Water Test Procedure and Leakage Limits

A drain which is to be water tested should be divided into sections so that the head of water at the lower end of the section should not exceed 4 m. The section of drain should be filled, left standing for 2 hours, topped up and the leakage measured after a further 30 minutes. The leakage during the 30 minute test period should not exceed 0.5 litres per meter diameter of pipe per metre run. For example – (a) for a 100 mm drain – 0.05 litres per metre run of drain (a drop of 6.4 mm per metre run); or (b) for a 150 mm drain – 0.08 litres per metre run of drain (a drop of 4.5 mm per metre run).