Septic Chambers Offer Wastewater Capacity to Private School

At South Kent School in Brookfield, Conn., a wastewater system covers 4,329 linear feet of trenching, 8,658 linear feet of CULTEC Contactor 100 chambers, occupying a surface of area of 59,400 sq. ft.

South Kent School, established in 1923, is a college preparatory school for boys in grades nine through 12, nestled in the hills of picturesque northwestern Connecticut. In recent years, the school has observed an expansion of its student and faculty population, creating a need for the facility to expand as well. An analysis of the existing subsurface sewage disposal system was conducted as part of the planning stage for the larger facility. The population currently generates an estimated 15,000 gallons of sewage per day with a future estimate of 18,300 GPD. The analysis revealed that the existing system has inadequate capacity to handle the projected future flow.

Engineers from DYMAR, Corp. of Southbury, Conn., believed that an entirely new SSDS would need to be constructed to handle all of the school's current and future sewage flow. Discharge is regulated by the Connecticut Department of Energy and Environmental Protection. Engineers chose to use CULTEC (https://landscapearchitect.com/products/listing.php?id=11458) Contactor???(R)???AE???? 100 plastic subsurface leaching chambers, arranged side –by-side in each trench. Each chamber measures 8" x 36" x 12.5" and has an effective leaching area of 5.9 sf./ft. The chambers have repeating support panels to add strength, feature a patented overlapping rib connection and have a greater contact with the primary leaching area, which promotes maximum infiltration.

"The CULTEC chambers we used for this project were not only lightweight and simple to install, but durable and reliable," said Mark Green, owner of Green Construction Management, LLC. "A different product was originally specified for this project, but in working closely with DYMAR in value engineering options, we agreed a CULTEC chamber was the best solution to satisfy the project and the school requirements. In addition, they provided us with field inspections, and a representative from the company was present to oversee the installation."

The new system consists of over 1,100 CULTEC Contactor 100 chambers arranged in a side-by-side configuration in 56 rows. They are located beneath the school's existing lower athletic field, which is being reconstructed into a regulation-size soccer field.

The subsurface chambers are being used for storage and dispersion of sewage effluent as it seeps into the native soils after conventional treatment to recharge the groundwater. In addition, there are about 240 linear feet of chambers being used as infiltration rechargers for the surface drainage of the soccer field and to provide nitrogen dilution. All of the chambers were placed on native material, and processed stone was placed above and on the sides of the chambers and topped off with common fill and topsoil.

A traditional septic system consists of a solid pipe from the building structure, the septic tank, a drain field and soil treatment. The school's wastewater management system consists of gravity collection piping from numerous buildings and pretreatment septic tanks. Sewage water flows from the tanks to a centralized effluent pump station and meter pit that doses the CULTEC chambers using an electromagnetic flow meter to regulate valves and the flow controller.

South Kent School occupies about 350 acres of land, and the area where the CULTEC system is being installed is the size of a baseball and football field combined. Because the site is so large, engineers chose to install the technically advanced metering system that includes a splitter box, which includes multiple outlets to disperse the flow to set trenches, segmenting the trenches into dispersal cells. This method provides better control of the effluent flow and long-term effect on the groundwater mound beneath the system.