Anaerobic Digestion Process Model Documentationjwlevis/AD.pdfAnaerobic Digestion Process Model...

Anaerobic Digestion Process Model Documentation

James W. Levis and Morton A. Barlaz

North Carolina State University

Raleigh, NC 27695‐7908

September 2013

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ContentsList of Acronyms ............................................................................................................................................ 4

1 Introduction .......................................................................................................................................... 5

2 Introduction to SWOLF ......................................................................................................................... 6

3 Introduction to Anaerobic Digestion .................................................................................................... 7

4 Material Flows ....................................................................................................................................... 8

5 Environmental Emissions .................................................................................................................... 11

5.1 Pretreatment and Material Handling .......................................................................................... 11

5.2 Biogas Production and Processing .............................................................................................. 11

5.3 Leachate Management ............................................................................................................... 14

5.4 Aerobic Curing ............................................................................................................................. 16

5.5 Land Application ......................................................................................................................... 16

6 Costs .................................................................................................................................................... 18

6.1 Capital Costs ................................................................................................................................ 18

6.2 Operating Costs ........................................................................................................................... 19

7 Default Life‐Cycle Inventory Results ................................................................................................... 21

References .................................................................................................................................................. 41

ListofFiguresFigure 1. Inputs and outputs for a generic waste treatment process model. Input masses and all outputs are specified per unit mass of each waste component. Model parameters are used to characterize the transformation of the incoming waste mass as well as the resulting emissions, fuel use, and costs. 1 Mg = 1 metric ton. .................................................................................................. 6

Figure 2. Generalized modeling framework showing how energy system modeling is connected to LCA models for a SWM system, and how the outputs of these models are then used as inputs into an optimizable LCA framework to systematically analyze future SWM. ........................................... 7

Figure 3. Mass flow diagram for AD process. Values are approximate for the default model values and are in kilograms. ............................................................................................................................... 10

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ListofTables

Table 1. Waste components considered in SWOLF and derived composition of inlet stream to anaerobic digestion. .................................................................................................................................. 9

Table 2. Material properties used in the LCA model. ................................................................................. 12

Table 3. Food waste methane yield values. ................................................................................................ 13

Table 4. Emission factors for flaring and energy generation (kg/m3 CH4).a ................................................ 14

Table 5. The allocation property and concentration for each emission type in the liquid digestate. The Allocation Property is the material property used to allocate each emission type to each waste material as explained in the text (Eq. 1 and 2). ............................................................................ 14

Table 6. Wastewater treatment plant removal efficiencies for each emission type.................................. 15

Table 7. Land application diesel fuel use inputs. ........................................................................................ 17

Table 8. Land application diesel fuel use inputs. ........................................................................................ 17

Table 9. Agricultural Nutrient Demands and Compost Requirements. ...................................................... 18

Table 10. Default data values used to determine capital costs of AD. ....................................................... 19

Table 11. Inputs values related to personnel costs. ................................................................................... 20

Table 12. Input values related to curing equipment costs. ........................................................................ 20

Table 13. Material flows associated with each component during AD (kg/Mg). ....................................... 22

Table 14. Electricity use and generation for each material (kWh/incoming Mg). ...................................... 23

Table 15. Diesel use for each material (L/incoming Mg). ........................................................................... 23

Table 16. Biogas generation from each material (m3/incoming wet Mg). ................................................. 24

Table 17. Biogas engine combustion emissions (kg/incoming Mg). ........................................................... 25

Table 18. Biogas flare combustion emissions (kg/incoming Mg). .............................................................. 26

Table 19. Leaked biogas emissions (kg/incoming Mg). ............................................................................... 27

Table 20. Emissions from WWTP (kg/incoming Mg)................................................................................... 28

Table 21. Emissions from aerobic curing (kg/incoming Mg). ...................................................................... 29

Table 22. Emissions after land application of compost (kg/incoming Mg). ................................................ 30

Table 23. Airborne offset emissions associated with avoided peat use (kg/Mg incoming). ...................... 31

Table 24. Waterborne offset emissions associated with avoided peat use (kg/Mg incoming). ................. 33

Table 25. Airborne offset emissions associated with avoided fertilizer use (kg/Mg incoming). ................ 35

Table 26. Waterborne offset emissions associated with avoided fertilizer use (kg/Mg incoming). .......... 37

Table 27. Capital costs associated with AD ($/Mgpy) ................................................................................. 39

Table 28. Operating costs from AD. (kg/Mg incoming). ............................................................................ 39

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ListofAcronyms

AD Anaerobic digestion

AF Allocation factor

AP Allocation property

BOD Biochemical oxygen demand

COD Chemical oxygen demand

EF Emission factor

GHG Greenhouse gas

HDPE High‐density polyethylene

LCA Life cycle assessment

LCI Life cycle inventory

MSW Municipal solid waste

OFMSW Organic fraction of municipal solid waste

PET Polyethylene terephthalate

SWM Solid waste management

SWOLF Solid Waste Optimization Life‐cycle Framework

TSS Total suspended solids

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1 Introduction

Proper management of solid waste is essential to minimize risks to human health and the environment.

Solid waste contains significant quantities of recoverable materials and can be used for energy recovery,

making solid waste management (SWM) a highly visible and potentially high‐impact target for enhancing

environmental sustainability. Greenhouse gas (GHG) mitigation policies that affect the U.S. energy mix

as well as the cost of energy and emissions could significantly alter the cost and strategic direction of

SWM. As such, SWM systems must proactively adapt to changing waste composition, policy

requirements, and an evolving energy system to cost‐effectively and sustainably manage solid waste.

An integrated analysis of the solid waste system requires an understanding of the environmental

performance of each process used to collect, separate, treat and ultimately dispose of municipal solid

waste (MSW). The foundation of such an analysis is a process model in which the cost, energy

consumption, and environmental emissions associated with a solid waste process are calculated as a

function of a number of model parameters that can be specified by the model user. A generic process

model is represented in Figure 1. Ultimately, a series of process models is linked together to build a life

cycle assessment (LCA) model for an entire solid waste system, by combining unit processes from waste

collection through treatment, final disposal and beneficial recovery of material.

The functional unit for each process model is 1 Mg (Mg = metric ton) of mixed waste arriving at the gate.

For each process model, default model parameters are provided, but can also be changed by the user.

Each process model calculates the masses of output waste materials, emissions, and fuel use, as well as

electricity use, capital costs, and operating costs based on the incoming waste composition and model

parameter values. Emission factors have been developed for the emissions associated with equipment

fuel use, transportation, chemical and biological transformations, and electricity use in each process.

Life cycle impact factors can then be used with the life‐cycle inventory (LCI) results to calculate

environmental impacts from the emissions (e.g., global warming potential, acidification potential, or

human toxicity).

This document is one of a series that describes the approach used to model each process in the solid

waste system. This document describes the data and modeling approach used to model anaerobic

digestion (AD).

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Figure 1. Inputs and outputs for a generic waste treatment process model. Input masses and all outputs are specified per unit mass of each waste component. Model parameters are used to characterize the transformation of the incoming waste mass as well as the resulting emissions, fuel use, and costs. 1 Mg

= 1 metric ton.

2 IntroductiontoSWOLF

The Solid Waste Optimization Life‐cycle Framework (SWOLF) was developed to perform analysis of SWM

as an integrated system. Given the complexity and heterogeneity of SWM systems, rigorous analysis of

system response under changing policies requires a modeling framework that links detailed process‐

level LCA models into an integrated SWM system and to the larger energy system. LCA is a framework

for estimating the environmental impacts associated with products, processes, or systems. SWM LCA

models estimate the environmental impacts of waste management processes and systems, and can

facilitate “what‐if” scenario analyses to quantify the environmental effects of incremental changes to

the integrated system. While these models are an essential foundation for systematic integrated

analysis of SWM systems, an integrated LCA‐based optimization framework is required to systematically

generate and analyze potential SWM strategies. Real‐world SWM strategies must adapt to population

Generic Process Model

Physically Separated Materials (e.g.,

recyclables, residuals) (Mgout/Mgin)

Direct Emissions (kg/Mgin)

Equipment Fuel Use (L/Mgin)

Electricity Use (kWh/Mgin)

Capital Cost ($/Mgin yr-1)

Operating Cost ($/ Mgin)

Incoming Waste Materials (Mgin)

Model Parameters

Biologically/Chemically Transformed Materials

(e.g., ash, compost) (Mgout/Mgin)

Stored Mass (Mgstored/Mgin)

Transportation Use (kg-km/Mgin)

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and policy changes as well as to changes to waste generation and composition, which necessitates the

use of a stage‐wise optimization framework.

A stage‐wise life‐cycle optimization framework should also be capable of considering changes to energy

infrastructure in response to evolving environmental policy and technological innovation that may affect

the performance of SWM. Since SWM infrastructure is often in operation for decades, it is essential that

integrated SWM models provide useful insights into how such changes may affect SWM. The

generalized modeling framework for this research is shown in Figure 2.

As shown in Figure 2, the foundation of this research is bottom‐up LCA models of SWM processes. The

purpose of this document is to describe the data and modeling approach used in the AD process model

to calculate life‐cycle costs and environmental emissions. SWOLF considers 40 waste materials that are

shown in Table 1. Each process model used in SWOLF reports costs and emissions coefficients for each

waste material. Allocating the costs and emissions to individual waste materials allows SWOLF to

optimize technology choices and mass flows of materials through the system.

Figure 2. Generalized modeling framework showing how energy system modeling is connected to LCA

models for a SWM system, and how the outputs of these models are then used as inputs into an optimizable LCA framework to systematically analyze future SWM.

3 IntroductiontoAnaerobicDigestion

An AD facility generates biogas via the anaerobic biodegradation of organic materials. AD facilities can

accept various waste materials that comprise the organic fraction of municipal solid waste (OFMSW)

usually through separate collection of these materials. Food and yard wastes are the most common

materials, but various types of paper can also be accepted. The inclusion of yard wastes is usually

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dependent on the history of separate yard waste collection and composting in the area considering AD.

