This project was necessitated because the District received a total phosphorous limit of 1 mg/L in its TPDES permit. The new limit was very rare for the region and due to the plant’s outfall into Lake Conroe was deemed unacceptable. The project was a wastewater treatment plant with biological nutrient removal (BNR) sized for 0.95 million gallons per day average daily flow. The project included rehabilitation of the existing influent lift station piping and controls, construction of a concrete headworks with a mechanical step screen and screenings wash press, two carrousel-style main process units with a flow splitting structure, a concrete junction box to allow operational flexibility between trains and the addition of chemical coagulant for effluent polishing, two secondary clarifiers, two cloth-media filters, two chlorine contact basins, conversion of the existing clarifier into an aerobic digester, and additional aerobic digesters to meet digester volume requirements. An orthophosphate analyzer and alum feed system were constructed to serve as a backup to the BNR and to assist the BNR process in the event plant upsets or influent loading spikes. This project also included new electrical service, a 600-kW diesel generator and 2,000 gallon fuel tank, and a new control building. The existing outfall pipe and outfall structure was utilized. The design incorporated the reuse of existing equipment wherever practical. To read the entire article, please click here.