Manchester constructed a sewer collection system between 1912 and 1914 to service the densely populated center of town. This original system operated by gravity flow to a pump station along Manchester Harbor behind the current hardware store. The sewage was pumped out into the ocean (probably without any treatment) via a one and one half mile cast iron outfall pipe. The gravity system continued to grow gradually. As new subdivisions were constructed during the 1960’s, it was necessary to install sewer lift stations to pump sewage from low lying areas into the gravity sewer collection system.
Manchester’s first secondary treatment plant went on line in 1971 in the same location as the original pump station. This treatment facility had problems accommodating the fluctuating sewer flows resulting from infiltration/inflow (clean water entering the sewer system from rainfall or groundwater) and was often in violation of the EPA discharge permit.
A new outfall sewer was constructed in the early 1990’s and roughly followed the route of the original outfall. The outfall pipe discharges in approximately 35 feet of water that studies have proven to provide complete dispersion. The complete dispersion is not affected by wind direction of tidal flow.