPD


Chemical Hazards



Soluble salts, principally potassium, fluoride and chloride Soil quality, livestock, crops, groundwater and surface water

Nuisance


* BPD appears to contain concentrations of barium above background rural UK soils, but no testing results have been


Table 4.16 Master List of Hazards for CKD


Chemical Hazards

Metals and metalloids – Metals and metalloids – antimony, cadmium, chromium, copper, lead, thallium, zinc, molybdenum, silver, vanadium, nickel, barium, selenium**, mercury**, cobalt


Soluble salts, principally potassium, fluoride and chloride Soil quality, Livestock, crops, groundwater and surface water

Dioxins and furans Soil quality, humans and livestock / ecology

Nuisance


** Selenium and mercury have been identified as Master List hazards for BPD, but no testing results have been provided

for selenium or mercury in CKD so these are considered as a possible hazard.

4.5.2 Principal List of Hazards

The BPD Master List has been assessed to determine which hazards have the potential to present a

significant risk to receptors under generic conditions and therefore represent a Principal List hazard. The

assessment of chemical hazards for BPD has focused on using median concentrations, where derived31, for

unconditioned BPD. This comprises a larger dataset than that currently available for conditioned BPD.

Although the analytical data obtained to date appears to show that concentrations in solid and leachate for

conditioned BPD are lower than in unconditioned BPD, there is considered to be no physical or chemical

reason for this. Hence the unconditioned BPD chemical dataset is considered to be representative of what

could also be present in conditioned BPD. Reference has also been made to concentrations of

contaminants recorded in conditioned BPD if these lie outside of the range considered for unconditioned

BPD.

In undertaking the hazard screening, Amec Foster Wheeler considered the following factors, where relevant:

31 Where the sample number is less than 10, the maximum concentration has been used.



Evidence and opinion provided through expert interviews;

Evidence and opinion provided within the published literature on the risks presented by a

particular hazard to a given receptor;

Typical concentrations of the contaminants of concern in comparison to existing environmental

levels in soils and in comparable non-wastes such as fertilisers, manures, and soil substitutes

when applied at similar application rates (taking into consideration good agricultural practice

and the potential for enrichment);

The potential likelihood of a hazard occurring under generic conditions, with controlled

application rates and the risk criteria specified within SR2010 No. 4; and

Any underlying requirements for management practices or mitigation to be implemented to

minimise the risk (for example, standard permit conditions and good practice under statutory

codes).

In the absence of sufficient information relating to the chemical composition of CKD, it is not considered

possible to identify a Principal List of hazards for consideration at deployment stage for this waste stream.

As a result, the Master List of hazards for this waste cannot be refined at this time. However, given that this

dust has similar physical characteristics to BPD, the evaluation of potential nuisance from this waste stream

is considered alongside BPD.

Chemical Hazards (BPD only)

Concentrations of chemical contaminants identified in UK BPD have been compared to median

concentrations of these contaminants present within UK rural soils. The following metals have been

identified in BPD at concentrations in excess of background:

Antimony;

Cadmium;

Chromium;

Copper;

Lead;

Thallium;

Zinc;

Silver;

Molybdenum;

Mercury;

Selenium; and

Barium (assumed due to its presence at high concentrations in CKD, but no results for this

contaminant have been provided for BPD).

Concentrations of potassium, fluoride and chloride have also been noted to be present at high

concentrations within BPD, with these concentrations generally in excess of that present within other

fertilisers and liming materials. Although these are recognised as also providing a benefit to land, these have

been identified in the literature as having the potential to present an unacceptable risk to environment

receptors at high concentrations in associated leachate (Peters, 1998).

In order to evaluate the potential significance of identified concentrations of these metals and soluble salts

within BPD in the context of application to agricultural land, the following assessment has been undertaken:

A direct comparison of median contaminant concentrations present within BPD with the

maximum permissible concentrations of potentially toxic elements (PTE) in soils, as specified in



the Department of Environment Code of Practice for the use of Sewage Sludge in Agriculture

(DoE, 1996);

Estimation of the potential addition of contaminants on an annual and 10 year basis, based on

an application rate of 4.5 t/ha and one application every 3 years, in comparison to the maximum

permissible PTE limits (DoE, 1996); and

Estimation of approximate percentage enrichment of background concentrations with a single

4.5 t/ha application of BPD32.

The above assessment approach is considered to form the basis to allow an informed evidence based

judgement of which Master List hazards could potentially present a significant risk to identified receptors and

hence be considered as Principal List hazards. The risk evaluation for each identified receptor in Table 4.15

is also presented below.

Comparison with Maximum Permission Concentrations

The median and maximum concentrations of contaminants identified within UK BPD are compared against

the maximum permission concentrations below.

Table 4.17 Concentrations of potentially toxic elements (PTE) in BPD compared with maximum permissible concentrations

Determinand BPD (mg/kg) Maximum permissible concentration in soil (mg/kg dry solids)

Median Maximum Arable Grassland

Zinc 220 690 200 (pH 5) – 300 (pH >7) 200 (pH 5) – 300 (pH >7)

Copper 195 1200 80 (pH 5) – 200 (pH >7) 130 (pH 5) – 330 (pH >7)

Cadmium 12 78 3 3

Lead 775 9400 300 300

Chromium 26 3261 400 600

Mercury 0.23 1.3 1 1.5

Molybdenum -2 51 4 4

Selenium -3 5431 3 5

Fluoride -3 13511 500 500

Arsenic, nickel and mercury are not included above as concentrations in BPD are comparable with those identified in UK

rural soils

Exceedance of the maximum permissible levels are highlighted in bold

1 – Maximum concentrations for conditioned BPD

2 - No results provided for unconditioned BPD for molybdenum

3 – Insufficient sample results provided to calculate a median concentration

The results show exceedances of the maximum permissible concentrations in soil for both arable and

grassland for copper, cadmium and lead based on median concentrations reported in unconditioned BPD.

The maximum concentrations in BPD for zinc, copper, cadmium, lead, molybdenum, selenium and fluoride

are also identified in excess of the limit values.

32 This is based on simple enrichment, which does not take into account the mass of the carrier material



The maximum concentration of mercury reported (1.3 mg/kg) is marginally in excess of the limit for arable

land, but is below that specified for grassland.

The potential significance of these high concentrations in comparison to the limit values for each receptor is

considered further below.

Comparison with Maximum Permissible Average Annual Rate of PTE Addition

In addition to the above maximum permissible concentrations, the Code of Practice for the use of Sewage

Sludge in Agriculture (DoE, 1996) also specifies limits for the maximum permissible average annual rate of

PTE addition over a 10 year period (kg/ha). Information relating to the typical application rate of this material

to land has been provided by the UK landspreading operator, with a maximum rate of 4.5 t/ha suggested and

material being applied to land every 3 years (Expert interview, 2015a). This rate of application has been

supported by information identified within the literature (USEPA, 1998), although it is recognised that the

latter is not UK specific. It should be noted that the agricultural application rate will vary on a site by site

basis, due to a number of factors including receiving soil type, pH, buffering capacity etc. However,

assuming an application of rate of 4.5 t/ha and considering the maximum and median concentrations of

PTEs identified in UK BPD, the following Table presents the estimated addition of contaminants following a

single application and three applications over a 10 year period. These have been subsequently compared

against the maximum permissible average annual rate of PTE addition limits specified in the Code of

Practice for the use of Sewage Sludge in Agriculture (DoE, 1996) .

Table 4.18 Estimated rate of PTE addition based on an application rate of BPD at 4.5 t/ha

Determinand Max permissible average annual rate of PTE addition over 10yr period (kg/ha)

PTE addition per application of BPD (kg/ha)

PTE addition over 10 years following 3 applications of BPD (kg/ha)

Based on median concentrations

Based on maximum concentrations

Based on median concentrations

Based on maximum concentrations

Zinc 15 1.0 3.1 0.3 0.9

Copper 7.5 0.9 5.4 0.3 1.6

Cadmium 0.15 0.05 0.35 0.02 0.11

Lead 15 3.5 42.3 1.0 12.7

Chromium 15 0.1 1.51 0.04 0.441

Mercury 0.1 0.001 0.006 0.0003 0.0018

Molybdenum 0.2 -2 0.022 -2 0.0072

Selenium 0.15 -3 2.41 -3 0.71

Fluoride 20 -3 6.11 -3 1.81

Bold highlights an exceedance of the maximum permissible annual addition

1 – Maximum concentrations for conditioned BPD



4 – Makes no allowance of contaminant concentrations in receiving soils

Table 4.18 indicates that, based on the maximum concentrations of lead, cadmium and selenium recorded in

BPD, one application of this material at a rate of 4.5t/ha would result in an exceedance of the maximum

permissible levels for these contaminants. Based on an application rate of 4.5 t/ha and an application

frequency of once every 3 years, cadmium and lead are unlikely to result in an exceedance of the limit

values averaged over a 10 year period, although selenium is still identified as exceeding the maximum

permissible concentration. With regards to selenium, a limited number of results have been provided for this



contaminant in unconditioned and conditioned BPD, with the result for unconditioned BPD noted to be

substantially lower than that reported for conditioned BPD. It is noted in one of the analytical certificates

provided by the MPA (2015a) that there is the potential for interference with the measurement of selenium

due to the inherently high concentrations of calcium and potassium in the dusts. As a result, these high

concentrations of selenium reported in conditioned BPD may not truly represent the concentrations present

within the material.

None of the above contaminants exceed the maximum permissible levels based on the median

concentrations reported in BPD.

The potential significance of the above results to each receptor is discussed further below.

Calculation of Potential Soil Enrichment

The potential enrichment of the receiving soils has been estimated using the median and maximum

concentrations of contaminants identified in BPD. The calculations have assumed a single application at a

rate of 4.5 t/ha and simple enrichment with a mixing zone depth of 5cm for grassland and 25cm for arable

land33. The enriched soil concentration after waste application is based on the median background

concentration of contaminants in UK rural soils and reported as percentage enrichment compared to the

background level. Note that the actual enrichment of the receiving soils for any one application will be

dependent on the site-specific contaminant concentrations present within the receiving soils and chemical

composition of the waste being considered for deployment.

The estimated potential enrichment for grassland and arable land is presented below in Table 4.19. The

estimates do not take into account any potential loss of metals through leaching and hence are likely to be

conservative. For the purpose of this hazard evaluation, a percentage enrichment of greater than around

10% is considered to be potentially significant with respect to overall soil loading and enrichment34.

Table 4.19 Estimated Potential Enrichment of median UK rural soils following one 4.5 t/ha application

Determinand Percentage of enrichment based on median concentrations in BPD

Percentage of enrichment based on maximum concentrations in BPD

Grassland Arable Grassland Arable

Antimony 3.2% 0.6% 8.7% 1.7%

Cadmium 28.6% 5.7% 186.2% 37.2%

Chromium 0.6% 0.1% 7.7%1 1.5%1

Copper 7.8% 1.6% 48.0% 9.6%

Lead 14.3% 2.9% 174.0% 34.8%

Mercury 1.6% 0.3% 9.0% 1.8%

Molybdenum -2 -2 3.8%1 0.8%1

Thallium 14.5% 2.9% 166.2% 33.2%

Silver -3 -3 11.5% 2.3%

Selenium -3 -3 751.8%1 150.4%1

Zinc 2.3% 0.5% 7.2% 1.4%

Percentage enrichment of >10% are highlighted in bold

33 With an assumed density of 1300kg/m3

34 Does not take into account potential loss through leaching and has been used to identify priority substances only



1 – Based on maximum concentrations for conditioned BPD



The results above indicate that, based on an application rate of 4.5 t/ha and considering both median and

maximum concentrations in BPD, antimony, chromium, mercury, molybdenum and zinc are unlikely to make

a significant contribution to receiving soils35.

The results above show that silver has the potential to result in an enrichment marginally above 10% for

grasslands based on the maximum concentrations recorded in BPD. However, the potential enrichment

based on the maximum concentration recorded for BPD for arable land is substantially lower. Note that

given the limited number of samples analysed for silver in BPD, it has not been possible to derive a median

concentration for silver in BPD.

Based on the median concentrations of copper in BPD, this is unlikely to result in significant enrichment of

receiving soils. However, the maximum concentration of 1200 mg/kg recorded in BPD has the potential to

result in significant enrichment of grassland.

The results indicate that cadmium, lead, selenium and thallium recorded in BPD have the potential to result

in significant contaminant loading in the receiving soils, for grassland based on both median and maximum

concentrations and for arable land based only on maximum concentrations.

Livestock - Hazard Evaluation

No assessments of potential risks to livestock from the application of CKD or BPD to agricultural land have

been identified as part of this REA. USEPA (1993) made reference to the use of this waste as a feed

ingredient in livestock diets and indicated that this had previously been the subject of strong interest by

industry. However, they concluded that it had been deterred by the presence of various trace metals present

within the dusts. One of several studies noted by USEPA identified no undesirable accumulations of

elements, such as arsenic, cadmium, lead or selenium in the kidney and liver of steers and lambs. The

USEPA also indicated that similar research had not identified any significant levels of heavy metals or cases

of toxicity in the animals studied.

Rodd et al. (2010) indicated that the application of CKD36 to land resulted in an approximate doubling of the

concentration of potassium in forage tissue in comparison to that arising from the application of agricultural

lime. They noted as part of their study that the concentrations of potassium in the forage were higher than

the nutritional requirement for dairy cattle, but that the concentrations following CKD application were below

the maximum tolerable limit of potassium in the diet (reported as 30 g/kg). The authors indicated that the

repeat application of CKD could lead to an intake of greater than this maximum tolerable limit37 due to luxury

consumption38, which could lead to the interference of magnesium metabolism and utilisation in cattle. No

UK threshold for potassium in feed for livestock has been identified as part of this study. It should be noted

that the landspreading operator commented that at the rate of typical application of BPD, there is an over

provision of potassium in the soils. This could therefore potentially result in associated hazards to livestock,

as noted by Rodd et al. (2010). However, the Code of Good Agricultural Practice (Defra, 2009) indicates that

the exposure of livestock from contaminants present in the soil is likely to be dominated by ingestion of soils

rather than the amount of contaminants present in the grass. On this basis, the potential for potassium to

present a significant risk to livestock through plant ingestion is considered unlikely. Given the high

concentrations of potassium present within this waste, evidence of this being an issue with regards to

livestock would have been expected to have been identified in the literature, although only a single reference

has been identified. Furthermore, no evidence has been found which identified potassium as a significant

hazard for livestock. Anecdotal evidence provided by the landspreading operator also indicates that the

farmers in the UK that have used BPD on their land have not reported any problems (Expert interview, 2015a

35 Based on potential contribution to UK rural background soil concentrations.

36 CKD is defined as a by-product of the cement industry and hence may also include BPD in its definition.

37 Not UK specific.

38 Defined as the absorption of nitrogen or potash from the soil by a crop in excess of crop needs.



& b). The example deployment applications provided by the UK landspreading operator also indicated that

there were no significant negative impacts from the target application rates proposed (Expert interview,

2015a). This again suggests that there are no significant risks to livestock with respect to the potassium

present in the waste when applied to agricultural land.

For initial screening purposes, the maximum concentrations of metal contaminants have been compared

directly to the Maximum permissible limits specified by the DoE (1996) (see Table 4.17). This identifies

concentrations of zinc and chromium below their respective limits, which suggests that these contaminants

are unlikely to present an unacceptable risk to livestock through direct ingestion. Note that zinc and

chromium have also been identified in Table 4.18 and 4.19 as being unlikely to result in an issue with

regards to accumulation and enrichment following repeated applications of BPD.

Table 4.17 indicates that the median and maximum concentrations of mercury recorded in BPD are below

the limit specified for mercury in grassland soils and hence is considered unlikely to present a significant risk

to grazing livestock.

Concentrations of selenium have been identified in excess of the 5 mg/kg threshold for grassland in both

unconditioned and conditioned BPD. The concentrations of selenium in conditioned BPD are substantially

higher than this threshold, with a maximum concentration of 543 mg/kg being recorded. This maximum

concentration would also result in the maximum annual average application rate over a 10 year period being

exceeded for a single application and over a ten year period (see Table 4.18). This may have the potential

to result in significant enrichment of the receiving soils (see Table 14.9). As noted previously, the presence

of calcium and potassium in the dust can result in falsely high results for selenium and hence the reported

concentrations may not be representative of the actual BPD concentration (MPA, 2015a). Due to this

uncertainty this contaminant is considered to be a potentially significant risk to livestock.

The median and maximum concentrations of copper in unconditioned BPD has been recorded above the

maximum permissible limits as specified in the Code of Practice for Agricultural use of Sewage Sludge for

grassland (DoE, 1996). However, based on an assumed application rate of 4.5t/ha this contaminant does

not exceed the maximum permissible limits for copper based on an annual application or average over a 10

year period (assuming a frequency of application of once every 3 years). The Soil Code (MAFF, 1998) also

made reference to a toxic threshold of 500 mg/kg in soil for susceptible animals such as sheep and lambs.

Note that it is considered unlikely that cattle will be affected by copper present in soil or plants (MAFF, 1998).

The median concentration of copper in unconditioned BPD is below this threshold concentration. The

maximum concentration is over double the threshold, but further review of the dataset indicates that only 6

No. of the 57 No. samples analysed for copper in unconditioned BPD recorded a concentration in excess of

500 mg/kg, with five of these concentrations being <600 mg/kg. The range of concentrations identified in

conditioned BPD are also all less than the toxic threshold concentration of 500 mg/kg. Given the above, and

fact that Table 14.5 indicates that at the median concentration copper is unlikely to result in significant

enrichment of receiving soils, it is considered unlikely that copper within BPD will present a widespread

significant risk to livestock.

Both the median and maximum concentrations of lead recorded in BPD are in excess of the precautionary

threshold of 300 mg/kg in soils for monogastric animals (pigs, poultry and horse), which are considered more

at risk of lead poisoning than cattle or sheep (MAFF, 1998). Table 4.18 also indicates that a single

application of BPD to land would result in an exceedance of the maximum permissible limit for lead, although

when the average addition of lead over a 10 year period (assuming one application every 3 years) is taken

into account the concentration of lead would be marginally less than the limit. MAFF (1998) commented that

in alkaline soils (pH of more than 7), lead is not available to plants, although livestock could potentially be

exposed to lead through the direct ingestion of soils containing BPD following its application to land. Given

the consistently high concentrations of lead recorded in BPD and potential for significant enrichment of the

receiving soils following application, it is considered to have the potential to present a significant risk to

livestock.

The guideline concentration limit for cadmium in soil is 3 mg/kg (DoE, 1996), which has been set to protect

the food supply of animals and man (MAFF, 1998). This guideline level is exceeded by the median and

maximum concentrations of cadmium reported in BPD, with 56 No of the 57 No. samples reporting a

concentration in excess of 3 mg/kg in unconditioned BPD. Table 4.18 also indicates that a single annual

application of BPD to land would result in an exceedance of the maximum permissible limit, although when

averaged over a 10 year period (assuming 3 applications) the concentration of cadmium would be marginally



less than the limit. Generally, cadmium is considered to be less mobile in alkaline soils and this is

demonstrated to some degree in the leach test results for both CKD and BPD (MPA, 2015a) and in the

literature (Mahmoud and Rimes, 2012), with low concentrations of cadmium being recorded in comparison to

other metals. This has the potential to minimise the potential bioavailability of this contaminant for plant

uptake. However, as is the case for lead, there is the potential for livestock to be exposed to cadmium

through direct ingestion of soil. Given the consistently high concentrations of cadmium recorded in BPD in

comparison to the maximum permissible limit, it is considered to have the potential to present a significant

risk to livestock.

A maximum concentration of molybdenum of 5 mg/kg has been reported in conditioned BPD. This is

marginally above the 4 mg/kg threshold limit (DoE, 1996). Table 4.18 indicates that based on this maximum

concentration, this contaminant is unlikely to exceed the annual average maximum permissible limit for

addition of molybdenum to land. On the basis of the limited analytical results available for BPD, it is

considered unlikely that molybdenum in BPD will present a significant risk to livestock.

MAFF (1998) indicated that long term exposure to soils with high concentrations of fluoride can result in

fluorosis in teeth and bones of livestock. Limited analytical results have been provided for fluoride for

unconditioned and conditioned BPD, with the maximum concentration exceeding the threshold of 500 mg/kg

(DoE, 1996). However, when BPD is applied at a rate of 4.5 t/ha, the maximum annual average rate of

addition does not result in an exceedance of the threshold based on one annual application or averaged over

a 10 year period. As a result, this contaminant is considered unlikely to present a significant widespread risk

to livestock.

MAFF (1998) indicates that the maximum permissible limit for zinc specified under the Code of Practice for

agricultural use of sewage sludge (DoE, 1996) is based on the threshold for risks to plants and crops.

Symptoms of adverse effects for these receptors may occur at concentrations well below this level. Given

the marginal exceedance of the median concentration of zinc identified in BPD in comparison to this

threshold limit and the fact that zinc is unlikely to result in significant enrichment of receiving soils, it is

considered unlikely that zinc will present a significant risk to livestock.

Note that no UK soil limits exist for livestock for antimony, silver and thallium. However, based on the

potential enrichment calculations it is considered unlikely that either antimony or silver would present a

significant risk to livestock. In contrast, based on the results obtained for thallium and subsequent estimated

level of enrichment to the receiving soils, there is the potential for this contaminant to present a significant

risk to livestock, particularly given that this contaminant is regarded as highly toxic (HSDB, 2008).

In summary, the potential adverse risks to livestock from the landspreading of BPD have not been

adequately addressed within the evidence sources reviewed. Amec Foster Wheeler has undertaken an

initial assessment of the potential hazards in the Master List by comparing contaminant concentrations in

BPD to maximum permissible concentrations specified in the Code of Practice for agricultural use of sewage

sludge (DoE, 1996), taking into consideration the potential enrichment of receiving soils. The results have

identified that cadmium, lead, selenium and thallium could potentially present a significant risk to livestock.

As discussed above, the Code of Good Agricultural Practice (Defra, 2009) indicates that the exposure of

livestock from contaminants present in the soil is likely to be dominated by ingestion of soils rather than the

amount of contaminants present in the grass. The Code of Practice for Agricultural use of Sewage Sludge

(DoE, 1996) recommends that land is not grazed for a period of 3 weeks following application. In Amec

Foster Wheeler’s opinion following this approach would allow the BPD to become established into the soil,

minimising the potential for livestock to be exposed to lead, cadmium, lead, selenium and thallium present

within the BPD through direct ingestion and the associated hazard. However, this will not remove the

potential for rapid soil enrichment following repeated applications of BPD.

Human Health - Hazard Evaluation

No consideration of human health risks using UK approaches has been identified in the literature.

USEPA (1993) undertook a human health risk assessment for CKD, although this was on the basis it would

be located in stockpiles, with the potential for this to be deposited onto adjacent farming land through wind

erosion and deposition. USEPA (1993) assumed worst-case scenarios with a low probability of occurrence.

Furthermore, in a general sense the USA approach to risk assessment is different from the UK, such as the

approach to chemical carcinogens, and hence these results cannot be directly applied.



The risk scenarios adopted a number of extremely health protective assumptions, which included a farmer

who was highly subsistent from their land, taking 75% of their total consumption from crops, milk and meat

from the farm exposed to CKD. USEPA (1993) modelled the predicted potential risks via the food chain and

identified a higher cancer risk for arsenic and dioxins for a farmer and his family. Note that this assessment

was based on the maximum concentrations of arsenic in CKD identified in the study, which as discussed in

Section 4.4, are well in excess of that reported in UK for CKD or BPD.

A further risk assessment was undertaken for CKD by the USEPA in 1998 (USEPA, 1998), which looked at

the potential risks to identified receptors as a result CKD being applied to agricultural land, as a liming

substitute and fertiliser. This again considered farmers and their children who consumed crops etc. from the

land where CKD had been applied. This assessment identified maximum concentrations reported in CKD

above risk-limiting concentrations derived as part of the study for lead, thallium, arsenic, cadmium and

dioxins. Note that the USEPA report is still in draft form and appears to have been heavily criticised with

regards to the assumptions and modelling undertaken as part of the assessment during peer review

(USEPA, 1998).

The generic conceptual model for landspreading (see Appendix A) identifies the following human receptors

and pathways for exposure to BPD:

By-standers and residents - exposed to dusts via dust inhalation during and immediately post

application;

Consumers - exposure via the food chain through the consumption of contaminated crops and

livestock; and

Operators – exposure through direct contact, ingestion and potential inhalation of dusts during

storage, transport and application.

Of the above, potential hazards and risks associated with the release of fugitive dusts can be mitigated

against through adoption of good practice in accordance with the Code of Good Agricultural Practice (Defra,

2009) and SR2010 permit conditions. On this basis, the potential risk presented by this potential transient

exposure to by-standers is considered unlikely to be significant.

Exposure to contaminants in BPD for workers involved in landspreading is likely to be confined to the period

of transport and spreading, and on an intermittent basis subsequently for farm workers. Such short term

exposure events can be mitigated by compliance with health and safety legislation and through the use of

gloves and good hygiene practice i.e. not eating, drinking or smoking on site and washing of hands, the

wearing of masks as necessary to minimise inhaling any dusts and undertaking the works in accordance with

good practice and SR2010 permit conditions. As a result, any potential risks to the workforce involved in the

landspreading activity can be avoided.

With regards to risks presented to humans via the food chain, cadmium, lead, selenium and thallium have

been identified at concentrations which could impact negatively upon livestock (see discussion above).

MAFF (1998) has indicated that cadmium has the potential to build up in animals in the kidneys and liver,

which if consumed by humans can present an adverse health risk. However, there is some evidence in the

literature to suggest that cadmium is less mobile and leachable under alkaline conditions. This is supported

to some degree with the BPD leachate results (see Appendix B). This may minimise the potential

bioavailability of this contaminant for plant uptake, reducing the potential contaminant concentrations present

within crops and livestock, and ultimately human consumers. However, this will not prevent exposure of

livestock to this contaminant via direct ingestion and hence cadmium is considered to have the potential to

present a significant risk to human consumers.

As discussed previously thallium is considered to be highly toxic, and is a suspected human carcinogen.

Thallium and its compounds are generally highly water soluble and mobile in the terrestrial environment, but

can be immobilised by vermiculite and clays present in the soils, increasing the potential for livestock to be

exposed to this contaminant (HSDB, 2008). HSDB (2008) reported that thallium has the potential to

bioaccumulate in the terrestrial food chain, but is unlikely to biomagnify. On the basis of this information, and

the fact that this contaminant can be significantly enriched in the receiving soils, there is a potentially

significant risk to humans via the food chain.



