Greater Nanaimo Pollution Control Centre

Greater Nanaimo Pollution Control Centre


Greater Nanaimo Pollution Control Centre (GNPCC) treats wastewater from approximately 104,000 people in the City of Nanaimo, Snuneymuxw First Nation land, and the District of Lantzville. GNPCC also treats septage from residential onsite (septic) systems and wastewater from pump-and-haul properties.  

Sewers are built to follow the natural slope of land, allowing gravity to do most of the work to transport wastewater. Low elevation areas use a pump station to pump the wastewater to a treatment plant. GNPCC uses three pump stations: Wellington Pump Station, Departure Bay Pump Station and Chase River Pump Station. View a map of the sewer service area.

The GNPCC provides primary and secondary treatment and removes more than 90% of the biochemical oxygen demand (BOD) and total suspended solids (TSS), two of the main methods used to measure wastewater quality. Learn more about how treatment works and the different levels of wastewater treatment.

Biosolids, a soil-like material produced during the wastewater treatment process, are managed in the RDN's Biosolids Management Program.

GNPCC treated over 12 billion litres of wastewater in 2023. Treated wastewater is discharged into the Strait of Georgia 2,030 m offshore at a depth of 70 m. For more information see the 2023 GNPCC Annual Report.

Major Projects & Improvements

Major Projects & Improvements
2017-2020 Secondary Treatment Upgrade Project
2014-2016 Construction of a new outfall  
2013 Construction of a fourth primary sedimentation tank, to improve plant efficiencies and support increasing flows
2011-2013 Construction of a third digester to improve plant efficiencies and support increasing flows
2009-2012 Construction and commissioning of a Cogeneration system
2008-2012 Phase II Odour Control installed
2007-2009 Gravity Thickeners constructed to improve solids handling
2005-2007 Phase I Odour Control installed
2002 Introduction of Chemically Enhanced Primary Treatment
1988-1990 Stage II expansion to improve plant efficiencies and support increasing flows
1972 The RDN took over operational responsibility of GNPCC
1971-1974 Construction of GNPCC with primary treatment, ending the discharge of raw sewage to the Strait of Georgia