Sewage treatment plant process audits: guidance manual

Executive Summary

This manual describes techniques to assess existing municipal wastewater treatment plants to identify their hydraulic and process bottlenecks, and to establish the plants' actual capacity. Hydraulic modelling, oxygen transfer tests, online data acquisition, digester tracer studies, and dye tests are some of the tools used for evaluation and optimization. These tools assist in the generation of accurate design information for plant expansions, and combine process operating and design information not readily available from traditional evaluation approaches. In conjunction with traditional plant operating information, the results are used to determine a plant's ability to treat future loads while forestalling plant expansion when possible. If the results indicate that a plant expansion is needed, the information gathered will be useful for design.