Because your business may use water for a number of different purposes, you should try to avoid an ad hoc approach to improving water efficiency. It is much more efficient to develop a business-wide water policy that includes all of your water needs.

Adopting a systematic approach can also help you to:

• identify all of the achievable savings
• avoid the exercise becoming a one-off 'purge'
• pursue ongoing savings
• ensure staff are motivated to help
• implement ideas more easily
• make sure the programme doesn't lose momentum and disappear

You can manage your water use by adopting a systematic approach that includes:

• assessing how much water your business uses
• creating a water use policy or incorporating information into a more general environmental policy
• setting up a water reduction plan that defines who will be involved, what they will do and how they will communicate progress
• identifying and selecting the most appropriate water efficiency measures
• setting environmental targets and objectives
• reviewing performance of the water reduction plan and programme
• reporting results to internal and external stakeholders

If your business has an environmental management system (EMS) - or you're setting one up - you should use it to manage your water use.

Before you can design a structured plan to improve your business' overall water use, you must have a clear idea of how much water you are currently using and where it is being used. A water survey can help you answer the following questions:

• How much water are you using?
• Where is water used by your business?
• Are you using too much water?
• Are you paying too much in effluent charges?
• How have you tried to save water?
• How could you save more water?
• Is your business at a commercial disadvantage because your competitors already use water saving measures?

Carrying out a water use survey

Before carrying out a detailed water survey, you should carry out a brief initial survey to ensure that any potential water and effluent cost savings are worth investigating. Generally, reductions in water and effluent charges of 30 per cent are achievable.

An initial survey of water use and patterns of use typically reveals:

• excessive or unnecessary use
• unknown use
• unauthorised use

A survey of wastewater discharges and routes to sewer typically reveals:

• clean water discharges direct to sewer
• unauthorised surface water discharges to sewer
• possible savings in sewerage charges

It can be helpful to create a water balance to show where water enters and leaves your business and how it is used in between. This can help you identify areas where quick and simple savings can be made.

For more information about water surveys and how to check and benchmark your water use, see how to monitor your water use.

Your water reduction plan should describe how you will reduce your water use, who will be involved and when the improvements will be carried out.

Writing a water reduction plan

Your water reduction plan should be written in a concise manner and contain the following elements and information:

• The scope of the water reduction programme, eg whether it will cover the whole site or just one area or department, and whether only water will be addressed or water and contaminants simultaneously.
• A timetable covering all of the planned activities. The overall programme may last 12 months or more so monthly milestones may be important.
• A description of who is involved. You may want to involve representatives from each of the key departments that are affected. Larger businesses may want to appoint a team leader or champion to advocate water and wastewater minimisation throughout the business.
• The training needs of anyone involved in the work.
• Ways of promoting awareness and communicating progress to the rest of the site. You should also identify how you will report regularly to senior management.
• The resources needed to carry out the programme and whether these have been approved.
• How you will achieve ongoing improvements.
• A definition of the systematic approach that your business will be adopting.

Some water saving measures are quick and free to implement. Others may require significant investment but lead to sizeable, long-term savings. You should look at what your budget is, what the payback periods are for the different measures and choose the most appropriate measures for your business.

Ways to save water

Water saving measures you may want to consider include:

• checking water meters and for leaks and overflows
• reviewing heating and hot water systems
• checking cooling systems
• collecting rainwater
• reducing water use from washrooms, catering facilities, laundry facilities and other commercial activities
• using efficient cleaning and rinsing techniques and redesigning processes

Northern Ireland Water should understand your business' particular needs and may be able to offer practical advice on saving water - for example by installing sub-meters or using on-site monitoring.

Inspecting your water meters and checking for unnecessary water loss from leaks, overflows and high pressure are usually good places to start your efforts to reduce water.

Water meters

Often under-utilised, your water meter is one of the most important components in your fight against wasted water. It can help you to identify and isolate leaks and overflows and monitor water use at particular times or by particular processes. Ask yourself:

• Do you know where your water meter is located? If not, you could be wasting the opportunity to monitor your water use.
• Do you have more than one incoming water meter, or are any areas of your business sub-metered? Ensure you understand how your metering system works or your monitoring may not be accurate.

Leaks and overflows

You can waste significant amounts of money if leaks and overflows remain undetected for any length of time. If your business only operates during the daytime, water use should be near to zero at night. By reading your meters at night you can identify unusual water use, which could suggest you have one or more leaks.

Overflows can also become a major drain on water use. They can occur because of:

• perished tap washers
• worn cistern valves
• corroded pipework
• flooded floats in water tanks and cisterns

To minimise leaks and overflows:

• make sure overflow outlets are visible
• carry out regular checks on overflows, pipework and valves
• develop a system that reports any leaks or faults immediately
• install level sensors and on/off control systems for pumps
• install shut-off valves
• closely monitor all your meters including sub-meters

Isolation and water pressure

One important measure your business can take to vastly reduce the amount of water it wastes is to isolate water. Installing quarter-turn ball valves at major junctions will ensure it is clear whether a valve is open or closed. It also enables quick and effective isolation of the water supply.

