A RELIABILITY STUDY OF MECHANICAL EQUIPMENT AT MUNICIPAL WASTEWATER TREATMENT PLANTS (FAILURES, MEAN DOWNTIME, MTBF, MANPOWER, SURVEY)

The failure of equipment has been identified by various researchers to be among the major causes of municipal wastewater treatment plant failures. This research is initiated as a result of the concern with the questions involving the reliability of treatment equipment. Using a mail questionnaire survey, equipment performance data as well as operation and maintenance information were collected from over 300 municipal wastewater treatment plants in 20 states. The reliability data base established represents data from plants in the 1 MGD or larger size group. The data base consists of data such as mean time between failures, mean downtime and others. Data application to assist in equipment related decision-making processes such as the selection of equipment and the improvement of maintenance programs were discussed. Attempts made at correlating equipment reliability with operation and maintenance factors, however, yielded no positive result.