The Sudlersville Wastewater Treatment Plant has a permitted capacity of 200,000 gpd with average daily flows of approximately 75,000 gpd. The Plant currently discharges higher than acceptable levels of nitrate. The installation of a newly constructed Post Anoxic Reactor (PAR) will aid in the removal of nitrates to return the total nitrogen concentration to ENR regulatory levels and bring the plant back into NPDES compliance. The current layout and design of the plant make these levels difficult to achieve without the incorporation of a mechanism dedicated to nitrate conversion. The PAR tank is to be a separate tank which would provide enhanced nitrate conversion after the long sludge age treatment (Biolac), and before the clarifiers. Current process is as follows. Raw flow travels through the influent bar screen at the headworks where it is then diverted to the influent side of the Biolac basin, mixing with the return activated sludge (RAS). Once the flow has entered the Biolac basin there are seven (7) air chains that allow for mixing and nitrification. From the Biolac basin, flow spills over an effluent weir and then continues to the splitter box before entering the clarifiers. Once entering the clarifiers, the RAS is diverted back to the headworks. Waste Activated Sludge (WAS) is diverted to the holding lagoon as needed. The clear water from the top of the clarifier goes over the edge of both clarifiers which then leads to the monitoring manhole. Once entering the monitoring manhole, the flow then goes through a pinch valve and into the effluent lift station. The flow is then pumped up into the sand filters. Methanol is fed upstream of the sand filters. The reject water from the sand filters is sent to the plant drains and then back to the headworks building. The effluent flow leaving the filters then goes through UV treatment where it then reaches the effluent post aeration cascade and out to the receiving stream, Red Lion Branch.