Lead has proven risks to human health, with the most significant health effect associated with exposure to

lead considered to be reduced cognitive development and intellectual performance in children (Environment

Agency and Defra, 2002 and HPA, 2011). HSDB (2010) reported that lead has a high bioaccumulation

potential for in aquatic species, particularly for saltwater species used for human food (mussels and oysters),

although the evidence is not as clear for terrestrial species. A range of lead concentrations has been

recorded in unconditioned and conditioned BPD which are consistently above the threshold limit for potential

risks to livestock (DoE, 1996). Defra (2014) indicated that lead is relatively immobile in soils and tends to

accumulate in the top horizons of a soil profile. Based on both the median and maximum concentrations

there is the potential for this to result in significant enrichment of receiving soils as a result of BPD application

to land at a rate of 4.5 t/ha. On this basis, the potential for lead to present a significant risk to human health

via the food chain cannot be discounted.

Selenium is an essential element, but when ingested at high concentrations can be toxic to human health.

Environment Agency (2009) has indicated that “excess selenium can result in pathological changes to the

hair and nails (selenosis), skin lesions and neurological effects. Convulsions and paralysis may also

develop”. The main forms of selenium in soil are selenite and selenide. These can absorb to clays, iron and

manganese minerals and organic matter within soils and can be taken up by plants. Environment Agency

(2009) also indicated that the most important influencing factor affecting plant uptake of selenium is soil pH,

with greater availability to plants noted with increasingly alkaline conditions. On this basis, selenium in the

BPD has the potential to be available to plants once applied to land. Given the uncertainty with regards to

the high concentrations recorded in conditioned BPD for selenium, this contaminant cannot be discounted as

potentially presenting a significant risk to human health.

Note that in reality an unacceptable risk to humans via the food chain for metals is likely to be dependent on

the chemical composition of BPD spread to land, including the bioavailable fraction, the potential for dilution

when incorporated into the soil39, the long-term accumulation in soils following repeat applications, crops or

livestock present at the site and application of this waste in accordance with good practice, along with the

rate and frequency of ingestion of certain food groups by an individual. Note that the testing of the

bioavailable fraction of a contaminant is not current practice, with maximum permissible limits specified for

metals provided as total concentrations. Furthermore, there is currently uncertainty with regards to the

acceptance of such tests by regulators, such as the Environment Agency.

Crops - Hazard Evaluation

Several studies which demonstrate the benefits of this waste applied to land, in terms of crop yield, have

been identified within the literature (see benefits section above in Section 4.4). Lafond and Simard (1999)

indicated that during their investigation of the effect of CKD on soil and potato quality, they found no impact

on the heavy metal content of the receiving soil or plant uptake as result of the spreading of CKD to

agricultural land.

Darley (2012) found that dusting of CKD directly onto plants caused considerable leaf injury (leaf scorch).

This was thought to be due to the high KCI present within the finer particles of CKD. Note that this study

looked at high application rates directly onto the surface of the vegetation. From discussions with the

landspreading operator it is apparent that direct applications are only undertaken on grasslands, with the

application of BPD to arable land taking place in autumn prior to planting (Expert Interview, 2015a). As such

any potential risk is likely to be confined to grasses present on the receiving land. Furthermore, application

rates are considered to be low and only undertaken approximately every 3 years (Expert interview, 2015a).

Anecdotally the Environment Agency are not aware of any issues with respect to leaf scorch on grasslands

as a result of the application of BPD to land. As a result, under normal controlled applications this is unlikely

to present a significant risk to plants.

High concentrations of soluble salts, such as chloride, have been reported in BPD (maximum of 130,000 mg

Cl/kg, with high concentrations also recorded in BPD leachate). Chloride is an essential element for plants,

acting as a counter ion for transport of other nutrients, such as potassium, as well as assisting in the

maintenance of cell hydration and playing a key role in photosynthesis (Murphy et al. 2007). However, at

high concentrations chloride can result in injury to plants. Chloride is not absorbed or held back by the soils

and hence is readily available in the soil-water and can be subsequently taken up by plants and accumulate

39 Taking into account the contaminant concentrations present within the receiving soils.



in leaf tissue. Note that given that the dust is incorporated into the receiving soils on arable land there is the

potential for a high degree of dilution and the potential dispersion of chloride quickly within the soils prior to

planting taking place. However, in the event that chloride concentrations exceed the tolerance of the plant,

injury symptoms can develop, with some species of plants, such as peas, beans, clover and other legumes,

being more sensitive to others (A&L Canada Laboratories Inc., 2008).

The magnitude of risk is likely to be influenced by the chloride levels present within the dust itself, the nature

of the receiving soil and the types of crops planted at the site. Given the high concentrations of chloride

present within this waste, evidence of this being an issue with regards to crops would have been expected to

have been identified in the literature. However, no evidence has been found which identified chloride as a

significant hazard for crops. Anecdotal evidence provided by the landspreading operator also indicates that

the farmers in the UK that have used BPD on their land have not reported any problems (Expert interview,

2015a & b). The example deployment applications provided by the UK landspreading operator also

indicated that there were no significant negative impacts from the target application rates proposed (Expert

interview, 2015a). This again suggests that there are no significant risks to crops with respect to the chloride

present in the waste when applied to agricultural land.

MAFF (1998) indicates that the maximum permissible limit for zinc specified under the Code of Practice for

agricultural use of sewage sludge (DoE, 1996) of 200 mg/kg is based on the threshold for risks to plants and

crops. A median concentration of zinc of 220 mg/kg has been identified within BPD, which is marginally

above the threshold limit. A maximum concentration of 690 mg/kg has been recorded, which is well in

excess of the threshold limit. Based on an application rate of 4.5 t/ha this contaminant is unlikely to exceed

the maximum permission concentration for zinc on a single application or averaged over a 10 year period

and is unlikely to result in significant enrichment of receiving soils (<10% enrichment). On this basis,

concentrations of zinc identified in BPD are considered unlikely to present a significant risk to crops.

Soil Quality and Ecology - Hazard Evaluation

The potential risks to livestock and human health, which comes under a broad definition of soil quality (see

Glossary) are discussed separately below and this section focuses on the risks to soil microbiology, ecology,

function and structure.

No assessment of potential risks to ecology has been identified within the evidence sources obtained as part

of this REA. For initial screening purposes, the median and maximum concentrations of contaminants within

BPD have been compared to Environment Agency Soil Screening Values (SSVs) for ecological risk

assessment (Environment Agency, 2008b). SSVs only currently exist for a small number of contaminants

including cadmium, chromium, copper, lead, mercury, nickel and zinc. A comparison of the median and

maximum concentrations of these contaminants identified in BPD with the SSVs has identified a potential

risk from all of these contaminants. Based on the maximum concentration of selenium recorded there is

considered to be the potential for this to accumulate in soils at concentrations which could be an issue with

respect to soil quality and ecology (see Table 4.18). The potential for significant enrichment of the receiving

soils has also been identified for cadmium, lead, selenium and thallium. As such, in reality only these

contaminants are likely to have the potential to present a significant risk to ecology.

The Soil Code (MAFF, 1998) has noted that soil biology (soil rhizobia) can be affected by additions of zinc

above 200 mg/kg. A median concentration of zinc of 220 mg/kg has been identified within BPD, which is

marginally above the threshold limit. A maximum concentration of 690 mg/kg has been recorded, which is

well in excess of the threshold limit. Based on an application rate of 4.5 t/ha this contaminant is unlikely to

exceed the maximum permissible concentration for zinc on a single application or averaged over a 10 year

period and is unlikely to result in significant enrichment of receiving soils (<10% enrichment). On this basis,

it is considered unlikely that zinc will present a significant risk to soil biology.

Given the high pH of the BPD, there is the potential for this to result in caustic properties within the receiving

soil. However, the pH requirements of the receiving soil are taken into account by the landspreading

operator at deployment stage (Expert interview, 2015a), minimising the potential for the over-application of

this material resulting in issues with causticity.

Controlled Waters - Hazard Evaluation

Amec Foster Wheeler has not identified any assessments of risk to groundwater or surface water as a result

of the application of CKD or BPD to agricultural land within the literature reviewed. USEPA (1993)



considered these potential risks, but this work was undertaken for individual cement works using site specific

factors reflecting local groundwater and surface water sensitivity. USEPA (1993) also assumed that CKD

was managed in stockpiles on site, not spread to land, and therefore it is not relevant to the activity under

consideration in this REA.

USEPA (1993) referenced several incidences of damage or potential damage as a result of CKD leachate

entering surface water courses and groundwater. Again these incidences were based on the storage of CKD

in large quantities either in stockpiles or landfills, which were typically unlined. This information is considered

likely to represent a worst-case scenario with regards to potential risks to controlled waters. The main

contaminants of concern in these cases were varied, but tended to include elevated pH, total dissolved

solids, metals and metalloids and sulphate, with chloride, potassium and sodium concentrations also

identified above background levels.

For initial screening purposes, Amec Foster Wheeler conducted a brief Tier 1 screen of the maximum

leachate concentrations40 reported for BPD by comparing them against current Environmental Quality

Standards (EQS) and UK Drinking Water Standards (DWS). This identified a potential risk to surface waters

from the maximum leachate concentrations for specific pollutants: chloride, copper, zinc, chromium and

arsenic and priority substances cadmium, lead and mercury. This applies particularly in soft water areas.

Concentrations in leachate in excess of the DWS were also identified for selenium, arsenic, sulphate,

chromium and lead.

There is evidence in the literature relating to the potential risks from the high concentrations of soluble salts,

such as potassium, present within BPD leachate. Peters (1998) indicated that if this material was improperly

managed, these can lead to high total dissolved solid concentrations in leachate. High total dissolved solid

(TDS) concentrations are evident in the laboratory leachate results for BPD (see Section 2.2 and Appendix

B), with TDS of up to 55,300 mg/l being reported. The presence of a high TDS is likely to be more of an

issue for surface waters, as this can be toxic to aquatic organisms present within the watercourses.

Most of the evidence available for this study is based on CKD and BPD either being stockpiled or co-

disposed to landfill. While useful for considering issues with on-site storage of materials, the applicability to

the impacts after landspreading is limited. In particular, the evidence does not take into account the impact

of mixing with soil over a wider area with the potential to affect bulk chemical properties and sorb/retard the

leaching process. Table 14.9 has considered the potential enrichment of receiving soils41 from the

application of BPD at a rate of 4.5 t/ha, with cadmium, lead, selenium and thallium identified as having the

potential to provide a significant contribution and enrichment of these contaminants to receiving soils. There

is no EQS or DWS for thallium or leachate results available for thallium in BPD but cadmium, lead and

selenium are discussed above as having concentrations in excess of EQSs and / or DWS.

Given the contaminants identified within these dusts, particularly the soluble salts, it is likely that these will

react and mineralise very quickly when exposed to the atmosphere and soil conditions once applied and

hence are unlikely to be mobilised at high concentrations for long distances. There is the potential for an

initial flush of contaminants following application, arising from heavy rain. This has also been discussed in

the literature with respect to lead, with the soluble salts potentially enhancing the dissolution of lead initially,

but as the pH drops due to mixing with the receiving soil, the lead solubility falls, reducing the leaching

potential for lead (Kunal et al., 2012). As a result, the potentially significant risk identified using laboratory

leachate results may not actually be present in practice and is an uncertainty which this REA cannot address

based on the existing information. The issue has also been discussed in the literature. Mahmoud and Rimes

(2012) suggested that despite identified exceedances of the Canadian drinking water quality guidelines in

CKD leachate, in their opinion once in combination with the receiving soils, little or no exceedance was likely

(discussed further above in Section 4.4).

The magnitude of risk to both groundwater and surface water as a result of the application of BPD to

agricultural land will be highly dependent on site setting and conditions which will need to be taken into

account in the conceptual model for the individual deployment being applied for. Specific guidelines are

detailed within the standard rules permit, including set off distances to surface water and potable boreholes,

40 Insufficient samples using a consistent method were provided to calculate median concentrations for BPD leachate.

41 Based on median concentrations reported for UK rural soils



which will assist in minimising the potential risk to water receptors with a higher sensitivity. The example

deployment applications provided by the UK landspreading operator indicated that spreading will comply with

the Codes of Good Agricultural Practice (Defra, 2009) and that care would be taken when spreading this

waste close to watercourses (Expert interview, 2015a). The consideration of these factors relating to good

practice etc. will help in mitigate against any risk presented to controlled waters. However, in the absence of

representative leachate testing results for this material, the potential significant risk from soluble salts and

metals, such as cadmium, lead, selenium and thallium cannot be discounted.

Nuisance (BPD and CKD)

Evidence within the literature reviewed as part of this REA indicates that the release of fugitive dusts is

minimal when the material is applied to land. There is evidence in the literature to suggest that CKD and

BPD is spread to land in a conditioned form. It is our understanding after discussions with a UK

landspreading operator (Expert interview, 2015a) that this is normal practice. However, further confirmatory

evidence is required from other landspreading operators to ensure that this is widespread practice across the

UK. The example deployment applications provided by the UK landspreading operator also considers the

need to mitigate any risks from the dusts, with the spreading noted to comply with the Codes of Good

Agricultural Practice and that care must be taken when spreading this waste close to watercourses (Expert

interview, 2015a).

On the basis that the dust is applied in conditioned form, the potential for workers and by-standers to be

exposed to dusts as a result of this activity is considered to be low. Note that, in the event that

unconditioned dusts are also applied to land in the UK, a dust management plan will be required and hence

this hazard would be a principal hazard for these waste types (waste codes 10 13 12 and 10 13 13).

Summary of Principal List Hazards

The Principal List hazards associated with BPD are presented in Table 4.21, with justification for the hazard

inclusion or exclusion provided in Table 4.20 below. As noted above, due to insufficient testing results for

CKD it has not been possible to refine the Master List of chemical hazards for CKD.

Table 4.20 Justification for Choice of Principal List of Hazards for BPD

Hazards Comments Principal Hazard

Chemical Hazards

Metals and metalloids –cadmium, lead, thallium, selenium, barium

These contaminants have been found to have concentrations reported above the maximum permission levels specified by the DoE (1996). There is also the potential for these contaminants to result in significant enrichment of receiving soils.

Due to the uncertainty with regards to the representativeness of the leachate results for metals in BPD the potential risk to controlled waters cannot be discounted at this time.

No analytical results provided for barium so this contaminant cannot be assessed.

Yes

Metals and metalloids – antimony, chromium, copper, zinc, silver, molybdenum, mercury

These contaminants are unlikely to result in significant enrichment of the receiving soils. Concentrations recorded are also unlikely to exceed the maximum permissible limits (DoE, 1996) based on one 4.5 t/ha application or averaged over a 10 year period.

No


Due to the uncertainty that leachate results are representative of these contaminants in BPD the potential risk to controlled waters cannot be discounted at this time.

Based on the current evidence it is considered unlikely that soluble salts will present a significant risk to livestock following application to grassland.

Yes

Nuisance

Dust Dust is considered unlikely to be a principal hazard for conditioned BPD and CKD. However, in the event that unconditioned dusts are to be applied to land a dust management plan will be required.

Yes



Table 4.21 Principal List of Hazards for BPD


Chemical Hazards

Metals and metalloids – cadmium, lead, thallium, selenium, barium*


Soluble salts, principally potassium, fluoride and chloride Groundwater and surface water

Nuisance




4.6 Refined Generic Conceptual Model

Based on the findings of the hazard assessment and evaluation, the generic conceptual model for

landspreading has been refined for CKD and BPD and is presented below as Table 4.22, taking account of

those hazards identified on the Master and Principal lists.



Table 4.22 Summary Generic Conceptual Model for Landspreading CKD and BPD to Agricultural Land

Source Pathway Receptor Potential effect

Chemical contamination

Metals and metalloids (antimony, cadmium, chromium, copper, lead, thallium, zinc, molybdenum, silver, vanadium, nickel, barium, selenium, cobalt, mercury, cobalt)

Soluble salts, including potassium and chloride

Dioxins and furans

Direct contact, ingestion and inhalation (dust) Livestock Toxic, hazardous to health

Uptake via plants and ingestion

Direct contact, ingestion and inhalation (dust) Humans (operator) Toxic, carcinogenic, hazardous to health

Inhalation (dust) Humans (bystanders)

Uptake via plants and ingestion of produce Humans (consumer)

Ingestion of livestock and ingestion of produce

Plant uptake Crops Reduction in crop yield and productivity due to phytotoxicity, plant die-back, detrimental conditions to plant growth etc.

Leaching from soil to groundwater and vertical migration through the unsaturated zone

Groundwater Groundwater contamination – deterioration of quality, impact on potable water resource requiring treatment or closure of source of supply (borehole, well or spring)

Surface run off and lateral migration within groundwater Surface Water Surface water contamination – deterioration of water quality, sediment loading

Direct application to land Soils Deterioration of soil quality, damage to soil structure, toxicity and other adverse changes to soil micro-organisms impacting soil functions, or increased contaminant loading within site soils affecting amenity and use.

Direct application to land, direct contact and uptake via soil vertebrates and invertebrates followed by transmission through the ecological food web

Ecological designation / Wildlife

Harm to protected site through toxic contamination or habitat interference (nutrient enrichment, loss, disturbance etc.)

Release of dust Airborne transport Air Quality Deterioration of air quality

Release of dust Airborne transport and inhalation (dust) Humans (bystanders) Nuisance, impact on quality of life and loss of amenity



5. Conclusions and Recommendations

5.1 Conclusions

This REA has focused on identifying the potential hazards associated with CKD and BPD and its application

to agricultural land. The evidence collected has been examined to establish a Master Lists of hazards for

both BPD and CKD (see Table 4.15 and 4.16, respectively). Further consideration of the potential for these

hazards to occur and have a significant impact on identified receptors has been undertaken for BPD to

identify a Principal List of hazards (see Table 4.21).

The Master List of hazards for CKD is summarised below:

Chemical hazards – metals (antimony, cadmium, chromium, copper, lead, thallium, zinc,

molybdenum, silver, vanadium, nickel, barium, selenium, mercury, cobalt) and dioxins and

furans, and their potential to present a significant risk to crops, livestock and subsequently

human consumers, soil quality;

Chemical hazards – soluble salts (including potassium, chloride and fluoride) and their potential

to present a significant risk to crops, soil quality and livestock;

Chemical hazards - metals (cadmium, lead, selenium and thallium) and soluble salts including

potassium, sulphate, chloride and fluoride, and their potential to present a significant risk to

surface waters and groundwater; and

Dusts – potential risks from unconditioned CKD to land and associated risks to air quality and

human health.

The Principal List of hazards associated with BPD is as follows:

Chemical hazards – metals (cadmium, lead, selenium and thallium), and their potential to

present a significant risk to livestock and subsequently human consumers and soil quality;

Chemical hazards - metals (cadmium, lead, selenium and thallium) and soluble salts including

potassium, sulphate, chloride and fluoride, and their potential to present a significant risk to

surface waters and groundwater; and

Dusts – potential risks from unconditioned BPD to land and associated risks to air quality and

human health.

The risks from Master and Principal List hazards are likely to be successfully mitigated through the use of

good practice during the transport, storage and application of these dusts to land and through the use of

appropriate management practices and compliance with the restrictions on application rates, frequency and

number of applications to the same area of land, and set-off distances under a standard rules permit.

The identification of potential significant enrichment of soils from certain contaminants will require the

consideration of long term effects on receiving soils prior to application. These factors should be considered

by the operator and evident on the deployment application.

5.2 Limitations and constraints

The limitations and constraints of this REA and data obtained are discussed below:

Literature review:

Due to time constraints on the project, the literature review had to be undertaken during

discussions with the upstream producers. Ideally, the literature review should have been

undertaken prior to meeting with industry, with time allowed for further review of evidence later

in the project to fill any identified gaps in knowledge / evidence;



A lot of the evidence collected in the literature was from studies carried out in the early 1990s in

the US and other countries. This information is therefore old and is unlikely to compare well

with the kiln types used in the UK today;

The majority of the literature based information obtained relates to international studies and

assessments of CKD and BPD. It is apparent that the chemical composition of the raw

materials used can have a substantial influence on the composition of the dusts produced and

hence the concentrations identified in CKD and BPD from international sources is not directly

comparable within that identified within the UK dusts;

It was apparent during the literature review that more recent investigations involving the

spreading of CKD and BPD to land relate to its use as a stabilising agent for biosolids and their

subsequent spreading on agricultural land. As this is likely to dramatically change the nature of

the dust, these sources of evidence were disregarded;

The literature sources reviewed very rarely distinguished between CKD and BPD or whether it

was in a conditioned or unconditioned form. As a result, it is not always possible to identify

which hazards identified in the literature relate to CKD and / or BPD and whether any of these

hazards are mitigated through the conditioning of the waste; and

Due to time and cost constraints on the project it was not possible to fully characterise and

document the range of concentrations from different sources for the raw materials and fuels

used in the kilns.

Upstream Producer Liaison

Time constraints on the project meant that the MPA could only provide existing information that

was available rather than undertaking further testing in accordance with a required specification.

This meant that there were limitations to the data provided which has impacted on the findings

of the REA, particularly with respect to CKD. These limitations are discussed further below;

Amec Foster Wheeler liaised with one UK landspreading operator as part of the REA. Whilst

this information was useful in understanding the benefits and landspreading process, in isolation

it could not be taken as typical or good practice across the UK; and

A second landspreading operator was approached by industry to take part in this REA.

However, they did not want to be involved in the project.

Quantitative Data

For confidentially reasons, only the range of contaminants identified in BPD and CKD have

been reported and included in Appendix B, with summary statistics being provided for those

contaminants where 10 of more samples has been provided. No reference has been made to

individual cement facility results, although notable differences in concentrations of certain

contaminants such as lead have been observed between results from different facilities;

A large amount of quantitative data has been provided by industry for BPD, although this related

to testing undertaken by different laboratories and to different methods and may not be directly

comparable;

Some leachability results have been provided by UK industry for BPD and CKD. However, the

methods of testing vary and are not considered relevant to the application of these dusts to land

as they do not consider the potential for dilution and dispersion of contaminants as a result of

the dust incorporation into the receiving soil matrix. Uncertainty with respect to the leachability

of contaminants contained within both CKD and BPD is a significant limitation to the REA;

A small amount of data was provided by UK industry for CKD and for one facility only, which

limits the reliability of the range of concentrations referenced and assessed in this REA for this

waste stream. Furthermore, no data was provided for key contaminants of concern such as

dioxins and furans, selenium and mercury. Although it is recognised that this waste stream is

likely to take up a small proportion of these dusts that are applied to land in comparison to BPD,

full characterisation is required to inform the hazard evaluation and refine the Master List of

Hazards;



Different analytical suites appear to have been undertaken over time and between producers,

which has meant that for some contaminants little or no data have been provided by UK

industry. Limited data was particularly evident for organic contaminants such as PAHs and TPH

and metals such as beryllium, boron, selenium, silver and thallium;

High concentrations of selenium have been reported in conditioned BPD. Only one sample

result has been provided for selenium in unconditioned BPD, which has a substantially lower

concentrations reported. Evidence in one of the analytical certificates provided by industry

indicates that high concentrations of potassium and chloride can interfere with selenium

measurements. As a result, it is not known whether those concentrations reported for

unconditioned BPD are representative of that present in the material;

It is apparent from the waste data provided by the UK landspreading operator that testing is not

undertaken for all potential Master List hazards (e.g. vanadium, thallium). As a result, it was not

possible to assess the differences in concentrations between that provided for unconditioned

BPD for these contaminants;

Differences in concentrations have been observed for both solid and leachate data between

conditioned and unconditioned BPD. The reasons for this difference are currently uncertain and

may be due to the differences in the size of the two datasets;

No consideration or testing of radionuclides in UK CKD or BPD has been undertaken. Although

the USEPA indicated that this is unlikely to be a risk it would have been advantageous to have

confirmed this using UK data;

There is consensus within the literature that the incineration process is an effective method for

removing organic contaminants from the dusts but there are few quantitative data from UK

industry to support this assumption;

There appears to be a variance in concentrations (which can be high for some contaminants),

not only between different producers, but also over time for an individual producer. This

includes some spikes of high concentrations within the data set, such as that identified for

mercury and lead in one sample. Several reasons for potential variability within the chemical

composition have been discussed within the REA. However, insufficient information has been

provided to confirm which factors have resulted in the variances identified in the data set

provided by Industry;

Occasional spikes / very high concentrations or anomalous results have been identified in the

data provided by industry. This is particularly the case for thallium, with two very high

concentrations being recorded. Based on the other thallium concentrations reported for BPD

these two results appear to have the incorrect units. However, as Amec Foster Wheeler was

not involved in the testing and has not been provided with the analytical certificate for the testing

in question, we are unable to confirm this.

Hazard Evaluation

No UK based quantitative risk assessments have been found during this REA which could

inform the risk evaluation and refinement of hazards;

Insufficient chemical data for CKD meant that it was not possible to refine the Master List of

hazards;

Several metals including barium for BPD and selenium and mercury for CKD had to be added to

the Master / Principal List of Hazards as no analytical results had been provided and high

concentrations had been identified in the other form of dust;

The hazard evaluation was hampered by a wider range of benchmarks for assessing the

chemical hazards. Hazard assessment is therefore conservative and based primarily on

accumulation potential from repeated applications;



As noted above, the uncertainty with regards to the representativeness of the leachate data

provided for CKD and BPD in the context of it being spread to agricultural land meant that it was

not possible to exclude risks to controlled waters from the Principal List of Hazards; and

It was apparent that the UK landspreading operator involved in the project only applied

conditioned BPD / CKD to land. However, in the absence of supporting information it has not

been possible to exclude the potential for dusts from unconditioned BPD / CKD from the

Principal List of hazards.

5.3 Recommendations

Based on the above, it is recommended that further quantitative data is collated to fill data gaps identified

within the UK industry data. This should include the following:

At least 10 sample results for CKD for a range of contaminants including metals and metalloids

(including all Master List of elements), pH, soluble salts, speciation PAHs, dioxins, furans and

dioxin-like PCBs; and

At least 10 sample result for BPD for boron, beryllium, selenium, silver, fluoride, speciated

PAHs.

Further investigation should be undertaken to allow an informed assessment of what risk / hazards are

actually present to livestock, humans and controlled waters under true field conditions. This may involve the

undertaking of pot and field trials to allow an insight into the potential dilution of contaminants present in the

dusts and enrichment of receiving soils and potential for soil scorch. The investigations should include an

assessment of the potential bioavailability and leachability of lead once applied to land under a range of

conditions. This is considered likely to demonstrate that the metals recorded in the dusts are not 100%

bioavailable which will reduce the presumed potential risk presented by these contaminants to livestock and

humans.

The field trial should be undertaken for BPD and CKD and for arable and grassland to identify any

differences in hazards associated with the different dust types and key routes for agricultural transfer for the

two different agricultural uses.