In an AD facility, degradable materials are digested in a reactor in the absence of oxygen to produce

biogas that is between 50 and 70% CH4 (with the remainder mainly CO2). The biogas may either be

burned on‐site for electricity generation, or upgraded to vehicle fuel or pipeline quality natural gas. The

facility represented in this model produces electricity on site from the resulting biogas. The generated

electricity is used to power the AD facility, and excess energy is sold to the regional electrical grid. Most

of the default data is for a continuous single‐stage, wet, mesophilic digester. This is a typical

configuration for organic waste management, but various combinations of dry, two‐stage, and

thermophilic digesters are also used and can be modeled by changing input parameters.

4 MaterialFlows

The AD process model calculates emissions and costs for each of the waste components listed in Table

1, so the model can consider any potential incoming waste composition, but an assumed composition is

used to allocate costs and emissions to the individual materials. The AD facility has an assumed

composition based on the U.S. EPA municipal solid waste (MSW) generation estimates and estimates of

collection efficiencies for source‐separated organic wastes (U.S. EPA, 2013). Table 1 shows waste

composition as generated, the fraction of each waste component that is sent to AD, and the resulting

assumed composition for each of the waste materials. The majority of the incoming material is food and

yard wastes with smaller amounts of paper, and some residual inorganics that are contaminants. The

fraction of each waste component sent to AD can be adjusted by the user to reflect an overall level of

system contaminants.

Figure 3 shows the mass flow through the AD facility based on the assumed composition and default

parameters. The first processing step is screening and sorting with the purpose of removing non‐

degradable materials. The materials that are screened out are directed to a landfill or waste‐to‐energy

(WTE) combustion facility. The materials that pass through sorting are then then mixed with water to

achieve the reactor moisture content (92% by default). Materials degrade in the reactor to produce

biogas, and the resulting digestate is sent to dewatering. Some of the water produced during

dewatering is recycled and sent back to the mixer. The proportion of the water that can be recovered

depends on the concentration of salts and the final use of the digestate. The example mass flow diagram

limits the recovered water to 80% of the water added in the mixer. By default, the solids from

dewatering are aerobically cured in large windrows, but the user can choose to bypass curing and

directly apply the anaerobic digestate. The decision to cure the digestate will vary based on the location

of the facility (e.g., local odor concerns, proximity to horticulture) and the availability of markets for the

final product. During curing, wood chips and screen rejects are used as bulking agents to provide

structure and facilitate air flow through the pile. Aerobic curing produces off gases and compost. The off

gases are primarily water vapor and CO2, but trace amounts of CH4, NH3, N2O, and VOCs are also

present. After curing, the compost is screened and sold for use in horticulture, with screen rejects

recycled to make new windrows.

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Table 1. Waste components considered in SWOLF and derived composition of inlet stream to anaerobic digestion.

Percent Generated

Percent Collected

Percent Incoming to AD Facility

Yard Trimmings, Leaves 6.7 90 15.9 Yard Trimmings, Grass 5.0 90 12.0 Yard Trimmings, Branches 4.9 90 11.7 Food Waste ‐ Vegetable 13.9 90 33.0 Food Waste ‐ Non‐Vegetable 3.5 90 8.2 Wood 5.0 5 0.7 Textiles 4.4 5 0.6 Rubber/Leather 0.5 5 0.1 Newsprint 4.9 5 0.7 Corr. Cardboard 14.5 5 1.9 Office Paper 2.6 5 0.4 Magazines 0.8 5 0.1 3rd Class Mail 2.2 5 0.3 Folding Cartons 2.7 5 0.4 Bags and Sacks 0.5 20 0.3 Paper ‐ Non‐recyclable 7.3 20 3.9 HDPE ‐ Translucent Containers 0.4 20 0.2 HDPE ‐ Pigmented Containers 0.7 20 0.4 PET – Containers 1.3 20 0.7 Plastic Film 2.0 20 1.0 Plastic ‐ Non‐Recyclable 5.6 20 3.0 Ferrous Cans 1.2 5 0.2 Ferrous Metal ‐ Other 0.2 5 0.0 Aluminum Cans 0.7 5 0.1 Aluminum – Foil 0.2 20 0.1 Al ‐ Non‐recyclable 0.1 5 0.0 Glass 4.7 20 2.5 Misc. Inorganic 3.6 20 1.9

Totals

Yard waste 16.6 40 Food waste 17.3 41 Paper/fiber 35.5 8 Other 30.6 11

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Figure 3. Mass flow diagram for AD process. Values are approximate for the default model values and are in kilograms.

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5 EnvironmentalEmissions

The major sources of environmental emissions from the AD facility are electricity and diesel use, biogas

combustion, and emissions during curing and after land application. Environmental offsets are

generated from avoided electricity production as well as from avoided fertilizer and/or peat production

with the associated carbon storage.

5.1 PretreatmentandMaterialHandling

The model uses a single value for the electric house load associated with pre‐screening, mixing,

operating the reactor, and dewatering. The default value of 58 kWh/incoming Mg was developed by

Sanscartier et al. (2011) and is based on the wet, single‐stage, mesophilic Dufferin facility in Toronto.

The default pretreatment diesel use value of 0.3 L/Mg was developed from the same data and includes

rolling stock and material handling from the tipping floor through delivery to the curing tipping floor.

5.2 BiogasProductionandProcessing

Each material in the reactor will produce different amounts of methane based on its ultimate methane

yield and decay rate. Table 2 shows the moisture content, VS content, and methane yield for each waste

component.

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Table 2. Material properties used in the LCA model.

Moisture Contenta

(%ww) VS Contenta

(%TS) Degradable C Content (%TS)

Methane Yieldb

(m3/dry Mg)

Leaves 38.2c 90.2c 48.6 30.6Grass 82c 86.4c 57.8 136Branches 15.9 96.6 48.1 62.6Food Waste‐Veg. 77 96.4 47.7 361d

Food Waste‐Non‐Veg. 57 94.2 56.5 361d

Woode 16 90.6 51.3 11.6Textiles 6 96.6 39.1 46.4Rubber/Leatherf 7 89.3 0 0Newsprint 13 92.7 44.6 74.3Corr. Cardboard 17 89.0 40.7 152.3Office Paper 9 87.8 37.3 217.3Magazines 6 76.7 34.0 84.43rd Class Mail 9 75.1 34.4 84.4Folding Cartons 22 88.8 40.9 152.3Bags and Sacks 22 88.8 40.9 152.3Paper‐Non‐recyclable 25 91.5 43.0 132.1HDPE‐Translucent Cont.g 10 93.8 0 0HDPE‐Pigmented Cont.g 10 93.8 0 0PET‐Containersg 10 93.8 0 0Plastic Filmh 14 95.8 0 0Plastic‐Non‐Recyclable 7 94.9 0 0Ferrous Cansi 13 0 0 0Ferrous Metal‐Otheri 13 0 0 0Aluminum Cans 8 0 0 0Aluminum‐Foil 19 21.8 15 0Al‐Non‐recyclable 19 0 0 0Glass 5 0 0 0Glass‐Green 3 0 0 0Glass‐Clear 12 0 0 0Misc. Inorganicj 37 3.6 0 0a. Moisture, VS, and C content adapted from Riber and Christensen (2009) except as noted in note e. b. Methane yield provided by Staley and Barlaz, except wood. c. Moisture content from NRAES (1998) VS and C content from “yard waste, flowers” category in Riber and Christensen (2009).

d. Food waste methane yield developed from 12 studies shown in Table 3. e. Methane yield from Wang et al. (2009) f. Rubber/Leather values based on 10% rubber and 90% leather weighted average for moisture, VS, and C content.

g. Used plastic bottle values in Riber and Christensen (2009) for HDPE moisture, VS and C content. h. Used soft plastic values in Riber and Christensen (2009) for plastic film moisture, VS and C content. i. Used food Cans values (tinplate/steel) in Riber and Christensen (2009) for ferrous cans, moisture, VS and C content.

j. Used Other non‐combustibles in Riber and Christensen (2009) for moisture, VS and C content.

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An in‐depth literature review was performed for food waste material properties because there is more

data, and the majority of the methane generated in AD facilities is due to food waste. The food waste

methane yield of 361 m3/dry Mg is the average of 12 studies shown in Table 3.

Table 3. Food waste methane yield values.

Methane Yield Source Moisture

Content (%ww)

VS Content (%TS) m3/Mg VSa m3/dry Mg m3/wet Mga

Mohan and Bindu, 2008 78 95 288 274 60

Zhang et al., 2007 74 87 445 387 101

Cho and Park,1995a ‐ 95 472 448 107

Heo et al., 2004 82 92 489 450 81

EBMUD, 2008 72 88 420 370 103

CIWMB, 2008a,b ‐ ‐ 375 343 82

Eleazar et al., 1997a,c ‐ 94 320 300 71

Staley et al., 2006a,b,c ‐ ‐ 197 180 43

Zhang et al., 2012 76 91 352 321 76

Qiao et al., 2012 80 86 531 459 90

Browne and Murphy, 2013 71 95 498 475 140

Trzcinski and Stuckey, 2011a,b ‐ ‐ 357 327 78

Average 76 92 395 361 86a. Moisture content was not reported, so the average moisture content of 76% was used. b. VS content was not reported, so the average VS content of 92% was used. c. Results were reported in m3/dry Mg and methane yield per VS was calculated from VS content.