High water pressure can be damaging, using excessive water and causing leaks which put additional strain on your water system. You could install pressure-reducing valves to control the pressure in the incoming mains supply to minimise the effects of high pressure.

You can face significant costs and potential water losses from boilerhouses and other heating systems. The value of water used is often underestimated, despite hot water representing a major cost to your business.

It is important to understand how your hot water systems and boiler use water. Often not all water and steam is returned to the boiler for reuse. Evaporation and blowdown can occur, which means that new 'make-up water' has to be added. Improving the reuse of lost water in your hot water systems can bring significant cost savings.

Pre-treatment of water

Demineralisation or softening often occurs when water is pre-treated before entering a boiler using ion exchange columns. These columns require regeneration typically using hydrochloric acid/caustic soda for demineralisation plants and salt solution for softening plants. These processes use more water and chemicals, and also generate effluent. Optimising how often ion exchange columns are regenerated will minimise costs and environmental impact.

Boiler blowdown

Blowdown removes impurities from your boiler preventing the build-up of total dissolved solids. Blowdown can be controlled manually or via timers and conductivity measurements. Boiler blowdown should be discharged to sewers and not your surface water drain.

Steam recovery

The water that is turned to steam (condensate) is very valuable to businesses. Where possible, steam should be collected and returned to the boiler hotwell as this reduces the energy required to heat new water. Because steam is usually low in total dissolved solids, your ion exchange costs are also reduced.

Steam losses and leaks

The cost of generating and distributing steam is often underestimated - to produce steam at 100 degrees Celsius requires the energy equivalent of heating water to around 650 degrees Celsius. You should keep losses from leaks and poorly maintained steam vents to a minimum with regular maintenance checks and repairs.

For information about reducing the energy used by heating and hot water systems, see how to use heating and hot water systems efficiently.

Any machinery in your business that requires cooling can be a major cost in lost water. You have a number of potential options to improve your use of water used for cooling purposes.

Cooling water flow control

You can use the manual switch to control cooling water flow, but automatic systems are also available. A control valve linked to a thermostat on your machinery will automatically switch off the water flow when the machine is idle.

Closed loop cooling water cycle

Equipment that requires constant cooling will often be connected to the mains water supply. Water is used and then discharged to the main drain. You should replace this with a closed loop system so that the water is reused if it does not become too contaminated.

Evaporative cooling towers

There are a number of approaches your business could take when using cooling towers.

• Automatic blowdown control - evaporative cooling towers usually operate with a continuous source of water, which keeps the build-up of impurities to a minimum and maintains cooling efficiency. Automatic systems regulate when blowdown is discharged to sewers and thus use water more economically.
• Cooling load reduction - as cooling towers need to be periodically replenished with water, minimising the cooling load will reduce the need for fresh water make-up.
• Spray/mist recovery - you are likely to find it more cost-effective to install automatic blowdown control than to upgrade the spray/mist eliminator.

Alternative cooling processes

You can replace conventional cooling towers with:

• air blast coolers, in situations where 'cooled' water temperatures - of up to 40 degrees Celsius - can be tolerated during the summer months
• refrigerated closed loop systems

Pre-heating boiler feed water is a good use of waste low-grade heat. Heat exchange with incoming cold water can often achieve lower temperatures in the cooling circuit than in cooling towers.

Rainwater harvesting systems enable you to collect rainwater for use in your business. This reduces the amount of water you need from the mains water supply. To work out if harvesting rainwater could benefit your business, you should consider the following steps.

Quantify water use and costs

Before you install any rainwater harvesting systems, your business should compare the costs of these systems with how much you are paying for water and carefully evaluate any potential cost savings.

You can find out your mains water supply costs by checking your water bills carefully. If you want to quantify how much rainwater you can harvest in a year you should use the following equation:

You can find annual precipitation information on the Met Office website.

Harvesting considerations

Think about the quality of the water you will gain from rainwater harvesting and the quality of water you need to operate your business efficiently. If you need high levels of purity, rainwater may not be suitable.

The reuse of rainwater can improve the overall Building Research Establishment Environmental Assessment Method (BREEAM) performance for a building. BREEAM is an environmental assessment for new and existing buildings, which was developed by the Building Research Establishment and is the leading - and most widely used - environmental assessment method for best practice in sustainable design.

You should invest in a tank large enough to collect water - without it overflowing - at the wettest time of year. There are many businesses that can help you develop bespoke rainwater harvesting systems.