A series of bench scale column tests could also be undertaken to provide further information on the

behaviours or soils / CKD and soil / BPD mixes and allow a better understanding of the potential risks to

controlled water receptors from these dusts.



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10.4141/S03-087 (http://pubs.aic.ca/doi/abs/10.4141/S03-087)

Salminen, R., Batista M.J., Bidovec M., Demetriades A., De Vivo B., De Vos W., Duris M.,Gilucis A.,

Gregorauskiene V., Halamic J., Heitzmann P., Lima A., Jordan G., Klaver G., Klein P., Lis J., Locutura J.,

Marsina K., Mazreku A., O'Connor P.J., Olsson S.Å., Ottesen R.-T., Petersell V., Plant J.A., Reeder S.,

Salpeteur I., Sandström H., Siewers U., Steenfelt A., Tarvainen T, 2005. Geochemical Atlas of Europe. Part

1 – Background Information, Methodology and Maps. http://weppi.gtk.fi/publ/foregsatlas/index.php.

Smedley, Pauline L.. 2008 Sources and distribution of arsenic in groundwater and aquifers. In: Appelo, Tony,

(ed.) Arsenic in Groundwater : a World Problem. Utrecht, the Netherlands, IAH, 4-32. (International

Association of Hydrogeologists Publication, 5).

United Nations (UN), 2011, Technical guidelines on the environmentally sound co processing of hazardous

wastes in cement kilns

USEPA, 1998. Draft Risk Assessment for Cement Kiln Dust Used as an Agricultural Soil Amendment

USEPA, 1993. Report to Congress – Cement Kiln Dust Waste

Various, Materials Safety Data Sheets. Collated as CKD_25 within Appendix B of this report.

http://pubs.aic.ca/doi/abs/10.4141/S03-087

http://weppi.gtk.fi/publ/foregsatlas/index.php



7. Abbreviations

BPD By-Pass Dust

CKD Cement Kiln Dust

DWS Drinking Water Standard

EPR Environmental Permitting Regulations 2010

EQS Environmental Quality Standard (surface water quality)

GAC Generic Assessment Criteria

IEEE The Institute of Electrical and Electronics Engineers

MPA Mineral Products Association

NPS National Permitting Service

REA Rapid Evidence Assessment

SPZ Groundwater Source Protection Zone

SR Standard Rules Permit

USEPA United States Environment Protection Agency

WRAP Waste and Resources Action Programme



8. Glossary

Agricultural land Meaning given by Section 109 of the Agriculture Act 1974 and

includes land for the production of timber and non-agricultural crops.

Anoxic soil conditions Soil depleted in oxygen.

Bioaccumulation Accumulation of substances, such as pesticides, or other organic

chemicals in an organism at levels higher than ambient.

Breakdown products or

metabolites

A chemical compound produced as a result of metabolism or a

metabolic reaction by living organisms such as soil microbes.

By Pass Dust from cement

kilns

Highly calcined fine particulate material collected from cement kiln by-

pass systems

Cement Kiln Dust Fine particulate material generated from cement clinker, comprising a mixture of partly calcined and unreacted raw feed, clinker and ash

Cumulative or additive

effects

A series of repeated actions / contaminants / hazards etc. which have a

greater effect than the sum of their individual effects.

Deployment Form The Environment Agency form (LPD1) which requires site specific

information and control measures to be provided and agreed prior to the

use of any mobile plant under the Standard Rules.

Emerging contaminants Chemicals that have recently been either shown to occur or suspected

of occurring widely in wastes and the wider environment, and are

identified as being a potential environmental or public health risk.

However there is often inadequate data to determine the risk posed.

Endocrine disrupting Chemicals that at certain doses can interfere with the endocrine

(hormone) system in mammals.

Exotic species Non-native plants (to the UK) which can spread and establish

themselves rapidly, presenting a threat to indigenous species and

problems for farming.

Hazardous substances Substances which are considered to be highly persistent, highly

bioaccumulative and highly toxic in accordance with the Groundwater

Daughter Directive (2006/118/EC) or a substance which gives rise to an

equivalent level of concern to that previously classified under 1980

Groundwater Directive (80/68/EEC).



Invasive weeds Weeds which are native to the UK but can spread and establish

themselves rapidly, presenting a threat to indigenous species and

problems for farming.

Master List A list of all potential hazards associated with a waste type which can

impact upon identified receptors.

Neutralising Value The ability of a material to neutralise acid

Non hazardous substances Any potential pollutant other than a hazardous substance.

Non impact question Aim to address the less quantifiable or defined effect, such as ‘How

does it work?’, ‘What is required to make it work?’, etc.

Pathway A route, or means by which a receptor could be exposed to, or affected

by, a hazard.

Primary question Defines the topic and scope of the review.

Principal List A list of primary potential hazards which are considered to have the

potential to present a significant risk to identified receptors.

Priority Hazardous

substances

Substance of concern to surface water identified within Directive

2008/105/EC. Compliance with EQSs for Priority and Priority Hazardous

Substances provides the basis for ‘Good Chemical Status’

classification.

Rapid Evidence Assessment A tool for obtaining information and available research evidence on a

specific topic, as comprehensively as possible, within the constraints of

a given timetable.

Receptor Something which could be adversely affected by the hazard. This can

be a collective term for humans, controlled waters, and dependent

ecosystems, wildlife, soil (quality), air quality and property in the form of

livestock and crops. The relevant receptors will be dependent on the

type of waste and site specific information for each deployment

application.

Risk Assessment The formal process of identifying, assessing and evaluating the risks to

health and the environment that may be posed by the waste and the

associated activity.

Secondary Question Questions which contribute to the build-up of evidence surrounding the

Primary Question. These are generally more open questions than the

Primary Question.

Site The place where mobile plant is to be deployed as detailed in the

agreed Deployment Form(s).



Soil Quality The capacity of a specific kind of soil to function and sustain plant and

animal productivity, maintain or enhance water and air quality, and

support human health and habitation by soil microbiology, invertebrates

and vertebrates.

Source Properties of the waste including biological, chemical and physical

contaminants, which have the potential to cause an adverse impact or

harm.

Specific Pollutants Those contaminant identified in the UK to support the aim of achieving

“Good Status” by 2015 under the Water Framework Directive (WFD).

Specific polluting substances are part of the classification of “Good

Ecological Status” in the UK.

Toxic or injurious plants Five weeds are classified under the Weeds Act 1959: Common Ragwort

(Senecio jacobaea), Spear Thistle (Cirsium vulagare), Creeping or Field

Thistle (Cirsium arvense), Broad-leaved Dock (Rumex obtusifolius) and

Curled Dock (Rumex crispus).

Waste Code The six digit code referable to a type of waste in accordance with the

List of Wastes (England) Regulations 2005.

Waste Stream Single waste, generated from a single site.

A1 © Amec Foster Wheeler Environment & Infrastructure UK Limited


Appendix A Generic Conceptual Model



Table A1 Summary Generic Conceptual Model for Landspreading to Agricultural Land


Chemical contamination Direct contact, ingestion and inhalation (dust and vapour) Livestock Toxic, hazardous to health

Uptake via plants and ingestion

Direct contact, ingestion and inhalation (dust and vapour) Humans (operator) Toxic, carcinogenic, hazardous to health

Inhalation (dust and vapours) Humans (bystanders)

Uptake via plants and ingestion of produce Humans (consumers)

Uptake via livestock and ingestion of produce

Plant uptake Crops Reduction in crop yield and productivity due to phytotoxicity, plant die-back, detrimental conditions to plant growth etc.

Leaching from soil to groundwater and vertical migration through the unsaturated zone

Groundwater Groundwater contamination – deterioration of quality, impact on potable water resource requiring treatment or closure of source of supply (borehole, well or spring)

Surface run off and lateral migration within groundwater Surface Water Surface water contamination – deterioration of water quality, sediment loading

Direct application to land Soils Deterioration of soil quality, damage to soil structure, toxicity and other adverse changes to soil micro-organisms impacting soil functions, or increased contaminant loading within site soils affecting amenity and use.

Direct application to land, direct contact and uptake via soil vertebrae and invertebrate followed by transmission through the ecological food web


Harm to protected site through toxic contamination or habitat interference (nutrient enrichment, loss, disturbance etc.)

Migration of dusts and leachate to adjacent sites, direct contact and uptake via soil vertebrate and invertebrate followed by transmission through the ecological food web


Harm to protected sites and species through indirect contamination of sites adjacent to spreading area

Plant pathogens Direct application to land Crops on site Reduced crop yield and productivity, deterioration of soil quality

Windblown migration Crops on adjacent land Reduced crop yield and productivity, deterioration of soil quality

Animal pathogens Ingestion of soil Livestock Toxic, hazardous to health

Uptake via livestock and ingestion of produce Humans (consumers) Toxic, hazardous to health

Toxic or injurious plants Ingestion of plants Livestock Toxic, hazardous to health




Invasive weeds Direct application to land Crops on site Reduced crop yield and productivity due to additional competition and potential deterioration of soil quality

Seed dispersal (by animals or wind) Crops on adjacent land Reduced crop yield and productivity due to additional competition and potential deterioration of soil quality

Physical contamination, including glass, plastic, metal etc.

Direct application to land Soil Deterioration of soil quality

Release of vapour and dust Airborne transport Air Quality Deterioration of local air quality

Release of odours Airborne transport and inhalation (odours) Humans (bystanders) Nuisance, impact on quality of life and loss of amenity

Release of dust Airborne transport and inhalation (dust) Humans (operator and bystanders)

Hazardous to health, nuisance, impact on quality of life and loss of amenity

Attraction of pests and scavenging animals

Airborne transport Humans (bystanders) Nuisance, impact on quality of life and loss of amenity

B1 © Amec Foster Wheeler Environment & Infrastructure UK Limited


Appendix B Search Strategy and Evidence Extracted

Rapid Evidence Assessment V1.0

Waste Code:

REA Reference: Example 3

Undertaken by: Date: 17/02/2015

Checked by: Date: 18/02/2015

REA Primary Question

Methodology

This spreadsheet is provided to document evidence obtained during an REA for the above primary

question.

The reviewer should refer to the REA Methodology for guidance on undertaking an appropriate search

strategy for evidence. The search strategy undertaken should be recorded on Tab AA - Search Strategy.

The evidence collected should be screened against the inclusion / exclusion criteria and if still considered

relevant should be documented in Tab A - Data sources. This will generate a numerical evidence

number to be used throughout the REA. Where these documents are referred to outside of this REA,

they should be referenced as [specific waste stream]_[evidence no.]

Once the evidence source has been documented, the reviewer should proceed to the evidence extraction

phase and complete Tabs B and C, where relevant. Drop down lists have been provided for the majority

of questions to ensure consistent responses. A comments box is also provided to allow supporting

information to be documented in the relevant sections for ease of future review.

Following evidence extraction, the quality of the data and information obtained is scored in accordance

with the REA Methodology to identify potential confidence issues in the data, bias and data gaps.

Becky Whiteley

What key hazards are associated with cement kiln dust and by pass dust from cement kilns which could

present a risk to critical receptors during or after landspreading on agricultural land

10 13 12, 10 13 13, 19 02 03 and 19 02 04

Cement kiln dust and By pass dust from cement kilnsWaste type under

consideration:

Tom Sheen

Cover Page 1

Summary of Keyword Searches

The following table provides a summary of search strategy used within this REA

Keyword(s) Date of Search Source

Source hyperlink or

other tracing

information

No. of hitsNo. of hits

screened

No. of hits taken

forward for

review

cement producers uk 23/12/2014 google www.google.co.uk 233000 30

0 (several

organisations

identified which have

been reviewed as

well)

cement kiln dust 23/12/2014 google www.google.co.uk 217000 50 3

UK cement industry guidance 07/01/2015 google www.google.co.uk 359,000 30 1

CKD cement kiln dust 19/01/2015 google www.google.co.uk 88,900 50 0

CKD cement agriculture 19/01/2015 google www.google.co.uk 97,200 50 2

by-pass dust landspreading 20/01/2015 google www.google.co.uk 42,300 50 4

CBPD agriculture 21/01/2015 google www.google.co.uk 16,800 50 0

CBPD cement spreading 21/01/2015 google www.google.co.uk 3,860 50 0

cement bypass dust application 21/01/2015 google www.google.co.uk 357,000 50 1

UK cement application to land 21/01/2015 google www.google.co.uk 150,000,000 50 0

kiln bypass dust landspreading 21/01/2015 google www.google.co.uk 2,650 50 1

CKD fertilizer 21/01/2015 google www.google.co.uk 73,900 50 2

human health risk cement kiln dust 21/01/2015 google www.google.co.uk 36,600 50 2

cement bypass dust msds 21/01/2015 google www.google.co.uk 8,740,000 50 2

cement bypass dust material safety data sheet21/01/2015 google www.google.co.uk 208,000 50 0

cement kiln dust material safety data sheet 21/01/2015 google www.google.co.uk 32,200 50 4

bypass dust 28/01/2015 scopus www.scopus.com 141 141 5

ckd agricultural 28/01/2015 scopus www.scopus.com 23 23 4

cement kiln dust leaching 29/01/2015 google www.google.co.uk 59,500 50 2

cement bypass dust leaching 29/01/2015 google www.google.co.uk 111,000 50 0

cement dust 30/01/2015 EFSA www.efsa.europa.eu 6 6 0

AA - Search Strategy Page 2

Organisation

website or

Database

Source identified

via?Date of Search

Source hyperlink

or other tracing

information

Any useful information?

Kerneos Aluminate

Technologies google 23/12/2014 www.kerneos.com

UK plant located in Essex - West Thurrock. No specific information

relating to the plant or cement kiln dust identified.

Mineral Products

Association tender and google 23/12/2014

cement.mineralproduct

s.org/

Provides summary information for processing and manufacturing

process. Lists 4 of the main manufacturers in UK and provides links

to these. Several useful fact sheets downloaded.

Concrete centre.com MPA 23/12/2014

www.concretecentre.co

m/

publications in the cement industry uk. Downloaded information

relating to the use of CKD in contaminated land remediation

European cement

association MPA 23/12/2014 www.cembureau.eu

General information on the cement industry. Useful information on

types of alternative wastes used as fuel, but no information identified

for CKD

Concrete society google 23/12/2014 www.concrete.org.uk

Presents map of main cement manufactuers in uk. No specific

information relating to CKD or bypass dust or kiln processing / fuels

etc.

Cement Kiln Bypass

Dust google 21/01/2015

http://www.cementkilnb

ypassdust.com/ckd-

recycling-utilization/

Website owned by Safwan Elfar, Qatar. Presents general description

of the history and use of Portland Cement. Section included on

utilisaiton of CKD in construction and agriculture, including several

citations of studies mainly performed in USA and Canada. "Because

the placement of a fine dust, such as CKD, on agricultural lands is

difficult, it has been suggested that granules or agglomerates of dust

should be made (Kachinski, 1983; Wommack et al.,2001). The larger

particles help to limit fugitive releases of dust while transporting,

handling, and placing the CKD. Conversely, care must be taken so

that the granules are not so rigid that rain and other natural processes

cannot dissolve or break down the particles to release the beneficial

constituents of the dust. One of the concerns with using CKD as a

fertilizer or soil amendment is the level of trace metals it may contain.

The effect of those metals on the food chain through possible

extraction by soil and subsequent movement into vegetation should be

determined before such applications are to be considered. However,

in a specific study on the use of CKD as a fertilizer in Iowa, Preston

(1993) demonstrated that trace metals in CKD were well below the

permissible levels for land application. The USEPA (1999b) studied

metals and other constituents of fertilizers including CKD. Their

findings showed that the metals content of various fertilizers ranged

over several orders of magnitude but did not provide any specific

recommendations on the use of CKD on agricultural lands.

Kanare (1999) completed a study comparing CKD to soils, agricultural

limestones (aglime), and sewage sludges. He found that sludges

generally have the highest levels of chromium, lead, mercury, nickel,

and silver compared to CKD, aglime, and North American soils. The

highest levels of thallium and selenium are found in CKD. Other

elements of interest are present in these materials at non-detectable

or comparable concentrations." The website includes a note relating to

PCA 1992 study of CKD from 79 USA plants and 10 Canada plants

using conventional and WDF, each tested for As, B, Cd, Cr, Pb, Hg,

Se, Ag, An, Be, Th, Ni. Average levels reported to be significantly

Mindfully.org google 21/01/2015

http://www.mindfully.org

/Air/Cement-Kilns-

Burning-Waste5.htm

Presents summary of pollutants potentially associated with CKD.

Potential bias although website proclaims to be neutral by intent.

Website states that CKD contains heavy metals and toxic organic

compounds. The most prevalent metals found in metals (referencing a

1993 Draft Report to Congress (USA) are listed as Cd, Cr, As, Pb and

Se. Certain metals were reported to be present at higher

concentrations in co-process kilns than fossil fuel only kilns.

Internationalcement EA 26/01/2015 www.cemnet.com

One potentially useful article identified, but required subscription to

ICR to view.

world cement.com EA 26/01/2015 www.worldcement.com

General information about the cement industry, but nothing identified

in links or search which would be useful for this study.

scopus REA methodology 26/01/2015 www.scopus.com

Identified several useful articles which have been included in evidence

review.

ECHA website google 30/01/2015 http://echa.europa.eu

Database of chemical data. CAS information extracted into evidence

review.

AA - Search Strategy Page 3

Summary of Evidence Identified as part of this REA

The following table provides a summary of evidence collected, which meets the inclusion / exclusion criteria and has been reviewed within this REA

Evidence

No.Evidence reference, date Evidence Type Evidence Description Source of Evidence

Date evidence

obtained /

reviewed

Brief description of content

1

EA, 2008 The use of substitute fuels in the

UK cement and lime industriesScience Report:

SCO30168

(https://www.gov.uk/government/uploads/system/uploads/

attachment_data/file/291698/scho1207bnna-e-e.pdf/) Peer reviewed EA published report / review Environment Agency 18/11/2014

Report quotes British Cement Association published data on UK Cement Plant capacity - 13

sites in total. Clinker production sites as follows:

-Dunbar Works - 1 No. mid-1980s air separate pre-calciner suspension pre-heater (SP5) kiln of

3300 tonnes/day output with grate clinker cooler

-Hope Works - 2 No. pre-heater SP4 kilns including LP cyclones and enlarged riser ducts

-Cauldon Works - 1 No. pre-calciner AS-SP4 kiln process with grate clinker cooler, 1 No. AS

precalciner suspension pre-heater (SP5) kiln with grate clinker cooler.

-Aberthaw Works - 1 No. pre-heatre kiln (SP4) with planetary clinker cooler.

-Westbury Works - 2 No. wet process kilns with grate clinker coolers.

-Northfleet Works - 2 converted semi-wet kilns (reported to close in 2007)

-Cookstown Works - 1 Lepol kiln process

-South Ferriby Works - 2 No. Lepol process kilns with grate type clinker coolers

-Rugby Works - 1 No. SP2 precalciner kiln with combustion chamber and grate type clinker

cooler

-Barrington Works - 1 No. wet kiln process with planetary clinker cooler

-Ketton Works - 1 No. SP4 preheater kiln with planetary clinker coolers, 1 No. SP4 AS

precalciner kiln with grate type clinker cooler

-Padeswood works - 1 No. modern SP5 precalciner kiln with separate line calciner downdraft

calciner and grate type clinker cooler.

-Ribblesdale Works - 1 No. SP4 in line calciner pre-calciner kiln with grate type clinker cooler

-Tunstead Works - 1 No. SP4 pre-calciner kiln process with multistage combustion and grate

type clinker cooler...

Substitute fuel categories used in the UK cement and lime industries are classed as Secondary

Liquid Fuels (SLF), Recovered Fuel Oil (RFO) and Recycled Liquid Fuel (RLF); whole or

chipped tyres; Solid Recovered Fuels (SRF) including Refuse Derived Fuel (RDF), Profuel and

Climafuel; Biofuels including Meat and Bone Meal (MBM) / Agricultural Waste Derived Fuel

(AWDF) and Processed Sewage Pellets (PSP); and secondary liquid fuel.

2

United Nations, 2011, Technical guidelines on the

environmentally sound co processing of hazardous

wastes in cement kilns Peer reviewed

European or overseas paper or

transcript Internet search engine 26/11/2014

With respect to cement kiln emissions, the report states that the non-volatile behaviour of most

heavy metals means most pass through the kiln system and are incorporated into clinker.

Volatiles are partly recycled internally by evaporatoin and condensation until equilibrium is

reached, the other part being emitted in exhaust gas. Thallium, mercury and their compounds

are described as highly volatile, with Cd, Pb, Se and their compounds less volatile. Dust control

devices can only capture the particle-bound fraction of heavy metals and their compounds.

Treated wood preservatives containing Cu, As and Cr require particular consideration for the

exhaust gas treatment system. The report also states that Hg due to its volatility may be present

as both particle-borne and vapour forms in the air pollution control systems. Due to its presence

in limestone, clay and sand, chromium is an unavoidable and variable input chemical. The

report (Paragraph 53 on page 18) presents a list of hazardous wastes suitable for co-processing

in cement kilns.

Section 3 states that Destruction and Removal (DRE) efficiency for thermal destruction of

PCBs in well designed and operated cement kilns is high. The US Toxic Substances Controls

Act required DRE is 99.9999%. A targeted POP DRE of at least 99.9999% is also stated in the

report. An emissions limit of 0.1 ng TEQ/Nm3 is identified for PCDDs/PCDFs.

Section 2 presents an environmental impact summary of CKD and BPD. A study by Karstensen

(2006) reported an average concentration of 6.7ng I-TEQ/kg for PCDDs/PCDFs in CKD and a

maximum concentration of 96ng I-TEQ/kg. This is below the stated Maximum Permissible

concentration of 100 ng/ TWQ/kg for sewage sludge application to agricultural land.

Annex I includes a compilation of performance verification and trial burns to demonstrate the

effectiveness of cement kilns at DRE of hazardous pollutants

3

IEEE, 2008, Benficial uses of cement kiln dust

(www.concretethinker.com/content/upload/437.pdf) Grey literature Paper Internet search engine 23/12/2014

Content of paper is American based, but provides useful information on the composition and

characterisation of CKD

A - Data Sources Page 4

Evidence


Date evidence

obtained /

reviewed


4

M. K. Rahman, S. Rehman & O. S. B. Al-Amoudi, 2011,

LITERATURE REVIEW ON CEMENT KILN DUST

USAGE IN SOIL AND WASTE STABILIZATION AND

EXPERIMENTAL INVESTIGATION

(www.arpapress.com/volumes/vol7issue1/ijrras_7_1_12.p

df) Peer reviewed Paper Internet search engine 23/12/2014

The paper includes a review of research on CKD usage for waste treatment and agricultural

use. Refers to McBride et al., 1997 findings significant concentrations of metals, organic

compunds and pathogens in waste materials. Once added to soils, trace metals from biosolids

can be taken up by plants (Dudka and Miller, 1999). According to a study by Dinel et al, 1999,

the organic matter in soil amended with CKD treated biosolids appeared more biodegraded and

biochemically inert thn those receiving lime treated biosolids, calcitic lime, and the control. A

study by Dinel et al (2000) found that total concentrations of all metals, other than As in

biosolids and CKD, were relatively low compared with maximum concentrations recommended

for clean sludge by the USEPA. The paper cites a study showing that adding CKD to sewage

sludge reduces the total heavy metal concentration, and a separate study showed that alkaline

sludge treatment serves to mobilise heavy metals and minimise metal solubility in the treated

matrix.

5 BGS (www.bgs.ac.uk/downloads/start.cfm?id=1408) Peer reviewed Other Internet search engine 29/01/2015

BGS report concerning raw materials used in cement production in the UK. The report defines

the types, and component raw feed ingredients of, cements produced in the UK for concrete

(Portland Cement, Portland-Composite Cement, Blastfurnace Cement, Pozzlanic Cement and

Composite Cement). The report summarises alternative raw materials used in cement

production, and the use of alternative fuel sources.

The report provides a list of the UK resources used in cement manufacture, a then-current list of

the cement plants in operation in Britain, production and export data.

6

European Commission, 2013, Best Available Techniques

(BAT) Reference Document for Production of Cement,

Lime and Magnesium Oxide. (BREF -

http://eippcb.jrc.ec.europa.eu/reference/cl.html) Peer reviewed EC published report / review Environment Agency 07/01/2015

Guidance document providing Best Available Technique information with respect to cement,

lime and magnesium oxide production. Document produced in 2013 by EC and provides limited

UK specific information.

7

SINTEF, 2006. Formation and Release of POPs in the

Cement Industry, Second Edition Peer reviewed Other Environment Agency 19/01/2015

Report provides a useful summary of the methods of cement manufacture in use globally, and

presents summary data from 1970s to 2006 of persistent organic pollutant emissions from

cement kilns. Specifically, polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs),

hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs).

"Heavy metals delivered by either conventional raw materials and fuels or by alternative raw

materials and fuels from industrial sources will be mainly incorporated in clinker or - to a lesser

extent - in kiln dust. Bypass dust extracted from the kiln system may be highly enriched in

alkalis, sulphates and chlorides and - similarly to filter dust - in some cases cannot be

completely recycled to the process. For both types of dust, conditioning and safe disposal

avoiding contamination of groundwater or soil is a site specific requirement"p48

Volatile metals e.g. lead and thallium are easily volatilised and condense on raw material

particles at lower temperatures in the kiln system (Th at approx. 300-350 C, Hg at approx. 120-

150 C. Thallium is nearly completely precipitated onto kiln dust particles, and part of the Hg

component is collected with the rest lost in gaseous phase (p54).

"In a DRE testing of a dry process cement kiln equipped with a preheater,

carbon tetrachloride and trichlorobenzene were chosen as the POHCs. When fed to

the burning zone of the kiln, DREs obtained were greater than 99.999 % for carbon

tetrachloride and greater than 99.995 % for trichlorobenzene. To determine the limits

of the system, DREs were also determined when these POHCs were fed to the kiln

inlet (i.e. cool end) of the kiln along with tyres. DREs obtained were greater than

99.999 % for carbon tetrachloride and greater than 99.996 % for trichlorobenzene." (p70)

8

USEPA, 1998. Draft Risk Assessment for Cement Kiln

Dust Used as an Agricultural Soil Amendment Unpublished Other Internet search engine 19/01/2015

Risk assessment for CKD application to agricultural soils in USA, dated 1998. Quantitative

information largely relates to 1992/1993 USEPA sampling study, including 45 CKD samples

from 20 US facilities including 10 burning hazardous wastes and 10 that do not. Metals were

analyzed for 15 facilities and dioxins for 11. The report includes discussion of CKD

concentrations vs. USA background soil concentrations of a range of metals and dioxin

congeners (Table 2.1 and 2.2). Report also provides discussion of environmental fate and

transport, exposure scenarios and routes, and agricultural liming practices. Although not UK or

EU specific, this is considered a useful resource.