Materials with lab decay rates above 10 yr‐1 were assumed to reach 100% of their methane yield, and

materials with decay rates below 10 yr‐1 were assumed to reach 50% of their methane yield. The percent

of methane yield reached for each material can be changed by the user and will depend on material

decay rate, retention time, and operating conditions. The total carbon conversion was calculated from

the initial carbon content of each waste component, the assumed methane yield, and the percent of

that yield that is realized during AD. The model includes a default leak rate of 3% of the biogas

generated in the reactor (Sancartier et al., 2011). The collected biogas is either flared, or combusted for

energy recovery in a gas turbine or internal combustion engine (default values are provided for a gas

turbine). There is also a user defined energy option, so users can model direct use or CHP systems. If the

biogas is combusted for energy, the model also includes a default 3% downtime for the engine, during

which time the gas is flared. The combustion efficiency and emissions for the flare and energy recovery

options were developed from the Nielsen and Illerup (2006) as shown in Table 4. The generated

electricity is assumed to offset electricity from the regional grid chosen by the user.

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Table 4. Emission factors for flaring and energy generation (kg/m3 CH4).a

Compound Flare Turbine/Engine

CO2 ‐ Biogenic 3.93E+00 3.91E+00 CH4 7.16E‐04 7.16E‐03 Nitrous Oxide 1.89E‐05 1.89E‐05 Particulates (Total) 9.92E‐05 9.92E‐05 PM10 1.70E‐05 1.70E‐05 PM‐2.5 7.77E‐06 7.77E‐06 Nitrogen Oxides 2.04E‐02 2.04E‐02 NMVOCs 3.38E‐05 8.22E‐05 Sulfur Oxides 7.24E‐04 7.24E‐04 Carbon Monoxide 1.03E‐02 1.03E‐02 Ammonia 3.04E‐05 3.04E‐05 Hydrogen Sulfide 6.53E‐06 1.59E‐05

Conversion Efficiency (%) 0 45 a. Emission factors developed from Nielsen and Illerup (2006). Default Turbine/Engine values are for a gas

turbine.

5.3 LeachateManagement

After the digestate is dewatered, a proportion of the resulting liquid is returned to the mixer (Figure 2)

and the rest is treated prior to release. The model defaults assume that the wastewater is sent offsite to

a wastewater treatment plant (WWTP), but onsite treatment can also be modeled by adjusting

transport and treatment parameters. Table 5 shows the default concentration used for each emission

type in the leachate as well as the material property used to allocate that emission to each waste

material.

Table 5. The allocation property and concentration for each emission type in the liquid digestate. The Allocation Property is the material property used to allocate each emission type to each waste material

as explained in the text (Eq. 1 and 2).

Emission Material Allocation Property Concentration (mg/L)

BOD Methane potential 2300a COD Biogenic carbon 61,610b

TSS Equal 1450a

Total N N content 1350a

Phosphate P content 60a

Cadmium Cd content 0.03c

Mercury Hg content 0.026c

Lead Pb content 2.6c

a. Adapted from Sancartier et al., 2011. b. Adapted from Arsova, 2010. c. Adapted from Schmidt et al., 2001.

The calculation of the allocation factors and the resulting emission factors for each material and

emission type is shown in Eqs. 1 and 2. These equations are used to take the concentrations of each

emission type and allocate them to each of the incoming waste materials based on its contribution to

that emission. Allocation factors are non‐negative values that scale the emission factor of a material

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based on the average contribution to that emission. For example, an inert material would have an

allocation factor of 0 for BOD. Materials with higher methane yields (the chosen proxy for degradability)

would have higher allocation factors for BOD.

, = , ,

Eq. 1

, = , ∙ ,

Eq. 2

where

AFe,m The allocation factor for emission e and material m (unitless).

APe,m The allocation property for emission e and material m (x/wet Mg m; e.g., m3 CH4/wet

Mg m for BOD , % P/wet Mg m for PO4, etc.).

APe,msw The average allocation property for emission e for the assumed incoming composition

(x/wet Mg OFMSW; e.g., m3 CH4/wet Mg OFMSW for BOD , % P/wet Mg OFMSW for

PO4, etc.).

EFe,m The emission factor for emission e and material m (kg e/wet Mg m; e.g., kg BOD/wet Mg

m for BOD, kg PO4/wet Mg m for PO4, etc.).

EFe,MSW The overall emission factor for emission e from the AD facility (kg e/wet Mg; e.g., kg

BOD/wet Mg for BOD, kg PO4/wet Mg for PO4, etc.).

Eq. 1 and Eq. 2 are used to determine the mass of each emission from each waste material. The leachate

is then treated in a WWTP, where the final effluent emissions are reduced based on default removal

efficiencies shown in Table 6. The effluent nitrogen is then split into NH3 and NO3. By default, 43% of the

released nitrogen is as NO3‐ and 28% of the effluent nitrogen is emitted as NH3 with the balance

released as organic nitrogen (Lassaux, 2007).

Table 6. Wastewater treatment plant removal efficiencies for each emission type.

Emission type Removal Efficiency

BOD 97a

COD 95b

TSS 96a

Total Nitrogen 72b

Total Phosphorous 84b

Heavy Metals 85a

a. Adapted from ERG, 2011. b. Adapted from Rodriguez‐Garcia, 2011.

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Leachate treatment at a WWTP also generates sludge that must be managed. The default value for

sludge generation is 1.2 kg/m3 leachate treated. This mass is assumed to be transported by truck to a

landfill and disposed. In addition, BOD removal results in biogenic CO2 production with a default value of

3.6 kg CO2/kg BOD. The electricity used at the WWTP is assumed to vary based on the BOD removal with

a default electricity use of 0.99 kWh/kg BOD removed (ERG, 2011).

5.4 AerobicCuring

By default, the solids remaining after dewatering are sent to aerobic curing, but the user can skip this

step and send the solid digestate directly to land application or landfill. Before aerobic curing, the solid

digestate is mixed with woody materials (screen rejects and/or wood chips). The materials are mixed at

a second tipping floor, and are then built into windrows. The windrows are turned periodically (default is

3 times per week) to increase aeration and improve degradation. Material remains in curing piles for

three weeks by default. The emissions and energy use are assumed to vary linearly with the amount of

compost to be turned. The volume of diesel consumed to turn the compost was developed by Levis and

Barlaz (2011).

During aerobic curing, the digestate further degrades producing off‐gases. CO2 and water vapor make up

the bulk of these off gasses, but CH4, N2, NH3, N2O and VOCs are also produced. The mass of C emitted

during curing depends on the C emitted during digestion. By default, 58% of the C entering the reactor is

emitted during digestion or curing, and 1.7% of the C emitted during curing is CH4 (Boldrin et al., 2009).

The C released during digestion is calculated as described in the Section 5.2, and then the rest of the

aerobically degradable C (up to 58% of the initial C) is emitted during curing. If more than 58% of the C

in a feedstock is emitted during digestion, then it is assumed to not degrade further during curing. Of

the incoming N, 38% is emitted, with 4% of the emitted N as NH3, 0.4% of the emitted N as N2O and the

rest as N2 (Beck‐Friis et al., 2001 and Boldrin et al., 2009). Finally VOC emissions depend on the mass of

volatile solids (VS) entering curing with a default value of 0.238 kg VOC/Mg VS (Cadena et al., 2009; and

Davidsson et al., 2007). After curing, the compost is screened, and the screen rejects are returned to the

curing tipping floor and the finished compost is sold for horticulture use.

5.5 LandApplication

The net emissions from land application are generated from the fuel used to transport and apply the

finished compost as well as from natural release of nitrogen to the air and water. Emissions savings from

land application occur due to carbon storage associated with increased humus formation, and avoided

use of fertilizer and/or peat.

The finished compost is transported by truck to the land application site. The compost is then land

applied using a spreader. The default values and sources for diesel use for transport and application of

compost or digestate (when the curing step is skipped) are shown in Table 7.

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Table 7. Land application diesel fuel use inputs.

Parameter Units Value

Digestate Compost

Loading and transport to field diesel usea L/Mg 0.21 0.4

Land application diesel use per areaa L/ha 14 10

Land application rateb Mg/ha 30 25 a. Adapted from Berglund and Börjesson, 2006. b. Adapted from Arsova, 2010.

After land application of the compost or digestate, a proportion of the nitrogen is emitted as NH3 and

N2O and some runs‐off as NO3‐. Table 8 shows the default values for the nitrogen emissions associated

with land application of compost.

Table 8. Land application diesel fuel use inputs.

Parameter Value

Digestate Compost

Percent nitrogen that is NH3a 50 1

Percent of NH3 that evaporatesa 15 15

Percent of applied nitrogen evaporated as N2Oa 1.5 1.5

Percent of nitrogen run‐off as NO3‐b 22 14

a. Adapted from Hansen et al., 2006. b. Adapted from Bruun et al., 2006 using the average values for loamy arable soil.

The fertilizer offset model assumes that there is a market for all of the available nitrogen in finished

compost. As is typical, nitrogen was assumed to be the controlling nutrient for fertilizers and the

demands of phosphorous and potassium were determined based on the total amount of nitrogen that

can be applied. Any phosphorus or potassium applied above the demand does not receive offset credit.

Nitrogen in compost is not as available to plants as nitrogen in mineral fertilizers, so a mineral fertilizer

equivalent of 0.40 was applied (Boldrin et al., 2009). This means that 2.5 times as much nitrogen in

compost is required compared to mineral nitrogen fertilizer. Since soybeans and corn are the leading

crops in the U.S., the model thus uses the average nitrogen, phosphorus, and potassium demand of

soybeans and corn developed from USDA, 2003. Table 9 illustrates how the ratio of phosphorus and

potassium to nitrogen was determined. The emissions associated with the production of mineral N, P,

and K were developed from the EcoInvent database (EcoInvent, 2013). Additional benefits associated

with compost use such as increased moisture retention and weed suppression were not quantified.

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Table 9. Agricultural Nutrient Demands and Compost Requirements.

