DWSD Long Term CSO Control Plan Implementation
The Detroit Water and Sewerage Department (DWSD) has followed a demonstrative approach to the development and implementation of their $1-billion Long Term Combined Sewer Overflow Control Plan (LTCSOCP) to address 20 billion gallons of annual discharges from 78 outfalls. Wade Trim assisted the DWSD for 18 years providing all of the technical and administrative functions for management of the DWSD CSO program development and implementation. From 1992 to 2011, we evaluated the collection system and wastewater treatment plant (WWTP); monitored/evaluated in-stream water quality; evaluated CSO control and treatment technologies; formulated and evaluated alternatives using complex modeling; recommended control strategies and specific projects; sited and confirmed sizing and design criteria of remote CSO control facilities; evaluated performance of facilities; and assisted in development of a wet weather collection system and CSO treatment facilities operational plan.
To date, 6 retention treatment basins, 3 screening and disinfection facilities, in-system storage improvements and primary treatment WWTP upgrades have been completed and are operating as planned. Wade Trim conducted performance assessments for 7 demonstrative and pilot CSO treatment facilities providing valuable information relative to the design detention time, level of treatment, innovative technologies employed and efficiency of different operational modes. Wade Trim assisted DWSD in the development of its initial LTCSOCP as well as two subsequent updates as required by the NPDES permit. The most recent update modified the plan based on additional pilot facilities performance results, such as the screening and disinfection facilities and in system storage devices, and water quality work that was performed on the Detroit River.