GG26 GUIDE

SAVING MONEY THROUGH WASTE MINIMISATION: REDUCING WATER USE

GOOD PRACTICE: Proven technology and techniques for profitable environmental improvement

SAVING MONEY THROUGH WASTE MINIMISATION: REDUCING WATER USE This Good Practice Guide was produced by the Environmental Technology Best Practice Programme

Prepared with assistance from: W S Atkins Consultants Ltd March Consulting Group Aspects International

With particular acknowledgement for contributions from: Pilkington’s Tiles Ltd

Stoves plc

Chloride Motive Power Batteries Ltd

Borden Decorative Products Ltd

J W Lees and Company

Lever Brothers Ltd

Colgate-Palmolive Ltd

Milliken Industrials Ltd

© Crown copyright. First printed March 1996.

This material may be freely reproduced except for sale or advertising purposes.

The Environmental Technology Best Practice Programme is a joint Department of Trade and Industry and Department of the Environment initiative managed by AEA Technology through ETSU and the National Environmental Technology Centre. The Environmental Technology Best Practice Programme promotes the use of better environmental practices that reduce business costs for UK industry and commerce. The Programme concentrates on two ‘permanent themes’ to achieve its aims: WASTE MINIMISATION Management methods for systematically reducing emissions to land, water and air. COST-EFFECTIVE CLEANER TECHNOLOGY Technological solutions for reducing waste at source. While these themes are applicable to every industrial sector, the Programme supplements them by focusing on ‘areas of special attention’ which can either be an industrial sector or a particular pollutant. The Programme provides all areas of industry and commerce with information and advice on environmental technologies and techniques. This is achieved through the elements described on the opposite page.

For more information about the Programme please phone the Environmental Helpline on 0800 585794

ENVIRONMENTAL HELPLINE 0800 585794 the gateway to the Environmental Technology Best Practice Programme The Programme’s Environmental Helpline has access to a wide range of environmental information. It offers free advice to companies on technical matters, environmental legislation, conferences and promotional seminars. For smaller companies, a free counselling visit may be offered at the discretion of the Helpline Manager.

ENVIRONMENTAL PERFORMANCE GUIDES the benchmark for profitable environmental improvement Environmental Performance Guides contain data on current environmental performance for a particular industry sector, technology or operation and are compiled on the basis of replies to confidential questionnaires. The Guides enable individual companies to compare their performance with that of others undertaking similar operations and to identify potential areas for improvement.

BEST PRACTICE IN ACTION environmental improvements that save money GOOD PRACTICE

NEW PRACTICE

FUTURE PRACTICE

Proven technology and techniques for profitable environmental improvement.

New technology and techniques for profitable environmental improvement.

Tomorrow’s technology and techniques for profitable environmental improvement.

Good Practice Guides are handbooks that provide detailed guidance on proven technologies and techniques that save money and reduce waste and pollution.

The aim of New Practice is to help UK industry and commerce to adopt new technologies and techniques that save money and reduce waste and pollution.

Good Practice Case Studies are prime examples of proven, cost-effective technologies and techniques that have already improved environmental performance. Independent experts evaluate projects that have been implemented in industrial companies, and the details are published in Programme literature. In return for co-operating with this process, host companies are eligible for access payments of up to £10 000.

New Practice Case Studies are the first commercial applications of innovative measures that improve environmental performance. As with Good Practice, independent experts evaluate the projects and the details are published in Programme literature. In return for co-operating with this process, host companies are eligible for access payments of up to £50 000.

This is the Programme’s Research and Development element. It supports work progressing novel environmental technologies and techniques. The results of Future Practice projects are published to encourage companies to take up successful developments.

For more information about the Programme please phone the Environmental Helpline on 0800 585794

SUMMARY

While water costs may appear insignificant, the true cost is considerably higher than the basic charges for supplying water and discharging effluent. Pumping, maintenance, capital depreciation and treatment costs should also be considered, as well as the value of lost materials. Inappropriate use of water could cost a company 1% of its turnover, with half being technically and cost-effectively recoverable. Minimising the ‘hidden costs’ alongside water purchase costs and effluent charges would save £10 000/year for a company with a £2 million annual turnover. This Good Practice Guide outlines a systematic approach to reducing the costs associated with water use and wastewater disposal. This procedure, which can be incorporated within existing management systems, stresses the importance of: ■

involving all members of staff from senior management to plant operators;

■

developing a clear, easily understood plan;

■

determining the true costs of water consumption and wastewater generation;

■

identifying all water inputs and outputs;

■

drawing up a water mass balance;

■

allocating annual water consumption between major users;

■

brainstorming to generate water saving ideas;

■

implementing all feasible options;

■

maintaining savings.