Nutrient

Nutrient Demand

(kg/ha/year)a

Nutrient Content (kg nutrient/dry Mg compost)b

Mineral Fertilizer Equivalent

Compost Required (dry Mg/ha/yr)

Ratio to Nitrogenc

Nitrogen 93 18.4 0.4 12.6 ‐

Phosphorus 76.5 5.1 1.0 15 1.0

Potassium 123.5 20.7 1.0 6.0 0.48 a. Average nutrient demand for corn and soybeans developed from USDA, 2003. b. Based on default assumed composition. c. The demand for phosphorus and potassium for each kg of nitrogen in the compost based on assumed

default composition. All of the applied phosphorus and 48% of the potassium will count towards a fertilizer

offset. It is assumed that the rest of the applied potassium is unnecessary, and therefore no avoided

emissions are counted.

Soil amendment with compost leads to increased soil carbon storage by two mechanisms. The first is

from the carbon content of the compost as some carbon will remain after 100 years, and is thus

considered stored. A carbon storage factor of 0.10 kg C per kg C applied in compost was adopted from

Bruun et al. (2006). Compost addition to soil may also lead to incremental humus formation and

resulting carbon storage. An estimate of 0.19 kg C stored per kg‐C input due to incremental humus

formation was developed from U.S. EPA (2006) data.

Peat production requires preparing the land, excavating the peat, transporting the peat, and peat

decomposition. By default, compost replaces peat with a 1:1 volumetric substitution based on Boldrin et

al. (2010). The emissions associated with peat harvesting were developed from the EcoInvent database

(EcoInvent, 2013).

6 Costs

The model calculates capital costs associated with initially building and starting the facility as well as

operating costs associated with processing each material. The capital costs associated with AD refer to

the upfront costs that must be paid prior to operating the facility and are reported in units of $/Mg per

yr (Mgpy). Operating costs are the costs associating with processing a mass of material through the AD

facility and are reported in units of $/Mg. The model can calculate these costs for the user, or the user

can directly enter the capital and operating cost coefficients, if these costs are known. There may be no

capital costs associated with AD, if solid waste is being co‐digested in an existing wastewater digester.

6.1 CapitalCosts

The capital costs primarily consist of land acquisition, engineering, construction, and equipment

installation. The direct project costs (DPC) are those associated with the actual construction of the

facility. Engineering and management costs are estimated as a percent of the DPC to estimate the

installed project costs (IPC). Commissioning, contingency, and contractor’s fees are calculated as a

percent of the IPC to get the total plant costs (TPC).The final capital costs are then calculated as the sum

19

of TPC and land acquisition costs. Land acquisition costs will vary significantly based on the location of

the facility, and site‐specific values should be used when available. The primary construction costs are

shown in Table 10.

Table 10. Default data values used to determine capital costs of AD.

AD capital costs (excludes curing) Units Valuea

Direct project cost (DPC) 2010 $/Mgpy 167

Engineering, design, supervision %DPC 15

Management overheads %DPC 10

Commissioning %IPC 5

Contingency %IPC 10

Contractor's fees %IPC 10

Interest during construction %IPC 10

Land cost Units Value

Land acquisition cost 2010 $/ha 4000b

Land required m2/Mgpy 6.2b

a. Data adapted from Karellas et al., 2010 except when noted otherwise b. Adapted from Komilis and Ham, 2004 assuming most land use is due to curing windrows.

The default model values lead to a total capital cost of $284 per Mgpy, which is 28% less than the

average of $396 per Mgpy reported by Tsilemou and Panagiotakopoulos (2006), but it is in their range of

$122‐800 Mgpy for AD facilities.

6.2 OperatingCosts

The primary operating costs are fuel and electricity, personnel, and equipment maintenance. Diesel

costs are calculated by multiplying the total diesel use calculated in the previous section by the current

price of diesel. Electricity costs are calculated similarly except the model allows different costs for sold

and purchased electricity. Most AD plants will be net electricity producers, so the sold price would be

used with the assumption that in‐house electricity use is met by the plant itself.

The model divides personnel costs into two category types: 1) managers/engineer and 2) laborers and

administrative staff. The requirement of each type of employee varies with plant throughput. Input

values related to personnel are shown in Table 11.

20

Table 11. Inputs values related to personnel costs.

Personnel parameters Units Value

Manager and engineer requirements persons/Mgpy 1.40E‐05a

Laborer and administrative requirements persons/Mgpy 3.40E‐05a

Manager pay rate (wages + benefits) $/person‐year 100,000b

Laborer pay rate (wages + benefits) $/person‐hour 20b

Overhead percent % personnel cost 10a

Hours worked by each laborer per day hours 8 a. Data adapted from Karellas et al., 2010. b. Illustrative values that will vary by location.

There are operations and maintenance (O&M) costs associated purchasing, installing, and maintaining,

and from purchasing consumables. The model splits O&M costs from the anaerobic digester and aerobic

curing separately to accommodate facilities that do not cure the digestate. By default, the annual

variable O&M cost for the digester system is 7.5% of the total project cost which was developed from

Karellas et al. (2010) and includes spare parts, external maintenance assistance, and consumables. The

costs associated with the curing equipment were divided by piece of equipment and the model

calculates the amortized purchase cost, repair costs, and tire cost for each piece of equipment based on

the values in Table 12. The only consumable used in aerobic curing is the wood chips or other bulking

agents. The price of wood chips is variable, and the default value is $5 per Mg.

Table 12. Input values related to curing equipment costs.

Equipment Costs Requirements (units/Mgpd)a

Cost (2010 $/unit)a

Life (years)

Repair Cost (% Initial Cost)b

Tire Cost ($/set)b

Tire Life (hours)b

Windrow turner 0.173 26,701 10 60 2,000 2,100

Tub grinder 0.0038 370,844 10 60

Front End Loader 0.003 222,506 10 60 1,000 2,100

Bobcat 0.003 44,501 10 60 600 2,000

Post‐screen 0.0025 148,337 10 60

Installation cost (%) 30 a. Adopted from Komilis and Ham, 2004.

b. Developed from Nunnally, 2007.

Revenue from product sales is also included in the operating costs. The value of the produced soil

amendment will vary significantly based on quality and the availability of markets. Bagged compost

demands the highest price, but if markets are not available, facilities may rely solely on bulk sales. The

default product sales price is $20 per Mg, which assumes mostly bulk sales. If most of the sales are

bagged compost, then the price could be greater than $100 per Mg.

Using the assumed compostion in Table 1, the average cost to process the inlet stream is $38.45 per Mg.

This is 8% greater than the average $35.45 per Mg reported by Tsilemou and Panagiotakopoulos (2006),

and in their range of 4‐80 $/Mg for AD facilities with full cost data.

21

7 DefaultLife‐CycleInventoryResults

This section shows the LCI results from the model based on the defaults provided. Table 13 shows the

mass flow in and out of the system per incoming Mg of each waste component. For dry materials, more

than 1 Mg leaves the system due to the added wood chips and water. Table 14 shows the electricity

used by each process for each material and Table 15 shows the diesel use.

Table 13 (part 1/2). Material flows associated with each component during AD (kg/Mg).

Leaves Grass Branches Veg. Food Waste

Non‐Veg Food Waste Wood Textiles

Misc. Organic

New water added 1129 358 1444 510 951 1397 1581 1249 Wood chips added 153 29 203 9 17 228 244 169 Residual to landfill or WTE 50 50 100 50 50 100 100 50 Biogas produced 98 85 102 211 394 12 53 108 Wastewater to WWTP 802 254 1026 363 675 993 1123 887 Substrate in final compost (dry) 358 58 479 30 57 524 620 553 Compost produced (ww w/added water and wood chips) 1126 196 1504 84 157 1664 1887 1532

Table 13 (part 2/2). Material flows associated with each component during AD (kg/Mg).

Newsprint Corr.

Cardboard Office Paper Magazines 3rd Class Mail

Folding Containers/ Paper Bags

Paper ‐ Non‐recyclable Inert

New water added 1474 1476 1650 1649 1688 1375 1383 148 Wood chips added 221 179 176 206 156 166 130 24 Residual to landfill or WTE 100 100 100 100 100 100 100 911 Biogas produced 67 187 275 191 348 174 280 0 Wastewater to WWTP 1047 1049 1172 1171 1199 977 982 105 Substrate in final compost (dry) 537 451 463 552 429 420 322 73 Compost produced (ww w/added water and wood chips) 1665 1377 1389 1645 1266 1281 990 210

23

Table 14. Electricity use and generation for each material (kWh/incoming Mg).

Leaves

Grass

Branches

Veg. Food

Waste

Non‐Veg

Food W

aste

Wood

Textiles

New

sprint

Cardboard

Office Paper

Magazines

3rd Class M

ail

Folding

Containers/

Bags

Paper ‐ Non‐

recyclable

Misc. Organic

Inert

Pre‐processing 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58

Post‐curing screen 1 0 1 0 0 2 3 2 2 2 2 2 2 1 2 0

Leachate treatment 1 0 4 1 3 0 3 3 8 15 5 10 7 5 3 0

Generated 148 129 155 321 597 18 80 102 283 417 290 527 263 425 164 0

Net ‐88 ‐70 ‐92 ‐262 ‐536 43 ‐16 ‐38 ‐215 ‐342 ‐224 ‐457 ‐197 ‐360 ‐101 58

Table 15. Diesel use for each material (L/incoming Mg).

