Wastewater Treatment Plants

SD1 operates three major and several smaller wastewater treatment plants. Wastewater from thousands of local homes, businesses and commercial buildings flow here for treatment. In fact, we clean and release millions of gallons of water every day (MGD). Each treatment facility is unique and helps provide our community with cleaner and safer waterways.

Wastewater Treatment 

Our wastewater treatment process varies at each facility but consists of the following steps:

Preliminary  Treatment

Incoming wastewater, known as influent, goes through a series of screens to remove large objects like wipes and plastics. 

Primary Treatment

Primary treatment separates solids and oils from the wastewater through large tanks. Organic solids still remain in the wastewater.

Secondary Treatment

Secondary treatment applies biological processes to remove organic materials from the wastewater. Solids handling manages any remaining materials removed from the flow, sending them to a nearby landfill, and final disinfection makes the treated water, known as effluent, safe for the environment.