The Guide also explains that reducing water consumption is both compatible and consistent with reducing contaminant concentrations. The approach needed to minimise water consumption successfully is also applicable to reducing contaminant levels in wastewater and may produce additional cost benefits. The potential cost savings and other benefits of reducing water consumption are highlighted in a series of Industry Examples. All these successful water saving schemes are selected from projects undertaken by participants in the regional waste minimisation club, Project Catalyst. This Good Practice Guide is one of a series of three complementary Guides on waste minimisation. The others cover the use of raw materials, and teams and champions. Both are available free through the Environmental Helpline on 0800 585794.

CONTENTS

Section 1

2

Page

Introduction

1

1.1

Industry examples

1

1.2

Adopt a systematic approach

2

The use of water

3

2.1

Water supply

3

2.2

Water disposal

3

2.3

Typical uses

4

2.4

Reducing contaminant levels

5

3

Costs associated with the use of water

6

4

Other benefits of reducing water consumption

8

5

Developing a water reduction programme

9

5.1

Who should be involved?

9

5.2

The plan

9

6

7

How to reduce water and wastewater costs

11

6.1

Draw up a water mass balance

11

6.2

Allocate consumption

12

6.3

Identify water saving ideas

13

6.4

Analyse different options

14

6.5

Maintain savings

14

6.6

Report success

16

Action plan

17

1 INTRODUCTION

This Good Practice Guide describes the costs associated with water use and wastewater disposal and outlines a cost-effective procedure for reducing these costs. Participants in UK waste minimisation clubs have already achieved significant cost savings and waste reduction by applying this procedure to wastewater generation.

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Other Good Practice Guides in this series are Good Practice Guide (GG25) Saving Money Through Waste Minimisation: Raw Material Use and Good Practice Guide (GG27) Saving Money Through Waste Minimisation: Teams and Champions. Both are available free through the Environmental Helpline on 0800 585794.

1.1 INDUSTRY EXAMPLES The nine Industry Examples (see Table 1) on the loose-leaf sheets in the back of this Guide describe the achievements of some of the participants in Project Catalyst, a regional waste minimisation club covering the Mersey Basin region. It is hoped that their success in reducing costs will encourage other companies to consider how they can reduce both water consumption and wastewater generation. Industry

Company

Title

1

Pilkington’s Tiles Ltd

Wastewater reprocessing at a wall tile manufacturer

2

Chloride Motive Power Batteries Ltd

Site water savings at a lead acid battery manufacturer

3

J W Lees and Company

Tank room water savings at a brewery

4

Colgate-Palmolive Ltd

Site water savings at a soap manufacturer

5

Stoves plc

Recirculation of cooling water at a cooker manufacturer

6

Borden Decorative Products Ltd

Site water savings at a wallpaper manufacturer

7

Lever Brothers Ltd

Ongoing savings at a detergent manufacturer

8

Milliken Industrials Ltd

Reduction in dye volumes at a carpet tile manufacturer

9

J W Lees and Company

Wort cooling water reduction at a brewery

Example

Table 1 Good Practice Guide 26 - Industry Examples

1

PROJECT CATALYST

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The Mersey Basin has one of the major concentrations of industry in the UK and it is recognised that industry is a significant contributor to pollution of the three environmental media: air, water and land. Project Catalyst was initiated to achieve and promote cleaner production through waste minimisation in the region’s businesses, including manufacturing and service industries. The project involved the participating companies’ sites in conducting a systematic audit and monitoring programme to identify waste minimisation opportunities as demonstration models for other companies to follow. It introduced management systems and training into the participant companies to ensure that the improvements continued as part of the company philosophy after the project had been completed. Further details are available through the Environmental Helpline on 0800 585794.

