Subsurface Sewage Disposal
Where public sewer systems are not available, domestic sewage is disposed of using on-site sewage disposal systems. Septic systems treat and disperse wastewater from individual or small numbers of homes and commercial buildings such as schools and restaurants. A properly designed, installed and maintained septic system provides a safe and efficient way of disposing domestic sewage. The type and/or size of the septic system determine which agency has regulatory authority.
A conventional subsurface sewage treatment and disposal system consists of a house sewer, septic tank followed by a leaching field, any necessary pumps or siphons, and any groundwater control system on which the operation of the leaching field is dependent. A community subsurface sewage treatment and disposal system consists of one system serving two or more buildings, regardless of system size.
In Connecticut the Department of Energy and Environmental Protection (DEEP) regulates conventional systems with design flows greater than 5,000 gallons per day, including sites where multiple smaller systems on a single "lot" have a combined flow greater than 5,000 gallons per day, community systems, and any system utilizing alternative treatment, regardless of size. The Department of Public Health (DPH) regulates conventional systems with design flows greater than 2,000 gallons per day but less than 5,000 gallons per day. Local health departments regulate conventional systems with design flows less than 2,000 gallons per day.
In Massachusetts, the Department of Environmental Protection (MA-DEP), through its State Environmental Code known as Title 5, regulates the criteria for Septic Systems. The approval of septic systems is by the Local Approving Authority, except for State and Federally owned systems and systems with a design flow of 10,000 gallons per day or greater, for which the MA-DEP is the Approving Authority.
LEI has designed more than 2,500 on-site subsurface sanitary disposal systems for public and private clients throughout New England.
