Papers and Reports

A widespread problem facing many utilities is that their sanitary sewer lift stations are often not equipped with flowmetering equipment, especially older lift stations. This makes it difficult to determine whether the pumps are performing in accordance with the original design specifications. Without a flowmeter, the operator will not know the actual capacity of each pump at a lift station and will not be able to determine if flow capacity decreases. Mechanical problems and minor blockages may not be evident and pumps could fail unexpectantly. This paper considers alternative practical methods for drawdown testing of sewage lift stations to assess approximate pump capacities and how to use the tests to diagnose potential operational problems. The presentation also recommends some additional diagnostic techniques to use in conjunction with drawdown testing to determine a comprehensive assessment of the lift station.