1.2 ADOPT A SYSTEMATIC APPROACH Companies considering a water and wastewater minimisation programme are advised to investigate all possible options before selecting the most appropriate for their circumstances. They should not be tempted to simply follow one of the Industry Examples described in the Guide. Such a piecemeal approach will not necessarily produce the maximum savings possible nor will it generate a system that allows savings to be maintained and improved. The recommended method of reducing water and wastewater use and the associated costs is to adopt the systematic approach described in this Guide. This approach will enable a company to identify cost-effective, achievable savings. Once savings opportunities have been identified, an effective system of Monitoring to Manage should be implemented. Such a system will provide managers with the information they need to maintain control over water and wastewater costs.

2

2 T H E U S E O F W AT E R

In the UK, the use of water tends to be taken for granted. The perceived low costs are not regarded as significant and the infrastructure for its supply and removal is poorly understood.

2.1 WATER SUPPLY Industry and commerce consume considerable quantities of water each year. This water is obtained in two ways: ■

supplied by the local water company through the mains water system as potable water, ie water that is fit to drink;

■

abstracted directly from rivers or boreholes sunk into an underground aquifer.

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Licensed abstraction of water, by industry, totalled 1 420 million m3 in 1993. Nondomestic (ie mostly industry and commerce) use of water from the public supply was approximately 1 600 million m3/year in 1993/94. Hence, total water use by industry is around 3 000 million m3/year. Digest of Environmental Protection and Water Statistics No. 17 1995 (Department of the Environment); Waterfacts 1994 (Water Services Association); 1993/94 Report on the Cost of Water Delivered and Sewage Collected (Ofwat).

A particular site may use water from several sources, eg from the mains, a river, a borehole, a canal, etc, depending on availability, quality and cost. Before it can be used for a particular purpose, the water may require treatment. Treatment processes include solids removal, pH adjustment, deionisation, chlorination, deaeration, sterilisation, etc. These treatment processes usually generate their own wastewater flows.

2.2 WATER DISPOSAL Virtually all the water supplied to a site, factory or office is returned to a river or the sea by: ■

direct discharge;

■

via the sewer and the local sewage treatment works.

Some of the water entering a manufacturing site leaves that site either as emissions to the atmosphere (eg due to drying operations) or in the site’s products (eg in the food and drink industry). However, these amounts of water generally form a small part of total consumption. Wastewater may need to be treated on-site before being discharged either to a watercourse or to the sewerage system. Fig 1 shows a typical cycle for water taken from a river by industry and commerce.

3

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Fig 1 Generalised flow of water to industry or commerce

A saving in water consumption - and therefore purchasing costs - usually leads to a saving in wastewater volumes and thus disposal costs. A reduction in water consumption may also reduce the environmental impact of any subsequent discharge to a river. At Pilkington’s Tiles Ltd wastewater volumes decreased by up to 100 000 m3/year. (See Industry Example 1)

2.3 TYPICAL USES Water is used for different purposes depending on the nature of the business and the processes carried out. Table 2 lists some typical uses, together with the normal source of water for each category. Purpose

Description

Typical source

Cooling

To remove heat from rotating machinery.

Direct from river (when available).

To reduce the temperature of process

Returned directly to river.

materials.

Borehole.

To condense vapours. Processing

Direct contact with raw materials and

Mains water.

products to dilute, mix, heat/cool, separate raw materials and products. Cleaning

Used during maintenance activities to

Mains water.

clean equipment for: - hygiene reasons; - product quality reasons; - product changeover. Sanitary

Used by people for drinking, washing

Mains water.

and flushing toilets. Steam raising

Generation of steam for process heating.

Mains water.

Treating

Abnormal events where water is used to

Mains water.

spills/leaks/drips

dilute and disperse. Table 2 Typical uses of water

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2.4 REDUCING CONTAMINANT LEVELS During its passage through a site, water becomes contaminated with various soluble and insoluble chemicals. A frequently expressed initial concern is that a significant reduction in water use will increase the concentration of these contaminants. Since both disposal costs and legislative requirements tend to be concentration-based, it can be argued that there is no benefit from reducing water consumption. There are two major reasons why this argument is wrong: ■

■

Dilution is not the solution to pollution. Current best practice and the basic approach required by the Environmental Protection Act 1990 is to minimise all emissions at source and not to simply dilute them down to an apparently ‘acceptable’ level.

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Contaminant levels should be reduced as well. The approach required to minimise water consumption successfully is also applicable to reducing contaminant levels in the water.

The need to reduce water consumption is both compatible and consistent with reducing contaminant concentrations.

