BENCHMARKING WATER USE IN DAIRIES

Transcription

1 BENCHMARKING WATER USE IN DAIRIES

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3 BENCHMARKING WATER USE IN DAIRIES This publication was produced by Envirowise Prepared with assistance from Ashact

4 SUMMARY This 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.

5 CONTENTS Section Page INTRODUCTION 2 Why save water? 3 Structure of the guide 4 CALCULATING KEY PERFORMANCE INDICATORS 7 USEFUL FACTS AND FIGURES 8 WATER-SAVING TIPS 11 Further reading 13 DAIRY: FRESH LIQUID MILK 14 DAIRY: BUTTER AND CHEESE 16 DAIRY: OTHER MILK PRODUCTS 18 USEFUL CONTACTS 20 1

6 INTRODUCTION This 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 chemical oxygen demand (COD) load discharged for three dairy activities: fresh liquid milk; butter and cheese; other milk products. These benchmarks provide an indication of how a dairy is performing in terms of water consumption and effluent generation (ie product loss) compared with the rest of its sector. Sectors are characterised by Standard Industrial Classification (SIC) Code. 1 The guide complements Water Account ( an online water benchmarking tool developed by Envirowise. Water Account also contains specific information for the three sectors of the dairy industry. Companies with internet access can use this tool to manage their water use and to find out more about water-saving measures. The benchmarks in this guide are based on data collected during an independent survey of water use in dairies carried out by Dairy UK during 2004/2005 and 2005/ These data also form the basis of information used in the dairy sector of the Water Account database, which allows dairies to enter their water use and obtain an instant indication of how their performance compares with similar dairies. 1 Office for National Statistics (ONS), UK Standard Industrial Classification of Economic Activities Available at: 2 The source of all data is confidential 2

7 Why save water? Companies are often unaware of the true cost of water. They think it costs 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 amount charged for supply and disposal, and can amount to 1% of turnover. Companies that adopt a systematic approach to water reduction typically 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 systematic approach to water minimisation could increase profits by 10%. Furthermore, cutting water costs can also help dairies meet supply chain pressures to improve environmental performance. Investment in selected sustainable technologies, products and systems, eg cleaning-in-place (CIP) systems, may qualify for an Enhanced Capital Allowance (ECA). This provides for 100% tax relief against a company s taxable profits for expenditure on eligible equipment, such as water meters and monitoring equipment, flow controllers, leakage detection equipment, low-flush toilets and efficient taps. Details of qualifying equipment are given on the Water Technology List ( 3

8 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 at areas or processes that use: large volumes of water; water unnecessarily; water with significant added value such as steam or treated water (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 advice to UK companies seeking to reduce their water use and improve their environmental performance. Further free advice and information are available from Envirowise. Call the Advice Line on or visit the Envirowise website ( 4

9 Sub-sector pages The sub-sector pages provide information to help you assess and reduce your dairy s water use. The pages follow the same format and include summary tables and graphs. Table showing water use and effluent load benchmarks Water use data. Water consumption data are calculated using water use (litre) per litre milk (equivalent to m 3 water per m 3 milk) or litres per kg product (equivalent to m 3 per tonne product). COD discharged data. COD data are calculated using COD discharged (in raw untreated effluent) expressed as kg/m 3 or kg/tonne product. The number of samples in each dataset is also shown. Each table gives values for the minimum, maximum, average, lower quartile and upper quartile benchmarks. The lower quartile is the dataset containing the 25% lowest water use values. If a company s water use lies within this range, its performance is better than average but there may still be some room for improvement. The upper quartile is the dataset containing the 25% highest water use values. If a company s water use lies within this range, its performance is below average and there is significant room for improvement. 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 vary between sub-sectors. COD:product ratios for different sites. The units used vary between sub-sectors. 5

10 Those dairies with the lowest ratios are performing better in terms of these key performance indicators (KPIs) than others in their sub-sector. Use the graphs to find out how your dairy s performance compares with that of others in the sector. Could your dairy do better and save money? All data shown on the sub-sector tables and graphs are courtesy of Dairy UK. 6

11 CALCULATING KEY PERFORMANCE INDICATORS Dairies can calculate their water consumption for use as an internal benchmark or key performance indicator (KPI), usually expressed as the water:milk or water: product ratio. The following form provides an easy stepby-step approach to calculating water consumption KPIs. Calculating water consumption KPIs Date Meter reading Water consumption (m 3 ) 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 m 3 7

