Existing drainage systems in the area were limited and not adequate to drain stormwater runoff. Streets were flooding regularly. Groundwater was approximately two feet below grade which limited the function of the on-site sanitary system for the homes. All parcels were within the zero to two year groundwater travel time to the Great South Bay. Several studies have documented the impacts of excessive nitrogen from sanitary systems in reducing dissolved oxygen levels to the detriment of aquatic life and in supporting harmful algal blooms. In conjunction with this study to provide sanitary sewers, we investigated the feasibility of making storm drainage-related improvements to help address existing flooding conditions related to the proposed sanitary sewer improvements. The report identified potential drainage improvements that could be implemented while the roadways were disturbed during the construction of the sanitary sewers.
The drainage improvements included the installation of approximately 4,750 linear feet of porous concrete gutter, along with drainage pipe and underground stone storage space along the shoulders of each of the roadways. In addition, a shallow vegetated stormwater management basin was proposed to temporarily store excess runoff during storm events. This system was incorporated to help alleviate flooding during storm events and improve drainage in this flat, low-lying section of Patchogue.
During design, we conducted a utility coordination meeting with representatives of National Grid, the Village DPW and the Suffolk County Water Authority. Our personnel also met with homeowners to review the proposed installation location of the on-site pump station and low pressure sewer connection. Plans were submitted to and approved by the Suffolk County Department of Health Services.
We worked with the Dormitory Authority of the State of New York (DASNY), Suffolk County and the Village of Patchogue in order to receive funding through two DASNY grants, an Infrastructure Program Grant provided by Suffolk County, and the Village of Patchogue Sewer Fund. Remaining funds were bonded by the Village.
We provided a resident engineer during construction. Construction phase services included full time construction inspection, shop drawing review, review of contractor payment requests and periodic meetings. During construction the project scope was expanded to include the abandonment of the existing on site sanitary system at each home.