Chloride Motive Power Batteries Ltd achieved a saving of nearly £8/tonne of lead processed, by separating out the oxides from contaminated water. This meant that both the oxides and the water could be recycled, and represented annual water-based savings of £110 000. (See Industry Example 2)

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3 C O S T S A S S O C I AT E D W I T H T H E U S E O F W AT E R

One of the early priorities when implementing a programme to reduce water and wastewater costs is to identify the true cost associated with the utility. In general, this is unknown and sometimes mistakenly regarded as too low to be of concern. The many possible components making up the total cost of water use are listed in Table 3. The true cost may be more than three times the total amount charged for supply and disposal. Component

Comments

Purchase price

If mains water, this is usually charged per m3, and paid monthly. The cost is currently set to rise at a rate greater than inflation.

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Disposal price

If discharged to sewer, this is usually charged per m3, and paid monthly. The cost is currently set to rise at a rate greater than inflation. Trade effluent charges are usually levied (on the basis of the Mogden formula) to account for the chemicals present in the effluent, eg chemical oxygen demand (COD), suspended solids content, etc.

Pumping costs

Distributing water on the site incurs a pumping cost. The amount of electricity used by the pumps is a function of: - flow rate; - distribution pressure; - pumping efficiency.

Maintenance costs

These are associated with: - pumps; - flow meters; - corrosion of, or deposition in, pipework and equipment. Maintenance of the pipework distribution system also incurs a cost.

Capital costs

Excess capital costs will be incurred if the water supply system is not minimised during the design stage of either a new supply or extension of an existing supply.

Treatment costs

Costs are associated with treatment prior to use and/or treatment prior to discharge. These costs are made up of operating costs (usually per m3) and depreciation of capital costs.

Loss of valuable materials

These include raw materials, products, by-products

and

treatment/cleaning

chemicals. Table 3 Cost components of water use

In general, those responsible for water use within a manufacturing process are not responsible for its supply, disposal or costs. In many cases the actual consumption of water by a particular manufacturing area of the site is not known. It is therefore allocated as a proportion of the site’s measured consumption. However, this approach tends to encourage the incorrect notion that water is a fixed cost in the manufacturing manager’s budget.

6

The allocation of costs and how to manage them are discussed in more detail in Section 6. Purchase and disposal costs for the whole site are usually known accurately from the invoices sent by the water company. However, the additional costs can be significant. Pumping costs, maintenance costs, capital depreciation costs, treatment costs and the value of lost materials should be identified in order to estimate the true costs of water use. While water costs may appear trivial compared with turnover (1 - 2%), in absolute cost terms they often represent a significant amount of money, eg £20 000 - £40 000/year for a company with an annual turnover of £2 million. Both water purchase and disposal costs are also increasing at a rate higher than inflation. Significant reductions (up to 80%) can be achieved with paybacks that are acceptable to management (see the Industry Examples in the back of this Guide). Cash flow is also improved as the savings result in lower monthly bills.

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4 OTHER BENEFITS OF REDUCING W AT E R C O N S U M P T I O N

Although the main perceived benefit of reducing a site’s water consumption is cost savings, there are several other potential benefits. ■

Avoiding potential bottlenecks. The water company’s piped distribution system means that the supply of water to a site is relatively fixed. Increased supplies may not, therefore, be instantly available for a site wishing to increase production and thus requiring more water. Providing an increased water supply can be both expensive and time-consuming, depending on the site location, the distribution network, the water company’s priorities, etc. Reducing the consumption of water per unit of output is often the most cost-effective way of avoiding a potential supply problem.

■

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Helping water company planning. Water companies often produce medium-term and long-term water demand estimates, which are then coupled with plans for new or uprated water supplies. The high capital costs of providing new supplies mean that there can be benefits to the water company - and hence to their customers - of a systematic approach by industry and commerce to reducing water consumption, despite the short-term loss of revenue to the water company.

4

■

Environmental benefits. Even after appropriate treatment to comply with consent conditions, the discharge of effluent to the river or sea may still have an impact on that aquatic environment. Reducing the amount of material lost in wastewater reduces its impact on the environment as well as saving money.

Any reduction in water consumption may also be linked to a reduction in the environmental impact associated with supplying water, especially if water is abstracted from a river. The environmental benefit is doubled when both water abstraction from the river and wastewater flow to the river are reduced.

8

5 D E V E L O P I N G A W AT E R REDUCTION PROGRAMME

5.1 WHO SHOULD BE INVOLVED? At the beginning of the project, the following should be involved: ■

site management;

■

the project team (see Section 5.2.1);

■

the team leader.

