Bureau of Wastewater

What We Do

The City of Lancaster is directly responsible for the collection, conveyance, and treatment of wastewater from the City and portions of Lancaster, East Hempfield, Manheim, and Manor Townships. The other municipalities and authorities listed below have independent sanitary sewer systems that deliver wastewater to the City’s collection and/or conveyance facilities prior to the AWWTP.

The City of Lancaster Advanced Wastewater Treatment Plant (AWWTP) is owned and operated by the City of Lancaster for the sole purpose of treating wastewater, which is a combination of residential, commercial, and industrial used water discharges.  The City’s AWWTP processes wastewater from the City of Lancaster and portions of Manheim Township, Lancaster Township, East and West Lampeter Townships, Strasburg Borough, Strasburg Township, Upper Leacock Township, West Earl Township, Manor Township, Pequea Township, and East Hempfield Township.  

Upon collection and conveyance to the AWWTP, wastewater is physically treated through screening, grit removal, and primary clarification, in which inorganic and organic solids are removed.  Biological treatment of the wastewater follows primary clarification. The biological treatment of wastewater utilizing the OASES® activated sludge process (anaerobic/oxic with anoxic stage inserted between oxic stages) further removes organic material as well as the nutrients nitrogen and phosphorus.  Final clarification then separates the mixture of wastewater and active biological solids. The majority of biological solids are reused to treat incoming wastewater, but a portion of these solids are removed from the treatment process by reducing the water content, lime stabilizing for pathogen/vector reduction and then hauling off-site for beneficial reuse.  Chlorine and sodium bisulfite are used to disinfect and dechlorinate the wastewater respectively.  The rated hydraulic capacity of the AWWTP in 2020 was 32.08 million gallons per day (MGD).  

The AWWTP is authorized to discharge treated wastewater to the Conestoga River under the terms of National Pollutant Discharge Elimination System (NPDES) Permit No. PA 0026743.  It is well documented that the Chesapeake Bay is an ecologically sensitive area that is impacted greatly by nutrients such as phosphorus and nitrogen.  To ensure water quality protection, many actions have been taken within its watershed and at the AWWTP to reduce nutrient loadings to the Bay.   

The City has an approved industrial pretreatment program and regulates industrial wastewater discharged to the AWWTP.  In order to protect the treatment plant as well as the environment, the pretreatment program requires industrial dischargers to use treatment techniques and management practices to reduce or eliminate the discharge of harmful pollutants to the sanitary sewer.  Federal and state regulations establish pretreatment rules and wastewater discharge standards. The City’s industrial pretreatment program implements the rules and monitors the wastewater discharge from local industries and other non-domestic wastewater sources for compliance with the wastewater discharge standards listed in Chapter 249 of the Sewer Ordinance. To ensure compliance, yearly industrial sampling events and inspections are conducted by City of Lancaster pretreatment staff.      

 A Fats, Oil, and Grease (FOG) program was developed to protect residents, businesses and the environment from sewer backups and overflows, which may be caused from the accumulation of FOG in the sewer collection and conveyance system.  Controlling the sources of FOG from food service establishments (FSE) and petroleum oil establishments (POE), as well as ensuring proper maintenance and cleaning of the collection system, can reduce FOG blockages and overflows.  The FOG control program consists of FSE and POE inventory efforts, grease interceptor and oil/water separator sizing design and installation oversight, inspection of FOG facilities on a routine basis, implementation of best management practices (BMPs), public education on FOG prevention practices, and FOG data management.