BENCHMARKING WATER USEIN DAIRIES

BENCHMARKING WATER USE IN DAIRIES

This publication was produced by EnvirowisePrepared with assistance from Ashact

SUMMARYThis guide is designed to help dairy staff who carry

out water audits and are involved with managing

water use. It presents simple benchmarks for water

use and effluent load discharged for three dairy

sectors: fresh liquid milk; butter and cheese; and

‘other’ milk products. Separate tables for each sector

contain minimum, maximum, average, lower quartile

and upper quartile values, while graphs of key

performance indicators from different dairies allow

dairies to see how well they are performing. All data

are provided by Dairy UK.

The benchmarks provide an indication of how a dairy

is performing in terms of water consumption and

effluent generation (ie product loss) compared with

others in its sector. Dairies that adopt a systematic

approach to reduce water use and effluent generation

(volume and load) can save money and increase their

profits without having to raise prices.

The guide also contains water-saving tips and details

of useful contacts. It complements Envirowise’s

online water benchmarking tool, Water Account.

CONTENTS

Section Page

INTRODUCTION 2Why save water? 3

Structure of the guide 4

CALCULATING KEY PERFORMANCE INDICATORS 7

USEFUL FACTS AND FIGURES 8

WATER-SAVING TIPS 11Further reading 13

DAIRY: FRESH LIQUID MILK 14

DAIRY: BUTTER AND CHEESE 16

DAIRY: ‘OTHER’ MILK PRODUCTS 18

USEFUL CONTACTS 20

1

INTRODUCTIONThis guide is designed to help dairy staff who carry outwater audits and are involved with managing water use. Itpresents simple benchmarks for water use and chemicaloxygen demand (COD) load discharged for three dairyactivities:

• fresh liquid milk;

• butter and cheese;

• ‘other’ milk products.

These benchmarks provide an indication of how a dairy is performingin terms of water consumption and effluent generation (ie product loss)compared with the rest of its sector. Sectors are characterised byStandard Industrial Classification (SIC) Code.1

The guide complements Water Account(www.envirowise.gov.uk/wateraccount), an online water benchmarkingtool developed by Envirowise. Water Account also contains specificinformation for the three sectors of the dairy industry. Companies withinternet access can use this tool to manage their water use and to findout more about water-saving measures.

The benchmarks in this guide are based on data collected during anindependent survey of water use in dairies carried out by Dairy UKduring 2004/2005 and 2005/2006.2 These data also form the basis ofinformation used in the dairy sector of the Water Account database,which allows dairies to enter their water use and obtain an instantindication of how their performance compares with similar dairies.

2

1 Office for National Statistics (ONS), UK Standard Industrial Classification of EconomicActivities 2003. Available at:www.statistics.gov.uk/methods_quality/sic/downloads/UK_SIC_Vol1(2003).pdf

2 The source of all data is confidential

Why save water?

Companies are often unaware of the true cost of water. They think itcosts what they pay for its supply and forget the cost of:

• water treatment;

• effluent treatment and discharge;

• the value of lost raw materials and product;

• pumping;

• maintenance;

• capital depreciation of equipment.

The true cost of water may be more than three times the total amountcharged for supply and disposal, and can amount to 1% of turnover.

Companies that adopt a systematic approach to water reductiontypically achieve a 20 - 50% decrease in the amount of water used -and the amount of effluent generated.

For a dairy operating with a profit margin of 5%, adopting a systematicapproach to water minimisation could increase profits by 10%.Furthermore, cutting water costs can also help dairies meet supplychain pressures to improve environmental performance.

Investment in selected sustainable technologies, products andsystems, eg cleaning-in-place (CIP) systems, may qualify for anEnhanced Capital Allowance (ECA). This provides for 100% tax reliefagainst a company’s taxable profits for expenditure on eligibleequipment, such as water meters and monitoring equipment, flowcontrollers, leakage detection equipment, low-flush toilets and efficienttaps. Details of qualifying equipment are given on the WaterTechnology List (www.eca-water.gov.uk).