9

Cooperative State Research Education and Extension

Service Technical Committee W-1 70, Undated

document. Cement Kiln Dust Peer Review Grey literature Other Internet search engine 20/01/2015

Peer review of Source 8, undated but presumed to have been generated during or following the

issue of the reviewed document in 1998. The objectives of the review included the appraisal of

the assumptions made for agricultural application practices, the applicability of the selected

plant soil bioaccumulation factors used in the assessment, modelling used in the assessment,

the evaluation of phytotoxicity and ecological risk, and uncertainty/variability analysis.


Evidence


Date evidence

obtained /

reviewed


10

Ellis F. Darley (1966) Studies on the Effect of Cement-

Kiln Dust on Vegetation, Journal of the Air

Pollution Control Association, 16:3, 145-150.

http://dx.doi.org/10.1080/00022470.1966.10468456 Peer reviewed Paper Internet search engine 20/01/2015

Journal is significantly old (1966), produced by the University of California. The paper presents

the results of short term laboratory experimentation on plant leaves dusted with CKD,

undertaken on bean leaves in Germany. The results found that finer particles of certain cement

kiln dusts collected from electrostatic precipitators interfered with CO2 exchange and in some

cases caused considerable leaf injury. The effect on plants of uptake via root was not

considered.

X-ray diffraction undertaken as part of the experiment found clear evidence that the chemical

composition of CKD varied with particle size, although further investigation was required in order

to derive conclusions as to the interaction of particle size, chemical composition and deposition

rate. One dust in particular was found to cause considerable leaf injury, which was assumed to

relate to a high concentration of KCl in the finer particles.

11

Mineral Products Association, August 2013. Proposal to

change the Standard Specifications of Waste-Derived

Fuel Grey literature Waste specific data (UK) Environment Agency 19/01/2015

The document states that 80% of input of Group 3 metals (antimony, arsenic, cobalt, copper,

chromium, lead, manganese, nickel and vanadium) correspond to raw materials input, with 5%

deriving from waste derived fuels and the remainder from fossil fuels. The report states that the

increase in use of WDF between 2007-2009 has not increased emission to air of Group 3

metals. The study states that Group 3 metals, other than lead and arsenic, are stable and

remain in solid phase through the kiln system, with 99.9% of metals input being retained within

the clinker product. Table 3 of the report shows that metals input into the kiln system (in mg/kg)

from raw materials and fuel source is variable by contaminant, although the input feed in tonnes

per hour is significantly higher for raw materials than fuel. Waste derived fuels (Solid Recovered

Fuel, Refuse Derived Fuel, Recycled Liquid Fuel and Secondary Liquid Fuel are shown to

contain detectable concentrations of all analysed metals, notably arsenic, copper and lead in

SLF (up to 10mg/kg, 547mg/kg and 195.6mg/kg respectively). Copper was typically present in

higher concentrations in waste derived fuels than in raw material input.

12

ERATech Environmental Ltd. Recirculation of Metals in

Cement Kilns Grey literature Other Environment Agency 19/01/2015

The document provides process information for wet kiln systems (not relevant to project) and

dry process kilns (relevant). Cyclone capture typically captures 70-80% of CKD leaving the kiln

and prior to entering final dust collector. CKD is described as resembling raw mix but with an

elevated concentration of volatile compounds. CKD from long dry kilns with cogenerating boilers

is described as being a highly calcined product concentrated in volatile elements.

Preheater/precalciner dry process kilns with bypasses usually return CKD from the main

exhaust gas stream into the raw feed, with significant amounts of volatile inorganic compounds

diverted through the bypass system. BPD is therefore highly concentrated in volatile

compounds. In kilns without bypasses, the main dust collector CKD composition is similar to

raw meal.

Potassium chloride, lead oxide and other materials volatilised in the burning zone tend to

condense onto particle surfaces - materials volatilised in the burning zone and condensed

downstream tend to become fume particles <0.1um, then forming particles 0.1-1.0um in size by

accretion. Most European cement plants are reported to blend all or part of dust into cement

when clinker is ground - a practice excluded from USA plants due to the requirements of the

ASTM. This is described as being a major source of CKD disposal.

13

https://consult.environment-

agency.gov.uk/portal/ho/waste/landfillpermits/landfillpermi

ts?&page=1&pageSize=20&pointId=ID-2685815-

QUESTION-VIEWS-ON-OUR-PLANS-TO-CHANGE-

LANDFILL-PERMITS&do=view&q:sortMode= Grey literature Other Internet search engine 20/01/2015

Letter from the MPA to Environment Agency calling specifically discussing the end fate of BPD.

The letter states that one of the key routes for BPD recovery is as a soil improver by land

spreading, due to the high concentrations of K, P and lime in BPD. The letter states that MPA

Cement members balance the kiln inputs (fuel and raw materials) to ensure the BPD remains

usable for landspreading. The letter calls on the EA to simplify the EA approval of CKD and

BPD use on land, and to retain the availability of landfilling disposal options.

14

https://www.brownfieldbriefing.com/news/cement-dust-

warning Grey literature Other Internet search engine 21/01/2015

Open letter to Brownfield Briefing members stating that the EA is warning farmers not to allow

CKD or BPD to be spread on their land without an environmental permit as these are controlled

wastes and can cause heavy metal contamination. The letter indicates that some companies

have been selling CKD / BPD as a fertilizer or lime substitute without an appropriate permit.

15

EC, 2001. Survey of waste spread on land. Report No.

CO 4953-2 published July 2001 Peer reviewed EC published report / review Internet search engine 21/01/2015

The report provides a summary of waste materials used in land spreading, corresponding to a

range of sources including cement manufacture AND gas processing. The report provides an

assessment of agricultural value (% DM) in mean, max and min values for 'waste lime' (Table

4.20) and heavy metals in mg/kg DS (Table 4.20). Data are stated as taken from the UK and

Belgium. The report states that CKD usually contain residues from the combustion of materials

used to generate the high temperature requirements of the process, and that waste organic

solvents as fuel sources can produce organic residues in kiln dusts. The report also states that

the quality of CKD will depend on the systems and methods of production used, and

landspreading use should be accompanied with a full analysis of potentially toxic elements

including Cu, Ni, Zn, Cd, Hg, Cr, Pb, B, As, Se, Mo and Fe, and assurance based on analysis to

demonstrate the product contains no organic contaminants.


Evidence


Date evidence

obtained /

reviewed


16

Environmental Solutions', edited by Franklin J Agardy,

Nelson Leonard Nemerow

https://books.google.co.uk/books?id=dKrZMK-9-

RgC&pg=PA374&lpg=PA374&dq=cement+bypass+dust+

application&source=bl&ots=hnze6d8oPN&sig=hW08GTr

nzF7FRbRdGq34zuk2dqM&hl=en&sa=X&ei=8pW_VPa9

LoGyUIu6gZgG&ved=0CEEQ6AEwBTgK#v=onepage&q

=cement%20bypass%20dust%20application&f=false Grey literature Paper Internet search engine 21/01/2015

Table 13.7 on p.374 of the book presents a percentage range by chemical component of the

composition of cement by-pass dust (although the kiln types producing the CBPD are not

specified). The article states that the addition of CBPD with sewage sludge produces a good

quality fertilizer, with the CBPD enhancing the fermentation process of the organic waste and

killing any microbes or parasites present. "The high alkalinity CBPD fixes the heavy metals

present in the product and converts them into insoluble metal hydroxide. Hence preventing

metal release in the leachate." Passive composting of primary sewage sludge with CBPD is

described. Primary sludge is mixed with 5% cement dust for 24h. Secondly, agricultural waste

as a bulking agent is mixed in for passive composting treatment. Passive composting piles are

formed from sludge mixed with agricultural waste (bulking agent) and cement dust with

continuous temperature and CO2 generation monitoring.

17

SEPA, Environment Agency and Environment and

Heritage Service, 2001. Sector Guidance Note IPPC

S3.01 Guidance for the Cement and Lime Sector. Peer reviewed EA published report / review Internet search engine 21/01/2015

Useful document summarising the various cement processes in operation in the UK. Provides

information with respect to pollution control / monitoring.

18

J. Lafond, R. R. Simard, 1999. Effects of Cement Kiln

Dust on Soil and Potato Crop Quality. American Journal

of Potato Research, March-April 1999. Volume 76, Issue

2, pp. 83-90 Peer reviewed Paper Internet search engine 21/01/2015

Presents the results of experimentation in Canada, examining potato growth with CKD, lime and

K fertilizer. The results were considered to show CKD provides Ca and K for potato growth

without significant heavy metal pollution.

19

Francis, M., 2000. Background Report on Fertilizer Use,

Contaminants and Regulators.

https://books.google.co.uk/books?id=xzwRzV6J0WwC&p

g=PA51&lpg=PA51&dq=ckd+fertilizer&source=bl&ots=zz

Rfh5Qgt2&sig=4oTaF-FsR0bcJ12lSmM1-

hEVQzA&hl=en&sa=X&ei=PgXAVKLWEcOBU4mQg7gP

&ved=0CEkQ6AEwBg#v=onepage&q=ckd%20fertilizer&f

=false Grey literature Other Internet search engine 21/01/2015

Section 3.5 p.51. The book reports that tetra- through octa-CDD and CDF were detected in the

'Gross CKD' of 10 of 11 sampled kilns (presumed to be the cited 1994 USEPA Dioxin

Reassessment report earlier in the text). 6 of the kilns were reported to burn hazardous waste

along with fossil fuel. The same CDD and CDF were also detected in the 'net CKD' (particulate

material collected by air pollution control system following recycling of the 'gross CKD' were also

detected in 8 of the 11 kiln samples. PCB congeners were not detected in the samples.

The CDD and C DF content of gross CKD was 0.008-247 ng TEQ/kg, net CDD and CDF

content of net CKD was 0.045-195 ng TEQ/kg. The mean CDD/CDF content of hazardous

waste burning kilns was higher than the fossil-fuel only burning kilns (35ng TEQ/kg compared

with 0.03ngTEQ/kg) respectively.

20

A V Rodd, K B McRae, J A MacLeod, P R Warman, M G

Grimmett, 2009, Surface application of cement kiln dust

and lime to forage

land: Effect on forage yield, tissue concentration and

accumulation of nutrients, Canadian Journal of Soil

Science, 2010, 90(1): pp. 201-213, 10.4141/CJSS09010

(http://pubs.aic.ca/doi/abs/10.4141/CJSS09010) Peer reviewed Paper Electronic database 26/01/2015

Identified through scopus.com. This paper presents the results of a two year field forage trial

(1998-1999) to compare the effect of surface applications of CKD and lime on forage yield, and

the accumulation of nutrient chemicals (N, P, K, Ca, Mg, Mn, Zn and B) within forage tissue.

The study demonstrated that increased CKD deployment resulted in increased K, Ca, Cu and

Mn (1998) or Ca and K (1999) content in tissue, with a decrease in concentrations of N, P and

Mg (1998) or N, P, Mg, Mn, and Zn (1999). Surface applied CKD was reported to increase

forage yield to a greater extent than lime, and to be a more readily available source of Ca and K.

No analysis of chemical contaminants, or contamination assessment, was undertaken as part of

the study.

21

A. V. Rodd, J. A. MacLeod, P. R. Warman, K. B. McRae ,

2004, Surface application of cement kiln dust and lime to

forages: Effect on soil pH, Canadian Journal of Soil

Science, 2004, 84(3): pp. 317-322, 10.4141/S03-087

(http://pubs.aic.ca/doi/abs/10.4141/S03-087) Peer reviewed Paper Electronic database 26/01/2015

Identified through scopus.com. This paper presents the results of a two year field forage trial

(1998-1999) to compare the effect of surface applications of CKD and lime on soil pH. Soil pH

was monitored before applications and was monitored afterwards for two growing seasons. The

paper found that CKD appeared to be effective as a quick-acting lime substitute, due primarily to

the relatively low particle size compared with lime.

22

Defra, July 2009. Review and Update of the UK Source

Inventories of Dioxins, Dioxin-Like

Polychlorinated Biphenyls and Hexachlorobenzene for

Emissions to Air,

Water and Land - Annex. ED43184 - Issue 2

file:///C:/Users/tom.sheen/Downloads/10539_Annex_UKP

OPsIndustrySectors_27_7_2009_v2.pdf Peer reviewed EA published report / review Internet search engine 28/01/2015

Defra report updating information known with respect to sources of emission of PCDD/Fs, PCBs

and HCB. The report estimates the emission of dioxins to land from the cement and lime

industry being effectively 0 g/l-TEQ between 1999 and 2006. PCB emission estimates are given

for air emission only.


Evidence


Date evidence

obtained /

reviewed


23

USEPA, 1993. Report to Congress - Cement Kiln Dust

Waste Peer reviewed Other Internet search engine 28/01/2015

Extensive USEPA report concerning the evaluation of the US Cement Industry, and a review of

the waste CKD produced. The review included a 1991 appraisal of cement kiln

processes/technology, and two phases of clinker / CKD sampling and chemical analysis, in

1992 and 1993, focusing on 20 facilities in total. Samples were analysed for VOCs, SVOCs,

pesticides, PCBs, PCDD/Fs, metals, radionuclides and general chemical composition.

Table 3.14 (ch. 3)provides a summary of particle size distribution of CKD by process type. The

median particle size varies substantially between Long Dry kilns (3.0um) and dry kils with

precalciners (22.2 um). Dry kiln with precalciner dust produced approximately 17% PM10,

compared with 90% from Long Dry kilns.

Due to the dehydrated nature of CKD, the process of weathering results in a net absorption of

water and generation of heat. This property is used to both dewater and sterilize sewage sludge

when blended. CKD hydraulic conductivity is also inherently low, with compacted CKD

conductivities as low as 1x10-10 cm/sec given in the report (p3-28).Testing of waste CKD piles

also appears to indicate that humidity and rain may decrease hydraulic conductivity even further.

Section 3.2 lists the following primary bulk constituents in CKD: silicates, calcium oxide,

potassium oxide, sulphates, chlorides, various metal oxides, and sodium oxide. Trace

constituents include certain organic chemicals, metals such as cadmium, lead and selenium,

and radionuclides. The EPA sampling identified all of the metals in most of the CKD samples

collected. The predominant trace metals identified were An, Ba, Pb, Mn, Sr, Th and Zn, with

lower concentrations of Be, Cu, Cr VI, Hg, Ni, Ag and Th. An, Cd, Pb, Hg, Se, Ag and Zn are

reported outside the naturally occurring range, and As and Sr within natural soil ranges but

above average for natural soils. Exhibit 3-18 and 3-21 provides concentration ranges.

6.3.6 (p6-58) discusses risk assessment of agricultural liming with CKD.

24

Renzoni, R., Ullrich, C., Belboom, s., Germain, A. April

2010. 'Mercury in the Cement Industry'. CEMBUREAU /

Universite de Liege Peer reviewed



Report produced from study launched by CEMBUREAU, The European Cement Association

and the WBCSD Cement Sustainability Initiative (CSI) to compile worldwide data on the status

of mercury emissions from cement kilns, and define best environmental practices for cement

kilns.

p.32: "Very few analyses of mercury concentration have been conducted in alkali bypass

streams. The mercury levels in these streams should be lower than in the main kiln gas stream,

because mercury entering the pyroprocessing system with the raw materials is assumed to

have volatilised within the preheater tower or precalciner vessel. Therefore fuel mercury is the

only significant source of mercury in the kiln gas stream...some of the oxidised mercury

compounds (i.e. HgCl2, HgO and HgSO4 can...adsorb and condense onto the dust particles.

The remaining mercury compounds pass through the stack."

The report cites a 1992 PCA study (USA and Canada) on CKD constituents, which found an

average Hg content of 0.00051mg Hg/g with a maximum concentration of 0.0255 mg Hg/g. 27

of the 95 samples analysed were below the laboratory limit of detection (not specified). A

separate 2003 study reported by Johansen is cited, which showed CKD mercury concentrations

of 0.00013-0.001 mg Hg/g, with an average of 0.0003 mg Hg/g, and half of the samples

analysed being below the laboratory limit of detection. Table 12-2 of the report shows mercury

concentrations in a range of intermediate and output products for an unspecified cement plant in

2008.


Evidence


Date evidence

obtained /

reviewed


25

Material Safety Data Sheets for various producers of CKD

and/or BPD - international Grey literature Other Internet search engine 28/01/2015

-Argos Cement, Alpharetta, GA. Listed as potentially carcinogenic by inhalation due to trace

amounts of respirable crystalline silica and hexavalent Cr. MSDS describes material as

chemically stable under normal use, storage and transport conditions, and without hazardous

decomposition products. No other hazardous chemical components are listed.

-Ash Grove Cement Company, KS. Product listed as 'may contain 200-2000ppm lead and

traces of other heavy metals including but not limited to arsenic, chromium, cadmium, antimony,

barium, beryllium, silver, mercury, thallium, selenium and nickel.'

-Essroc Italcementi Group, Nazareth, PA. MSDS describes CKD and BPD as synonymous with

respect to MSDS information. Listed possible trace constituents include compounds of As, Cd,

Cr, Ni and Pb. MSDS states that the IARC and NTP consider crystalline silica and hexavalent

Cr to be known human carcinogens.

-Riverton Corp, Riverton, VA. MSDS lists no carcinogenic properties.

-Grupo Pum, S.L., Spain. Trade name MORCEMREST RF35. Risk phrases R36, R37, R38,

R43. Described as mixture of cement, organic additives and mineral loads (CrVI content

<2ppm).

-Lafarge North America Inc. Reston, VA. MSDS covers 'New Lime', CKD, Baghouse Dust.

MSDS identifies potential for trace amounts of potassium and sodium sulphate compounds,

chromium compounds, nickel compounds and other trace compounds. The presence of trace

amounts of crystalline silica and hexavalent Cr are identified as providing carcinogenic potential.

-Roanoke Cement, Troutville, VA. MSDS lists the potential for trace amounts of heavy metals

recognised as carcinogens by the NTP, OSHA or IARC, along with crystalline silica (Group I

carcinogen).

Caustic properties of wet CKD mixture are listed in all reviewed MSDS.

26 Information provided by waste management company Unpublished Waste specific data (UK) Operator 27/01/2015

Information provided includes copies of two distribution permit application forms including

analytical results from waste for deployment, soil analysis, benefit analysis, one additional set of

analytical results from dust analysis, and information with respect to spreading methodology.

27

Office of Solid Waste. USEPA. Draft Technical

Background Document on Ground Water Controls at

CKD Landfills. June 1998 Unpublished



Although a relatively old report (1998) and published in draft form, the report includes

information describing the physical characteristics of CKD, and concerns the methods used to

control CKD leachate emissions from landfills in the USA.

28 Expert Interview transcript Unpublished Waste specific data (UK) Expert interview 28/01/2015

Information provided with respect to the deployment of CKD/BPD to land as a liming agent.

Information includes form, storage arrangements, transport arrangements and deployment

details.

29

Eckert Jr, J.O., Guo, Q. Heavy Metals in Cement and

Cement Kiln Dust from Kilns Co-fired with Hazardous

Waste-derived Fuel: Application of EPA leaching and

acid-digestion procedures. Journal of Hazardous

Materials 59 (1998) 55-93 Peer reviewed



The paper describes the application of US EPA standard Toxicity Characteristic Leaching

Procedure (TCLP) methods for determining whether heavy metal leachate is generated from

CKD and cement, and assessing the suitability of the applicability of USA standard leaching

methodologies (method SW-846) to such materials.

The study used 17 cement and CKD samples collected from cement facilities in the USA, seven

of which used waste derived fuel (WDF) as a primary element of cement production and four

indicated to burn WDF in an alternative or unknown capacity.

The report cites several criticisms of the TCLP and EPTox (Extraction Procedure Toxicity Test)

towards leaching of heavy metals from alkaline solids. One key criticism is that very high pH

solutions, where CKD is disposed, could enhance lead dissolution (high Pb solubility, which may

then lead to lead precipitation as the pH drops to the range ~9-11.5.

The samples were analysed using a range of procedures following, or variations based on, the

standard US EPA TCLP method. Detectable concentrations of a range of metals were identified

using TCLP, including Cr at up to 986ppb, Ba at up to 4108ppb, and Ni at up to 105ppb. Notably

arsenic and lead were not found to be leached in comparatively high concentrations (0.97ppb

and 17.24ppb respectively).CKD leachate was found to develop a pH of 11.79.

Use of chlorinated water to leach metals yielded higher concentrations of Cr than the standard

method, however are not representative of the deployment scenario.

30

Kunal, P., Siddique, R., Rajor, A. Use of Cement Kiln

Dust in Cement Concrete and its leachate characteristics.

Resources, Conservation and Recycling 6 (2012) 59-68 Peer reviewed



Scientific paper providing an overview of research relating to beneficial use of CKD in

construction materials, and leachate methods and characteristics of CKD. Provides a useful

summary of various trace metal concentrations in CKD in studies between 1982-1994.

Cited studies found that pH values for CKD leachate range from 6.11 to 12.98 pH units (EPA,

1993) and that high concentrations of potassium, sulphate and caustic alkalies in leachate were

observed when CKD was brought into contact with water (Duchesne and Reardon, 1998). The

1998 study also demonstrated that CKD leachate contained high concentrations of Cr and Mo.


Evidence


Date evidence

obtained /

reviewed


31 ECHA website Peer reviewed EC published report / review Electronic database 30/01/2015

Website collating available peer reviewed information relating to a wide range of chemicals,

including uses, EU package labelling requirements, and available human and ecotoxicity data.

CKD is registered under 'Flue Dust, Portland Cement' CAS No. 68475-76-3. Due to the inherent

variability of CKD - specifically variation in the primary constituent of calcite due to production

variation in the degree of calcining between facilities - ECHA determined that CKD generated by

different facilities, with significantly varying mineral content, would have to be considered under

the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) Regulations

as different substances.

32

Preston, M. L. 1993. Use of Cement Kiln Dust as an

Agricultural Lime and Fertilizer. Portland Cement

Association's Emerging Technologies Symposium of

Cement and Concrete in the Global Environment Grey literature



Presentation during Portland Cement Association symposium. The presentation identifies that

CKD manufactured by Lafarge Corporation's Davenport Plant has been marketed successfully

in Iowa, USA as an agricultural liming aid and fertilizer, and that agricultural producers have

ongoing concerns with respect to the presence of hazardous heavy metals e.g. arsenic,

chromium, lead and mercury.

The paper presents the results of 1992 analysis of heavy metal content of CKD from the

Davenport Plant, 1989 analysis of a broader range of metals including TCLP leachability testing,

which were compared in the report with USEPA leachability limits for hazardous waste. The

results were found to show that CKD would not be considered by the USEPA to be hazardous

waste on the basis of TCLP analysis, and were considered to be consistent with previous

findings.

The report also undertook comparison with published naturally occurring soil concentration of

metals such as arsenic, chromium, lead and mercury across the USA according to a USGS

study. The results were stated to show that levels of metals in CKD at the Davenport Plant were

within the range of naturally occurring soil concentrations.

33

Peters, C. S. 1998. Investigative and Management

Techniques for Cement Kiln Dust and Pulp and Paper

Process Wastes. Environmental Progress (Vol. 17, No. 3)

Fall 1998. Peer reviewed



Paper presenting the summary of studies completed on CKD and paper mill sludge, that

highlight the investigative and remedial technologies or beneficial uses of the two waste types.

The report demonstrates that the chemical composition of CKD can vary significantly dependent

on raw feed components and kiln process types, with Table 2 of the report showing significant

CKD compositional variation between CKDs from a long wet kiln, a long dry kiln and an alkali

bypass system.

Table 3 of the report shows comparative chemical analysis of unconditioned and conditioned

and compacted CKD derived leachate (NB it is presumed that the term 'conditioned' in the

report relates to the generation of a monolith by addition of moisture to CKD rather than

conditioning for agricultural application). Loose dust was tested using the EPA Synthetic

Precipitation Leaching Procedure (Method 1312).

34

Powrie, W., Bevan, M., Roberts, T. O. L. Transport of

Cement Kiln Dust Leachate from an Unlined Landfill

during Construction Dewatering. Proceedings Sardinia

2005, Tenth International Waste Management and

Landfill Symposium. S. Margherita di Pula, Cagliari, Italy. Grey literature Other Internet search engine 04/02/2015

Presentation of a UK study into transport of CKD leachate from unlined landfill during the

dewatering of the Channel Tunnel Rail Link Thames Tunnel, North Kent. The report states that

CKD is comprised of oxidised, anhydrous phases which will dissolve completely or precipitate

as more stable and less soluble secondary phases contact with water. The principle

determinands identified by the report for the detection of CKD, and therefore the main leachable

determinands, are listed as chloride, potassium, sodium, sulphate, pH, electrical conductivity

and dissolved solids. Heavy metals are not cited in the report as significant. Experimental

leaching tests undertaken by Duhesne and Reardon in 1998 are cited in the text as

demonstrating that CKD leaches particularly high concentrations of potassium and sulphate.

The modelling undertaken as part of the study confirmed the observations of generally

increasing salinity of groundwater extracted from the monitoring cell during the first year of

dewatering, which may be indicative of CKD leachate from the landfill although the document is

careful to identify that the area of study is pront to saline intrusion and therefore this may not be

the case. The results of potassium modelling compared with observed concentrations did not

match closely, with the authors concluding that the overestimation of K in the model may mean

that leachate is attenuated more than anticipated within pore space.


Evidence


Date evidence

obtained /

reviewed


35

Mahmoud, M., Rimes, B. Leaching Characteristics of

Cement Kiln Dust from Alberta. 12th International

Environmental Specialty Conference. Edmonton, Alberta,

Jule 6-9, 2012. Grey literature



Presentation of a study of the leaching characteristics of CKD produced at Lehigh Inland

Cement plant in Edmonton, Alberta, Canada. The results of chemical analysis are provided for a

single CKD sample from the Lehigh Plant, and other CKD samples analysed in other studies

(LaFarge Holnam Washington, USA (1997), US Bureau of Mines (1982), and Rahman et al

Saudi Arabia Plant (2011). The results of analysis show that the CKD from Inland has the

potential to leach lead, selenium and manganese at concentrations above published Canadian

Drinking Water Quality guidelines. The report does however state that CKD-amended soils may

demonstrate little or no exceedances, in particular with respect to lead concentrations, and that

Static Leaching Tests (SLTs) on CKD amended soils would be necessary to evaluate this. The

report states that the total Loss on Ignition value (LOI) for CKD indicates the quantity of free lime

in the CKD, and that the LaFarge Holnam and Saudi CKD had notably higher LOI than the

Lehigh Inland and US Bureau of Mines CKD. The report also shows the chemical composition

(not including heavy metals or other contaminants) for the three main kiln cement dust types

(long wet kiln, long dry kiln, and alkali bypass preheater/precalciner). The CKD from alkali

bypass preheater/precalciner was found to have the highest content of free lime and the lowest

LOI, and long-dry kiln CKD has the lowest concentration of free lime and the highest LOI.

