Stormwater Management

What you should know about safe winter roads and parking lots, and the environment

Phase II

The United States Environmental Protection Agency (EPA) has mandated that certain communities create a Stormwater Management Plan under the Phase II National Pollutant Discharge Elimination System (NPDES) program. The program is intended to improve water quality by reducing the discharge of pollutants from storm water runoff into local storm drains, rivers, ponds, streams and other receiving waterbodies.

Please review the Stormwater Management Program (SWMP), the Illicit Discharge Detection and Elimination (IDDE) Plan, the Phosphorus Source Identification Report, and the Salt Reduction Plan (draft) to learn more about the steps Andover will be taking to protect our natural resources. These plans are living documents and will be updated as this program proceeds forward.


Andover is one of 189 communities affected by this Phase II rule in Massachusetts. In order to comply with the Permit Program, a plan has been developed which comprises the following six elements:

  • Public Education and Outreach
  • Public Participation/Involvement
  • Illicit Discharge Detection and Elimination
  • Construction Site Runoff Control
  • Post Construction Runoff Control
  • Municipal Pollution Prevention/Good Housekeeping

This information is provided to the public regarding Storm Water Management practices to better inform residents of the need to help eliminate non-stormwater discharges and protect water quality.

When it rains or as snow melts, the resulting stormwater flows over roads or ground surfaces, picking up debris, chemicals, oils, grease, salt, sediment and other pollutants. These can have harmful effects on drinking water supplies, recreation, fisheries and other wildlife.

Collage of Water Systems

Prevent Pollution

What you can do to help prevent stormwater runoff pollution:

  • Don’t dump anything into a catchbasin or drain pipe.
  • Properly dispose of all paints, used motor oil and other hazardous waste
  • Sweep up driveways, sidewalks and walkways
  • Use fertilizers and pesticides sparingly
  • Pick up after your pet and dispose waste in the toilet or trash.
  • Check you vehicles for any leaking fluids
  • Wash your vehicles at a car wash. If washing at home, use a low-phosphate detergent.
  • Have your septic tank pumped and inspected at least once every two years.

Remember: Only rain down the drain!

Storm Water Image

What is an Illicit Discharge?

An illicit discharge is the discharge of pollutants or non-stormwater materials into a storm drain system via an illegal pipe connection or other direct tie-in and also via overland flow or direct dumping into a catch basin or stormdrain. Municipal storm drains are intended to convey stormwater runoff to nearby lakes and streams to prevent flooding, but they are not intended to carry flow from sources such as sanitary sewers, septic systems, carwashes, laundromats, or other similar sources. Illicit discharges are a problem because stormwater generally flows to a river, pond, or stream without any additional treatment, unlike wastewater or sewage which flows to a wastewater treatment plant. Dumping anything other than stormwater into a storm drain is illegal and considered an illicit discharge.

Sources of Illicit Discharges

  • Sanitary wastewater (sewage)
  • Septic tank waste or overflows
  • Car wash, laundry, and industrial wastewaters
  • Improper disposal of auto and household toxins, such as motor oil, antifreeze, and pesticides
  • Spills on roadways and other accidents

Stormwater Resources

Stormwater Videos