3

Structure of the guide

The guide consists of the following sections:

• Calculating key performance indicators.

• Useful facts and figures, including:

– potential reductions in water use for different applications;

– typical rates of water use;

– average costs for different types of water;

– emissions of greenhouse gases;

– unit conversion factors.

• Water-saving tips - opportunities to reduce consumption aimed atareas or processes that use:

– large volumes of water;

– water unnecessarily;

– water with significant added value such as steam or treatedwater (eg softened, demineralised and chlorinated).

• Sub-sector pages (see opposite):

– fresh liquid milk;

– butter and cheese;

– ‘other’ milk products.

• Useful contacts - details of organisations that offer help and adviceto UK companies seeking to reduce their water use and improvetheir environmental performance.

Further free advice and information are available fromEnvirowise. Call the Advice Line on 0800 585794 or visitthe Envirowise website (www.envirowise.gov.uk).

4

Sub-sector pages

The sub-sector pages provide information to help you assess andreduce your dairy’s water use. The pages follow the same format andinclude summary tables and graphs.

Table showing water use and effluent load benchmarks

• Water use data. Water consumption data are calculated usingwater use (litre) per litre milk (equivalent to m3 water per m3 milk) orlitres per kg product (equivalent to m3 per tonne product).

• COD discharged data. COD data are calculated using CODdischarged (in raw untreated effluent) expressed as kg/m3 orkg/tonne product.

The number of samples in each dataset is also shown.

Each table gives values for the minimum, maximum, average, lowerquartile and upper quartile benchmarks.

• The lower quartile is the dataset containing the 25% lowest wateruse values. If a company’s water use lies within this range, itsperformance is better than average but there may still be someroom for improvement.

• The upper quartile is the dataset containing the 25% highest wateruse values. If a company’s water use lies within this range, itsperformance is below average and there is significant room forimprovement.

Graphs showing the performance of dairies in the sub-sector

The two graphs for the sub-sector show:

• Water:product ratios for different sites. The units used varybetween sub-sectors.

• COD:product ratios for different sites. The units used varybetween sub-sectors.

5

Those dairies with the lowest ratios are performing better in terms ofthese key performance indicators (KPIs) than others in their sub-sector.

Use the graphs to find out how your dairy’s performance compareswith that of others in the sector. Could your dairy do better and savemoney?

All data shown on the sub-sector tables and graphs arecourtesy of Dairy UK.

6

CALCULATING KEY PERFORMANCEINDICATORSDairies can calculate their water consumption for use asan internal benchmark or key performance indicator(KPI), usually expressed as the water:milk or water:product ratio. The following form provides an easy step-by-step approach to calculating water consumption KPIs.

Calculating water consumption KPIs

Date Meter reading Water consumption (m3)

First day of Month 1 M1 -

First day of Month 2 M2 Month 1 = M2 - M1

First day of Month 3 M3 Month 2 = M3 - M2

First day of Month 4 M4 Month 3 = M4 - M3

First day of Month 5 M5 Month 4 = M5 - M4

First day of Month 6 M6 Month 5 = M6 - M5

First day of Month 7 M7 Month 6 = M7 - M6

First day of Month 8 M8 Month 7 = M8 - M7

First day of Month 9 M9 Month 8 = M9 - M8

First day of Month 10 M10 Month 9 = M10 - M9

First day of Month 11 M11 Month 10 = M11 - M10

First day of Month 12 M12 Month 11 = M12 - M11

Last day of Month 12 M13 Month 12 = M13 - M12

Annual water consumption (AWC) M13 - M1

Parameter Value Units

Annual production T tonnes milk in or product out

KPI Value Units

Water use per tonne product AWC/T m3

7

USEFUL FACTS AND FIGURES

Typical achievable reductions in water use

Water-saving initiative Typical reduction

Per project As percentage ofsite’s total use

Commercial applications

Toilets, urinals, showers, taps 40% 1%

Industrial applications

Closed loop recycle seal water 90% 5%

CIP optimisation 25% 6%

Re-use of UHT cooling water 90% 8%

Borehole water optimisation 30% (less mains) 10% (of bill)

