The leak-testing of manholes with water is performed by level testing. All connections entering the manhole are blocked with bladders; then the manhole is filled up to the upper rim with water and the level is checked for 30 minutes in accordance with EN 1610. During this phase not more than 0.4 l of water per m” of surface are in the manhole must be lost in order for the test to be positive.
Leak-testing of manholes with air is only possible, if the blocking bladders can be positioned and secured. If this is the case, this method is a good alternative to the level testing.