12 USEFUL FACTS AND FIGURES Typical achievable reductions in water use Water-saving initiative Typical reduction Per project As percentage of site 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 Employee (full-time, no canteen) Employee (full-time, with canteen) Toilets Leaky tap (continual 5 mm stream) Average water use 35 litres/person/day 50 litres/person/day 6-9 litres/flush 60 litres/hour 1 hose 1 m 3 /hour 2 pipe 4.2 m 3 /hour 8

13 The true cost of water Water type UK mains supply** Typical average* /m 3 (standard metered tariff) Chlorinated water /m 3 Softened water /m 3 Demineralised/deionised water /m 3 Condensate /m 3 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 In treating 1Ml sewage tonnes tonnes Source: Water UK, 2005/2006 Note: These figures indicate supply of water and treatment of effluent. 9

14 Water conversion units To convert from: To: Multiply by: Volume litres cubic metres cubic metres litres 1,000 UK gallons cubic metres US gallons UK gallons Flow rate UK gallons/hour cubic metres/hour UK gallons/minute cubic metres/hour UK gallons/second cubic metres/hour cubic metres/hour litres/second litres/second cubic metres/hour 3.6 Weight cubic metres of clean water kilograms 1,000 litres of clean water kilograms 1 10

15 WATER-SAVING TIPS This list suggests some simple actions that can minimise the amount of water you use in your dairy. Check for leaking taps and pipework. Prevent unnecessary water use by fitting water-minimising controls where 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 pump pressure means the site s water distribution system is operating at too high a pressure; flow through a tap will increase from around 10 litres/minute to around 30 litres/minute for a pressure increase of kpa (3-5 bar). Operate distribution systems at the minimum acceptable pressure. Recover condensate for boiler feed make-up. Also make sure pipes (including steam pipes) are adequately lagged. Check boiler blowdown control. Pay particular attention to areas and processes which use water that has been processed prior to use and, therefore, has added value (savings will be worth more), eg: heated or chilled water; deionised (or demineralised), softened or chlorinated water. 11

16 Where cooling water is used on a once-through basis, use closed loop systems where possible. It may also be possible to recover heat from the water using a heat exchanger. If the cooling water is clean but warm, it may be possible to re-use it. Washing vessels and pipework. Where possible, remove product from systems before washing using scrapers, pigging systems or compressed air lines. Alternatively, it may be possible to rinse out systems and re-use the rinse water as subsequent batch make-up, but take care not to compromise product quality or hygiene standards. Cleaning-in-place (CIP) systems can minimise water use and effluent generation. To reduce water use further, consider full automation of the system and the use of final rinse water as initial rinse water on subsequent cleaning operations. Place trays under machines and install guards on conveyor belts to reduce waste to floor. Where possible, recover waste for use as animal feed. Fit screens on drains to retain solid waste. Minimise water use in manual cleaning by dry cleaning waste on floors 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 for crate washing. Where appropriate, treat wastewater or condensate by membrane filtration. For example, reverse osmosis permeate (often around 60 C) can then be used in CIP operations or to feed a hose network. Alternatively, heat can be recovered in heat exchangers for use where processes require heating stages, such as pasteurisation or fat separation. Yogurt has a very high COD, contributing 1.3 kg COD per kg of waste. This makes it essential to collect waste from around filling machines in containers rather than hosing it to the floor. 12

17 Adopt best practice in water management by considering the following: Yes Yes Yes Can you eliminate water use at source? No Can you reduce water use? No Can you re-use/recycle water? No Calculate the cost of disposal IMPLEMENT WATER MANAGEMENT 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 - for commercial sites GG523 Cost-effective water saving devices and practices - for industrial sites WaterNet ( 13

18 DAIRY: FRESH LIQUID MILK Sector: DAIRY SIC Code: 15.51/1 Sub-sector: FRESH LIQUID MILK Did you know? Milk has a COD of around 200,000 mg/litre. Pump seal water may be as much as 4% of a site s total water use. Sub-sector Water use units Water use or COD discharged Minimum Average Maximum Quartile No. of (good) (poor) Lower Upper samples Fresh liquid milk Litre/litre or m water/m 3 product COD load (kg/tonne product)