Leachable concentrations of heavy metals from the Lehigh Inland CKD were variable, with lead

between 0.11-0.12mg/l under the TCLP method and 0.05-0.07mg/l under the SLT method.

Notably no detectable concentrations of leachable mercury or chromium were recorded in the

CKD. The differences between the SLT and TCLP test data were attributed to differences in

leaching fluid and agitation process. The detected lead, selenium and manganese

concentrations in the leachate were attributed primarily to the iron incorporated into the raw

feed. Unpublished data cited by the study also highlighted leachable concentrations of barium,

chromium, lead and selenium in TCLP data for the LaFarge CKD.

36

Palmer, G. Using Cement Kiln Dust for Acid Soils. Water

January 2000. Grey literature



Paper presenting the results of a study of CKD undertaken by Griffith University and

commissioned by Queensland Cement Ltd. The paper presents the results of chemical analysis

and discusses ecological and other effects of CKD on water quality and soil chemistry when

used as an ameliorant on acid sulphate soils.

The paper mentions the presence of the following trace elements in cement production

materials: antimony, arsenic, barium, beryllium, cadmium, chromium, lead, mercury, nickel,

selenium, strontium, silver, thallium, vanadium, zinc, bromine, chlorine, fluorine and iodine.

CKD was sampled and analysed for major chemical analysis, metals and metalloid content, and

organic contaminants (Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls

(PCBs), benzene, toluene, ethylbenzene and xylenes (BTEX)). None of the organic analytes

were recorded above the laboratory limit of detection. A range of metals and non-metals were

recorded in the CKD, with all results below the respective Queensland EPA contaminated land

environmental guideline (1992) other than a single sample with elevated chromium (53mg/kg

compared with a guideline concentration of 50mg/kg).

The paper also presents the results of CKD-treated soil filtrate analysis. The filtrate contained

bromine, sodium, strontium and zinc above the ECOTOX or AQUIRE international surface water

guideline values. The results were concluded in the study to show that CKD as an ameliorant

has no greater impact on water quality than that of background when the amended soil is

exposed to an acid environment.

37

Expert Interview transcript with Industry and

Landspreading operator Unpublished Waste specific data (UK) Expert interview 10/02/2015 Transcript from expert interview

38 Industry Questionnaire Response Unpublished Waste specific data (UK) Operator 06/02/2015 Consolidated response from industry for REA questionnaire

39

A TEC Production & Service GmbH, The ReduDust

Project - an innovative solution for treatment of bypass

dust Cement International 1/2012, Volume 10. Grey literature Other Internet search engine 16/02/2015

Published report identifying a new process for removing alkali salts from cement kiln bypass

dust. The report includes a chemical compositional breakdown of heavy metal contaminant

concentrations within eight samples of BPD analysed as part of the study.

40 Environment Agency provided data Unpublished Waste specific data (UK) Environment Agency 19/01/2015 Data previously collated by EA for CKD and BPD - publicly available

41

Gossman, D., Black., M., Ward., M., 1990, the fate of

trace metals in the wet process cement kiln, Presented at

the AWMA International Speciality Conference on Waste

Combustion in Boilers and Industrial Furnaces. April 1900 Grey literature Paper Environment Agency 26/03/2015

Investigation into the fate of metals in a wet kiln. Although these are not currently used in the

UK it provides some useful information relating to the behavous of a number of metals in the

kiln system when subjected to very high temperatures, which is likely to also be applicable to the

kilns used in the UK.

42

MPA, 2013, MPA code of practice for the use of waste

materials in cement and dolomite lime manufacturing Grey literature Waste specific data (UK) Environment Agency 26/03/2015

Code of Practice that the MPA members operate to. This includes a specification for different

waste types used as fuel and alternative raw materials.


Evidence Extraction

The following questions are aimed at identifying key information to inform hazard identification and subsequent risk assessment.

Some answers have drop-down boxes for standard responses. Further information and summary data (e.g. statistics) should be entered in comments box.

Question

No.Question Answer Comments

Evidence No(s).

(see A - Data Sources tab)

Evidence Confidence

Rating (see D - Supporting

Information)

Relevant Receptor, if

present


1How many producers are there for this waste within the

UK?>10

Table 1.2 of Data Source 6 (Ch. 1 p. 4) cites 14 cement plants with kilns in UK according

to 72, CEMBUREAU, 2006-2008

There are currently 11 operational cement plants in the UK, but these are operated by 4

producers.

6

37/38

Medium - single source of

current UK specific

information obtained via

expert interview.

n/a

2Is the waste from a single producer or as a result of a

collection of waste from a number of producers?Single producer

CKD/BPD is provided from one cement kiln facility only, and is kept segregated in

separate stockpiles by the Operator in order to avoid intermixing.28


UK specific information

obtained via expert

interview.

n/a

3

Are there different production processes for this waste

and how long have these been in place? Please

provide summary information

Yes

Undated internal EA document ('Guidance on the classification of wastes from the

manufacture of cement and their recovery using a Standard Mobile Plant Permit for

Landspreading') states that two types of cement kiln are currently used for cement

production in England and Wales. These are Dry Process and Wet/Semi Dry Process.

Eight of the nine operating cement works listed in the report are dry process, with the

South Ferriby plant being a Semi-dry process. A 2008 EA report (Source 01) includes

reference to two wet process kilns, which are now closed.

Information provided by MPA: "Both CKD and BPD are forms of kiln dust and are

products associated with the quality control of cement clinker, primarily alkali content.

Alkali levels of more than 0.6% in the cement can have a deleterious impact on the

performance of the finished concrete.

The only difference is the point of production and the degree of calcination (free lime

content) Otherwise, there is no difference between CKD and BPD, both of which are

made up of the natural raw materials used in cement manufacturing and just subjected

to different temperature ranges.

The cement industry refers to CKD when it is produced from kilns that do not have a

bypass system and BPD when it is produced from a bypass system.

The point of production for BPD is a part of the process that is subject to higher

temperatures (up to 1000 oC) and as a result it contains higher levels of calcium oxide

(free lime) due to increased calcination levels of the raw materials. In CKD production,

the raw materials are not subjected to high temperatures (less than 200 oC) so no

calcination occurs and calcium oxide (free lime) is lower.

Wherever possible and within quality control restraints, CKD and BPD are recovered at

the site of production either by insufflation into the kiln or by intergrinding with cement. In

general, packed cement products have less restrictions on alkali content and as a result,

these dusts can be added in controlled quantities. "

1

38



obtained via expert

interview.

n/a

This is a hazard assessment, not a risk assessment, but where the potential for a hazard to be present is raised this is in the context of a proposed landspreading operation under a standard rules permit.

B - Evidence Extraction Page 12

Question


Evidence No(s).


Evidence Confidence


Information)


present

4a

Information provided by MPA: "BPD - The cement-making process consists of two main

stages. The first and most complex stage is to make an intermediate product called

cement clinker. The clinker-making process consists of a rotary kiln along with a fixed

pre-heater plant around 100m high. The second, much less complicated stage is to grind

this clinker in cement mills along with minor additions of other materials to make cement

otherwise known as the clinker grinding or cement milling process.

The clinker-making process involves heating the raw materials, mainly chalk or limestone

and clay, to around 1450 C for very specific chemical reactions to take place. In the

majority of processes of this type the whole of the combustion and process gases leaves

at one point, and well over 99% of the particulate matter is removed from the gas before

discharge to atmosphere. The dust collected from this de-dusting process is generally

known as cement kiln dust (CKD), and is all returned to the process.

The clinker-making process can involve a small proportion of the exhaust gas from the

process being drawn off part way through the process, through what is known as a

bypass system. This is for quality reasons and is related to the composition of the raw

materials used. This bypass gas is de-dusted before discharge to atmosphere and the

dust collected is known as bypass dust (BPD).

BPD has been partly processed by virtue of passing through the high temperature part of

the kiln and preheater. It contains a high proportion of calcium oxide, a material with

cementitious properties, and dust having similar properties to cement that comes from

the hottest part of the kiln. It is higher in sodium and potassium compounds than

cement. BPD is therefore suitable for mixing with cement. It can enhance the qualities

of some grades of cement by leading to a reduced setting time. However, the sodium

and potassium content of BPD limit the quantity that can be added to some grades of

cement. The Bypass system is an integral part of a modern cement kiln to enable quality

control of cement clinker by intentionally removing and collecting BPD rather than gas

cleaning, so that it can be reused in cement products (such as bag products that have

higher alkali limit specifications) before the stream re- enters the process. This approach

enables the production of one consistent cement clinker, which can then form the basis

of all cement products with the addition of BPD where quality constraints allow down

stream ."

38



obtained via expert

interview.

4b

Information provided by MPA: "CKD - South Ferriby and Cookstown cement works use

semi-dry process technology as mentioned in appendix 2 of the EA note above. Instead

of having a pre-heater tower or pre-calciner, they have a Lepol Grate system as

explained below. Crudely, a Lepol Grate could be described as horizontal pre-heater/pre-

calciner tower and was the latest technology before the dry process was introduced in

the 1970’s.

The process is based on the use of chalk or limestone and clay which are quarried in

adjacent quarries. Raw material preparation involves quality controlled mixing of the raw

materials within ball mills known as Double Rotators

The ground raw materials i.e. raw meal is then stored in holding silos before being mixed

with water on rotating pan dishes known as a nodulising pans. This converts the powder

into small round balls.

The Lepol grate preheater contains a slotted grate onto which the nodules are fed. The

grate transports the nodules towards the kiln. Within the Lepol grate the nodules

experience a range of gas temperatures from 100 – 1100 OC. At these temperatures the

added water is driven off and the calcination process starts (the conversion of chalk into

lime and carbon dioxide gas). The air stream in the Lepol grate passes through the

slotted grate twice and after the first pass, the cyclones remove partly calcined dusty

material from the kiln feed nodules to control alkalis. This is known as cyclone dust.

The kiln exhaust gases are pulled through the system by a fan. They pass through an

electrostatic precipitator that removes the dust. CKD is rejected from the kiln system as a

means of controlling the level of alkali metals in the finished cement.

In both cases conditioning with water was historically undertaken for ease of handling to

prevent dust emissions when sending to landfill. CKD and BPD can both be supplied dry

and conditioned material dependant on the end use, recipient site and the handling

facilities available. Conditioning with water has never been undertaken to change

composition of the material. "

38 n/a

Is the waste produced as part of a treatment process

e.g. effluent treatment, pollution control practices etc.Yes


Question


Evidence No(s).


Evidence Confidence


Information)


present

5

If yes, please provide details for the primary treatment

process, particularly whether this has the potential to

introduce contaminants such as disinfectants etc.

Yes

Waste used as raw materials in the European cement industry comprise: Fly ash; blast

furnace slag; silica fume; iron slag; paper sludge; pyrite ash; spent foundry sand; soil

containing oil; and artificial gypsum from flue-gas desulphurisation and phosphoric acid

production.

Wastes are increasing in use as fuel for clinker production, with greater increase in use of

non-hazardous waste compared with hazardous. 2003/2004 survey of waste used as

cement kilns (Table 1.14 of source 6): wood, paper cardboard; textiles; plastics;

processed fractions (e.g. RDF); rubber/tyres; industrial sludge; municipal sewage sludge;

animal meats and fats; coal/carbon waste; agricultural waste; solid waste (impregnated

sawdust); solvents and related waste; oils and oily wastes; and others. Pretreatment is

undertaken, and can include sorting, crushing, pelletising dependent on fuel application.

6Medium - single EU report,

peer reviewed.n/a

6Is there any information on the primary product or raw

materials for this waste e.g. material safety sheets?Yes MSDS provided as source CKD_25 25

Medium - grey literature

however multiple MSDS

available for review

n/a

7

How variable is the waste between batches and what

factors influence this variability? Please provide

summary information if available.

Moderate

The major factors determining CKD characteristics are the raw feed material, type of kiln

operation, dust collection systems, and fuel type. Since the properties of CKD can be

significantly affected by the design, operation, and materials used in a cement kiln, the

USEPA recommend the chemical and physical characteristics of CKD must be evaluated

on an individual plant basis. (United States EPA, 2011).

Batches of waste dust from a single facility are therefore unlikely to be highly variable

unless the input materials (feed and fuel) are subject to change or are inhomogeneous.

Batches of dust from different facilities is likely to be more variable.

2Medium - single EU report,

peer reviewed.n/a

8How variable is the waste between producers and what

factors influence this variability?Moderate

Report states that because plant operations differ considerably with respect to raw feed,

operation type, dust collection facility and type of fuel used, comparison of CKD across

different plants can be misleading, with marked variation in dust characteristics. Dusts

collected from dry kilns are described (according to a 1977 study) as being finer than

those from wet and semi-wet/semi-dry kilns. A 1992 study found that modern cement

kilns equipped with alkali by-pass produced relatively coarse CKD compared with wet and

dry kiln processes (median size 22.2um compared with 9.3um and 3.0um respectively).

High variability has been observed in the analytical results provided by industry.

However, generally the variability is considered to be moderate. Discussions with

industry indicate that the main reason for variability in concentrations of metals, such as

lead and cadmium in CKD/BPD between producers is due to differences in the chemical

composition of raw input materials.

3

37/38

High due to multiple

sources of information

inclusive of recent UK

producer/operator specific

data.

n/a

9 Is the waste to be applied as a solid, sludge or liquid? other(specify)

CKD can be either unconditioned (solid) or conditioned (treated with water). According to

the expert interview conducted by AMEC, the CKD (referred to as BPD by the producer)

is provided to the application Operator in unconditioned form by powder tanker from the

subject site. The CKD is then conditioned in a silo on site and screened in order to

provide a consistent particle size for application, and to remove lumps. The Operator

confirmed that other Cement Facilities provide CKD/BPD in conditioned form, with

screening taking place either onsite at the Cement Facility, or offsite. Conditioned

CKD/BPD is transported to the Operator via covered wagons.

28



obtained via expert

interview.

n/a


Question


Evidence No(s).


Evidence Confidence


Information)


present

10

What is the method of application of this waste to land

and are any special measures used to achieve

satisfactory spreading?

Liming frequency and liming rates (including CKD appliction) are determined by several

factors - desired change in pH; and buffering capacity of the soil. Due to economic factors

(cost of operation of spreading equipment), reapplication of liming agents is normally

delayed until at least 2 tonnes of liming agent are required to achieve the desired pH.

Application frequency is assumed to vary from once per 2 years to once per 5

years.Tilling equipment is assumed to be used to incorporate the liming agent to depths

of 10,15 or 20cm. Tilling assumed 15 days/year.

"The wastes are inherently stable so storage in dry conditions should not affect their

suitability for landspreading." (Section 4.10.7 paragraph 2).

Placement of fine dust on agricultural land is difficult. The source identifies that granules

or agglomerates of dust should be made, to help limit fugitive release of dust whilse

transporting, handling, and placing CKD (i.e conditioning of waste). Care must be taken

so the particles are not so rigid that rain and other natural processes cannot dissolve or

break down the particles.

Description taken from information provided to USEPA by a CKD distribution agent,

NewLime, New York State. Liming may occur during any season of the year with the

majority taking place in autumn. Following delivery to site the dust is placed in spreader

boxes, holding up to 11 metric tons of CKD and measure approximately 10m in width.

The spreader boxes have holes of 2.5cm diameter spaced at 10cm intervals on the base

of the spreader box, for even distribution onto the ground. The soil is first disked and

harrowed before CKD is spread. The soil is then disked again and ploughed. CKD is

usually spread to a depth of 15-20cm, with typical application of 4.5 metric tons CKD

applied per ha, with reapplication once per 3-5 years.

Deployment information received indicates application rates of between 2.8 and 4.5t/ha

for bypass dust, at intervals of 3 years. The spreading is undertaken from towed

spreading machines, which have a moving belt to discharge the BPD onto spinning discs

located at the rear of the spreader, from which the conditioned dust is spread onto the

field.

8

15

3

23

26

Medium literature evidence

confirmed through expert

interview

n/a

11 Why is this material to be spread to land?

Because of its alkalinity, CKD can successfully be used as a liming agent in acidic soils

(PENNSTATE, 2004).

CKD is used in application to agricultural soils in order to increase soil pH lost over time

(and accelerated by fertilizer application). Application is therefore required to repeated

over time over the lifetime of the agricultural field (approx. 100 years).

BPD can be used to replace a proportion of the bagged mineral fertilizer normally applied

to crop land at a suitable application rate.

4

8

26

Mediun due to multiple lines

of evidence including UK

specific literature from

waste management

company

n/a

Chemical Hazards

12Are there any analytical data available for this waste?

If yes, please complete Tab C - Quantitative DataYes See data attached 26, 28, 40

High due to multiple UK

specific sources of dataAll receptors

Groundwater

13

Does the waste contain any hazardous substances?

(as classified under the Groundwater Daughter

Directive, see Tab D - supporting information)

Yes

Detectable concentrations of the following listed Hazardous Substances have been

recorded in CKD and could potentially be present: Cadmium, Dioxins,

Hexachlorobenzene (HCB), Mercury and compounds and PCBs (formerly known as List 1

substances). However concentrations of HCB, dioxins and PCBs appear to be very low

where detected, and typically are identified in emissions data rather than CKD/BPD

analysis.

2, 28, 40High due to multiple EU/UK

specific sources of data

Controlled Waters -

Groundwater

14

Does the waste contain any non-hazardous pollutants

in concentrations substantially above (> x 2) typical

natural background for shallow groundwater/drinking

water standards?

Yes

US leachability data for CKD/cement found Cr concentrations of up to 986.21 ppb (ug/l),

19 times the DWS, Cu up to 8.63 ug/l (4.3 times the DWS), Ni up to 104.44 ug/l (5.2

times the DWS).

29

Medium - USA leachability

test data of moderate age

(1997) and questionable

methodology compared with

UK DWS.

Controlled Waters -

Groundwater

Classification under different regulatory regimes : presence should be at concentrations above the limit of quantification (below this concentrations are assumed to be insignificant). Summary basis of

classification (e.g. high toxicity, persistence) and contaminant group (e.g. pesticide, herbicide etc) should be noted in comments where appropriate.


Question


Evidence No(s).


Evidence Confidence


Information)


present

Surface water

15

Does the waste contain any Priority or Priority

Hazardous substances? See Tab D - Supporting

information

YesPriority Substances identified at detectable concentrations within CKD / BPD include

arsenic, chromium, copper and zinc.28





data.

Controlled Waters -

Surface Water

16Does the waste contain any Specific Pollutants? See

Tab D - Supporting informationYes

Specific Pollutants identified at detectable concentrations within CKD / BPD include

cadmium, lead, mercury and nickel.28





data.

Controlled Waters -

Surface Water

Soils etc .

17Does the waste contain potentially toxic elements

(PTEs) or other contaminants? If so, please specify.Yes

Concentrations of the following metals and metalloids listed as Potentially Toxic Elements

(PTEs) have been identified in CKD / BPD: Pb, Cu, Zn, Cd, Cr, Ni, Hg.28





data.

Soils (Quality), Livestock,

Crops, Human Health

18What substances does the waste contain that could

benefit the soil? Please specify-

Potassium, Phosphate, trace metals, elevated pH

CKD can be described as an agricultural lime fortified with potassium (typically 3.5% dry

weight from the Lafarfe Iowa Davenport Plant) and sulphur (4.3% dry weight from the

Lafarfe Iowa Davenport Plant).

Example delpoyment applications identify the beneficial uses for this waste including as a

material to alter the receiving soil pH (lime substitute) and as a fertiliser due to its high

potassium content among other elements / nutrients.

15

32

28

Medium due to multiple

lines of evidence including

UK specific data

n/a

19

Does the waste contain any contaminants which are

considered to be toxic to human health (i.e. have

proven or suspected carcinogenic, mutagenic,

reproductive toxic effects etc.)?

Yes

Human health risk assesment modelling by the USEPA (1993) predicted potential risks

via the food chain pathway from CKD liming practices for ingestion of vegetables from the

field, beef and milk raised on feed from the field, and farmers subsisting on vegetables,

beef and milk raised from the field. Best estimate cancer risks ranged up to 7x10-6, with

maximum high end risks 2.5x10-5. In bounding analysis the USEPA found the

subsistence farming scenario showed the greatest risk potential with a risk estimate of

2.1x10-4.

NTP and IARC list respirable quartz crystalline silica as a carcinogen; OSHA does not.

Trace metals potentially present, with proven or suspected toxicity: As, Cd, Pb, An, Ba,

Be, Ag, Hg, Th, Se, Ni.

ECHA indicates that under the CLP regulations portland cement flue dust is not noted to

be carcinogenic, mutagenic or have any reproductive toxic effects

23

25

31

Medium due to age of study

(1993), geographical bias

(USA specific) and limited

dataset.

Human Health

20

Does the waste contain any contaminants with a high

bioaccumulation potential? See Tab D - Supporting

information

No

Persistence / Bioaccumulation / Toxic (PBT) criteria are not applicable to Cement Kiln

Dust / BPD according to ECHA database due to substance being inorganic.

ECHA states that CKD has no potential for bioaccumulations.

31

High due to datasource

being collated peer

reviewed databank

Livestock, Human Health

21

Are there any contaminants present within the waste

that are proven or suspected to be persistent in the

environment? See Tab D - Supporting information

Yes

A study by Karsetnsen (2006) reported an average concentration of 6.7 ng I-TEQ/kg of

PCDDs PCDFs in CKD, and a maximum concentration of 100 ng TEQ/kg, however this

study was found to show that cement industry wastes contain PCDD/PCDF levels

comparable to those in foods such as fish, butter, breast milk, and less than the

maximum permissible concentration of 100 ng TEQ/kg for the application of sewage

sludge to agricultural land.

2

Medium - EU peer reviewed

report referencing a single

study.

Soils (Quality), Crops,

Controlled Waters

22

Does the waste contain any contaminants which are

proven or suspected of being endocrine disrupting?

See Tab D - Supporting information

No

Chemical information available to date is not inclusive of any of the List I, II or III

suspected or confirmed Endocrine Disruptive Compounds with the exception of PCBs -

however the data available show very low PCB concentrations, where identified at

detectable concentrations, and typically within emissions data rather than in analysed

CKD / BPD collected for disposal.

2


sources of analytical data


specific data.


The following four questions need only be answered if not already covered in the responses to the classification questions above.


Question


Evidence No(s).


Evidence Confidence


Information)


present

Supporting chemical hazard information

23

Describe any speciation or the form of contaminants

identified within the waste, which could influence the

hazards associated with these.

-

The USEPA undertook modelling using MINTEQ for soil and meteorological data

identified for geographic settings used for CKD deployment, in order to define metal

speciation and therefore soil-water distribution coefficients. The following were defined:

As (+3): Log Kd = 0.0322pH + 1.24

Cr (+6): log Kd = -0.177pH + 2.07

8

Low due to single literature

source, and data being

derived using modelling for

USA specific conditions

Livestock, Crops, Human

Health, Controlled

Waters

24Are pesticides, herbicides or fungicides likely to be

present within the waste?No

USEPA sampling (1992, 1993) of CKD included analysis of 13 target pesticides in

samples from 11 cement facilities. Three target compounds were detected at two of the

facilities - endrin and heptachlor epoxide in as-generated CKD in one facility, and

endosulfan in as-generated and managed CKD in a separate facility. The report

concluded that as only three pesticides were detected, at one facility each, the USEPA

did not consider pesticide to be present in CKD on an industry wide basis.

23Moderate due to non-UK

data


Health, Controlled

Waters

25

Are there any breakdown products or metabolites

associated with these contaminants, which could

present a significant hazard? See Tab D - Supporting

information

No ECHA states that CKD will not decompose into any hazardous products. 31


being collated peer

reviewed databank


Health, Controlled

Waters

26Does the waste contain any contaminants which could

potentially present a cumulative / additive effect?Yes

Concentrations of metals and metalloids (primarily Cu, Pb, Mn, Th and V) cumulatively in

excess of 1000mg/kg dry weight have been identified in several samples of BPD provided

by industry, and therefore pose a potential additive ecotoxic risk.

26, 28, 40


sources of analytical data


specific data


27

Does the waste contain any contaminants which could

present a significant hazard due to their volatility? See

Tab D - Supporting information

No

CKD and BPD are a waste product generated in a high temperature process. Due to the

high operating temperature, the majority of volatile organic contaminants which may be

present within the substance will have been destroyed. Other volatile substances (i.e. Hg)

are unlikely to be present in sufficiently high concentrations to pose a significant

inhalation hazard under the application scenario.

2, 7, 12

Moderate due to multiple

sources of non-UK specific

data


28Does the waste have a biological oxygen demand

(BOD) of >6 mg/l?No Not relevant for waste stream under consideration

Controlled Waters -

Surface Water

29 Does the waste have a pH of <2.5 or >11.0? Yes

Lime and lime sludge have pH values of 10-12+. 1998 waste lime characterisation study

data summary provided (Davis and Rudd, 1998) - 21 samples analysed, minimum pH 4.6

units, maximum 13.1 units, median 8.2 units and mean 9.2 units.1998 lime sludge from

cement manufacture or gas processing characterisation study data summary provided

(Davis and Rudd, 1998) - 9 samples analysed, minimum pH 6.5 units, maximum 12.5

units, median 12.0 units and mean 11.1 units.

MSDS states that saturated water solutions of cement kiln dust can have pH of 12-12.5.

15

25

HighLivestock, Crops,

Controlled Waters

30

Does the waste have the potential to contain any

emerging contaminants of concern? See Tab D -

Supporting information

No

No emerging contaminants of concern identified from review of likely waste content (CKD

/ BPD or exhaust gases). As a result of a study of dioxin emissions from 16 cement kilns

in Germany, a study cited by the Environment Agency (Kuhlmann, 1996) found that

dioxins are present at concentrations that are barely detectable and well below ELVs in

kiln emissions (note that this reflects airborne emissions, not CKD/BPD content).

1 High


Health, Controlled

Waters

Plant and animal pathogens and toxic compounds

31

Are Salmonella , Listeria monocytogenes , Escherichia

coli, Clostridium botulinum and / or Bacillus Cereus , or

other bacteria / pathogens or diseases such as BSE

and scrapie, likely to be present in the waste, post

spreading?

No Not relevant for waste stream under consideration 16 High Livestock, Human Health

32

Are plant pathogens, fungus and / or soil borne

diseases likely to be present in the waste post

spreading?

