A key issue to consider when looking at water efficiency projects is the total cost of water. Most sites look only at the cost of supply, but there are other costs which can be just as significant, such as:

• In-house treatment – for boiler feedwater, cooling towers, re-use;
• Pumping costs;
• Onsite treatment costs – operation and maintenance costs of save all, DAF;
• Disposal costs – to sewer, irrigation.