19 How do you perform? Where s your dairy on the graph? 3.0 Water:milk ratio (litre:litre) COD:milk ratio (kg:tonne) Site reference number Site reference number Assumptions The benchmark covers SIC Code 15.51/1 Liquid milk and cream production. Site reference numbers are held by Dairy UK. 15

20 DAIRY: BUTTER AND CHEESE Sector: DAIRY SIC Code: 15.51/2 Sub-sector: BUTTER AND CHEESE Did you know? 1 kg of milk fat is equivalent to 3 kg of COD, 1 kg of lactose to 1.13 kg of COD and 1 kg of protein to 1.36 kg of COD.* Extending a CIP pre-rinse helps to prevent milk getting in the detergent tank and saves water in the long run. * Pollution Prevention and Abatement Handbook, World Bank Group, 1998 Sub-sector Water use units Water use or COD discharged Minimum Average Maximum Quartile No. of (good) (poor) Lower Upper samples Butter and cheese Litre/kg product COD load (kg/tonne product)

21 How do you perform? Where s your dairy on the graph? 20 Water:cheese ratio (litre:kg) COD:cheese ratio (kg:tonne) Site reference number Site reference number Assumptions The benchmark covers SIC Code 15.51/2 Butter and cheese production. Site reference numbers are held by Dairy UK. 17

22 DAIRY: OTHER MILK PRODUCTS Sector: DAIRY SIC Code: 15.51/9 Sub-sector: OTHER MILK PRODUCTS Did you know? Yogurt has a COD of around 2-300,000 mg/litre depending on its fat and sugar content (sugar has a COD of around 1.3 million mg/litre; that s right kg/kg!). Cleaning water can account for 50-90% of a site s water consumption. Sub-sector Water use units Water use or COD discharged Minimum Average Maximum Quartile No. of (good) (poor) Lower Upper samples Other milk products Litre/kg product COD load (kg/tonne product)

23 How do you perform? Where s your dairy on the graph? 12 Water:product ( other dairy produce) ratio (litre:kg) 20 COD:product ( other dairy produce) ratio (kg:tonne) Site reference number Site reference number Assumptions The benchmark covers SIC Code 15.51/9 Manufacture of other milk products. Site reference numbers are held by Dairy UK. 19

24 USEFUL CONTACTS Envirowise Envirowise Advice Line Envirowise offers businesses of all sizes and sectors a wide range of free, independent and practical advice designed to improve their processes, profitability and competitiveness. Dairy UK Dairy UK acts for, and represents, dairy processing and farming organisations in England, Wales, Scotland and Northern Ireland. Environment Agency The Environment Agency is the leading public body responsible for protecting and improving the environment in England and Wales. Department for Environment, Food and Rural Affairs (Defra) Defra aims to protect and improve the environment, and to integrate the environment with other policies across Government and in international forums. Welsh Assembly Government The Welsh Assembly Government is responsible for most of the issues of day-to-day concern to the people of Wales. 20

25 ARENA Network ARENA Network is an independent organisation providing practical support on environmental issues to business and other organisations primarily in Wales. Scottish Environment Protection Agency (SEPA) SEPA is the leading public body responsible for protecting and improving the environment in Scotland. Scottish Government The Scottish Government is responsible for most of the issues of day-to-day concern to the people of Scotland. Environment & Heritage Service (EHS) EHS aims to protect and conserve Northern Ireland s heritage. Its Environmental Protection division provides information about water quality, regulating pollution, promoting environmental quality and waste management. Department of the Environment Northern Ireland The Department is part of the Northern Ireland Executive and aims to improve the quality of life for everyone in Northern Ireland. Invest Northern Ireland The role of Invest NI is to grow the economy by helping new and existing businesses to compete internationally, and by attracting new investment to Northern Ireland. 21

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28 Harwell Science and Innovation Campus Didcot Oxfordshire OX11 0QJ E advice@envirowise.gov.uk Envirowise - sustainable practices, sustainable profits. Envirowise is a Government-funded programme dedicated to putting the sustainable use of resources at the heart of business practice. It is managed by Momenta, an operating division of AEA Technology 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 Materials Action Programme (MAP) in Wales; and Invest Northern Ireland in Northern Ireland. EN740 Crown copyright. First printed November 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.