On-Site Sewage Disposal System and SPDES Permit

Bureau of Environmental Engineering

On-Site Sewage Disposal System and SPDES Permit


Engineering plans submitted to the Department must be designed by a project consultant who a New York State licensed Professional Engineer. An Owner’s Letter  and a Consultant’s Letter must be submitted to the Department authorizing the consultant to act and submit plans and forms on the developer’s behalf. Additionally, SQRA Form must be completed and submitted to the Department as part of the application package along with payment for the plan review fees. Click here to view the fee schedule

The plans must be approved by this Department prior to the construction or modification of an on-site sewage disposal system for any commercial facility with a design flow of 1,000 gallons per day or more, as determined by the Department. For more information, please read the Nassau County Department of Health Manual of On-Site Sewage Disposal.

All land development in the Special Groundwater Protection Areas of Nassau County must comply with the requirements of Article X of the Nassau County Public Health Ordinance. This regulation limits the number of dwelling units to one per 40,000 square feet for residential developments, limits the daily design rate of sewage discharged per square foot of net area for non-residential developments to no more than .00375 gallons per square foot, and prohibits all discharges of industrial wastewater, regardless of treatment. Click here for a map of the Special Groundwater Protection Areas of Nassau County.

Upon satisfactory completion of approved construction, a State Pollutant Discharge Elimination System (SPDES) permit must be obtained from this Department prior to the discharge of sanitary waste into the ground.