Leaves

Grass

Branches

Veg. Food

Waste

Non‐Veg

Food W

aste

Wood

Textiles

New

sprint

Cardboard

Office Paper

Magazines

3rd Class M

ail

Folding

Containers/

Bags

Paper ‐ Non‐

recyclable

Misc. Organic

Inert

Pre‐processing front end loaders

0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Curing front end loaders

8.9 1.7 11.8 0.5 1.0 13.2 14.1 12.8 10.4 10.2 11.9 9.1 9.6 7.5 9.8 0.8

Windrow turner 7.7 1.5 10.2 0.5 0.9 11.5 12.3 11.1 9.0 8.9 10.4 7.9 8.4 6.5 8.5 0.7

Tube grinder 1.6 0.3 2.2 0.1 0.2 2.4 2.6 2.3 1.9 1.9 2.2 1.7 1.8 1.4 1.8 0.1

Land application 0.9 0.2 1.2 0.1 0.1 2.3 2.6 2.3 1.9 1.9 2.2 1.7 1.8 1.4 1.8 0.2

Total diesel use 19.4 3.9 25.7 1.5 2.5 29.8 31.9 28.9 23.4 23.1 27.0 20.6 21.9 17.1 22.2 2.1

24

Table 16 shows the biogas generated from each material, and Tables 17‐19 show the resulting emissions from flaring, combusting for energy,

and biogas leaks.

Table 16. Biogas generation from each material (m3/incoming wet Mg).

Leaves

Grass

Branches

Veg. Food

Waste

Non‐Veg

Food W

aste

Wood

Textiles

New

sprint

Cardboard

Office Paper

Magazines

3rd Class M

ail

Folding

Containers/

Bags

Paper ‐ Non‐

recyclable

Misc. Organic

Inert

CH4 36 32 38 79 147 4 20 25 70 103 71 130 65 105 40 0

CO2 ‐ Biogenic 36 32 38 79 147 4 20 25 70 103 71 130 65 105 40 0

Total Biogas 73 63 76 158 294 9 39 50 139 205 142 260 130 209 81 0

25

Table 17 (part 1/2). Biogas engine combustion emissions (kg/incoming Mg).



Misc. Organic

CO2 ‐ Biogenic 8.7E+01 6.6E+01 2.0E+02 4.1E+02 1.4E+03 2.7E+00 5.4E+01 2.2E+02

CH4 1.6E‐01 1.2E‐01 3.7E‐01 7.5E‐01 2.6E+00 4.9E‐03 9.8E‐02 3.9E‐01

Particulates (Total) 2.2E‐03 1.7E‐03 5.2E‐03 1.0E‐02 3.6E‐02 6.8E‐05 1.4E‐03 5.5E‐03

Nitrogen Oxides 4.5E‐01 3.4E‐01 1.1E+00 2.1E+00 7.4E+00 1.4E‐02 2.8E‐01 1.1E+00

NMVOCs 1.8E‐03 1.4E‐03 4.3E‐03 8.6E‐03 3.0E‐02 5.6E‐05 1.1E‐03 4.5E‐03

Sulfur Oxides 1.6E‐02 1.2E‐02 3.8E‐02 7.6E‐02 2.6E‐01 5.0E‐04 9.9E‐03 4.0E‐02

Carbon Monoxide 2.3E‐01 1.7E‐01 5.4E‐01 1.1E+00 3.7E+00 7.1E‐03 1.4E‐01 5.7E‐01

Hydrogen Sulfide 3.6E‐04 2.7E‐04 8.3E‐04 1.7E‐03 5.8E‐03 1.1E‐05 2.2E‐04 8.8E‐04

Table 17 (part 2/2). Biogas engine combustion emissions (kg/incoming Mg).

Newsprint Corr.





CH4 1.6E‐01 1.2E+00 2.7E+00 6.5E‐01 2.1E+00 1.1E+00 1.4E+00 0.0E+00

Particulates (Total) 2.2E‐03 1.7E‐02 3.7E‐02 9.0E‐03 3.0E‐02 1.5E‐02 1.9E‐02 0.0E+00

Nitrogen Oxides 4.5E‐01 3.5E+00 7.6E+00 1.8E+00 6.1E+00 3.0E+00 4.0E+00 0.0E+00

NMVOCs 1.8E‐03 1.4E‐02 3.1E‐02 7.4E‐03 2.5E‐02 1.2E‐02 1.6E‐02 0.0E+00

Sulfur Oxides 1.6E‐02 1.2E‐01 2.7E‐01 6.5E‐02 2.2E‐01 1.1E‐01 1.4E‐01 0.0E+00

Carbon Monoxide 2.3E‐01 1.8E+00 3.9E+00 9.3E‐01 3.1E+00 1.5E+00 2.0E+00 0.0E+00

Hydrogen Sulfide 3.5E‐04 2.7E‐03 6.0E‐03 1.4E‐03 4.8E‐03 2.4E‐03 3.1E‐03 0.0E+00

26

Table 18 (part 1/2). Biogas flare combustion emissions (kg/incoming Mg).



Misc. Organic


CH4 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04


Nitrogen Oxides 1.4E‐02 1.4E‐02 1.4E‐02 1.4E‐02 1.4E‐02 1.4E‐02 1.4E‐02 1.4E‐02

NMVOCs 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05


Carbon Monoxide 7.1E‐03 7.1E‐03 7.1E‐03 7.1E‐03 7.1E‐03 7.1E‐03 7.1E‐03 7.1E‐03


Table 18 (part 2/2). Biogas flare combustion emissions (kg/incoming Mg).

Newsprint Corr.





CH4 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04 4.9E‐04



NMVOCs 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05 2.3E‐05




27

Table 19 (part 1/2). Leaked biogas emissions (kg/incoming Mg).



Misc. Organic

CO2 ‐ Biogenic 2.8E‐03 2.1E‐03 6.5E‐03 1.3E‐02 4.5E‐02 8.6E‐05 1.7E‐03 6.9E‐03

CH4 5.1E‐06 3.9E‐06 1.2E‐05 2.4E‐05 8.3E‐05 1.6E‐07 3.1E‐06 1.3E‐05



NMVOCs 5.9E‐08 4.4E‐08 1.4E‐07 2.8E‐07 9.5E‐07 1.8E‐09 3.6E‐08 1.4E‐07




Table 19 (part 2/2). Leaked biogas emissions (kg/incoming Mg).

Newsprint Corr.




CO2 ‐ Biogenic 2.8E‐03 2.1E‐02 4.7E‐02 1.1E‐02 3.7E‐02 1.9E‐02 2.4E‐02 0.0E+00

CH4 5.1E‐06 3.9E‐05 8.6E‐05 2.1E‐05 6.8E‐05 3.4E‐05 4.4E‐05 0.0E+00


Nitrogen Oxides 1.4E‐05 1.1E‐04 2.4E‐04 5.9E‐05 1.9E‐04 9.7E‐05 1.3E‐04 0.0E+00

NMVOCs 5.8E‐08 4.5E‐07 9.8E‐07 2.4E‐07 7.9E‐07 3.9E‐07 5.1E‐07 0.0E+00


Carbon Monoxide 7.3E‐06 5.7E‐05 1.2E‐04 3.0E‐05 9.8E‐05 4.9E‐05 6.4E‐05 0.0E+00


28

Table 20 shows the emissions from the WWTP as well as the volume of leachate treated from each material.

Table 20 (part 1/2). Emissions from WWTP (kg/incoming Mg).



Misc. Organic

CO2 ‐ Biogenic 4.4E+00 3.8E‐01 1.6E+01 1.9E+00 1.3E+01 1.7E+00 9.8E+00 1.2E+01

Suspended Solids 6.8E‐02 6.8E‐03 1.1E‐01 1.4E‐02 4.8E‐02 1.0E‐01 1.3E‐01 8.3E‐02

BOD 3.8E‐02 3.3E‐03 1.4E‐01 1.7E‐02 1.1E‐01 1.5E‐02 8.4E‐02 1.0E‐01

COD 4.0E+00 1.4E‐01 8.8E+00 3.0E‐01 2.3E+00 8.8E+00 9.6E+00 4.9E+00

Ammonia 1.3E‐02 1.6E‐02 1.9E‐03 1.3E‐02 8.6E‐02 1.4E‐02 6.5E‐02 1.5E‐02

Cadmium 6.6E‐03 1.1E‐04 1.5E‐02 2.2E‐05 1.7E‐04 2.8E‐02 5.5E‐02 1.0E‐02

Mercury 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00

Phosphate 6.8E‐03 1.1E‐04 1.6E‐02 6.6E‐06 4.2E‐05 2.4E‐02 1.4E‐02 6.7E‐03

Lead 5.8E‐03 1.9E‐03 7.5E‐03 3.1E‐03 2.5E‐02 1.0E‐03 9.5E‐03 3.7E‐03

Nitrate 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00

Leachate to WWTP (m3) 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00

Table 20 (part 2/2). Emissions from WWTP (kg/incoming Mg).

Newsprint Corr.

Cardboard Office Paper Magazines

3rd Class Mail





BOD 9.3E‐02 2.6E‐01 4.8E‐01 1.7E‐01 3.2E‐01 2.1E‐01 1.7E‐01 0.0E+00

COD 8.8E+00 7.7E+00 9.7E+00 9.1E+00 9.4E+00 6.3E+00 6.4E+00 2.4E‐04



Mercury 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00


Lead 2.9E‐04 4.8E‐04 1.7E‐04 7.8E‐04 6.9E‐04 4.6E‐04 2.0E‐03 5.8E‐05

Nitrate 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00

Leachate to WWTP (m3) 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00

29

Table 21 shows the emissions resulting from aerobic degradation during curing.

Table 21 (part 1/2). Emissions from aerobic curing (kg/incoming Mg).



Misc. Organic

CO2 ‐ Biogenic 1.4E+02 6.8E+02 4.1E+01 1.5E+02 8.0E+02 8.0E+02 5.4E+02 4.3E‐01

CH4 3.2E+00 8.5E‐01 4.2E+00 0.0E+00 0.0E+00 5.0E+00 4.1E+00 0.0E+00

Nitrous Oxide 1.2E‐02 1.3E‐02 1.8E‐03 9.5E‐03 6.5E‐02 1.4E‐02 6.3E‐02 1.4E‐02

Nitrogen Oxides 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00

NMVOCs 2.1E‐01 4.0E‐02 2.8E‐01 1.3E‐02 2.4E‐02 3.1E‐01 3.3E‐01 2.3E‐01


Table 21 (part 2/2). Emissions from aerobic curing (kg/incoming Mg).

