Water is a topical subject in certain parts of the country. However, it has not registered as a business issue on the radars of many companies in the timber industry. Spend on water is typically relatively small, perhaps in the order of £500-2,000 per year for companies in the £1-10m turnover range. Although this sum is obviously insignificant compared to the spend on timber, 10 minutes of attention on water issues could be time well spent.
There is a range of no and low cost measures which can make significant savings to water consumption. Take the simple example of urinals. These will be flushed via a cistern and there are still many companies with simple trickle systems which fill up gradually and flush every 20 minutes or so. Each time a flush occurs, up to 12.5 litres of water will be discharged and this process will continue 24 hours a day, regardless of whether anyone is on site. The chances are that from 5pm to 8am Monday to Friday, no-one uses the urinals, with the same being true at week-ends and during holidays.
Consequently, up to 200,000 litres or 200m3 can be wasted by each urinal cistern each year. This is a massive amount of waste – imagine how many vehicles would be required to deliver the equivalent volume in bottled water (it equates to 133,000 standard 1.5 litre bottles of water).
The solution is very simple – fitting controls. Various types are available including:
- simple timers which are programmed not to flush when no-one is on site;
- hydraulic valves which recognise change in washroom water pressure when people wash their hands, with more washing activity triggering more frequent urinal flushing;
- passive infra red detectors which trigger flushing after a pre-determined number of visitors to the area.
Payback time
Such controls cost between £60-120 with a payback of three to six months. Once fitted, they will generate savings year after year, with no further requirement for investment. Furthermore, with the current concern about water shortages, it is only logical that greater investment will be required in water infrastructure and this cost will ultimately be borne by the consumer. Therefore, measures which can be implemented today will help to protect against future price hikes.
If you want to further investigate the impact of such controls, some sites nominate a member of staff to turn off the supply of water to the urinals each night. If this task is undertaken for a week, the site water consumption can be compared to that in a normal week and the saving can be calculated.
The first stage of any minimisation programme is to measure exactly what you are using at present. This is extremely simple for those on water meters as the volume of water use is laid out on the quarterly bill. It is worth digging out the latest bill to see how much you are charged for incoming clean water, typically between 80p and £1.20/m3. A second charge will be levied on this volume as it is assumed to become effluent. Therefore, you will pay a further 80p to £1/m3.
If you have water-using processes on site or discharge some effluent to soakaway, a certain amount of incoming water may not be discharged into sewers. In this case, you should check that you are charged a lower percentage – for example, the volume of effluent is assumed to be 90% of incoming water. Water companies will alter the percentage charge if you can present a good argument.
A simple way of checking for leaks and unnecessary usage is to take a meter reading last thing on a Friday and first thing on a Monday to see if there is any water usage when no-one has been on site. This technique is also useful for highlighting unnecessary use of gas and electricity.
Target key areas
Once you have identified site water use, try to break it down into component parts such as washrooms, process water, leaks and filling fire sprinkler systems. Key areas can then be targeted.
If there are any leaks on site, these should be corrected as soon as possible. A tap leaking at a rate of two drops per second equates to an annual loss of 9.5m3 with an annual water and an effluent charge of around £16. A leak which is big enough to form a 2mm stream of water will incur an annual cost of around £250.
After leaks have been identified and fixed, one of the simplest water-saving measures is cistern reduction. Traditional cisterns hold 9-12 litres and a one or two litre reduction can be achieved with a brick or plastic milk carton filled with water. Even better are dual flush systems which use four or six litres depending on the flush type.
Push button/percussion taps should be fitted instead of conventional taps. The length of their run can be adjusted from 1-30 seconds and they can reduce water use by 50%. Even better are taps with a spray nozzle which force water through small holes leading to a 60-70% reduction in the amount used. Further reductions can be achieved by switching from traditional soap to foam soap. The latter requires less water to activate (taps are typically left running while a bar of soap is rubbed in the hands) as well as less water to remove.
Rainwater
More adventurous sites may want to make use of rainwater. If you have a competent maintenance engineer, it is perfectly feasible to collect rainwater to replace mains water in certain tasks.
For example, could rainwater be used for flushing certain toilets or even for filling sprinkler systems? A certain amount of treatment will be required, but this might just be the use of a 1mm screen filter to remove particulates. Failing this, rainwater is certainly suitable if you have any plant watering requirements on site, for grass or hanging baskets.
Certain water-using areas will add significant value to mains water. For example, hot water systems may take mains water (£1/m3) and condition it with water softeners and corrosion inhibitors, leading to a value of £2-3/m3. Once heated, the value increases to £3-4/m3. Losses may occur through evaporation, leaks, blowdown and poor condensate recovery. These areas are worthy of attention due to the value added nature of the water involved.