No Not relevant for waste stream under consideration Professional judgement Crops

33Are toxic or injurious plants likely to be present within

the waste, post spreading? No Not relevant for waste stream under consideration Professional judgement Livestock


Question


Evidence No(s).


Evidence Confidence


Information)


present

Invasive Weeds

34

Is there potential for invasive weeds to be present

within the waste, post spreading? See Tab D -

Supporting information

No Not relevant for waste stream under consideration Professional judgement Crops

35

Is there potential for exotic species to be present within

the waste, post spreading? See Tab D - Supporting

information

No Not relevant for waste stream under consideration Professional judgement Crops, Livestock


36

Is non biodegradable material, such as plastics, metal,

brick, concrete and / or glass etc., likely to be present

in the waste, post spreading?

NoNot relevant for waste stream under consideration due to high temperature that kilns

achieveProfessional judgement

Soil (Quality), Livestock,

Crops, Human Health

Nuisance

37Are unpleasant odours to be associated with the

waste?No MSDS describe material as odourless. 25

Moderate due to multiple

sources of informationHuman Health

38 Is dust likely to arise from this waste? Yes

If dust is unconditioned. Can be controlled by applying water to the waste - 'conditioning'

the waste. UK operator interview indicates that application in the UK is of conditioned

rather than unconditioned waste.

In the specific example of NewLime (USA supplier of CKD interviewed by USEPA), all

CKD is transported in enclosed trucks to the NewLime storage facility, where it is stored

in enclosed silos. The dust is then transported to individual farms in enclosed tanker

trucks, where it is placed into enclosed spreader boxes. The dust is dropped only

centimetres onto the ground and quickly tilled into the soil - it is not broadcast into the air

and allowed to settle. Reportedly, little dust becomes airborne even on windy days.

23, 28

High, evidence in literature

confirmed during expert

interview

Livestock, Human

Health, Air Quality

39Is the waste likely to attract pests, such as flies or

scavenging animals?No CKD is a mineral waste and therefore not likely to attract pests. Professional judgement Livestock, Human Health

Other Environmental Hazards

40 Does the waste have a high fat or oil content i.e. >4%? No Not relevant for waste stream under consideration Professional judgement Crops

41 Is the waste likely to cause anoxic soil conditions? No Not relevant for waste stream under consideration Professional judgement Crops

42Is there the potential for the stability of the waste to

come into question?No

ECHA has stated that when mixed with water (i.e. conditioned) CKD will harden into a

mass that is not reactive under normal environmental conditions. 31


being collated peer

reviewed databank

Soil Quality, Human

Health, Livestock


Question


Evidence No(s).


Evidence Confidence


Information)


present

43

Provide any further details on hazards identified within

this waste which are not covered in the questions

above.

-

Trace constituents in CKD include cadmium, lead, selenium and radionuclide[s]; and

these constituents are generally found at concentrations of less than 0.05 percent by

weight.' (USDOT, 1998)

Analysis of radionuclides in CKD was undertaken by the USEPA as part of the 1992 and

1993 industry sampling exercise. The results of analysis were found to show slightly

elevated concentrations of naturally occurring radionuclides, considered by the USEPA to

be consistent with processing of minerals containing Naturally Occurring Radioactive

Materials (NORM). Two man-made radioactive elements were identified in analysis

(plutonium-239 and caesium-137), which were considered to be derived from historical

weapons testing and consistent with other soils analysis.

4

23 Medium due to age of study

(1993), geographical bias

(USA specific) and limited

dataset.

-


Quantitative Data - Literature Based Data (Solid)

Analytical Data

Evidence No. CKD_04

Country of Origin Saudi Arabia

Analysis Date(s) not specified

Laboratory not specified

DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration

Mean Concentration (as

provided)Concentration Range 95th percentile Comments

Potentially Toxic Elements (PTEs)

Cadmium (Cd) mg/kg unknown unknown unknown unknown 29.7 unknown unknown unknown

Copper (Cu) mg/kg unknown unknown unknown unknown 46.5 unknown unknown unknown

Lead (Pb) mg/kg unknown unknown unknown unknown 278.2 unknown unknown unknown

Mercury (Hg) mg/kg unknown unknown unknown unknown 1.5 unknown unknown unknown

Molybdenum (Mo) mg/kg unknown unknown unknown unknown 104.6 unknown unknown unknown

Nickel (Ni) mg/kg unknown unknown unknown unknown 23.6 unknown unknown unknown

Zinc (Zn) mg/kg unknown unknown unknown unknown 185.1 unknown unknown unknown

Inorganics

pH pH units unknown unknown unknown unknown 10.85 unknown unknown unknown

Evidence No. CKD_07

Country of Origin EU

Analysis Date(s) not specified

Laboratory not specified

DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration



PCBs

Total PCBs

PCB-77 ng TEQ/m3 unknown unknown 3 0.0002 0.0005 unknown 0.0003 unknown


PCB-169 ng TEQ/m3 unknown unknown 3 <0.01 <0.01 unknown 0 unknown

PCB-189 ng TEQ/m3 unknown unknown 3 0.00007 0.00007 unknown 0 unknown

PCB-105 ng TEQ/m3 unknown unknown 3 0.00006 0.00007 unknown 1.0E-05 unknown

PCB-114 ng TEQ/m3 unknown unknown 3 <0.0005 <0.0005 unknown 0 unknown






Analytical Data

Evidence No. CKD_08

Country of Origin US

Analysis Date(s) 1992-1993

Laboratory not provided

DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration




Antimony (Sb) (mg/kg) unknown unknown unknown unknown unknown 5 unknown 64

Arsenic (As) (mg/kg) unknown unknown unknown unknown unknown 9 unknown 59

Barium (Ba) (mg/kg) unknown unknown unknown unknown unknown 137 unknown 410

Beryllium (Be) (mg/kg) unknown unknown unknown unknown unknown 1 unknown 4

Cadmium (Cd) (mg/kg) unknown unknown unknown unknown unknown 5 unknown 32

Chromium (Cr) (mg/kg) unknown unknown unknown unknown unknown 26 unknown 75

Lead (Pb) (mg/kg) unknown unknown unknown unknown unknown 113 unknown 1346

Mercury (Hg) (mg/kg) unknown unknown unknown unknown unknown 0 unknown 1

Nickel (Ni) (mg/kg) unknown unknown unknown unknown unknown 15 unknown 49

Selenium (Se) (mg/kg) unknown unknown unknown unknown unknown 6 unknown 37

Silver (Ag) (mg/kg) unknown unknown unknown unknown unknown 3 unknown 15

Thallium (Tl) (mg/kg) unknown unknown unknown unknown unknown 5 unknown 146

Dioxins/Furans and dioxin like compounds

2,3,7,8TCDF (µg/kg) unknown unknown unknown unknown unknown 0.0055 unknown 0.184

2,3,7,8TCDD (µg/kg) unknown unknown unknown unknown unknown 0.00274 unknown 0.02

1,2,3,7,8-PeCDF (µg/kg) unknown unknown unknown unknown unknown 0.004 unknown 0.06736

2,3,4,7,8-PeCDF (µg/kg) unknown unknown unknown unknown unknown 0.004 unknown 0.165

1,2,3,7,8-PeCDD (µg/kg) unknown unknown unknown unknown unknown 0.0065 unknown 0.037

1,2,3,4,7,8-HxCDF (µg/kg) unknown unknown unknown unknown unknown 0.0065 unknown 0.09186




1,2,3,4,7,8-HxCDD (µg/kg) unknown unknown unknown unknown unknown 0.008 unknown 0.0335



1,2,3,4,6,7,8-HpCDF (µg/kg) unknown unknown unknown unknown unknown 0.01 unknown 0.228

1,2,3,4,7,8,9-HpCDF (µg/kg) unknown unknown unknown unknown unknown 0.008 unknown 0.0235

1,2,3,4,6,7,8-HpCDD (µg/kg) unknown unknown unknown unknown unknown 0.02 unknown 0.428

OCDF (µg/kg) unknown unknown unknown unknown unknown 0.01 unknown 0.0335

OCDD (µg/kg) unknown unknown unknown unknown unknown 0.0449 unknown 0.461

Evidence No. CKD_20

Country of Origin Canada

Analysis Date(s) 1998

Laboratory n/a

DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration




Boron (B) (mg/kg) unknown unknown unknown 5 715 360 710 unknown

Calcium (Ca) (mg/kg) unknown unknown unknown 0.2987 0.3013 0.3 0.0026 unknown

Copper (Cu) (mg/kg) unknown unknown unknown 7.4 8.2 7.8 0.8 unknown

Magnesium (Mg) (mg/kg) unknown unknown unknown 0.0049 0.0051 0.005 0.0002 unknown

Manganese (Mn) (mg/kg) unknown unknown unknown 0.00027 0.00033 0.0003 0.00006 unknown

Zinc (Zn) (mg/kg) unknown unknown unknown 28 34 31 6 unknown

Inorganics

Potassium (K) (mg/kg) unknown unknown unknown 0.0241 0.0259 0.025 0.0018 unknown

Phosphorus (P) (mg/kg) unknown unknown unknown 0.00148 0.00152 0.0015 0.00004 unknown

Analytical Data

Evidence No. CKD_23 EPA sampling



Laboratory n/a

Trace metal concentrations in as generated CKD

DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration




Antimony (Sb) (mg/kg) unknown unknown 17 1.77 27.2 7.7 25.4 unknown

Arsenic (As) (mg/kg) unknown unknown 17 2.1 20.3 6.9 18.2 unknown

Barium (Ba) (mg/kg) unknown unknown 17 11 779 172.1 768.0 unknown

Beryllium (Be) (mg/kg) unknown unknown 17 0.158 1.6 0.71 1.4 unknown

Cadmium (Cd) (mg/kg) unknown unknown 17 0.89 80.7 13.2 79.8 unknown

Chromium (Cr) (mg/kg) unknown unknown 17 11.5 81.7 26.6 70.2 unknown

Lead (Pb) (mg/kg) unknown unknown 17 5.1 1490 388.4 1484.9 unknown

Mercury (Hg) (mg/kg) unknown unknown 17 0.005 14.4 1 14.4 unknown

Nickel (Ni) (mg/kg) unknown unknown 17 6.9 39 19 32.1 unknown

Selenium (Se) (mg/kg) unknown unknown 17 2.5 109 17.5 106.5 unknown

Silver (Ag) (mg/kg) unknown unknown 17 1.1 22.6 6.9 21.5 unknown

Vanadium (V) (mg/kg) unknown unknown 17 6.6 204 41.6 197.4 unknown

Thallium (Tl) (mg/kg) unknown unknown 17 0.99 108 17.1 107.0 unknown

Evidence No. CKD_23 PCA survey



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration




Antimony (Sb) (mg/kg) unknown unknown 1 0.53 0.53 0.53 n/a unknown

Arsenic (As) (mg/kg) unknown unknown 3 3.7 53 34.3 49.3 unknown

Barium (Ba) (mg/kg) unknown unknown 1 150 150 150 n/a unknown


Cadmium (Cd) (mg/kg) unknown unknown 3 3 12.1 8.05 9.1 unknown

Chromium (Cr) (mg/kg) unknown unknown 3 32.7 49 39 16.3 unknown

Hex Chromium (mg/kg) unknown unknown 2 7.05 8.59 7.82 1.5 unknown

Copper (Cu) (mg/kg) unknown unknown 2 28.2 28.7 28.4 0.5 unknown

Lead (Pb) (mg/kg) unknown unknown 3 151 270 210.3 119 unknown

Mercury (Hg) (mg/kg) unknown unknown 3 0.1 0.107 0.104 0.007 unknown

Manganese (Mn) (mg/kg) unknown unknown 5 200 222 211.2 22 unknown

Nickel (Ni) (mg/kg) unknown unknown 3 10 23.8 18.3 13.8 unknown

Selenium (Se) (mg/kg) unknown unknown 1 6.5 6.5 6.5 n/a unknown

Silver (Ag) (mg/kg) unknown unknown 1 0.504 0.504 0.504 n/a unknown

Vanadium (V) (mg/kg) unknown unknown 3 23 39.2 33.5 16.2 unknown

Zinc (Zn) (mg/kg) unknown unknown 3 86 116 104.3 30 unknown

Thallium (Tl) (mg/kg) unknown unknown 1 4.616 4.616 4.616 n/a unknown

Analytical Data

Evidence No. CKD_23 PCA report 1



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration




Antimony (Sb) (mg/kg) unknown unknown 6 37.8 161 112.8 123.2 unknown


Barium (Ba) (mg/kg) unknown unknown 6 101 323 183.5 222 unknown


Cadmium (Cd) (mg/kg) unknown unknown 6 4.73 44 18.6 39.3 unknown

Chromium (Cr) (mg/kg) unknown unknown 6 18.1 58.5 35.9 40.4 unknown




Thallium (Tl) (mg/kg) unknown unknown 6 68.6 146 88 77.4 unknown

Evidence No. CKD_23 PCA Report 2



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration




Antimony (Sb) (mg/kg) unknown unknown 95 0.083 3.43 0.395 3.3 unknown

Arsenic (As) (mg/kg) unknown unknown 95 1.323 159 13 157.7 unknown

Barium (Ba) (mg/kg) unknown unknown 95 35 1402 185.8 1367.0 unknown



Chromium (Cr) (mg/kg) unknown unknown 95 8.25 293 40.8 284.8 unknown


Mercury (Hg) (mg/kg) unknown unknown 95 1 60 17.3 59.0 unknown

Nickel (Ni) (mg/kg) unknown unknown 95 0.001 25.5 0.49 25.5 unknown




Evidence No. CKD_23 BOM IC 8885



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration





Arsenic (As) (mg/kg) unknown unknown 113 1.3 518 23.8 516.7 unknown

Cadmium (Cd) (mg/kg) unknown unknown 113 0.687 352 20 351.3 unknown

Chromium (Cr) (mg/kg) unknown unknown 113 11 172 41.6 161.0 unknown

Copper (Cu) (mg/kg) unknown unknown 113 7 206 30.1 199.0 unknown


Lithium (mg/kg) unknown unknown 113 1.754 76 18 74.2 unknown

Manganese (Mn) (mg/kg) unknown unknown 113 63 2410 385.6 2347.0 unknown

Nickel (Ni) (mg/kg) unknown unknown 113 5.421 91 19.3 85.6 unknown

Silver (Ag) (mg/kg) unknown unknown 113 1.291 17 5.1 15.7 unknown

Strontium (mg/kg) unknown unknown 113 100 8800 669 8700.0 unknown

Zinc (Zn) (mg/kg) unknown unknown 113 32 8660 462 8628.0 unknown

Analytical Data

Evidence No. CKD_23



Laboratory n/a

Total Concentrations of Dioxins and Dibenzofurans in As Generated CKD

DeterminandUnit of

measurementHW-1 sample 1 HW-1 sample 2 HW-2 HW-3 NH-1 NH-2 NH-3

Minimum

(excluding <LoD)

Maximum

(excluding <LoD)

Average

(excluding

<LoD)


2,3,7,8TCDF (µg/kg) 0.0005 <0.00065 0.038 0.0044 0.00039 <0.00087 <0.00099 0.00039 0.038 0.0108

2,3,7,8TCDD (µg/kg) <0.00031 <0.0011 0.0056 <0.00088 <0.0013 <0.00037 <0.0016 0.0056 0.0056 0.0056

1,2,3,7,8-PeCDF (µg/kg) <0.00046 ,0.00089 0.033 0.0061 0.00052 <0.00051 <0.00058 0.00052 0.033 0.0132

2,3,4,7,8-PeCDF (µg/kg) <0.00053 <0.00072 0.064 0.0038 <0.00046 <0.00033 <0.00057 0.0038 0.064 0.0339

1,2,3,7,8-PeCDD (µg/kg) <0.0005 <0.0012 0.03 <0.0012 <0.0015 <0.00057 <0.0021 0.03 0.03 0.0300

1,2,3,4,7,8-HxCDF (µg/kg) <0.00073 <0.0023 0.024 0.0028 <0.0011 <0.0007 <0.00096 0.0028 0.024 0.0134

1,2,3,6,7,8-HxCDF (µg/kg) <0.00044 <0.0016 0.025 0.0028 <0.00076 <0.00049 <0.00099 0.0028 0.025 0.0139

2,3,4,6,7,8-HxCDF (µg/kg) 0.0004 <0.0015 <0.037 0.0023 <0.00076 0.00057 <0.00074 0.0004 0.0023 0.0011

1,2,3,7,8,9-HxCDF (µg/kg) <0.00044 <0.0017 0.014 0.00096 <0.00073 <0.00085 <0.0012 0.00096 0.014 0.0075

1,2,3,4,7,8-HxCDD (µg/kg) <0.00079 <0.0014 0.025 <0.0014 <0.0012 <0.00083 <0.0012 0.025 0.025 0.0250

1,2,3,6,7,8-HxCDD (µg/kg) <0.00064 <0.0021 0.049 <0.0017 <0.0018 <0.00066 <0.00096 0.049 0.049 0.0490

1,2,3,7,8,9-HxCDD (µg/kg) <0.00095 <0.0019 0.041 <0.00093 <0.0014 <0.001 <0.0015 0.041 0.041 0.0410

1,2,3,4,6,7,8-HpCDF (µg/kg) <0.00056 <0.001 0.037 0.0024 <0.0013 0.00028 <0.0076 0.00028 0.037 0.0132

1,2,3,4,7,8,9-HpCDF (µg/kg) <0.00052 <0.001 0.0074 <0.0017 <0.0013 <0.00069 <0.00079 0.0074 0.0074 0.0074

1,2,3,4,6,7,8-HpCDD (µg/kg) 0.0019 0.0018 0.25 0.0048 0.0051 0.0011 <0.003 0.0011 0.25 0.0441

OCDF (µg/kg) <0.001 <0.0019 0.01 0.0017 <0.0032 <0.001 <0.0014 0.0017 0.01 0.0059

OCDD (µg/kg) 0.0036 0.0036 0.1 0.034 0.018 0.0046 0.0079 0.0036 0.1 0.0245

Total HpCDD (µg/kg) 0.0037 0.0037 0.55 0.011 0.0098 0.0026 0.0079 0.0026 0.55 0.0841

Total HpCDF (µg/kg) 0.0043 0.067 0.0024 0.00047 0.0013 0.00047 0.067 0.0151

Total HxCDD (µg/kg) 0.012 0.0076 1.5 0.00059 0.012 0.00059 1.5 0.3064

Total HxCDF (µg/kg) 0.0004 0.23 0.024 0.00089 0.0019 0.0004 0.23 0.0514

Total PeCDD (µg/kg) 0.0021 0.85 0.01 0.0021 0.85 0.2874

Total PeCDF (µg/kg) 0.00039 0.53 0.063 0.00052 0.00071 0.00039 0.53 0.1189

Total TCDD (µg/kg) 0.0054 0.0035 0.44 0.0091 0.0035 0.44 0.1145

Total TCDF (µg/kg) 0.0028 0.96 0.076 0.00039 0.014 0.00039 0.96 0.2106

Evidence No. CKD_27 Table 1.2



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration






Barium (Ba) (mg/kg) unknown unknown 59 0.43 900 181 899.6 unknown



Chromium (Cr) (mg/kg) unknown unknown 61 3.9 105 31.2 101.1 unknown

Lead (Pb) (mg/kg) unknown unknown 63 3.1 2620 287 2616.9 unknown


Nickel (Ni) (mg/kg) unknown unknown 45 3 66 19.9 63.0 unknown




Analytical Data

Evidence No. CKD_30 table 2


Analysis Date(s) n/a

Laboratory n/a

Typical chemical composition of CKD

DeterminandUnit of

measurement

Maslehuddin et al.

(2008a)

Sreekrishnavilasam

et al. (2006)

El-Aleem et al.

(2005)

Al-Harthy et al.

(2003)

Udoeyo and Hyee

(2002)Minimum Maximum Mean

Concentration

RangeComments

Inorganics

Loss On Ignition % 15.8 21.57 15.96 42.39 15.8 42.39 23.93 26.6

SiO2 % 17.1 15.05 13.37 15.8 2.16 2.16 17.1 12.696 14.9

Al2O3 % 4.24 6.75 3.36 3.6 1.09 1.09 6.75 3.808 5.7

Fe2O3 % 2.89 2.23 2.29 2.8 0.54 0.54 2.89 2.15 2.4

CaO % 49.3 43.99 42.99 63.8 52.72 42.99 63.8 50.56 20.8

MgO % 1.14 1.64 1.9 1.9 0.68 0.68 1.9 1.452 1.2

K2O % 2.18 4 3.32 3 0.11 0.11 4 2.522 3.9

Na2O % 3.84 0.69 3.32 0.3 0.3 3.84 2.0375 3.5

SO3 % 3.56 6.02 5.1 1.7 0.05 0.05 6.02 3.286 6.0

Evidence No. CKD_30 table 4 EPA

Country of Origin n/a


Laboratory n/a

trace metal conceentration in CKD

DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

ConcentrationMeidian Concentration Range 95th percentile Comments


Antimony (Sb) (mg/kg) unknown unknown unknown 1.77 2.72 6.2 1.0 unknown

Arsenic (As) (mg/kg) unknown unknown unknown 2.1 20.3 4.9 18.2 unknown

Barium (Ba) (mg/kg) unknown unknown unknown 11 779 103 768.0 unknown

Beryllium (Be) (mg/kg) unknown unknown unknown 0.158 1.6 0.59 1.4 unknown

Cadmium (Cd) (mg/kg) unknown unknown unknown 0.89 80.7 4.6 79.8 unknown

Chromium (Cr) (mg/kg) unknown unknown unknown 11.5 81.7 18.1 70.2 unknown

Lead (Pb) (mg/kg) unknown unknown unknown 5.1 1490 287 1484.9 unknown

Mercury (Hg) (mg/kg) unknown unknown unknown 0.005 14.4 0.11 14.4 unknown

Nickel (Ni) (mg/kg) unknown unknown unknown 6.9 39 15.9 32.1 unknown

Selenium (Se) (mg/kg) unknown unknown unknown 2.5 109 11.3 106.5 unknown

Silver (Ag) (mg/kg) unknown unknown unknown 1.1 22.6 3.7 21.5 unknown

Vanadium (V) (mg/kg) unknown unknown unknown 6.6 204 25.9 197.4 unknown

Thallium (Tl) (mg/kg) unknown unknown unknown 0.99 108 3.5 107.0 unknown

Analytical Data

Evidence No. CKD_30 table 4 PCA survey



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum




Arsenic (As) (mg/kg) unknown unknown unknown 3.7 53 46.2 49.3 unknown



Cadmium (Cd) (mg/kg) unknown unknown unknown 3 12.1 9.05 9.1 unknown

Chromium (Cr) (mg/kg) unknown unknown unknown 32.7 49 35.2 16.3 unknown

Lead (Pb) (mg/kg) unknown unknown unknown 151 270 21 119.0 unknown

Mercury (Hg) (mg/kg) unknown unknown unknown 0.1 0.107 0.106 0.0 unknown

Nickel (Ni) (mg/kg) unknown unknown unknown 10 23.8 21.1 13.8 unknown

Selenium (Se) (mg/kg) unknown unknown unknown 6.5 6.5 6.5 0.0 unknown


Vanadium (V) (mg/kg) unknown unknown unknown 23 39.2 38.3 16.2 unknown

Thallium (Tl) (mg/kg) unknown unknown unknown 4.616 4.616 4.616 0.0 unknown

Evidence No. CKD_30 table 4 PCA report 2



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum




Arsenic (As) (mg/kg) unknown unknown unknown 1.323 159 9.07 157.7 unknown



Cadmium (Cd) (mg/kg) unknown unknown unknown 0.008 59.6 3.27 59.6 unknown

Chromium (Cr) (mg/kg) unknown unknown unknown 8.25 293 29.1 284.8 unknown


Mercury (Hg) (mg/kg) unknown unknown unknown 1 60 14 59.0 unknown

Nickel (Ni) (mg/kg) unknown unknown unknown 0.001 25.5 0.045 25.5 unknown

Selenium (Se) (mg/kg) unknown unknown unknown 0.227 0.307 7.23 0.1 unknown


Thallium (Tl) (mg/kg) unknown unknown unknown 0.109 776 8.96 775.9 unknown

Evidence No. CKD_30 table 4 Haynes & Kramer



Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum



Antimony (Sb) (mg/kg) unknown unknown unknown 0.701 70 0.83 69.3 unknown

Arsenic (As) (mg/kg) unknown unknown unknown 1.3 518 10 516.7 unknown

Cadmium (Cd) (mg/kg) unknown unknown unknown 0.687 352 7.6 351.3 unknown

Chromium (Cr) (mg/kg) unknown unknown unknown 11 172 35 161.0 unknown


Nickel (Ni) (mg/kg) unknown unknown unknown 5.421 91 16 85.6 unknown

Silver (Ag) (mg/kg) unknown unknown unknown 1.291 17 4.7 15.7 unknown

Analytical Data




Laboratory Spectrochrom Ltd


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum



Arsenic (As) (mg/kg) unknown unknown 1 10 10 10 0 unknown

Chromium (Cr) (mg/kg) unknown unknown 1 14 14 14 0 unknown

Lead (Pb) (mg/kg) unknown unknown 1 120 120 120 0 unknown

Mercury (Hg) (mg/kg) unknown unknown 1 2 2 2 0 unknown




Laboratory QC Metallurgical Laboratory Inc


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum



Arsenic (As) (mg/kg) unknown unknown 1 3.76 3.76 3.76 0 unknown

Barium (Ba) (mg/kg) unknown unknown 1 68.87 68.87 68.87 0 unknown

Cadmium (Cd) (mg/kg) unknown unknown 1 12.02 12.02 12.02 0 unknown

Chromium (Cr) (mg/kg) unknown unknown 1 52.59 52.59 52.59 0 unknown

Iron (Fe) (mg/kg) unknown unknown 1 30023.17 30023.17 30023.17 0 unknown

Mercury (Hg) (mg/kg) unknown unknown 1 <2 <2 <2 0 unknown

Antimony (Sb) (mg/kg) unknown unknown 1 <2 <2 <2 0 unknown

Selenium (Se) (mg/kg) unknown unknown 1 <2 <2 <2 0 unknown

Lead (Pb) (mg/kg) unknown unknown 1 328.72 328.72 328.72 0 unknown

Zinc (Zn) (mg/kg) unknown unknown 1 62.3 62.3 62.3 0 unknown

Evidence No. CKD_32 table 3 PCA Study (SP109)





DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum



Arsenic (As) (mg/kg) unknown unknown 1 <13.3 <13.3 <13.3 0 unknown

Barium (Ba) (mg/kg) unknown unknown 1 240 240 240 0 unknown

Beryllium (Be) (mg/kg) unknown unknown 1 1.15 1.15 1.15 0 unknown

Cadmium (Cd) (mg/kg) unknown unknown 1 0.41 0.41 0.41 0 unknown

Chromium (Cr) (mg/kg) unknown unknown 1 30.8 30.8 30.8 0 unknown

Mercury (Hg) (mg/kg) unknown unknown 1 0.0318 0.0318 0.0318 0 unknown

Antimony (Sb) (mg/kg) unknown unknown 1 2.8 2.8 2.8 0 unknown

Selenium (Se) (mg/kg) unknown unknown 1 6.34 6.34 6.34 0 unknown

Silver (Ag) (mg/kg) unknown unknown 1 40.7 40.7 40.7 0 unknown

Lead (Pb) (mg/kg) unknown unknown 1 80.8 80.8 80.8 0 unknown

Nickel (Ni) (mg/kg) unknown unknown 1 35 35 35 0 unknown

Mercury (Hg) (mg/kg) unknown unknown 1 0.0318 0.0318 0.0318 0 unknown

Thallium (Tl) (mg/kg) unknown unknown 1 8.44 8.44 8.44 0 unknown

Analytical Data




Laboratory n/a

composition of CKD - dry kiln

DeterminandUnit of

measurement

Inorganics

Loss On Ignition % 30.24

SiO2 % 9.64

Al2O3 % 3.39

Fe2O3 % 1.1

CaO % 44.91

MgO % 1.29

K2O % 2.4

Na2O % 0.27

SO3 % 6.74

Na2O eq. %




Laboratory n/a

Typical chemical composition of CKD

DeterminandUnit of

measurement

Lehigh Inland

cement, Alberta plant

2000

Lafarge Holnam

Washington plant

1997

US bureau of

mines 1982

Rahman et al, Saudi

Arabia Plant 2011Minimum Maximum Mean

Concentration

RangeComments

Inorganics

Loss On Ignition % 0.14 22.48 0.7 15.8 0.14 22.48 9.78 22.3

SiO2 % 11.25 13.76 13.6 17.1 11.25 17.1 13.9275 5.9

Al2O3 % 0.99 3.72 4.5 4.24 0.99 4.5 3.3625 3.5

Fe2O3 % 2.03 1.61 2.1 2.99 1.61 2.99 2.1825 1.4

CaO % 46.91 8.1 49.3 8.1 49.3 34.77 41.2

MgO % 0.3 1.3 1.14 0.3 1.3 0.91 1.0

K2O % 0.57 2.13 2.18 0.57 2.18 1.63 1.6

Na2O % 0.1 0.69 3.84 0.1 3.84 1.54 3.7

SO3 % 0.63 8.4 3.84 0.63 8.4 4.29 7.8

Analytical Data

Evidence No. CKD_39 Tables 1 and 2

Country of Origin Eastern Europe - not specified


Laboratory n/a


DeterminandUnit of

measurement

Laboratory limit of

detection (LoD)

Analysis

accreditation

No. of samples

analysed

Minimum

Concentraton

Maximum

Concentration



Inorganics

Na2O

Not given - assume

% unknown unknown 15 1.24 3.96 2.6 2.7 unknown

K2O

Not given - assume


CaO_f

Not given - assume


Cl

Not given - assume

% unknown unknown 15 9.4 15.42 12 6.0 unknown

SO3

Not given - assume



Arsenic (As) (mg/kg) unknown unknown 8 <10 54 10 to 30 44.0 unknown

Barium (Ba) (mg/kg) unknown unknown 8 39 100 62 61.0 unknown

Cadmium (Cd) (mg/kg) unknown unknown 8 69 226 136 157.0 unknown

Cobalt (Co) (mg/kg) unknown unknown 8 4 5 <5 1.0 unknown

Chromium (Cr) (mg/kg) unknown unknown 8 13 136 54 123.0 unknown

Copper (Cu) (mg/kg) unknown unknown 8 179 606 399 427.0 unknown


Nickel (Ni) (mg/kg) unknown unknown 8 7 202 64 195.0 unknown

Lead (Pb) (mg/kg) unknown unknown 8 3890 9036 6044 5146.0 unknown

Antimony (Sb) (mg/kg) unknown unknown 8 9 34 19 25.0 unknown

Selenium (Se) (mg/kg) unknown unknown 8 <10 35 10 to 20 25.0 unknown

Tin (Sn) (mg/kg) unknown unknown 8 <5 72 10 to 30 67.0 unknown

Thallium (Tl) (mg/kg) unknown unknown 8 <5 16 <10 11.0 unknown

Quantitative Data - Literature Based Data (Leachate)

Evidence No. CKD_29 Table 3


Analysis Date(s) 1996/1997 (assumed)

Laboratory n/a

DeterminandUnit of

measurementLaboratory limit of detection (LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

Concentration

Mean Concentration

(as provided)Concentration Range


Aluminium (µg/l) unknown unknown unknown unknown unknown 15.62 unknown

Arsenic (As) (µg/l) unknown unknown unknown unknown unknown 4.36 unknown

Barium (Ba) (µg/l) unknown unknown unknown unknown unknown 830.38 unknown

Beryllium (Be) (µg/l) unknown unknown unknown unknown unknown 1.78 unknown

Cadmium (Cd) (µg/l) unknown unknown unknown unknown unknown 0.28 unknown

Chromium (Cr) (µg/l) unknown unknown unknown unknown unknown 217.93 unknown

Cobalt (Co) (µg/l) unknown unknown unknown unknown unknown 4.72 unknown

Copper (Cu) (µg/l) unknown unknown unknown unknown unknown 6.49 unknown

Lead (Pb) (µg/l) unknown unknown unknown unknown unknown 111.04 unknown

Nickel (Ni) (µg/l) unknown unknown unknown unknown unknown 31.82 unknown

Rubidium (µg/l) unknown unknown unknown unknown unknown 3954.18 unknown

Selenium (Se) (µg/l) unknown unknown unknown unknown unknown 144.93 unknown

Vanadium (V) (µg/l) unknown unknown unknown unknown unknown 13.88 unknown

Zinc (Zn) (µg/l) unknown unknown unknown unknown unknown 26.48 unknown

Titanium (µg/l) unknown unknown unknown unknown unknown 19.07 unknown

Inorganics

pH pH units unknown unknown unknown unknown unknown 11.9 unknown

Evidence No. CKD_29 Table 3 (PCA average)

Country of Origin Unknown


Laboratory n/a

DeterminandUnit of


Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

Concentration

Mean Concentration

(as provided)Concentration Range


Arsenic (As) (µg/l) unknown unknown unknown unknown unknown 66 unknown

Barium (Ba) (µg/l) unknown unknown unknown unknown unknown 1040 unknown

Beryllium (Be) (µg/l) unknown unknown unknown unknown unknown 0.4 unknown

Cadmium (Cd) (µg/l) unknown unknown unknown unknown unknown 28.8 unknown

Chromium (Cr) (µg/l) unknown unknown unknown unknown unknown 100 unknown

Lead (Pb) (µg/l) unknown unknown unknown unknown unknown 349 unknown

Nickel (Ni) (µg/l) unknown unknown unknown unknown unknown 130 unknown

Selenium (Se) (µg/l) unknown unknown unknown unknown unknown 152 unknown






DeterminandUnit of


Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

ConcentrationMeidian Concentration Range


Arsenic (As) (mg/l) unknown unknown 1 0.036 0.036 0.036 0

Barium (Ba) (mg/l) unknown unknown 1 0.76 0.76 0.76 0

Cadmium (Cd) (mg/l) unknown unknown 1 0.08 0.08 0.08 0

Chromium (Cr) (mg/l) unknown unknown 1 0.25 0.25 0.25 0

Iron (Fe) (mg/l) unknown unknown 1 25.17 25.17 25.17 0

Mercury (Hg) (mg/l) unknown unknown 1 <0.05 <0.05 <0.05 0

Antimony (Sb) (mg/l) unknown unknown 1 <0.05 <0.05 <0.05 0

Selenium (Se) (mg/l) unknown unknown 1 <0.05 <0.05 <0.05 0

Lead (Pb) (mg/l) unknown unknown 1 1.54 1.54 1.54 0

Zinc (Zn) (mg/l) unknown unknown 1 0.17 0.17 0.17 0

Analytical Data

Evidence No. CKD_32 table 3 PCA Study (SP109)





DeterminandUnit of


Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

ConcentrationMeidian Concentration Range


Arsenic (As) (mg/l) unknown unknown 1 <0.005 <0.005 <0.005 0

Barium (Ba) (mg/l) unknown unknown 1 1.41 1.41 1.41 0

Beryllium (Be) (mg/l) unknown unknown 1 <0.0005 <0.0005 <0.0005 0

Cadmium (Cd) (mg/l) unknown unknown 1 <0.002 <0.002 <0.002 0

Chromium (Cr) (mg/l) unknown unknown 1 0.061 0.061 0.061 0

Mercury (Hg) (mg/l) unknown unknown 1 0

Antimony (Sb) (mg/l) unknown unknown 1 0.017 0.017 0.017 0

Selenium (Se) (mg/l) unknown unknown 1 <0.006 <0.006 <0.006 0

Silver (Ag) (mg/l) unknown unknown 1 0.073 0.073 0.073 0

Lead (Pb) (mg/l) unknown unknown 1 0.056 0.056 0.056 0

Nickel (Ni) (mg/l) unknown unknown 1 <0.06 <0.06 <0.06 0

Mercury (Hg) (mg/l) unknown unknown 1 <0.000538 <0.000538 <0.000538 0

Thallium (Tl) (mg/l) unknown unknown 1 <0.083 <0.083 <0.083 0

Evidence No. CKD_33 Table 3 - moisture conditioned CKD


Analysis Date(s) 1998 (assumed)

Laboratory n/a

DeterminandUnit of


Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

ConcentrationMean Concentration Concentration Range


Aluminium (µg/l) unknown unknown unknown 440 700 unknown 260

Arsenic (As) (µg/l) unknown unknown unknown <1 <1 unknown 0

Barium (Ba) (µg/l) unknown unknown unknown 51 66 unknown 15

Cadmium (Cd) (µg/l) unknown unknown unknown <0.2 <0.2 unknown 0

Chromium (Cr) (µg/l) unknown unknown unknown 9 14 unknown 5

Copper (Cu) (µg/l) unknown unknown unknown <20 <20 unknown 0

Lead (Pb) (µg/l) unknown unknown unknown <3 <3 unknown 0

Mercury (Hg) (µg/l) unknown unknown unknown <0.2 <0.2 unknown 0

Silver (Ag) (µg/l) unknown unknown unknown <0.5 <0.5 unknown 0

Selenium (Se) (µg/l) unknown unknown unknown <3.0 4.4 unknown 1.4

Zinc (Zn) (µg/l) unknown unknown unknown <20 <20 unknown 0

Inorganics

pH pH units unknown unknown unknown 11.91 11.98 unknown 0.07

Chloride (mg/l) unknown unknown unknown 36 50 unknown 14

Potassium (mg/l) unknown unknown unknown 180 200 unknown 20

Sulphate (mg/l) unknown unknown unknown <10 10 unknown 0

Evidence No. CKD_33 Table 3 - insitu CKD


Analysis Date(s) 1998 (assumed)

Laboratory n/a

DeterminandUnit of


Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

ConcentrationMean Concentration Concentration Range


Aluminium (µg/l) unknown unknown unknown <100 1100 unknown 1000

Arsenic (As) (µg/l) unknown unknown unknown <3 <3 unknown 0

Barium (Ba) (µg/l) unknown unknown unknown 180 620 unknown 440

Cadmium (Cd) (µg/l) unknown unknown unknown <0.30 <0.30 unknown 0

Chromium (Cr) (µg/l) unknown unknown unknown 18 160 unknown 142

Copper (Cu) (µg/l) unknown unknown unknown <20 <20 unknown 0

Lead (Pb) (µg/l) unknown unknown unknown 8.2 24 unknown 15.8

Mercury (Hg) (µg/l) unknown unknown unknown <0.20 <0.20 unknown 0

Silver (Ag) (µg/l) unknown unknown unknown <1 <1 unknown 0

Selenium (Se) (µg/l) unknown unknown unknown 6.2 22 unknown 15.8

Zinc (Zn) (µg/l) unknown unknown unknown <20 71 unknown 51

Inorganics

pH pH units unknown unknown unknown 11.66 11.87 unknown 0.21

Chloride (mg/l) unknown unknown unknown 19 190 unknown 171

Potassium (mg/l) unknown unknown unknown 120 690 unknown 570

Sulphate (mg/l) unknown unknown unknown 17 110 unknown 93

Analytical Data

Evidence No. CKD-35 Table 3 - Static Leaching Test Method

Country of Origin Canada (Alberta)

Analysis Date(s)

Laboratory

leachable metals from CKD leaching test

DeterminandUnit of


Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

ConcentrationAverage Concentration Range


Antimony (Sb) mg/l 0.2 unknown unknown <0.2 <0.2 unknown 0

Arsenic (As) mg/l 0.2 unknown unknown <0.2 <0.2 unknown 0

Barium (Ba) mg/l 0.1 unknown unknown 0.7 0.8 unknown 0.1

Beryllium (Be) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Boron (B) mg/l 0.1 unknown unknown 0.2 0.2 unknown 0

Cadmium (Cd) mg/l 0.005 unknown unknown <0.005 0.007 unknown 0.002

Chromium (Cr) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Cobalt (Co) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Copper (Cu) mg/l 0.1 unknown unknown <0.1 <0.1 unknown 0

Iron (Fe) mg/l 0.1 unknown unknown <0.1 <0.1 unknown 0

Lead (Pb) mg/l 0.05 unknown unknown 0.05 0.07 unknown 0.02

Mercury (Hg) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Manganese (Mn) mg/l 0.01 unknown unknown 0.16 0.17 unknown 0.01

Molybdenum (Mo) mg/l 0.01 unknown unknown 0.05 0.05 unknown 0

Nickel (Ni) mg/l 0.02 unknown unknown <0.01 <0.02 unknown 0

Selenium (Se) mg/l 0.2 unknown unknown <0.2 <0.2 unknown 0

Silver (Ag) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Vanadium (V) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Zinc (Zn) mg/l 0.2 unknown unknown 0.3 0.3 unknown 0

Zirconium mg/l 0.1 unknown unknown <0.1 <0.1 unknown 0

Thallium (Tl) mg/l 0.05 unknown unknown 0.1 0.15 unknown 0.05

Uranium (U) mg/l 0.2 unknown unknown <0.2 <0.2 unknown 0

Evidence No. CKD-35 Table 3 - TCLP Method

Country of Origin Canada (Alberta)

Analysis Date(s)

Laboratory

leachable metals from CKD leaching test

DeterminandUnit of


Analysis

accreditation

No. of

samples

analysed

Minimum

Concentraton

Maximum

ConcentrationAverage Concentration Range


Antimony (Sb) mg/l 0.2 unknown unknown <0.2 <0.2 unknown 0

Arsenic (As) mg/l 0.2 unknown unknown <0.2 <0.2 unknown 0

Barium (Ba) mg/l 0.1 unknown unknown 0.1 0.7 unknown 0.6

Beryllium (Be) mg/l 0.01 unknown unknown 0.01 <0.1 unknown 0.09

Boron (B) mg/l 0.1 unknown unknown 0.1 0.2 unknown 0.1

Cadmium (Cd) mg/l 0.005 unknown unknown <0.005 0.005 unknown 0

Chromium (Cr) mg/l 0.01 unknown unknown <0.1 0.1 unknown 0

Cobalt (Co) mg/l 0.01 unknown unknown 0.01 0.01 unknown 0

Copper (Cu) mg/l 0.1 unknown unknown <0.1 0.1 unknown 0

Iron (Fe) mg/l 0.1 unknown unknown <0.1 0.1 unknown 0

Lead (Pb) mg/l 0.05 unknown unknown 0.11 0.12 unknown 0.01

Mercury (Hg) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Manganese (Mn) mg/l 0.01 unknown unknown 0.68 0.68 unknown 0

Molybdenum (Mo) mg/l 0.01 unknown unknown 0.1 0.11 unknown 0.01

Nickel (Ni) mg/l 0.02 unknown unknown 0.04 0.04 unknown 0

Selenium (Se) mg/l 0.2 unknown unknown 0.4 0.5 unknown 0.1

Silver (Ag) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Vanadium (V) mg/l 0.01 unknown unknown <0.01 <0.01 unknown 0

Zinc (Zn) mg/l 0.2 unknown unknown 0.5 0.5 unknown 0

Zirconium mg/l 0.1 unknown unknown <0.1 <0.1 unknown 0

Thallium (Tl) mg/l 0.05 unknown unknown 0.14 0.17 unknown 0.03

Uranium (U) mg/l 0.2 unknown unknown <0.2 <0.2 unknown 0

Quantitative Data

Analytical Data - BPD (unconditioned)

Evidence No. CKD_38

Country of Origin UK

Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

No. of

samples

analysed

Minimum Conc. Maximum Conc. Mean Conc. Median Conc. 95%ile Std Dev Conc. RangeGeneral comment about variability within dataset if

more than one sample result is identified


Antimony (Sb) mg/kg various 44 0.8 10 5.4 3.75 10 3.7 -

Arsenic (As) mg/kg various 57 0.6 19 7.8 7.8 12.2 3.3 18.4

Beryllium (Be) mg/kg <1 1 <1 - - - -

Boron (B) mg/kg various 1 0.9 - - - -

Cadmium (Cd) mg/kg various 57 0.9 78 17.8 12 44.2 14.6 77.1

Chromium (Cr) mg/kg various 37 14 40 28.5 26 40 7.6 26

Hex Chromium mg/kg various 21 0.4 31 16.4 18 26 8.1 30.6

Cobalt (Co) mg/kg various 56 0.4 25 6.6 5.55 12.5 4.8 24.6

Copper (Cu) mg/kg various 57 10 1200 258.4 195 592 212.1 1190

Gadolinium mg/kg various 2 6 121 - - 115

Gallium mg/kg various 2 7 81 - - 74

Germanium mg/kg various 1 49 49 - - 0

Gold mg/kg various 2 5 25 - - 20

Lanthanum mg/kg various 1 25 25 - - 0

Lead (Pb) mg/kg various 57 25 19000 1345.5 775 4700 1731.0 18975

Lithium mg/kg various 1 12 - - - -

Mercury (Hg) mg/kg various 57 <0.06 41 3.0 0.23 10 4.5 -

Manganese (Mn) mg/kg various 56 18 445 227.5 210 440 123.1 427

Nickel (Ni) mg/kg various 57 2 35 16.8 17 30 8.2 33

Niobium mg/kg various 2 24 106 - - 82

Rubidium mg/kg various 2 10 >250 - - > 240

Selenium (Se) mg/kg various 1 5.2 - - - -

Silicon mg/kg various 2 >250 - - - -

Silver (Ag) mg/kg various 2 3 5 - - 2

Vanadium (V) mg/kg various 57 12 870 56.2 29 45.2 144.9 858

Zinc (Zn) mg/kg various 57 1.9 690 219.4 220 555 165.1 688.1

Zirconium mg/kg various 2 23 53 - - 30

Tellurium mg/kg various 2 5 52 - - 47

Thorium mg/kg various 2 14 >250 - - -

Thallium (Tl) mg/kg various 56 <10 7200 19.5 10.5 49.75 20.1 >7190

Tin (Sn) mg/kg various 16 <10 - - - -

Inorganics

pH pH unit various 22 12.4 12.8 12.6 12.6 12.8 0.1 0.4

Bromide (Br) % various 3 0.4 8.03 - - 7.63

Chloride (Cl) % various 33 1.81 13.26 5.0 4.6 9.7 2.5 11.45

Fluoride (F) % various 3 <0.01 0.06 - - > 0.05

Iodide (acid soluble) % various 3 <0.01 0.04 - - > 0.03

Electrical conductivity uS/cm various 2 2100 2400 - - 300

TOC % various 1 0.76 - - - -

Sulphate mg/kg mg/kg various 21 25000 100000 65955.0 64800.0 97150.0 19675.5 75000

Loss On Ignition % various 35 <0.39 16.11 8.0 7.8 13.2 3.0 > 15.72

SiO2

not specified

(assume %) not specified 30 12.91 16.08 14.77 14.8 15.7 0.7 3.17

Al2O3

not specified


Fe2O3

not specified


CaO

not specified


2006-2014

numerous UK based

Mercury concentrations are generally <1 mg/kg, with the

exception of one sample which recorded a concentration

of 41 mg/kg. Based on the large dataset provided this

appears to be an isolated occurrance.

Results for lead vary signficantly between facility and

generally to a lesser degree between samples from

individual facilities. This is considered likely to be due to

differences in input materials used.

Two very high concentrations of thallium have been

reported at one facility. Concentrations of thallium in

other samples from this facility and from other facilities

are substantially lower. This is therefore a possible unit

reporting error.

Generally the I-TEQ for dioxins is low, although there are

occasional noticable spikes in concentrations at several

facilities.

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

No. of

samples

analysed



MgO

not specified


K2O

not specified


Na2O

not specified


SO3

not specified


Na2O eq.

not specified


Organics

Total petroleum hydrocarbons mg/kg <10 1 <10 - - - -

Total PAHs mg/kg <1 3 <1 2.7 - - > 1.7

EH >C6 - C8 mg/kg <1 2 32 410 - - 378

EH >C8 - C10 mg/kg <1 2 16 160 - - 144

EH >C10 - C12 mg/kg <1 2 <0.1 12 - - >11

EH >C12 - C16 mg/kg <1 2 <0.1 - - - -

EH >C16 - C21 mg/kg <5 2 <5 - - - -

EH >C21 - C40 mg/kg <10 2 <10 - - - -

EH >C6 - C40 mg/kg <10 2 47 590 - - 543

Acenaphthene mg/kg <0.1 3 <0.1 - - - -

Acenaphthylene mg/kg <0.1 3 <0.1 - - - -

Anthracene mg/kg <0.1 3 <0.1 0.043 - - -

Benzo(a)anthracene mg/kg <0.1 3 <0.1 0.11 - - -

Benzo(b)fluoranthene mg/kg <0.1 3 <0.1 0.15 - - -

Benzo(k)fluoranthene mg/kg <0.1 3 <0.1 0.033 - - -

Benzo(a)pyrene mg/kg <0.1 3 <0.1 0.049 - - -

Benzo(ghi)perylene mg/kg <0.1 2 <0.1 - - - -

Chrysene mg/kg <0.1 3 <0.1 0.086 - - -

Coronene mg/kg <0.1 2 <0.1 - - - -

Dibenzo(a,h)anthracene mg/kg <0.1 2 <0.1 - - - -

Fluoranthene mg/kg <0.1 3 <0.1 0.94 - - -

Fluorene mg/kg <0.1 3 <0.1 0 - - -

Indeno(1,2,3-cd)pyrene mg/kg <0.1 3 <0.1 0 - - -

Naphthalene mg/kg <0.1 3 <0.1 0 - - -

Phenanthrene mg/kg <0.1 3 <0.1 0.65 - - -

Phenol mg/kg <0.1 1 <0.1 - - - -

Pyrene mg/kg <0.1 3 <0.1 0.59 - - -

VOCs 0

Benzene mg/kg <0.1 2 <0.1 - - - -

Ethylbenzene mg/kg <0.1 1 <0.1 - - - -

o-Xylene mg/kg <0.1 2 <0.1 - - - -

p/m-Xylene mg/kg <0.1 2 <0.2 - - - -

Toluene mg/kg <0.1 1 <0.1 - - - -


Dioxin I-TEQ ng/kg various 51 0.004 67.000 6.151 0.940 20.250 11.338 66.996

Dioxin WHO Human/mammals ng/kg various 30 0.004 20.963 2.731 0.795 14.012 5.231 20.958

Dioxin WHO Birds ng/kg various 29 0.004 42.094 5.480 0.840 33.517 11.708 42.090

Dioxin WHO Fish ng/kg various 29 0.004 21.995 3.039 0.860 16.191 5.835 21.991

Total Dioxins ng/kg various 3 720.000 1300.000 - - 580.000

2,3,7,8TCDF ng/kg various 21 <0.025 11.067 1.758 0.088 10.869 3.805 -

2,3,7,8TCDD ng/kg various 21 <0.025 0.141 0.049 0.044 0.108 0.039 -

1,2,3,7,8-PeCDF ng/kg various 21 <0.033 10.866 0.765 0.124 2.063 2.535 -

2,3,4,7,8-PeCDF ng/kg various 21 <0.047 18.004 3.241 0.240 15.946 5.925 -

1,2,3,7,8-PeCDD ng/kg various 21 <0.040 6.600 0.645 0.126 3.212 1.583 -

1,2,3,4,7,8-HxCDF ng/kg various 21 <0.022 16.136 3.175 0.555 15.159 5.006 -




1,2,3,4,7,8-HxCDD ng/kg various 21 <0.051 3.467 0.368 0.163 1.001 0.813 -



DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

No. of

samples

analysed



1,2,3,4,6,7,8-HpCDF ng/kg various 21 <0.053 109.556 13.155 0.151 69.776 27.946 -

1,2,3,4,7,8,9-HpCDF ng/kg various 21 <0.072 26.495 2.599 0.162 14.130 6.494 -

1,2,3,4,6,7,8-HpCDD ng/kg various 21 <0.059 126.897 14.836 1.395 52.341 30.337 -

OCDF ng/kg various 21 <0.021 127.516 17.429 0.437 110.540 36.370 -

OCDD ng/kg various 21 <0.038 380.537 39.213 3.100 145.243 89.472 -

PCBs

TEQ-Humans 2005 ug/kg various 7 0.000001655 0.001162855 - - 0.0011612

PCB-77 ug/kg various 8 0.01276 0.01305 - - 0.00029

PCB-167 ug/kg various 8 0.00133 0.00324 - - 0.00191

PCB-169 ug/kg various 8 <0.0001 0.00768 - - -

PCB-170 ug/kg various 3 <0.00008 - - - -

PCB-189 ug/kg various 8 <0.00002 - - - -

PCB-81 ug/kg various 8 <0.000010 0.00638 - - -

PCB-105 ug/kg various 8 <0.00001 0.01071 - - -

PCB-114 ug/kg various 8 <0.00003 - - - -

PCB-118 ug/kg various 10 <0.000030 0.01262 0.302328 0.000365 1.55 0.67 -

PCB-123 ug/kg various 8 <0.00005 - - - -

PCB-126 ug/kg various 8 <0.00005 0.0093 - - -

PCB-156 ug/kg various 8 <0.00002 0.00408 - - -

PCB-157 ug/kg various 8 <0.00002 - - - -

PCB-101 ug/kg various 2 <1 - - - -



PCB-180 ug/kg various 5 <0.0002 - - - -



Other

Free Lime (Ca(OH)2 % not specified 76 6.9 33 20.64 20.91 29.13 5.97 26.1

Halides % not specified 17 5 27.03 16.84 17.70 25.04 5.66 22.03

Statistics are only presented for those determinands with a minimum of 10 samples. Where concentrations are reported as less than the detection limit, the detection limit has been assumed as the concentration for the statistical assessment

Isolated peak concentrations for mercury and lead have not been considered in the statistics. The two measurments of thallium which appear to have been reported incorrectly are also excluded from the statistical assessment

Quantitative Data

Analytical Data - BPD (unconditioned) Leachate 2:1

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Conc.Maximum Conc. Mean Conc. Conc. Range

General comment about variability within

dataset if more than one sample result is

identified


Antimony (Sb) mg/l <0.006 - 5 <0.006 0.017 0.017 -

Arsenic (As) mg/l <0.005 - 5 <0.005 0.089 0.062 -

Barium (Ba) mg/l - - 5 1.3 8.6 3.960 7.3

Cadmium (Cd) mg/l <0.0001 - 5 <0.0001 0.0016 0.001 -

Chromium (Cr) mg/l - - 5 0.097 1.1 0.399 1.003

Copper (Cu) mg/l <0.01 - 5 <0.01 0.029 0.017 -

Lead (Pb) mg/l - - 5 0.036 1.5 0.455 1.464

Mercury (Hg) mg/l <0.0005 - 5 <0.0005 - - -

Molybdenum (Mo) mg/l - - 5 0.073 0.3 0.201 0.227

Nickel (Ni) mg/l <0.02 - 5 <0.02 - - -

Selenium (Se) mg/l - - 4 1.3 3.3 2.500 2

Zinc (Zn) mg/l <0.025 - 5 <0.025 0.37 0.243 -

Inorganics

pH pH units - - 2 12.74 12.87 12.805 0.13

Chloride (Cl) mg/l - - 5 7120 22000 13476 14880

Fluoride (F) mg/l - - 5 0.8 1.7 1.22 0.9

Electrical conductivity uS/cm - - 2 9150 48700 28925 39550

Dissolved organic carbon mg/l - - 5 7.2 27 17.36 19.8

Sulphate mg/l - - 5 32.1 5200 2110.34 5167.9

Total Dissolved Solids mg/l - - 5 19200 53000 37380 33800

Organics

Phenol index mg/l <0.15 - 4 <0.15 - - -

2006-2014

UK based

Generally a higher variation in concentrations is

evident for barium, chromium and lead than other

metals.

