Sewer Division

The Sewer Division has a mission "To provide the City of Danbury and the neighboring Region with sound disposal and treatment methods for wastewater and septic system wastes to ensure the protection of human health and the preservation of the environment".

The Danbury Water Pollution Control Plant (WPCP) provides wastewater and septage treatment for Danbury, Bethel, Brookfield, Ridgefield, and Newtown, and also accepts septage from New Fairfield, Redding, and Bridgewater, and some out-of-region towns. The WPCP currently treats an average wastewater flow of 9 million gallons per day and an average septage load of 14 million gallons per year. In addition to WPCP operations, oversight of the sanitary sewer collection system involves the operation and maintenance of 20 sewer pump stations, 164 miles of sewer line, and 4,500 sewer manholes.

Our capacity, management, operation, and maintenance (CMOM) program continues to be optimized to reduce the occurrence of sanitary sewer overflow (SSO) events. The implementation of our Fats, Oils, and Grease (FOG) prevention program through site inspections, FOG compliance education of all food preparation establishments and enforcement of the FOG Ordinance is helping reduce SSO events from occurring in our sewer collection system.

The successful operation of our WPCP's interim nitrogen removal facility by Veolia Water not only resulted in a net savings of $643,000 versus the cost of purchasing nitrogen credits had the system not been operating, but also resulted in the City being paid $37,718 by CT DEEP due to the WPCP removing more nitrogen then was required in the General Permit for Nitrogen Dischargers. The use of reclaimed methanol, when available, continues to help reduce the chemical cost of operating this system. We continue to make improvements to the existing nitrogen removal system to further reduce overall nitrogen removal and to the existing phosphorus removal system to ensure compliance with the current NPDES permit for seasonal phosphorus removal limits of 0.6 milligrams per liter.

Ongoing WPCP Upgrades include construction of a new Tertiary Treatment Facility for improved phosphorus removal, Stormwater System Improvements, construction of a new Headworks Screening and Grit Removal Facility, construction of a new Fats, Oils and Grease (FOG) Receiving and REA Biodiesel Facility and Miscellaneous Plant Upgrades. Upgrades are required to meet stringent long-term nutrient (nitrogen and phosphorus) removal discharge permit requirements and are required to replace existing aging systems and equipment.

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