The Village of Patchogue, New York, has had continued growth of its downtown area in its Main Street business district. This continued growth has placed a burden on the sewer infrastructure because the Main Street sewers had reached their sanitary flow handling capacity.
This capacity issue resulted in recurring backups in the collection system, and it became obvious that the continued growth in Patchogue could not be sustained in its current state and would likely increase the frequency of sewer system backups along Main Street.
The villageʼs wastewater treatment plant was originally designed to accommodate a collection system that delivered 300,000 gallon per day (gpd) of sanitary flow, but by the 1980s the flow at the plant had risen to 500,000 gpd. The plant was expanded at that time to meet the demand, and the WWTP became a critical piece of the village’s growth.
By 2011, demand had risen to 800,000 gpd, and the plant was again expanded for estimated future flows nearing 1.2 million gallons per day (mgd). The limiting factor, in terms of sewage handling and in terms future development growth, shifted from the treatment plant capacity to the collection system capacity and its limitations.
A hydraulic analysis confirmed the sanitary sewer system was at capacity and did not have the additional capacity for the future projects to come on-line. While such developmental growth was not envisioned in the 1980s, the current village leadership embarked on an aggressive and responsible course to expand the sewer system and improve system capacity and reliability. This provided improved service and quality of life for residents and businesses, while improving overall system performance in the region.
The Main Street Sewer Reconstruction Project aimed to improve the gravity collection system by providing 1,200 linear feet of 16-inch DR-18 PVC and 550 linear feet of 24-inch-diameter CL52 DIP, replacing the existing system of 10-, 12-, and 15-inch gravity sewer pipe. In addition, all 52 lateral service connections to properties were upgraded to the right of way curb line, making future maintenance easier to conduct.
All work performed was staged so service interruptions were minimized for existing connections. The new sewer line was installed in place of the existing sewer line, so the active sewer use was required to be maintained throughout the construction period. To accomplish this, bypass pumps were used to allow for demolition of existing structures and sections of the sewer main for the subsequent installation of new sewer and structures. All connections and sewer mains were put into full service at the close of each workday.
The elevated groundwater table required trench dewatering for the installation of the 24-inch DIP, which was also installed in line with the existing sewers.
The villageʼs downtown area is a busy commercial and residential hub, therefore traffic control and maintenance was carefully planned to keep the flow of traffic safely moving while not requiring the full closure of the street section to accommodate the work.