Suffolk County Government Crest

Suffolk County Stormwater Management Program

Edward P. Romaine, County Executive

Department of Public Works

Department of Economic Development and Planning

  1. What is stormwater and why is it a problem?
  2. What are impervious surfaces and what do they have to do with stormwater pollution?
  3. Doesn't stormwater go to a sewage treatment plant?
  4. What are stormwater Best Management Practices (BMPs)?
  5. Who must comply with EPA's Phase II Stormwater Regulations?
  6. Why is recycling important for protecting water quality in Suffolk County's waterbodies?
  7. What is an illicit discharge?
  8. What is low-impact development?
  9. What is an MS4?
  10. How do I report an illict discharge?
  11. What is integrated pest mangement (IPM)?
  12. What is the small construction activity component of Phase II?

What is stormwater and why is it a problem?

When it rains, impervious surfaces such as roads, roof tops, parking lots, and most driveways prevent water from being absorbed into the ground. The portion of water that is not absorbed into the ground is known as stormwater runoff. This flowing water picks up and transports pollutants like oil and grease, toxic metals, pet waste, litter, pesticides, herbicides, and fertilizers. These pollutants can flow into storm drains that empty directly into local lakes, estuaries, and embayments. Unlike household wastewater, stormwater is generally not treated. Therefore, the everyday pollutants found in stormwater have a direct impact on local water quality.

What are impervious surfaces and what do they have to do with stormwater pollution?

Impervious surfaces are hard surface areas that either prevent or impede the natural entry and percolation of rain water into the ground. Roof tops, streets, parking lots, driveways, sidewalks, asphalt and concrete are all examples of impervious surfaces.

Doesn't stormwater go to a sewage treatment plant?

No. Stormwater that enters a storm drain flows through underground pipes that direct it to a nearby waterbody or leaching basin. The end pipe that the stormwater flows out of is called the "outfall pipe". In Suffolk County, many outfall pipes discharge stormwater into ecologically valuable waterbodies such as Long Island Sound, Peconic Estuary, and Great South Bay.

What are stormwater Best Mangement Practices?

Best Management Practices (BMPs) is a general term used to describe the most effective, feasible methods to address and resolve a problem. Stormwater BMPs can be structural or non-structural (behavioral) changes to reduce stormwater pollution. Stormwater BMPs fall into four categories:

  1. Traditional measures-measures taken by most municipalities to filter or remove pollutants from stormwater (eg.leaching basins, catch basins).
  2. Pollution Prevention-measures taken to limit poullant exposure to stormwater (eg. pick up pet waste, removing floor drains from garages and automobile repair facilities, recycling, and using pesticides and fertilizers responsibily and sparingly or not at all.
  3. Low Technology Initiatives-restoring or maintaining the natural condition of the land so that it absorbs and filters stormwater (eg. using wetlands or vegetation as buffers, using vegetated swales instead of paved surfaces to direct stormwater, minimizing paved surfaces on residental properties).
  4. High Techology Initiatives-innovative technologies that can be used to minimize pollutant loadings to waterbodies (eg. green roofs, rain gardens).

Who must comply with EPA's Phase II Stormwater Regulations?

All municipal seperate storm sewer systems (MS4s) that are located in urban areas (as determined by the Census Bureau) must comply with the Phase II Regulations. Suffolk County along with many Towns and Villages must comply with the Phase II Regulations. At this time, the only town in Suffolk County that does not have to institue a stormwater management program is Shelter Island. Although some towns and villages are excluded from having to create a stormwater management program, all constructions sites in New York State that disturb greater than or equal to one acre of land are regulated under the small construction activity portion of Phase II.

Why is recycling important for protecting water quality in Suffolk County's waterbodies?

Many substances and items that have a high potential to cause water pollution can be recycled. For example, motor oil, antifreeze, paints and fertilizers can all be recycled. Check with your local recycling facility to determine where to bring these products. See our recycling page for more information!

What is an illict discharge?

Illicit discharges are any discharge to an MS4 that is not entirely composed of stormwater. Some examples of illicit discharges are septic systems that are illegally connected to the stormwater conveyance system and improper disposal of household products like paints and automobile fluids.

What is low impact development?

Low impact development (LID) is an approach to stormwter management that uses natural features to infiltrate and filter stormwater close to its source. LID techniques include conservation of forests and sensitive waters, water reuse, and stormwater controls that detain and retain runoff such as bioretention cells (rain gardens), porous pavement, and rain barrels or cisterns.

What is an MS4?

MS4 stands for "Municipal Seperate Storm Sewer System." It is a municipalities system of stormwater conveyances, including all roads, catch basins, gutters, man made channels, leaching basins, ditches, outfall structures, and storm drains. They are separate from traditional wastewater sewers and they only convey and discharge stormwater, unlike wastewater, stormwater is not treated.

How do I report an illicit discharge?

An illicit discharge to a Suffolk County-owned MS4 should be reported to the appropriate department within the Suffolk County Department of Health Services. For information on reporting stormwater pollution sources click here.

What is integrated pest management (IPM)?

IPM is an approach to pest management that uses minimal or no pesticides and alternative natural approaches to remove unwanted pests. This approach is preferable to traditional pest management since it causes minimal damage to human health, water quality, and the environment.

What is the small construction activity component of Phase II?

The small construction activity component of Phase II requires all construction projects that disturb great than or equal to one acre of land to obtain a SPDES permit from the New York State Department of Environmental Conservation (NYSDEC). Prior to construction, a notice of intent (NOI) for construction and a Stormwater Pollution Prevention Plan (SWPPP) must be prepared and submitted to DEC to obtain permit coverage.