The County has jurisdiction over commercial septic systems collecting over 1,000 gallons per day. Any commercial system under 1,000 gallons per day is under municipal jurisdiction. The County has jurisdiction over residential subdivisions with five or more homes. Subdivisions with less than five homes are under municipal jurisdiction. The County does not have an aggressive septic inspection and maintenance program.
Municipalities can adopt more stringent regulations.
A large portion of Nassau County is covered by artificial surfaces, such as pavement, which increase the amount of stormwater pollution flowing to the Sound. The County owns and maintains over 700 stormwater basins that collect runoff and allow water to percolate back into the groundwater aquifer system. County authority over municipal practices does not extend to land use or management. Thus, County stormwater regulations and controls apply only to County-owned lands and roadways, although they may also serve as recommendations to municipalities. County stormwater regulations are modest in any event.