Newsprint Corr.


3rd Class Mail


Paper ‐Non‐

recyclable Inert

CO2 ‐ Biogenic 4.8E+02 4.1E+02 4.4E+02 3.0E+02 4.5E+02 4.5E+02 3.6E‐01 0.0E+00

CH4 4.2E+00 3.0E+00 2.6E+00 2.8E+00 1.9E+00 2.8E+00 2.3E+00 0.0E+00

Nitrous Oxide 1.8E‐03 1.7E‐03 1.9E‐03 2.0E‐03 5.7E‐03 3.2E‐03 6.9E‐03 0.0E+00


NMVOCs 3.0E‐01 2.4E‐01 2.4E‐01 2.8E‐01 2.1E‐01 2.3E‐01 1.8E‐01 0.0E+00

Ammonia 1.4E‐02 1.3E‐02 1.5E‐02 1.5E‐02 4.4E‐02 2.5E‐02 5.4E‐02 0.0E+00

30

Table 22 shows the air and waterborne emissions resulting from the application of compost as a soil amendment as well as the dry mass of

compost produced.

Table 22 (part 1/2). Emissions after land application of compost (kg/incoming Mg).

Airborne Emissions Leaves Grass Branches Veg. Food Waste


Misc. Organic


CO2 ‐ Stored 1.1E+02 2.9E+01 1.4E+02 2.1E+01 7.7E+01 1.7E+02 1.4E+02 2.6E+02

CH4 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00



NMVOCs 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00

Ammonia 2.9E‐01 3.2E‐01 4.1E‐02 2.3E‐01 1.5E+00 3.3E‐01 1.5E+00 3.4E‐01

Nitrate 2.0E+00 2.2E+00 2.8E‐01 1.5E+00 1.1E+01 2.3E+00 1.0E+01 2.3E+00

Substrate in final compost (dry) 358 58 479 30 57 524 524 620

Table 22 (part 2/2). Emissions after land application of compost (kg/incoming Mg).

Airborne Emissions Newsprint Corr.


3rd Class Mail


Paper ‐Non‐

recyclable Inert

CO2 ‐ Biogenic 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 CO2 ‐ Stored 1.4E+02 1.0E+02 8.8E+01 9.4E+01 6.4E+01 9.7E+01 7.9E+01 1.8E-01 CH4 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 Nitrous Oxide 1.1E-02 1.1E-02 1.2E-02 1.2E-02 3.5E-02 2.0E-02 4.3E-02 0.0E+00 Nitrogen Oxides 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 NMVOCs 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 Ammonia 4.3E-02 4.1E-02 4.5E-02 4.6E-02 1.3E-01 7.6E-02 1.6E-01 0.0E+00 Nitrate 2.9E-01 2.8E-01 3.1E-01 3.1E-01 9.1E-01 5.2E-01 1.1E+00 0.0E+00 Substrate in final compost (dry) 537 451 463 552 429 420 322 45

31

Table 23 and 22 show the airborne and waterborne peat offsets associated with land application of compost, respectively.

Table 23 (part 1/2). Airborne offset emissions associated with avoided peat use (kg/Mg incoming).



Misc. Organic

CO2 ‐ Fossil 9.4E+00 4.3E‐01 1.6E+01 1.3E‐01 9.2E‐01 2.2E+01 2.0E+01 3.0E+01


CO2 ‐ Stored 1.1E‐05 4.9E‐07 1.9E‐05 1.5E‐07 1.0E‐06 2.5E‐05 2.2E‐05 3.4E‐05

CH4 ‐ Fossil 1.6E‐01 7.2E‐03 2.7E‐01 2.2E‐03 1.5E‐02 3.6E‐01 3.3E‐01 5.0E‐01

CH4 ‐ Biogenic 5.2E‐05 2.4E‐06 9.1E‐05 7.4E‐07 5.1E‐06 1.2E‐04 1.1E‐04 1.7E‐04



PM10 5.3E‐03 2.4E‐04 9.2E‐03 7.5E‐05 5.1E‐04 1.2E‐02 1.1E‐02 1.7E‐02

PM‐2.5 2.5E‐04 1.2E‐05 4.4E‐04 3.6E‐06 2.5E‐05 5.8E‐04 5.3E‐04 8.0E‐04


NMVOCs 1.6E‐03 7.4E‐05 2.8E‐03 2.3E‐05 1.6E‐04 3.7E‐03 3.4E‐03 5.1E‐03




Lead 6.4E‐06 2.9E‐07 1.1E‐05 9.1E‐08 6.2E‐07 1.5E‐05 1.3E‐05 2.0E‐05

Hydrochloric acid 8.0E‐04 3.7E‐05 1.4E‐03 1.1E‐05 7.8E‐05 1.8E‐03 1.7E‐03 2.6E‐03

Mercury 3.7E‐06 1.7E‐07 6.4E‐06 5.2E‐08 3.6E‐07 8.4E‐06 7.7E‐06 1.2E‐05

Benzene 1.7E‐04 7.9E‐06 3.0E‐04 2.4E‐06 1.7E‐05 4.0E‐04 3.6E‐04 5.5E‐04

Chloroform 8.6E‐08 4.0E‐09 1.5E‐07 1.2E‐09 8.4E‐09 2.0E‐07 1.8E‐07 2.8E‐07

Carbon tetrachloride 2.7E‐09 1.2E‐10 4.7E‐09 3.8E‐11 2.6E‐10 6.2E‐09 5.7E‐09 8.6E‐09

Ethylene dichloride 1.9E‐07 8.9E‐09 3.4E‐07 2.7E‐09 1.9E‐08 4.4E‐07 4.1E‐07 6.2E‐07

Methylene chloride 4.5E‐07 2.1E‐08 8.0E‐07 6.5E‐09 4.4E‐08 1.0E‐06 9.6E‐07 1.5E‐06

Trichloroethene 2.1E‐08 9.9E‐10 3.8E‐08 3.1E‐10 2.1E‐09 4.9E‐08 4.5E‐08 6.9E‐08

Tetrachloroethene 4.7E‐08 2.2E‐09 8.3E‐08 6.8E‐10 4.6E‐09 1.1E‐07 1.0E‐07 1.5E‐07

Vinyl chloride 1.1E‐09 5.1E‐11 1.9E‐09 1.6E‐11 1.1E‐10 2.5E‐09 2.3E‐09 3.5E‐09

Toluene 1.0E‐04 4.6E‐06 1.8E‐04 1.4E‐06 9.8E‐06 2.3E‐04 2.1E‐04 3.2E‐04

Xylenes 5.9E‐05 2.7E‐06 1.0E‐04 8.4E‐07 5.8E‐06 1.4E‐04 1.2E‐04 1.9E‐04

Ethylbenzene 7.7E‐06 3.6E‐07 1.4E‐05 1.1E‐07 7.6E‐07 1.8E‐05 1.6E‐05 2.5E‐05

Dioxins 9.2E‐11 4.2E‐12 1.6E‐10 1.3E‐12 9.0E‐12 2.1E‐10 1.9E‐10 2.9E‐10

Furans 8.6E‐11 3.9E‐12 1.5E‐10 1.2E‐12 8.4E‐12 2.0E‐10 1.8E‐10 2.7E‐10


32

Table 23 (part 2/2). Airborne offset emissions associated with avoided peat use (kg/Mg incoming).

Newsprint Corr.


Folding Containers/Paper Bags


CO2 ‐ Fossil 1.8E+01 1.1E+01 9.3E+00 1.2E+01 6.2E+00 9.4E+00 6.0E+00 1.7E‐03







PM10 1.0E‐02 6.0E‐03 5.2E‐03 6.6E‐03 3.5E‐03 5.3E‐03 3.3E‐03 9.7E‐07

PM‐2.5 4.9E‐04 2.9E‐04 2.5E‐04 3.1E‐04 1.6E‐04 2.5E‐04 1.6E‐04 4.6E‐08


NMVOCs 3.1E‐03 1.8E‐03 1.6E‐03 2.0E‐03 1.1E‐03 1.6E‐03 1.0E‐03 3.0E‐07




Lead 1.2E‐05 7.3E‐06 6.3E‐06 8.0E‐06 4.2E‐06 6.4E‐06 4.1E‐06 1.2E‐09















Furans 1.7E‐10 9.8E‐11 8.4E‐11 1.1E‐10 5.6E‐11 8.6E‐11 5.4E‐11 1.6E‐14


33

Table 24 (part 1/2). Waterborne offset emissions associated with avoided peat use (kg/Mg incoming).



