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Officially Started December 16, 1968
Secondary Started Summer 1989
Mercury Emissions Control 2002
Nitrogen Removal Started 2003, Substantial Completion July, 2015


20 – 35 million gallons/day
600 – 1,200 million gallons/month
9 billion gallons/year
In excess of 300 billion gallons since 1968

33 People:
16 Operations, including managers, 3 shifts/day, 365 days/year
10 Maintenance & 2 laboratory, including managers
5 Executive Management and Administration

4 primary tanks at 1 million gallons each
6 aeration tanks at 1 million gallons each
6 final clarifiers at 1 million gallons each
2 half million gallon sludge storage tanks

23 Blowers ranging in size from 200 cfm to 12,000 cfm
98 Pumps ranging in size from 1 gpm to 15 mgd
150 Motors ranging in size from 1/4 hp to 400 hp
Three 2,400-volt 400-hp blowers for the aeration system
Six 200-hp 15-million gallon/day raw sewage pumps
Two 1.5-megawatt emergency generators, and one 1.25-megawatt emergency generator

Supervisory Control and Data Acquisition (SCADA) System with programmable logic controlers (PLCs). One person on each shift can manage the entire facility from the control room.
2022 Average Daily Flows
Community New Britain

Flow 9.8 mgd
4.84 mgd
1.03 mgd
6.04 mgd
0.76 mgd

% of Total

  • The Mattabassett District employs a sophisticated process to remove dissolved solids, organic material, and nutrients in wastewater. This process regularly removes at least 98% of these pollutants. Between May 1st and October 15th, the District disinfects the effluent with Sodium Hypochlorite before discharging to the Connecticut River.
  • Accepts and treats septage and grease from septic tank cleaning trucks and liquid biosolids from other wastewater treatment plants.
  • The District maintains a nine-mile concrete trunkline sewer which ranges in size from 60” to 72” in diameter. This trunkline conveys wastewater from New Britain, Berlin, Cromwell, and Middletown.
  • Mattabassett uses 35,000 gallons of potable water each day.  More importantly, we use over one million gallons of our own treated water saving more than $125,000 each month