High leaching potential for chloride and sulphate

identified in all samples, although again the

concentrations have a high variability.

Analytical Data - BPD (conditioned) Leachate 2:1

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum




identified


Antimony (Sb) mg/l <0.006 - 2 <0.006 - - -

Arsenic (As) mg/l <0.005 - 2 0.031 0.079 0.055 0.048

Barium (Ba) mg/l - - 2 1.7 2.2 1.950 0.5

Cadmium (Cd) mg/l <0.0001 - 2 0.001 0.001 0.001 0

Chromium (Cr) mg/l - - 2 1.6 1.8 1.700 0.2

Copper (Cu) mg/l <0.01 - 2 0.016 0.022 0.019 0.006

Lead (Pb) mg/l - - 2 0.16 0.7 0.430 0.54

Mercury (Hg) mg/l <0.0005 - 2 <0.0005 0.00081 0.001 -


Nickel (Ni) mg/l <0.02 - 2 <0.02 - - -

Selenium (Se) mg/l - - 1 4.9 - 4.900 -

Zinc (Zn) mg/l <0.025 - 2 0.34 0.47 0.405 0.13

Inorganics

pH pH units - - 1 12.79 - - -

Chloride (Cl) mg/l - - 2 18600 21300 19950 2700

Fluoride (F) mg/l - - 2 1 1.1 1.05 0.1

Electrical conductivity uS/cm - - 1 83700 - - -

Dissolved organic carbon mg/l - - 2 10.2 15.4 12.8 5.2

Sulphate mg/l - - 2 4370 4830 4600 460


Organics

Phenol index mg/l <0.15 - 1 <1.5 - - -

UK based

2006-2014

No comment on variability due to small sample size

Analytical Data - BPD (unconditioned) Leachate 8:1

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum




identified


Antimony (Sb) mg/l <0.006 - 5 <0.006 0.007 0.007 -

Arsenic (As) mg/l <0.005 - 5 <0.005 0.023 0.014333333 -

Barium (Ba) mg/l - - 5 0.3 3 1.49 2.7

Cadmium (Cd) mg/l <0.0001 - 5 <0.0001 - - -

Chromium (Cr) mg/l - - 5 0.022 0.45 0.1258 0.428

Copper (Cu) mg/l <0.01 - 5 <0.01 0.017 0.017 -

Lead (Pb) mg/l - - 5 0.13 0.75 0.356 0.62

Mercury (Hg) mg/l <0.0005 - 5 <0.0005 - - -


Nickel (Ni) mg/l <0.02 - 5 <0.02 - - -

Selenium (Se) mg/l - - 4 0.19 0.49 0.2825 0.3

Zinc (Zn) mg/l <0.025 - 5 <0.025 0.094 0.077333333 -

Inorganics

pH pH units - - 2 12.36 12.7 12.53 0.34

Chloride (Cl) mg/l - - 5 880 3460 1888 2580

Fluoride (F) mg/l - - 5 0.7 1 0.82 0.3

Electrical conductivity uS/cm - - 2 1692 2070 1881 378


Sulphate mg/l <1 - 5 <1 1630 980.625 -


Organics

Phenol index mg/l <0.15 - 5 <1.5 - - -

2006-2014

UK based

As above for 2:1 dilution.

Analytical Data - BPD (conditioned) Leachate 8:1

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum




identified


Antimony (Sb) mg/l <0.006 - 2 <0.006 0.006 0.006 -

Arsenic (As) mg/l <0.005 - 2 <0.005 0.008 0.008 -

Barium (Ba) mg/l - - 2 0.93 2.9 1.915 1.97

Cadmium (Cd) mg/l <0.0001 - 2 <0.0001 - - -

Chromium (Cr) mg/l - - 2 0.045 0.23 0.1375 0.185

Copper (Cu) mg/l <0.01 - 2 <0.01 0.016 0.016 -

Lead (Pb) mg/l - - 2 0.13 0.47 0.3 0.34

Mercury (Hg) mg/l <0.0005 - 2 <0.0005 - - -


Nickel (Ni) mg/l <0.02 - 2 <0.02 - - -

Selenium (Se) mg/l - - 1 0.18 0.18 0.18 0

Zinc (Zn) mg/l <0.025 - 2 <0.025 - - -

Inorganics

pH pH units - - 1 12.76 - - -

Chloride (Cl) mg/l - - 2 1110 1280 1195 170

Fluoride (F) mg/l - - 2 0.8 0.9 0.85 0.1

Electrical conductivity uS/cm - - 1 14080 - - -


Sulphate mg/l - - 2 34.5 366 200.25 331.5


Organics

Phenol index mg/l <0.15 - 2 <0.15 - - -

No statistical assessment has been undertaken due to an insufficient number of samples

No comment on variability due to small sample size

2006-2014

UK based

Quantitative Data

Analytical Data - CKD (unconditioned)

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum


General comment about variability within dataset if


Potentially Toxic Elements (PTEs) No comment on variability due to small sample size

Aluminium (Al) mg/kg various No 2 >250 - - -

Antimony (Sb) mg/kg various No 2 10 18 - 8

Arsenic (As) mg/kg various No 2 4 9 - 5

Barium (Ba) mg/kg various No 2 158 250 - 92

Bismuth mg/kg various No 2 26 32 - 6

Cadmium (Cd) mg/kg various No 2 5 28 - 23

Calcium (Ca) mg/kg various No 2 >250 - - -

Cerium mg/kg various No 2 23 33 - 10

Chromium (Cr) mg/kg various No 2 84 104 - 20

Copper (Cu) mg/kg various No 2 39 140 - 101

Gadolinium mg/kg various No 2 4 6 - 2

Gallium mg/kg various No 2 6 7 - 1

Germanium mg/kg various No 2 32 49 - 17

Gold mg/kg various No 2 4 5 - 1

Iron (Fe) mg/kg various No 2 >250 - - -

Lanthanum mg/kg various No 2 18 25 - 7

Lead (Pb) mg/kg various No 2 >250 - - -

Lithium mg/kg various No 2 12 57 - 45

Magnesium (Mg) mg/kg various No 2 >250 - - -

Manganese (Mn) mg/kg various No 2 >250 - - -

Molybdenum (Mo) mg/kg various No 2 8 12 - 4

Nickel (Ni) mg/kg various No 2 146 192 - 46

Niobium mg/kg various No 2 80 106 - 26

Rubidium mg/kg various No 2 >250 - - -

Silicon mg/kg various No 2 >250 - - -

Silver (Ag) mg/kg various No 2 3 4 - 1

Zinc (Zn) mg/kg various No 2 >250 - - -

Zirconium mg/kg various No 2 36 53 - 17

Tellurium mg/kg various No 2 4 5 - 1

Thorium mg/kg various No 2 9 14 - 5

Thallium (Tl) mg/kg various No 1 18 - - -

Tin (Sn) mg/kg various No 2 25 28 - 3

Titanium mg/kg various No 2 >250 - - -

Inorganics

pH pH units - - 1 12.8 - - -

Potassium (K) mg/kg - - 2 >250 - - -

Phosphorus (P) mg/kg - - 2 >250 - - -

TOC % <0.02 - 1 0.25 - - -

Sulphur mg/kg - - 2 >250 - - -

Loss On Ignition % <0.2 - 1 4.1 - - -

Organics

Total petroleum hydrocarbons mg/kg <10 - 1 7060 - - -

Mineral oils mg/kg <10 - 1 137 - - -

2009 & 2013

UK based

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum




BTEX mg/kg <0.06 - 1 <0.06 - - -

Total PAHs mg/kg <1.28 - 1 <1.28 - - -

TPH >C10 - C40 mg/kg <10 - 1 126 - - -

Acenaphthene mg/kg <0.08 UKAS 1 <0.08 - - -

Acenaphthylene mg/kg <0.08 UKAS 1 <0.08 - - -

Anthracene mg/kg <0.08 UKAS 1 <0.08 - - -

Benzo(a)anthracene mg/kg <0.08 UKAS 1 <0.08 - - -

Benzo(b)fluoranthene mg/kg <0.08 UKAS 1 <0.08 - - -

Benzo(k)fluoranthene mg/kg <0.08 UKAS 1 <0.08 - - -

Benzo(a)pyrene mg/kg <0.08 UKAS 1 <0.08 - - -

Benzo(ghi)perylene mg/kg <0.08 UKAS 1 <0.08 - - -

Chrysene mg/kg <0.08 UKAS 1 <0.08 - - -

Coronene mg/kg <0.08 UKAS 1 <0.08 - - -

Dibenzo(a,h)anthracene mg/kg <0.08 UKAS 1 <0.08 - - -

Fluoranthene mg/kg <0.08 UKAS 1 <0.08 - - -

Fluorene mg/kg <0.08 UKAS 1 <0.08 - - -

Indeno(1,2,3-cd)pyrene mg/kg <0.08 UKAS 1 <0.08 - - -

Naphthalene mg/kg <0.08 UKAS 1 <0.08 - - -

Phenanthrene mg/kg <0.08 UKAS 1 <0.08 - - -

Pyrene mg/kg <0.08 UKAS 1 <0.08 - - -

VOCs

Benzene ug/kg <10 - 1 <10 - - -

Hexachlorobutadiene ug/kg <10 - 1 <10 - - -

Methyl Tertiary Butyl Ether ug/kg <10 - 1 <20 - - -

o-Xylene ug/kg <10 - 1 <10 - - -

p/m-Xylene ug/kg <10 - 1 <20 - - -

Toluene ug/kg <10 - 1 <10 - - -

PCBs

Total PCBs ug/kg <0.035 - 1 <0.035 - - -

PCB-118 ug/kg <5 - 1 <5 - - -

PCB-101 ug/kg <5 - 1 <5 - - -

PCB-138 ug/kg <5 - 1 <5 - - -

PCB-153 ug/kg <5 - 1 <5 - - -

PCB-180 ug/kg <5 - 1 <5 - - -

PCB-28 ug/kg <5 - 1 <5 - - -

PCB-52 ug/kg <5 - 1 <5 - - -

Other

Free Lime (Ca(OH)2 % - - 2 2.43 4.7 3.565 2.27


Quantitative Data

Analytical Data - CKD Leachate (Method: prEN12457-1) - assumed as unconditioned

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Conc.

Maximum

Conc.Mean Conc. Conc. Range




Antimony (Sb) mg/l Not specified Not specified 4 0.001 0.001 0.001 0

Arsenic (As) mg/l Not specified Not specified 4 0.003 0.006 0.0045 0.003

Barium (Ba) mg/l Not specified Not specified 4 0.207 0.454 0.32275 0.247

Cadmium (Cd) mg/l Not specified Not specified 4 0.0032 0.01 0.0064 0.0068

Chromium (Cr) mg/l Not specified Not specified 4 1.23 2.26 1.6575 1.03

Copper (Cu) mg/l Not specified Not specified 4 0.013 0.08 0.041 0.067

Lead (Pb) mg/l Not specified Not specified 4 0.0913 2.62 1.231325 2.5287

Mercury (Hg) mg/l Not specified Not specified 4 0.0002 0.0002 0.0002 0

Molybdenum (Mo) mg/l Not specified Not specified 4 1.22 4.1 2.5825 2.88

Nickel (Ni) mg/l Not specified Not specified 4 0.0246 0.0319 0.028125 0.0073

Selenium (Se) mg/l Not specified Not specified 4 0.214 1.15 0.55925 0.936

Zinc (Zn) mg/l Not specified Not specified 4 0.303 1.23 0.81375 0.927

Inorganics

pH ph units Not specified Not specified 4 13.2 13.3 13.275 0

Chloride (Cl) mg/l Not specified Not specified 4 273 2740 1067 2

Fluoride (F) mg/l Not specified Not specified 4 2.6 4.8 3.625 3

Electrical conductivity uS/cm Not specified Not specified 4 33400 62200 44625 6

Eh mV Not specified Not specified 4 -109 -87 -97.5 7

TOC mg/l C Not specified Not specified 4 2.19 9.32 5.1925 8

Sulphate mg/l Not specified Not specified 4 7100 17500 12755 11

Total Dissolved Solids - Not specified Not specified 0 - - - -

Results are fairly comparable, with higher variations

noted for molybdenum and lead.

No obvious difference in results between cyclone and

precipitation dusts, although this is based on only two

samples of each. The exception to this is sulphate, with

signficantly higher concentrations evident in leachate

from precipitation dusts.

2002

UK based

Analytical Data - CKD Leachate (Method: prEN12457-2) - assumed as unconditioned

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Conc.

Maximum






Arsenic (As) mg/l Not specified Not specified 4 0.0015 0.0015 0.0015 0






Mercury (Hg) mg/l Not specified Not specified 4 0.0001 0.0001 0.0001 0





Inorganics

pH ph units Not specified Not specified 4 12.8 13 12.925 0

Chloride (Cl) mg/l Not specified Not specified 4 64.8 527 222.2 2




TOC mg/l C Not specified Not specified 4 1 6.34 3.7375 8

Sulphate mg/l Not specified Not specified 4 1900 6210 4077.5 11


UK based

2002

Analytical Data - CKD Leachate (Method: prEN12457-3 L/S = 2) - assumed as unconditioned

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Conc.

Maximum






Arsenic (As) mg/l Not specified Not specified 4 0.002 0.003 0.00275 0.001






Mercury (Hg) mg/l Not specified Not specified 4 0.0001 0.0002 0.0001425 0.0001





Inorganics

pH ph units Not specified Not specified 4 13 13.1 13.025 0

Chloride (Cl) mg/l Not specified Not specified 4 281 2760 1082.75 2

Fluoride (F) mg/l Not specified Not specified 4 3.1 8 5.45 3


Eh mV Not specified Not specified 4 -109 -90 -101 7


Sulphate mg/l Not specified Not specified 4 6220 17400 11972.5 11


2002

UK based

Analytical Data - CKD Leachate (Method: prEN12457-3 L/S = 2-10) - assumed as unconditioned

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Conc.

Maximum






Arsenic (As) mg/l Not specified Not specified 4 0.0015 0.0015 0.0015 0






Mercury (Hg) mg/l Not specified Not specified 4 0.0001 0.00016 0.000115 0.00006





Inorganics

pH ph units Not specified Not specified 4 12.8 13 12.9 0

Chloride (Cl) mg/l Not specified Not specified 4 34.6 315 139.275 2





Sulphate mg/l Not specified Not specified 4 1400 5010 3150 11


2002

UK based

Analytical Data - CKD Leachate WAC 2:1 Dilution - assumed as unconditioned

Evidence No. CKD_38


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Conc.

Maximum





Antimony (Sb) mg/l Not specified UKAS 1 0.002 - - - No comment on variability due to small sample size

Arsenic (As) mg/l Not specified UKAS 1 0.389 - - -

Barium (Ba) mg/l Not specified UKAS 1 0.46 - - -

Cadmium (Cd) mg/l Not specified UKAS 1 0.0021 - - -

Chromium (Cr) mg/l Not specified UKAS 1 1.07 - - -

Copper (Cu) mg/l Not specified UKAS 1 0.046 - - -

Lead (Pb) mg/l Not specified UKAS 1 2.574 - - -

Mercury (Hg) mg/l Not specified UKAS 1 0.0006 - - -

Molybdenum (Mo) mg/l Not specified UKAS 1 0.517 - - -

Nickel (Ni) mg/l Not specified UKAS 1 0.036 - - -

Selenium (Se) mg/l Not specified UKAS 1 2.143 - - -

Zinc (Zn) mg/l Not specified UKAS 1 0.194 - - -

Inorganics

pH ph units Not specified UKAS 1 12.9 - - -

Chloride (Cl) mg/l Not specified UKAS 1 9560 - - -

Fluoride (F) mg/l Not specified UKAS 1 1.2 - - -

Electrical conductivity uS/cm Not specified UKAS 1 64400 - - -

Eh mV Not specified UKAS - - - - -

Dissolved organic carbon mg/l Not specified No 1 9.7 - - -

Sulphate mg/l Not specified UKAS 1 9530 - - -

Total Dissolved Solids - Not specified No 1 - - - -


2013

UK based

Quantitative Data

Analytical Data - BPD (Conditioned)

Evidence No. CKD_28


Analysis Date(s)

Laboratory

DeterminandNo. of samples

analysed

Unit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum




identified


Arsenic (As) 4 mg/kg <3 Not specified 4 <3 10.3 - -

Cadmium (Cd) 6 mg/kg - Not specified 6 4.35 51.2 - 46.85

Calcium (Ca) 7 mg/kg - Not specified 7 136104 349585 - 213481

Chromium (Cr) 6 mg/kg - Not specified 6 13 326 - 313

Copper (Cu) 7 mg/kg - Not specified 7 119 384 - 265

Lead (Pb) 6 mg/kg - Not specified 6 271 4626 - 4355

Mercury (Hg) 6 mg/kg <0.05 Not specified 6 <0.05 0.442 - -

Magnesium (Mg) 7 mg/kg - Not specified 7 2370 13642 - 11272

Molybdenum (Mo) 4 mg/kg - Not specified 4 2.93 4.95 - 2.02

Nickel (Ni) 6 mg/kg - Not specified 6 5.04 26.2 - 21.16

Selenium (Se) 4 mg/kg - Not specified 4 96.1 543 - 446.9

Zinc (Zn) 7 mg/kg - Not specified 7 55.6 526 - 470.4

Inorganics

pH 7 pH units - Not specified 7 7.64 12.8 - 5.16

Sodium (Na) 7 mg/kg - Not specified 7 4253 20050 - 15797

Fluoride (F) 4 mg/kg - Not specified 4 51.9 1351 - 1299.1

Potassium (K) 7 mg/kg - Not specified 7 59667 245000 - 185333

Phosphorus (P) 7 mg/kg - Not specified 7 208 1043 - 835

Nitrogen (N)w/w 7 % <0.01 Not specified 7 <0.01 0.13 - -

Electrical conductivity 7 uS/cm - Not specified 7 7550 1000500 - 992950

TOC 4 % - Not specified 4 1.48 7.14 - 5.66

Ammoniacal nitrogen 7 mg/kg <10 Not specified 7 <10 102 - -

Biological oxygen demand (BOD) 4 mg/l <2 Not specified 4 <2 580 - -

Sulphur 7 mg/kg - Not specified 7 9219 86500 - 77281

Nitrate as NO3 3 mg/kg <10 Not specified 3 <10 19 - -

Loss On Ignition 4 % - Not specified 4 0.1 2.11 - 2.01

Other

Free Lime (Ca(OH)2 4 % - Not specified 4 13.1 66.6 - -


2014

UK based

Results show less variation in metal concentrations

that is evident from the unconditioned waste data,

particularly with respect to lead. However, it

should be noted that this is based on a very limited

dataset.

Quantitative Data

Analytical Data - BPD (assumed to be unconditioned)

Evidence No. CKD_40


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum

Conc.

Maximum

Conc.Mean Conc. Median Conc. 95%ile Std Dev Conc. Range



identified


Antimony (Sb) mg/kg Various Not specified 23 <10 10 10.00 10.00 10.00 0.00 -

Arsenic (As) mg/kg Various Not specified 37 <10 17 9.91 10.00 11.00 1.82 -

Cadmium (Cd) mg/kg Various Not specified 37 <5 45 14.88 10.00 41.00 10.69 -

Chromium (Cr) mg/kg Various Not specified 37 16 110 37.05 30.00 110.00 23.19 94

Cobalt (Co) mg/kg Various Not specified 37 1.4 125 17.31 10.00 44.00 26.17 123.6

Copper (Cu) mg/kg Various Not specified 37 10 550 170.43 135.00 426.00 134.88 540

Lead (Pb) mg/kg Various Not specified 37 25 3985 896.89 475.00 3464.00 1149.13 3960

Mercury (Hg) mg/kg <0.06 Not specified 32 <0.06 0.25 7.52 10.00 10.00 4.36 -

Manganese (Mn) mg/kg Various Not specified 37 120 465 320.68 360.00 455.00 116.73 345

Nickel (Ni) mg/kg Various Not specified 37 8.8 55 24.42 22.00 55.00 12.31 46.2

Vanadium (V) mg/kg Various Not specified 37 22 50 36.73 35.00 45.00 7.27 28

Zinc (Zn) mg/kg Various Not specified 32 50 555 273.34 262.50 555.00 147.82 505

Thallium (Tl) mg/kg Various Not specified 11 60 130 48.18 10.00 117.50 47.45 70

Tin (Sn) mg/kg Various Not specified 18 <10 - - 10.00 10.00 0.00 -

Titanium mg/kg Various Not specified 26 5.3 120 16.08 10.00 41.50 22.66 114.7

Inorganics

pH pH units Various Not specified 9 12.5 12.7 12.56 - - - 0.2

Bromide (Br) % Various Not specified 5 0.42 0.83 0.66 - - - 0.41

Chloride (Cl) % Various Not specified 13 2.73 32.4 11.67 4.09 27.60 10.86 29.67

Fluoride (F) % Various Not specified 5 0.14 0.17 0.15 - - - 0.03

Iodide (acid soluble) % Various Not specified 5 <0.01 - - - - - -

Total Br, I & F % Various Not specified 5 0.58 0.98 0.82 - - - 0.4

Total S, Cl, Br, I & F % Various Not specified 5 21.69 34.18 26.30 - - - 12.49

Sulphur % Various Not specified 5 0.8 1.35 1.06 - - - 0.55

Sulphates % Various Not specified 8 4.5 8.92 6.24 - - - 4.42

Loss On Ignition % Various Not specified 18 3.2 16.11 11.18 12.14 15.76 3.81 12.91

Na2O Various Not specified 8 2.61 3.65 3.05 - - - 1.04


Dioxin I-TEQ ng/kg Various Not specified 31 0.077 67 3.34 0.50 10.43 12.40 66.923

Dioxin WHO Human/mammals ng/kg Various Not specified 31 0.077 66 3.12 0.40 9.95 12.26 65.923

Dioxin WHO Birds ng/kg Various Not specified 31 0.062 170 6.57 0.41 9.45 31.00 169.938

Dioxin WHO Fish ng/kg Various Not specified 31 0.062 64 3.62 0.39 17.91 12.70 63.938

Dioxins & Furans

WHO TEQ ng/kg Various Not specified 5 10.3 13.9 11.66 - - - 3.6

Dioxins & Furans

I TEQ ng/kg Various Not specified 5 10.1 13.5 12.08 - - - 3.4

Other

Free Lime (Ca(OH)2 % % Various Not specified 30 9.1 52.83 24.99 22.95 49.21 12.60 43.73

Halides (%) % Various Not specified 4 5 18.7 13.30 - - - 13.7

Sulphates % % Various Not specified 4 4.7 5.4 5.13 - - - 0.7

Total Metals mg/kg Various Not specified 4 <1418.3 1648.1 1648.10 - - - -

Statistics are only presented for those determinands with a minimum of 10 samples. Where concentrations are reported as less than the detection limit, the detection limit has been assumed as the concentration for the statistical assessment

2008

Not specified

High variations in concentrations of lead

observed between facilities and individual

samples.

High concentrations of thallium have been

reported from one facility, with all other

samples recording a concentration of less than

detection (<10 mg/kg).

Dioxin I-TEQ is fairly consistent across the

samples, with the exception of two samples

from one facility, which identified signficantly

higher concentrations. Two further samples

from this facility, however were within the

range identified in BPD at other facilities.

Quantitative Data

Analytical Data - CKD (assumed to be unconditioned)

Evidence No. CKD_40


Analysis Date(s)

Laboratory

DeterminandUnit of

measurement

Laboratory limit

of detection

(LoD)

Analysis

accreditation

No. of

samples

analysed

Minimum




identified


Arsenic (As) mg/kg not specified not specified 2 11 14 - 3

Chromium (Cr) mg/kg not specified not specified 2 45 50 - 5

Cobalt (Co) mg/kg not specified not specified 2 10 13 - 3

Copper (Cu) mg/kg not specified not specified 2 13 15 - 2

Lead (Pb) mg/kg not specified not specified 2 250 580 - 330

Manganese (Mn) mg/kg not specified not specified 2 850 910 - 60

Nickel (Ni) mg/kg not specified not specified 2 125 148 - 23

mg/kg not specified not specified 2 450 600 - 150

Other

Free Lime (Ca(OH)2 % % not specified not specified 2 6.2 7.8 - 1.6


2010

Not specified

No comment on variability due to small sample

size

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