Misc. Organic

Dissolved Solids 2.0E‐01 9.0E‐03 3.4E‐01 2.8E‐03 1.9E‐02 4.5E‐01 4.1E‐01 6.2E‐01

Suspended Solids 2.1E+00 9.5E‐02 3.6E+00 2.9E‐02 2.0E‐01 4.7E+00 4.3E+00 6.6E+00

BOD 2.8E‐03 1.3E‐04 4.9E‐03 4.0E‐05 2.7E‐04 6.4E‐03 5.9E‐03 8.9E‐03

COD 2.9E‐03 1.3E‐04 5.0E‐03 4.1E‐05 2.8E‐04 6.6E‐03 6.0E‐03 9.2E‐03

Sulfate 2.0E+00 9.0E‐02 3.4E+00 2.8E‐02 1.9E‐01 4.5E+00 4.1E+00 6.3E+00

Iron 9.4E‐01 4.3E‐02 1.6E+00 1.3E‐02 9.2E‐02 2.2E+00 2.0E+00 3.0E+00


Copper 3.1E‐05 1.4E‐06 5.5E‐05 4.5E‐07 3.1E‐06 7.2E‐05 6.6E‐05 1.0E‐04


Arsenic 7.1E‐06 3.3E‐07 1.2E‐05 1.0E‐07 6.9E‐07 1.6E‐05 1.5E‐05 2.3E‐05



Selenium 8.0E‐06 3.7E‐07 1.4E‐05 1.1E‐07 7.9E‐07 1.9E‐05 1.7E‐05 2.6E‐05

Chromium 5.3E‐06 2.4E‐07 9.3E‐06 7.5E‐08 5.2E‐07 1.2E‐05 1.1E‐05 1.7E‐05

Lead 5.6E‐06 2.6E‐07 9.8E‐06 8.0E‐08 5.5E‐07 1.3E‐05 1.2E‐05 1.8E‐05

Zinc 1.9E‐04 8.8E‐06 3.4E‐04 2.7E‐06 1.9E‐05 4.4E‐04 4.0E‐04 6.1E‐04

Barium 2.6E‐03 1.2E‐04 4.6E‐03 3.8E‐05 2.6E‐04 6.1E‐03 5.6E‐03 8.5E‐03

Silver 9.4E‐06 4.3E‐07 1.6E‐05 1.3E‐07 9.1E‐07 2.2E‐05 2.0E‐05 3.0E‐05

Nitrate 1.5E‐04 6.9E‐06 2.6E‐04 2.1E‐06 1.5E‐05 3.5E‐04 3.2E‐04 4.8E‐04









Hydrocarbons unspecified

1.3E‐06 6.0E‐08 2.3E‐06 1.9E‐08 1.3E‐07 3.0E‐06 2.8E‐06 4.2E‐06

34

Table 24 (part 2/2). Waterborne offset emissions associated with avoided peat use (kg/Mg incoming).

Newsprint Corr.




Dissolved Solids 3.8E‐01 2.2E‐01 1.9E‐01 2.4E‐01 1.3E‐01 2.0E‐01 1.2E‐01 3.6E‐05

Suspended Solids 4.0E+00 2.4E+00 2.0E+00 2.6E+00 1.4E+00 2.1E+00 1.3E+00 3.8E‐04

BOD 5.4E‐03 3.2E‐03 2.7E‐03 3.5E‐03 1.8E‐03 2.8E‐03 1.8E‐03 5.1E‐07

COD 5.5E‐03 3.3E‐03 2.8E‐03 3.6E‐03 1.9E‐03 2.9E‐03 1.8E‐03 5.3E‐07

Sulfate 3.8E+00 2.3E+00 1.9E+00 2.5E+00 1.3E+00 2.0E+00 1.2E+00 3.6E‐04

Iron 1.8E+00 1.1E+00 9.3E‐01 1.2E+00 6.2E‐01 9.4E‐01 6.0E‐01 1.7E‐04


Copper 6.1E‐05 3.6E‐05 3.1E‐05 3.9E‐05 2.1E‐05 3.1E‐05 2.0E‐05 5.8E‐09







Lead 1.1E‐05 6.4E‐06 5.5E‐06 7.0E‐06 3.7E‐06 5.6E‐06 3.6E‐06 1.0E‐09

Zinc 3.7E‐04 2.2E‐04 1.9E‐04 2.4E‐04 1.3E‐04 1.9E‐04 1.2E‐04 3.5E‐08

Barium 5.1E‐03 3.0E‐03 2.6E‐03 3.3E‐03 1.7E‐03 2.7E‐03 1.7E‐03 4.9E‐07

Silver 1.8E‐05 1.1E‐05 9.2E‐06 1.2E‐05 6.1E‐06 9.4E‐06 5.9E‐06 1.7E‐09











2.5E‐06 1.5E‐06 1.3E‐06 1.6E‐06 8.6E‐07 1.3E‐06 8.3E‐07 2.4E‐10

35

Table 25 and 24 show the airborne and waterborne fertilizer offsets associated with land application of compost, respectively.

Table 25 (part 1/2). Airborne offset emissions associated with avoided fertilizer use (kg/Mg incoming).



Misc. Organic

CO2 ‐ Fossil 8.5E+00 5.6E+00 6.5E+00 5.0E+00 3.3E+01 5.4E+00 2.6E+01 7.3E+00







PM10 5.6E‐03 2.6E‐03 5.8E‐03 2.9E‐03 2.1E‐02 2.2E‐03 1.3E‐02 4.2E‐03

PM‐2.5 3.9E‐03 2.3E‐03 3.4E‐03 2.2E‐03 1.6E‐02 2.1E‐03 1.1E‐02 3.2E‐03


NMVOCs 2.7E‐03 1.6E‐03 2.3E‐03 1.5E‐03 9.9E‐03 1.5E‐03 7.3E‐03 2.2E‐03




Lead 3.8E‐06 1.5E‐06 4.4E‐06 1.8E‐06 1.4E‐05 1.1E‐06 7.6E‐06 2.6E‐06















Furans 2.4E‐06 6.9E‐07 3.0E‐06 1.0E‐06 8.2E‐06 4.3E‐07 4.0E‐06 1.5E‐06


36

Table 25 (part 2/2). Airborne offset emissions associated with avoided fertilizer use (kg/Mg incoming).

Newsprint Corr.




CO2 ‐ Fossil 8.5E‐01 8.8E‐01 7.2E‐01 1.2E+00 2.3E+00 1.3E+00 3.4E+00 0.0E+00

CO2 ‐ Biogenic 5.9E‐03 8.2E‐03 3.7E‐03 1.3E‐02 1.3E‐02 8.9E‐03 3.2E‐02 0.0E+00

CO2 ‐ Stored 4.0E‐08 4.1E‐08 4.0E‐08 4.8E‐08 1.2E‐07 7.0E‐08 1.6E‐07 0.0E+00

CH4 ‐ Fossil 3.1E‐03 3.0E‐03 2.7E‐03 3.7E‐03 8.5E‐03 4.8E‐03 1.1E‐02 0.0E+00

CH4 ‐ Biogenic 1.3E‐05 1.9E‐05 7.3E‐06 3.1E‐05 2.8E‐05 1.9E‐05 7.5E‐05 0.0E+00

Nitrous Oxide 2.8E‐05 2.7E‐05 2.1E‐05 3.6E‐05 7.2E‐05 4.0E‐05 1.0E‐04 0.0E+00


PM10 4.2E‐04 5.3E‐04 3.2E‐04 7.7E‐04 1.1E‐03 6.7E‐04 2.1E‐03 0.0E+00

PM‐2.5 3.4E‐04 4.0E‐04 2.9E‐04 5.5E‐04 9.4E‐04 5.7E‐04 1.6E‐03 0.0E+00

Nitrogen Oxides 1.6E‐03 1.8E‐03 1.2E‐03 2.6E‐03 4.2E‐03 2.5E‐03 7.1E‐03 0.0E+00

NMVOCs 2.5E‐04 2.7E‐04 2.0E‐04 3.6E‐04 6.6E‐04 3.9E‐04 1.0E‐03 0.0E+00


Carbon Monoxide 1.3E‐03 1.4E‐03 1.1E‐03 1.8E‐03 3.6E‐03 2.1E‐03 5.3E‐03 0.0E+00


Lead 2.4E‐07 3.3E‐07 1.6E‐07 5.1E‐07 5.7E‐07 3.7E‐07 1.3E‐06 0.0E+00

Hydrochloric acid 2.6E‐05 3.0E‐05 2.0E‐05 4.2E‐05 6.7E‐05 4.0E‐05 1.1E‐04 0.0E+00

Mercury 3.5E‐08 3.8E‐08 3.2E‐08 5.0E‐08 1.0E‐07 5.9E‐08 1.5E‐07 0.0E+00

Benzene 1.9E‐05 1.8E‐05 1.7E‐05 2.2E‐05 5.4E‐05 3.0E‐05 6.9E‐05 0.0E+00

Chloroform 8.8E‐10 9.6E‐10 8.2E‐10 1.2E‐09 2.5E‐09 1.5E‐09 3.8E‐09 0.0E+00

Carbon tetrachloride 1.9E‐09 2.4E‐09 8.9E‐10 3.9E‐09 3.7E‐09 2.4E‐09 9.0E‐09 0.0E+00

Ethylene dichloride 1.4E‐06 2.2E‐06 7.8E‐07 3.6E‐06 3.0E‐06 2.1E‐06 8.8E‐06 0.0E+00

Methylene chloride 2.3E‐08 2.3E‐08 2.4E‐08 2.6E‐08 7.3E‐08 4.2E‐08 9.0E‐08 0.0E+00

Trichloroethene 2.1E‐10 2.1E‐10 2.2E‐10 2.4E‐10 6.5E‐10 3.7E‐10 8.2E‐10 0.0E+00

Tetrachloroethene 7.6E‐10 7.4E‐10 7.9E‐10 8.4E‐10 2.4E‐09 1.4E‐09 3.0E‐09 0.0E+00

Vinyl chloride 3.2E‐09 4.7E‐09 1.8E‐09 7.5E‐09 6.9E‐09 4.8E‐09 1.9E‐08 0.0E+00

Toluene 2.7E‐05 2.4E‐05 2.4E‐05 3.0E‐05 7.6E‐05 4.2E‐05 9.3E‐05 0.0E+00

Xylenes 1.6E‐05 1.5E‐05 1.4E‐05 1.8E‐05 4.5E‐05 2.5E‐05 5.6E‐05 0.0E+00

Ethylbenzene 2.0E‐06 1.9E‐06 1.8E‐06 2.3E‐06 5.8E‐06 3.2E‐06 7.1E‐06 0.0E+00

Dioxins 2.7E‐12 2.5E‐12 2.6E‐12 3.0E‐12 7.9E‐12 4.5E‐12 9.9E‐12 0.0E+00

Furans 1.2E‐07 2.0E‐07 6.8E‐08 3.1E‐07 2.6E‐07 1.9E‐07 7.8E‐07 0.0E+00


37

Table 26 (part 1/2). Waterborne offset emissions associated with avoided fertilizer use (kg/Mg incoming).