Recycle of autoclave cooling water 50% 14%

Re-use of spray drier condensate 90% 50%

Re-use of reverse osmosis (RO) 30% 2%reject water

Softener optimisation 40% 2%

Slat chain lube optimisation 25% 1%

Typical rates of water use

Item Average water use

Employee (full-time, no canteen) 35 litres/person/day

Employee (full-time, with canteen) 50 litres/person/day

Toilets 6 - 9 litres/flush

Leaky tap (continual 5 mm stream) 60 litres/hour

1” hose 1 m3/hour

2” pipe 4.2 m3/hour

8

The true cost of water

Water type Typical average*

UK mains supply** £0.50 - £1.50/m3 (standard metered tariff)

Chlorinated water £0.90 - £1.90/m3

Softened water £0.85 - £2.20/m3

Demineralised/deionised water £4.50 - £6.50/m3

Condensate £4.00 - £6.00/m3

Steam £21 - £24/tonne

* Excludes capital costs** Depends on supplier (2006/2007 figures)

Emissions of greenhouse gases

Indicator Results 2005/2006

Greenhouse gases emitted

In supplying 1Ml water 0.289 tonnes

In treating 1Ml sewage 0.406 tonnes

Source: Water UK, 2005/2006Note: These figures indicate supply of water and treatment of effluent.

9

Water conversion units

To convert from: To: Multiply by:

Volume

litres cubic metres 0.001

cubic metres litres 1,000

UK gallons cubic metres 0.0045

US gallons UK gallons 0.8327

Flow rate

UK gallons/hour cubic metres/hour 0.0045

UK gallons/minute cubic metres/hour 0.2727

UK gallons/second cubic metres/hour 16.36

cubic metres/hour litres/second 0.278

litres/second cubic metres/hour 3.6

Weight

cubic metres of clean water kilograms 1,000

litres of clean water kilograms 1

10

WATER-SAVING TIPSThis list suggests some simple actions that can minimisethe amount of water you use in your dairy.

• Check for leaking taps and pipework.

• Prevent unnecessary water use by fitting water-minimising controlswhere possible, eg:

– push taps;

– flow regulators/restrictors;

– cistern displacement devices;

– spray nozzles on hoses;

– low-flush toilets;

– sensor flushing controls on urinals.

• Overflow control:

– install float valves or sensors to control tank filling operations;

– make sure overflows can be seen.

• Fit pressure regulating valves if mains pressure or booster pumppressure means the site’s water distribution system is operating attoo high a pressure; flow through a tap will increase from around10 litres/minute to around 30 litres/minute for a pressure increase of300 - 500 kPa (3 - 5 bar). Operate distribution systems at theminimum acceptable pressure.

• Recover condensate for boiler feed make-up. Also make sure pipes(including steam pipes) are adequately lagged. Check boilerblowdown control.

• Pay particular attention to areas and processes which use waterthat has been processed prior to use and, therefore, has addedvalue (savings will be worth more), eg:

– heated or chilled water;

– deionised (or demineralised), softened or chlorinated water.

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• Where cooling water is used on a once-through basis, use closedloop systems where possible. It may also be possible to recoverheat from the water using a heat exchanger. If the cooling water isclean but warm, it may be possible to re-use it.

• Washing vessels and pipework. Where possible, remove productfrom systems before washing using scrapers, pigging systems orcompressed air lines. Alternatively, it may be possible to rinse outsystems and re-use the rinse water as subsequent batch make-up,but take care not to compromise product quality or hygienestandards.

• Cleaning-in-place (CIP) systems can minimise water use andeffluent generation. To reduce water use further, consider fullautomation of the system and the use of final rinse water as initialrinse water on subsequent cleaning operations.

• Place trays under machines and install guards on conveyor belts toreduce waste to floor. Where possible, recover waste for use asanimal feed.

• Fit screens on drains to retain solid waste.

• Minimise water use in manual cleaning by dry cleaning waste onfloors using brushes, squeegees and vacuum cleaners.

