In September 2020, CWS partnered with the City of St. Marys (City) to provide management, operations, and maintenance personnel for the Point Peter Wastewater Treatment Facility and water treatment facilities. In November 2020, the project scope was expanded for CWS to provide a full-time maintenance technician to work with staff for the City’s 75 wastewater lift stations.
Water Solutions by CWS for the City of St. Marys
The Point Peter WWTF is a is a 4.0 MGD Sequencing Batch Reactor (SBR) treatment facility with Ultra-Violet (UV) disinfection. For the previous two years, the City had utilized a private operations contractor. It was evident that certain problems at Point Peter were not being addressed and permit compliance was continuing to be an issue. CWS immediately conducted a facility assessment and determined that issues causing the permit violations were solids-related. The Effluent Equalization (EQ) Basin contained excessive amounts of solids. Mixed Liquor Suspended Solids (MLSS) testing determined concentrations in excess of 9900 mg/l. CWS drained and cleaned the basin. Accumulated solids were then pumped to the digestion process. This effort required the use of a crane and hydraulic pump for a week.
Once solids were removed from the EQ Basin, Effluent TSS was significantly reduced. The reduction in TSS allowed more efficient treatment in the SBR, thereby reducing Ammonia concentrations. The UV disinfection system was also found to be less than 25% efficient. Two out of the four disinfection banks were non-operational and the other two partially operational. CWS utilized parts on-site to repair the system and was able to increase operability to 75%. Components to bring the UV system back to fully-functional have been ordered. The solids reduction and repairs to the UV system resulted in significant reductions in fecal coliform colonies.