Misc. Organic

Dissolved Solids 3.2E‐01 2.8E‐01 1.5E‐01 2.1E‐01 1.3E+00 2.8E‐01 1.2E+00 3.2E‐01


BOD 8.5E‐03 3.4E‐03 9.7E‐03 4.0E‐03 2.9E‐02 2.6E‐03 1.7E‐02 5.9E‐03

COD 9.0E‐03 2.9E‐03 1.1E‐02 4.0E‐03 3.0E‐02 2.0E‐03 1.5E‐02 5.8E‐03

Sulfate 2.0E‐01 6.6E‐02 2.5E‐01 8.7E‐02 5.1E‐01 4.8E‐02 2.6E‐01 1.2E‐01

Iron 5.9E‐03 2.3E‐03 6.8E‐03 2.8E‐03 2.0E‐02 1.8E‐03 1.2E‐02 4.1E‐03


Copper 1.3E‐04 4.0E‐05 1.6E‐04 5.7E‐05 4.4E‐04 2.6E‐05 2.2E‐04 8.3E‐05







Lead 6.4E‐05 2.1E‐05 8.0E‐05 2.9E‐05 2.2E‐04 1.4E‐05 1.1E‐04 4.2E‐05

Zinc 4.5E‐04 1.5E‐04 5.6E‐04 2.0E‐04 1.5E‐03 1.0E‐04 7.8E‐04 2.9E‐04

Barium 2.9E‐03 2.6E‐03 1.2E‐03 2.0E‐03 1.2E‐02 2.7E‐03 1.2E‐02 3.0E‐03

Silver 1.5E‐05 1.3E‐05 7.0E‐06 1.0E‐05 6.1E‐05 1.3E‐05 5.6E‐05 1.5E‐05











5.1E‐06 2.4E‐06 5.2E‐06 2.6E‐06 1.8E‐05 2.1E‐06 1.2E‐05 3.8E‐06

38

Table 26 (part 2/2). Waterborne offset emissions associated with avoided fertilizer use (kg/Mg incoming).

Newsprint Corr.




Dissolved Solids 4.0E‐02 3.7E‐02 3.7E‐02 4.4E‐02 1.2E‐01 6.4E‐02 1.4E‐01 0.0E+00

Suspended Solids 1.3E‐03 1.5E‐03 1.1E‐03 2.1E‐03 3.5E‐03 2.1E‐03 6.0E‐03 0.0E+00

BOD 5.7E‐04 7.4E‐04 3.7E‐04 1.1E‐03 1.3E‐03 8.5E‐04 2.9E‐03 0.0E+00

COD 5.2E‐04 7.4E‐04 3.0E‐04 1.2E‐03 1.1E‐03 7.6E‐04 2.9E‐03 0.0E+00

Sulfate 1.3E‐02 1.4E‐02 5.9E‐03 2.3E‐02 2.5E‐02 1.5E‐02 5.3E‐02 0.0E+00

Iron 3.9E‐04 5.1E‐04 2.6E‐04 7.8E‐04 9.1E‐04 5.8E‐04 2.0E‐03 0.0E+00


Copper 7.1E‐06 1.1E‐05 4.0E‐06 1.7E‐05 1.5E‐05 1.1E‐05 4.2E‐05 0.0E+00

Cadmium 9.3E‐07 1.4E‐06 5.3E‐07 2.3E‐06 2.0E‐06 1.4E‐06 5.6E‐06 0.0E+00

Arsenic 1.6E‐06 2.3E‐06 9.8E‐07 3.5E‐06 3.6E‐06 2.4E‐06 8.9E‐06 0.0E+00

Mercury 6.1E‐07 9.5E‐07 3.3E‐07 1.5E‐06 1.3E‐06 9.2E‐07 3.8E‐06 0.0E+00

Phosphate 3.3E‐04 4.5E‐04 2.0E‐04 7.1E‐04 7.3E‐04 4.8E‐04 1.8E‐03 0.0E+00

Selenium 4.5E‐07 6.3E‐07 2.7E‐07 9.8E‐07 1.0E‐06 6.7E‐07 2.5E‐06 0.0E+00

Chromium 3.8E‐06 5.5E‐06 2.4E‐06 8.5E‐06 8.6E‐06 5.8E‐06 2.2E‐05 0.0E+00

Lead 3.6E‐06 5.4E‐06 2.1E‐06 8.5E‐06 7.9E‐06 5.5E‐06 2.1E‐05 0.0E+00

Zinc 2.6E‐05 3.8E‐05 1.5E‐05 5.9E‐05 5.6E‐05 3.8E‐05 1.5E‐04 0.0E+00

Barium 3.8E‐04 3.5E‐04 3.6E‐04 4.1E‐04 1.1E‐03 6.2E‐04 1.4E‐03 0.0E+00

Silver 1.9E‐06 1.7E‐06 1.7E‐06 2.1E‐06 5.4E‐06 3.0E‐06 6.7E‐06 0.0E+00

Nitrate 1.7E‐03 1.7E‐03 1.8E‐03 2.0E‐03 5.3E‐03 3.1E‐03 6.9E‐03 0.0E+00

Benzene 1.6E‐06 1.5E‐06 1.5E‐06 1.9E‐06 4.6E‐06 2.6E‐06 6.0E‐06 0.0E+00

Chloroform 2.3E‐11 3.5E‐11 1.2E‐11 5.6E‐11 4.8E‐11 3.4E‐11 1.4E‐10 0.0E+00

Ethylene dichloride 3.4E‐06 5.3E‐06 1.8E‐06 8.5E‐06 7.1E‐06 5.1E‐06 2.1E‐05 0.0E+00

Methylene chloride 1.9E‐08 2.7E‐08 1.1E‐08 4.3E‐08 4.2E‐08 2.8E‐08 1.1E‐07 0.0E+00

Vinyl chloride 4.0E‐11 6.0E‐11 2.3E‐11 9.5E‐11 8.7E‐11 6.0E‐11 2.3E‐10 0.0E+00

Toluene 1.7E‐06 1.7E‐06 1.5E‐06 2.2E‐06 4.7E‐06 2.7E‐06 6.7E‐06 0.0E+00

Xylenes 9.0E‐07 9.0E‐07 7.8E‐07 1.2E‐06 2.5E‐06 1.4E‐06 3.5E‐06 0.0E+00

Ethylbenzene 1.2E‐07 1.2E‐07 9.8E‐08 1.7E‐07 3.2E‐07 1.9E‐07 4.8E‐07 0.0E+00


3.9E‐07 4.7E‐07 2.9E‐07 6.7E‐07 9.8E‐07 6.0E‐07 1.8E‐06 0.0E+00

39

Table 27 and 28 show the capital and operating costs, respectively, for the AD facility.

Table 27. Capital costs associated with AD ($/Mgpy)

Installed project cost (IPC) 208.75Total plant cost (TPC) 281.81Total land cost 2.48

Total capital costs 284.29

Table 28 (part 1/2). Operating costs from AD. (kg/Mg incoming). Costs Leaves Grass Branches Veg. Food

Waste Non‐Veg Food

Waste Wood Textiles Misc.

Organic

AD variable O&M 1.49 1.49 1.49 1.49 1.49 1.49 1.49 1.49

Total equipment Cost 27.06 20.81 29.63 19.81 20.21 30.87 31.69 27.91

Manager/engineer cost 1.40 1.40 1.40 1.40 1.40 1.40 1.40 1.40

Laborer/admin cost 1.41 1.41 1.41 1.41 1.41 1.41 1.41 1.41

Overhead 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28

Leachate treatment 6.41 2.03 8.21 2.90 5.40 7.94 8.99 7.10

Wood chips 0.76 0.15 1.02 0.05 0.09 1.14 1.22 0.84

Diesel 18.46 3.77 24.48 1.40 2.36 27.41 29.32 20.39

Revenue Leaves Grass Branches Veg. Food Waste

Non‐Veg Food Waste

Wood Textiles Misc. Organic

Net electricity sales 4.39 3.51 4.59 13.10 26.79 ‐4.19 0.88 5.09

Product sales 22.52 3.92 30.08 1.68 3.14 33.27 37.74 30.65

Total Cost 30.38 23.90 33.24 13.95 2.72 42.86 37.17 25.09

40

Table 28 (part 2/2). Operating costs from AD. (kg/Mg incoming). Costs

Newsprint Corr.


Folding Containers/Paper

Bags

Paper ‐Non‐

recyclable Inert

AD variable O&M 1.49 1.49 1.49 1.49 1.49 1.49 1.49 1.49

Total equipment Cost 30.52 28.39 28.25 29.77 27.25 27.76 25.91 20.58

Manager/engineer cost 1.40 1.40 1.40 1.40 1.40 1.40 1.40 1.40

Laborer/admin cost 1.41 1.41 1.41 1.41 1.41 1.41 1.41 1.41

Overhead 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28

Leachate treatment 8.38 8.39 9.38 9.37 9.59 7.81 7.86 0.84

Wood chips 1.10 0.89 0.88 1.03 0.78 0.83 0.65 0.12

Diesel 26.58 21.55 21.23 24.78 18.88 20.09 15.73 3.22

Revenue Newsprint Corr. Cardboard

Office Paper Magazines 3rd Class Mail Folding Containers/Paper

Bags

Paper ‐Non‐

recyclable Inert

Net electricity sales 1.97 10.77 17.14 11.25 22.91 9.89 18.02 ‐5.82

Product sales 33.30 27.55 27.79 32.90 25.32 25.63 19.80 4.20

Total Cost 35.90 25.48 19.39 25.38 12.86 25.57 16.90 30.95

41

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