However, all employees have a contribution to make and this should be encouraged. For example, during the data collection stages (see Section 6.2.1) some employees can be involved by being asked about their use of water or asked to help with data collection. Other employees may be invited to attend brainstorming meetings (see Section 6.3) where water saving ideas are thrashed out.

5.2 THE PLAN Before embarking on a water and wastewater minimisation programme, it is important to have a clear and easily understood plan. Without an effective plan: ■

not all the achievable savings are identified;

■

the exercise becomes a one-off ‘purge’;

■

ongoing savings are not pursued;

■

employees are not motivated to help;

■

implementation of ideas is difficult;

■

the programme loses momentum and disappears.

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5

J W Lees and Company’s three-stage action plan for minimising water use led to savings of over £650/week. (See Industry Example 3)

5.2.1

Elements of the plan

To be successful, the plan needs to be written down in a concise manner. The elements of a successful water reduction plan are: ■

Scope of work The plan should state whether: - The whole site is to be addressed or just one part. Addressing the whole site has advantages (see Section 6), but for a large site, one area or department could be selected for a pilot study. - Water only will be addressed or water and contaminants simultaneously.

■

Programme A timetable covering all the planned activities should be drawn up. The overall programme may last 12 months or more. Monthly milestones are therefore important. 9

■

Project team A team approach, with representatives from all the appropriate departments, is the most effective. However, the team should not be allowed to become too large or bureaucratic. Essential members include representatives from the departments responsible for the use of water (eg production) and for the supply of water (eg the services or utility department).

Colgate-Palmolive Ltd encourages participation from as many people as possible within the Company. Identifying all areas of water use has led to an annual cost saving of £186 000. (See Industry Example 4) ■

Team leader or ‘Champion’ This post is generally applicable to larger companies. A ‘Champion’ is a member of staff whose role is to advocate water and wastewater minimisation throughout the company. ‘Teams and Champions’ are the subject of Good Practice Guide (GG27) Saving Money Through Waste Minimisation: Teams and Champions, available free through the Environmental Helpline on 0800 585794.

■

Training The team’s training needs should be identified. Information on useful publications and further guidance is available through the Environmental Helpline on 0800 585794.

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■

Reporting Ways of promoting awareness and disseminating details of progress to the rest of the site should be developed. It is also important to identify a method of reporting regularly to either the Chief Executive or the site’s management team. In this way, the team’s work will be recognised and become part of the site’s management system.

■

Resources The resources needed to carry out the programme should be defined and approved. As an initial guide, the team leader should allocate half a day each week during the early stages; team members will require less time.

■

Management systems for ongoing improvement The need for ongoing improvement should be recognised and accepted by the team. Basic requirements for maintaining savings (see Section 6.5) should also be considered.

■

Techniques and methodology The systematic approach to be adopted should be defined (see Section 6).

■

Commitment and motivation It is important to ensure that the team: - knows why the work is being done; - knows what it hopes to achieve; - is aware of any constraints imposed on the programme; - is able to communicate effectively; - is motivated to achieve success; - is committed to the task. It is also important to review these aspects regularly.

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6 H O W T O R E D U C E W AT E R A N D W A S T E W AT E R C O S T S

Before examining ways of reducing water and wastewater costs, it is necessary to determine the true costs of water supply and disposal (see Section 3) and to carry out a survey of water use around the site.

6.1 DRAW UP A WATER MASS BALANCE The amount of water entering a site equals the amount of water leaving the site. This simple observation is called the water mass balance. Quantifying the components making up a site’s water mass balance is a powerful technique for identifying waste.

6.1.1

Annual water consumption

The first step is to determine the quantity of water consumed by the site over the last 12 months. Possible sources of data include: ■

water company invoices;

■

site meter readings;

■

operating data from site distribution pumps, ie pump flow rate x operating hours.

If there is more than one source of water (eg mains, river, borehole, etc), then each source will require consideration.

6.1.2

Effluent volumes

The amount of wastewater discharged as effluent over the same period should be obtained by similar means. The data may need to be adjusted to allow for the presence of various contaminants in the wastewater. However, in many cases, this is not necessary because the total concentration of contaminants is relatively low.

