Paying Too Much for Water?

People don't usually consider water as a resource, but it is exactly that. You pay for it, you use it, then you pay for someone to clean it. The cost of fresh water is relatively high, when you think it is essential.

Businesses in specific can both improve their water efficiency and cut their bills substantially by taking simple, uncostly measures. Some of these are listed below:

1. Push button faucets. Instead of the standard turn or raise faucets, push down valves can be installed. This will regulate flow through the tap and limits the amount of time the tap is on. These are cheap to buy and cheap to install and it will mean that a tap is never left running.

2. Specialised shower heads. If there are showers on your premises, shower heads which restrict flow through can be installed. Again, these are cheap and easy to put into place and are designed to reduce the amount of flow without losing the pressure in your shower. Staff will most likely not notice any change.

3. Toilet cistern displacers. A bag or bottle filled with water and sealed (up to a volume of around 3 litres) can be placed inside the cistern of your toilet leaving less volume for water to fill after a flush. Therefore, the next flush will use less water and the cistern will fill up less each time. Again, a cheap and effective way to reduce water use by 3 litres per flush.

4. Waterless urinals. Urinals which don't flush are now commonplace in public toilets and aren't considered any less hygeinic than normal. They do not use any water and are not supplied by a plumbing system so maintenance is virtually non-existant.

5. An instant hot water device in staff kitchens will reduce the load on kettles and the waster produced by manually overfilling and cleaning kettles. Although the initial costs will be high, so make sure you determine the payback period before pursuing.

6. A dishwasher. A fully loaded dishwasher uses less water per piece of crockery than hand washing and is far more hygeinic. Again, initial costs will be relatively high but if demand on water for dishwashing is high then there ought to be a short payback period.

7. Rainwater harvesting. If your business is situated in a particularly rainy area, water harvesting is a great way to retain FREE water and use it for purposes that usually cost. It isn't drinkable, but it can be used in toilets and washing machines after only basic treatment.

Saving Water for Industrial Sites

Production plants and other industrial sites tend to use water for a number of different processes. This usage is usually relatively high, probably around 30-50000m³ per year. Therefore, it is essential for businesses in this situation to have a viable strategy to continually reduce water use to keep costs down.

This post will outline a strategy I have recently developed in my job which has the benefit of supplying information on:

-          Volumes of water used in real time,

-          Where these volumes of water are going.

Most industrial premises will have one water feed from the mains water network which supplies to all activities on site. This is metered and you will be billed based on the meter readings from this point. After this, do you know how much water supplies each aspect of your operation? The step by step guide below provides you with a sure-fire way to save water. You will have to do the research yourself to see if the pay-back period is short enough for your business, as there will be initial capital expenditure.

1.       Do you know where your sub-surface pipes are? If not, you should contract a company to scan for all underground water pipes. They will supply you with a CAD plan of your site with the pipe network plotted.

2.       Check underground for leaks. The same company as mentioned in step 1 will probably do this for you as part of the contract. If not, try and get them to. They cannot quantify any leaks to you, but it is certainly worthwhile.

3.       Check for above surface leaks. The first thing you should do is check all above ground pipes for leaks and have these repaired. Try to keep as detailed a record of them as possible, including costs. If you can, hold a jug under the leak for a set period of time and calculate a cost. This will all be useful in justifying the project and you can eventually quantify savings.

4.       Make sure you’re being billed right. Again, the company from step 1 will probably do a billing audit for free for you, which could end up in you receiving a rebate from any time within the last six years. It’s definitely worth the effort.

5.       Contact your supplier. Most suppliers will provide daily consumption data to you on request. There may be a charge for this service but it is small (around £100). Get as much data as you can from them. It will help you to calculate the possible savings to be made.

6.       Research the benefits of using a Smart Metering system across your site. They are a set of flow meters which can transmit data to a server allowing you real time access to your water consumption. These are to be installed at strategic points across site to isolate each process or set of equipment.

7.       Build a report suggesting the installation of Smart Metering. Your annual savings should be based on the below equation, where: Q_max(n) = a “savings limit”, q = total consumption on day n, and n = date (in number of days since first day of data).

     

      This works on the assumption that it would take two days to fix a problem which causes a spike in usage. Therefore, what you should do is subtract this “savings limit” for each day from the consumption data and remove all negative values. Add together all positive values and this will give you a total saving of water. Multiply this by the cost of water, divide by the number of days in the sample and multiply by 365 and you will have your total annual saving in £ or $.

8.       This saving should justify the initial expenditure on the system if the process highlighted in the flow diagram below is followed. In this diagram, v = the average difference in consumption from one day to the next and the other numbers are the same as the equation above.

Using the process above and the Smart Meter system, will ensure that your business continually reduces (where possible) water consumption until it converges on a level which is impossible to reduce any further.

I hope this helps! I'm currently in the process of getting this system installed for our site and if  you have any feedback or have noticed any problems, or indeed have any questions, please get in touch.

Best wishes.