Metropolitan St. Louis Sewer District
Project to design the process improvements to increase the secondary treatment capacity from 167MGD to 210MGD in order to meet new consent decree requirements. EDCS was responsible for providing electrical and controls design for this project. Site surveys were conducted of existing equipment for modification and reuse, as well as relocation due to building locations. After the study and report phase, it was apparent that the amount of screenings in the plant was impacting the secondary treatment; therefore, new screenings buildings were installed at the Wet Weather Screening Building and the Headworks Screening Building. The two screenings buildings are located in different areas of the plant and required new power feeds from the existing plant power distribution, provisions for generator connections, and electrical equipment rated for the Class I Division 2 area classifications. A new odor control system and HVAC system to reduce area classifications and new bar screen climber control panels and washer compactor control panels were required at each facility. The new facilities also have new PLC control panels which are networked together and integrated into the existing plant Invensys system. Other areas of work were instrumentation improvements for the replacement of magnetic flow meters at the aeration basins and secondary clarifiers. New suspended solids meters were installed to improve solids balancing through the system. These meters are connected into the plant SCADA system using wireless I/O.