• Where hoses are used, fit trigger action nozzles.

• Re-use water where possible, eg use lightly soiled rinse water forcrate washing.

• Where appropriate, treat wastewater or condensate by membranefiltration. For example, reverse osmosis permeate (often around60°C) can then be used in CIP operations or to feed a hosenetwork. Alternatively, heat can be recovered in heat exchangers foruse where processes require heating stages, such as pasteurisationor fat separation.

• Yogurt has a very high COD, contributing 1.3 kg COD per kg ofwaste. This makes it essential to collect waste from around fillingmachines in containers rather than hosing it to the floor.

12

• Adopt best practice in water management by considering thefollowing:

Further reading

• GG349 Water minimisation in the food and drink industry

• CS404 Dairy profits from zero water use

• GG152R Tracking water use to cut costs

• GG522 Cost-effective water saving devices and practices - forcommercial sites

• GG523 Cost-effective water saving devices and practices - forindustrial sites

• WaterNet (www.envirowise.gov.uk/waternet)

13

Can you eliminate water use at source?Yes

Yes

Yes

No

No

No

Can you reduce water use?

Can you re-use/recycle water?

Calculate the cost of disposal

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USEFUL CONTACTS

• Envirowisewww.envirowise.gov.ukEnvirowise Advice Line 0800 585794

Envirowise offers businesses of all sizes and sectors a wide rangeof free, independent and practical advice designed to improve theirprocesses, profitability and competitiveness.

• Dairy UKwww.dairyuk.org

Dairy UK acts for, and represents, dairy processing and farmingorganisations in England, Wales, Scotland and Northern Ireland.

• Environment Agencywww.environment-agency.gov.uk

The Environment Agency is the leading public body responsible forprotecting and improving the environment in England and Wales.

• Department for Environment, Food and RuralAffairs (Defra)www.defra.gov.uk

Defra aims to protect and improve the environment, and to integratethe environment with other policies across Government and ininternational forums.

• Welsh Assembly Governmenthttp://new.wales.gov.uk/

The Welsh Assembly Government is responsible for most of theissues of day-to-day concern to the people of Wales.

20

• ARENA Networkwww.arenanetwork.org

ARENA Network is an independent organisation providing practicalsupport on environmental issues to business and otherorganisations primarily in Wales.

• Scottish Environment Protection Agency (SEPA)www.sepa.org.uk

SEPA is the leading public body responsible for protecting andimproving the environment in Scotland.

• Scottish Governmentwww.scotland.gov.uk

The Scottish Government is responsible for most of the issues ofday-to-day concern to the people of Scotland.

• Environment & Heritage Service (EHS)www.ehsni.gov.uk

EHS aims to protect and conserve Northern Ireland’s heritage. ItsEnvironmental Protection division provides information about waterquality, regulating pollution, promoting environmental quality andwaste management.

• Department of the Environment Northern Ireland www.doeni.gov.uk

The Department is part of the Northern Ireland Executive and aimsto improve the quality of life for everyone in Northern Ireland.

• Invest Northern Irelandwww.investni.com

The role of Invest NI is to grow the economy by helping new andexisting businesses to compete internationally, and by attractingnew investment to Northern Ireland.

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Harwell Science and Innovation Campus | Didcot | Oxfordshire | OX11 0QJ E advice@envirowise.gov.uk | www.envirowise.gov.uk

Envirowise - sustainable practices, sustainable profits. Envirowise is a Government-funded programme dedicated to puttingthe sustainable use of resources at the heart of business practice. It is managed by Momenta, an operating division of AEATechnology plc, and Serco TTI. Envirowise is funded in England by Defra’s Business Resource Efficiency and Waste (BREW)Programme and supported by BERR; the Scottish Government in Scotland; the Welsh Assembly Government’s MaterialsAction Programme (MAP) in Wales; and Invest Northern Ireland in Northern Ireland.

EN740 © Crown copyright. First printed November 2007. Printed on paper containing 80% recycled post-consumer fibre.This material may be freely reproduced in its original form except for sale or advertising purposes.