Leak test in the wastewater technology according to DIN EN and rules of DWA – a technological analysis

Abstract

In the Water Resources Act (WHG) of Germany is demanded that technical devices for transport, the treatment (treatment plants) and temporary storage (septic tanks) of wastewater must be tight. Base for the tightness inspection of pressureless sewer pipes and ducts is the DIN EN 1610. The leak test can be done with water or with the comparison medium air. According to the principle of equivalence, a leak test must lead regardless of the used test methods to the same measurement result. Only the test procedures of the DWA work sheet A 139 and M 149 achieve this criterion. The leak test methods of DIN EN 12566 with water for basins are involved with an unjustifiably high technical effort, high costs and a large relative error of measurement at the test. Significantly unequal results, obtained by the different leak test methods of DIN EN 12566 with air, are inconsistent with the principle of equivalence. Furthermore in opposition to the water testing procedures the leak test method with air is tolerating leakages.