City of Danbury Water Pollution Control Plant (DWPCP)

Owned by the city of Danbury, CT and operated by the Department of Public Utilities, is the City of Danbury Water Pollution Control Plant (DWPCP).

The Public Utilities Division oversees the contract operation of the city’s Water Pollution Control Plant in accordance with the Wastewater Treatment Facility Service Agreement between the City of Danbury and Veolia Water North America. The Public Utilities Division also oversees the contract operation of a public yard waste management processing center, located on Plumtrees Road, in accordance with the agreement between the City of Danbury and Total Landscaping and Tree Service.


The DWPCP has the design capacity to handle 15.5 million gallon per day. The plant is a secondary treatment plant that includes trickling filters. Wastewater is received in the headworks and processed through three primary settling tanks. The discharge from the primary settling tanks is sprayed onto circular stone beds where contact is made with biological growth. The discharge from the trickling filters is processed through intermediate settling tanks and is then passed through aeration tanks and final settling tanks. Liquid Sodium Hypochlorite is injected into the treated sewage flowing through the chlorine contact tank and, when necessary, into the raw sewage at the head of the plant for disinfection purposes. Disinfection is accomplished in the contact tank. Sulfur dioxide is added to remove residual chlorine from the discharging treated wastewater.