6.1.3

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Data validation

This is essential to ensure that accurate data are being used as the basis for action. Validation can be achieved by comparing the volume of water entering the site, over a 12-month period, to the volume leaving the site. Inputs must equal outputs (see Fig 2).

Fig 2 Site water inputs and outputs

11

It may be necessary to allow for: ■

water removed through drying operations and discharged as vapour directly to atmosphere;

■

water removed in the product;

■

the addition of rainwater (see below).

While a balance of ±10% is acceptable, a balance of greater than 20% generally indicates an error. If the error cannot be found, try to complete the balance for each quarter of the year or, if possible, for each month. If the error is present in each time interval, then it is likely that a key measurement is suspect, eg meter calibration. If the error varies from one period of time to the next, then there is more likely to be a specific cause, eg an effluent meter may have been temporarily out-of-order. It may be necessary to estimate volumes to allow such information gaps to be filled. Rainwater The route taken by rainwater needs to be assessed carefully. If all the rainwater enters the effluent, then the input is the annual rainfall multiplied by the area from which the rainfall drains. For example, if the rainfall is 1 m/year, this represents 10 000 m3 of water per hectare discharged from the site (1 hectare is equivalent to 10 000 m2). If this volume of water exits the site alongside the trade effluent, unnecessary disposal charges will be incurred. To avoid a charge, rainwater should be collected - provided it is not contaminated - and discharged to a surface drainage system. Local or regional rainfall data can be obtained from the Meteorological Office.

6.2 ALLOCATE CONSUMPTION section

6

The site’s annual water consumption can now be allocated between key areas. Ideally, the consumption of each relevant item of equipment or key activity (eg cleaning operations) should be defined.

6.2.1

Data collection

Useful data can be obtained from: ■

equipment suppliers;

■

design specifications;

■

spot check measurements, eg disconnecting a pipe allows a flow rate to be estimated by measuring how long it takes to collect a known volume;

■

estimations, eg in a laundry, the daily water consumption could be estimated from the known volume of the machines and the number of times they are filled each day.

Relatively crude estimates are adequate for ‘trivial’ flows as the main purpose of this exercise is to distinguish the handful of major water users from the many minor ones. However, it is important to determine total actual consumption and not rely on what is believed to be used. Total annual estimates of water consumption should agree with the mass balance estimates to approximately ±10%. A discrepancy of greater than 20% indicates that one or more of the uses has been missed.

12

A site’s measured water consumption is often greater than the calculated quantity for identified plant items. Common reasons for this discrepancy include: ■

use of historically accepted data, not current data;

■

use of ‘normal’ or design data, not actual data;

■

cleandown water or ‘abnormal’ use is missed;

■

cooling water flow rates are higher than estimated;

■

areas or equipment that use water are left out of the calculation.

Collection of these data provides a valuable opportunity to involve a more diverse range of employees in the water minimisation programme.

6.2.2

Data display

The collected data should be displayed in a suitable format, showing individual water consumptions in order of value. The data can be expressed as a: ■

histogram of water consumption versus source of use, showing consumption figures in descending order of magnitude;

■

pie chart;

■

horizontal bar chart showing consumption in proportion to the width of the bars;

■

simple table.

A display that uses pictures is invaluable for disseminating results.

Stoves plc used colourful 3-D pie charts and other computer graphics to report the saving of some £35 000/year to their employees. (See Industry Example 5)

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A good display shows the relative consumption of the ‘important few’ consumers that account for the majority of the water used at the site. Adding the annual cost of the water to the display will help to emphasise the distinction.

6.3 IDENTIFY WATER SAVING IDEAS Brainstorming is a technique whereby a team generates as many ideas as possible for solving a problem. In this case, each significant area of consumption can be brainstormed to generate ideas of how to reduce the use of water at source.

6.3.1

The brainstorming team

The members of the brainstorming team need not be the same as the main project team. Other staff may be included who have either knowledge of the area to be brainstormed or the ability to think creatively and be innovative.

6.3.2

The brainstorming sequence

■

Give an initial reminder of the project objectives, the current cost of water, and the need to reduce water consumption.

■

Describe the area or activity to be brainstormed. A flowsheet is often useful for this purpose. It should be explained by someone familiar with the area. 13

■

Remind the team of the rules of brainstorming (see Fig 3).

■

Brainstorm and write down the ideas.

■

Stop after a set time or when new ideas stop coming.

■

Rank the ideas for likely success, likely effect on waste generation, and likely cost of implementation.

