Completely surrounded by salt water, Long Island derives almost all of its drinking water from groundwater aquifers. Suffolk County alone uses nearly 200 million gallons of groundwater daily. Protecting the underground aquifers that supply that water is a key mission of the County. With most of the county unsewered, the majority of homes and businesses have septic tank systems that discharge their wastewater back into the ground. This presents a risk to our aquifers, as nitrates leach from the septic systems into the groundwater.
Suffolk County recently hired H2M to investigate alternatives to septic systems using alternative on-site sewage disposal system (AOSSDS) technologies. The goal of the study was to explore the viability of alternative systems to traditional cesspools and leach fields. The systems investigated had to meet effluent requirements for total nitrogen of 10 mg/L or less.
Studying over 60 technologies for both residential and commercial applications, we developed a short list of five technologies that would reduce nitrogen concentrations by 87%. We also presented costs for design, installation, operations, and maintenance. A review of other states’ alternative treatment technology implementation and regulations included Massachusetts, Rhode Island, New Jersey, and Maryland.