■

Agree those ideas to be pursued.

Fig 3 Rules of brainstorming

Starting with the largest water user, the process should be repeated down the list of users to the point where, say, 80% of water use has been covered.

6.4 ANALYSE DIFFERENT OPTIONS

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The ideas generated by the brainstorming meeting will involve changes to systems, equipment and procedures. Further work will be necessary to ensure the feasibility of these ideas and to determine the costs and savings associated with each option. Those ideas that prove to be technically, economically and environmentally acceptable should be formally reported to the site management, the main project team, and all those concerned. The Industry Examples demonstrate that the payback for water saving ideas is usually sufficiently short to ensure that they are implemented. Once approval has been given, water saving ideas can be implemented.

6.5 MAINTAIN SAVINGS Once the main options for reducing water and wastewater have been identified, the programme can be continued by various means, including: ■

departmental competitions;

■

suggestion schemes;

■

appointment of ‘water wardens’ as the primary contact in each area of the site.

In many cases, a system for continuous improvement will already exist at the site.

At Borden Decorative Products Ltd, a water saving programme was incorporated into the existing Total Quality Management approach, saving the Company an extra £143 500/year. (See Industry Example 6)

14

It is only when the continuous striving to reduce water and wastewater costs becomes part of a site’s normal management system that the approach becomes permanently successful.

6.5.1

Monitoring to Manage

A system should be set up to provide managers with the information they need to manage. Monitoring to Manage will help to: ■

maintain the achieved savings;

■

create the basis for ongoing improvement;

■

demonstrate success.

The simplest and most effective parameter to calculate is the water consumption per unit of output, eg m3 per cell, m3 per roll, m3 per tonne of product, etc. For a large site, it may be necessary to install water meters at key positions to enable the allocation of water to the different site areas or products to be measured.

Chloride Motive Power Batteries Ltd calculated water consumption by tonne of lead processed, and saved nearly £8/tonne, a total of £110 000/year. (See Industry Example 2)

Production data will already be available. However, it is important to establish a system for bringing together the water consumption data for an appropriate period of time (eg weekly) and the corresponding production information. Use of trend charts The consumption per unit output parameter should be displayed versus time as a trend chart (see Fig 4). These data should be available to all employees. However, the statistical display must be accompanied by the key messages.

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Trend charts not only highlight success, they can also indicate failure. Any tendency to drift back to old ways can therefore be detected and corrected before problems arise. In addition, the reasons for any short-term improvement should be investigated so that the improvement can be implemented permanently. As experience is gained, a more sophisticated monitoring system giving more accurate data can be developed. For example, when several different products are produced with the same equipment, the basic parameter for each different product could be incorporated into the evaluation model instead of using the overall product output.

15

6.6 REPORT SUCCESS Successes should be reported in simple, clear, non-jargon English to maximise understanding by all employees. Possible reporting methods include: ■

bulletins;

■

posters;

■

newsletters;

■

company magazines;

■

company prizes;

■

accounts reporting.

Trend data is one way of demonstrating success (see Fig 4).

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Fig 4 Annual water use at Chloride Motive Power Batteries Ltd

‘We used to use 27 m3 of water per tonne of lead. We now use 17 m3 per tonne, saving over £100 000 per year. Well done everyone!’ Stan Hilton, Site Engineering Manager Chloride Motive Power Batteries Ltd.

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7 ACTION PLAN

Gain inspiration and motivation by looking at what other companies have achieved. Get people involved. Appoint a team leader and team members. Draw up a plan and a timetable of planned activities - a good plan is a simple plan. Determine the true costs of water use and wastewater disposal for your site. Decide whether to address contaminant levels as well. Draw up a water mass balance of water inputs and outputs to your site. Allocate consumption between uses. Rank uses in terms of annual water consumption. Concentrate initially on the major uses of water. Brainstorm to obtain water saving ideas appropriate to your situation and processes. Analyse options for technical and economic feasibility. Implement all ideas that are acceptable and particularly no cost/low cost options, eg good housekeeping. Report success in a way that will motivate all employees.

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Maintain savings, eg through Monitoring to Manage. Seek further improvements by integrating waste minimisation into existing management systems. If necessary, obtain help. The Environmental Helpline (0800 585794) can: send you copies of relevant Environmental Technology Best Practice Programme publications; suggest other sources of information; arrange for a specialist to contact your company.

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