Stormwater Management & Pollution Prevention


Stormwater runoff is generated from rain and snowmelt events and flows over land or impervious surfaces such as paved streets, parking lots, and building rooftops, and does not soak into the ground.  The runoff can pick up pollutants including trash, chemicals, oils, and dirt and sediment that can harm our rivers, streams, lakes, ponds, and coastal waters.

Population growth and the development of urbanized areas are major contributors to the amount of pollutants in the runoff, as well as the volume and rate of runoff from impervious surfaces.  Together, they can cause changes in hydrology and water quality that can result in habitat modification and loss, increased flooding, decreased aquatic biological diversity, and increased erosion and sedimentation.

To protect these resources, communities, construction companies, industries, and others, use stormwater runoff management controls, known as best management practices (BMPs).  These BMPs filter out pollutants and/or prevent pollution by controlling it at its source.

The benefits of effective stormwater runoff management can include:

  • Protection of wetlands and aquatic ecosystems
  • Improved quality of receiving waterbodies
  • Conservation of water resources
  • Protection of public health
  • Flood control

In addition to the management of stormwater runoff from rain and snowmelt events, the management of illicit dry-weather discharges into storm drainage systems that can contribute significant pollutant loadings to receiving waters is required.  If these loadings are ignored (by only considering wet-weather stormwater runoff for example), little improvement in receiving water conditions may occur.

Illicit dry-weather discharges originate from many sources.  The most common sources typically include failing septic tank systems, laundry wash water, floor drain discharges from commercial and industrial buildings, commercial and industrial pollutant discharges, or pollutant discharges such as motor oil, gasoline, antifreeze, pet waste, cigarette butts, cleaning products, pesticides, fertilizers, or trash.

These dry-weather flows may be directly connected to storm sewers or may enter the storm sewer system indirectly by infiltrating into pipe joints, draining into inlets, or by being dumped directly into inlets.

An effective stormwater management program includes the detection and elimination of these illicit discharges.

Federal and State Regulations regarding Stormwater Management

The U.S. Environmental Protection Agency published the National Pollutant Discharge Elimination System - Regulations for Revision of the Water Pollution Control Program Addressing Storm Water Discharges on December 8, 1999 as required by Section 402(p) of the Clean Water Act.  These regulations are commonly referred to as the National Pollution Discharge Elimination System (NPDES) Phase II Program.

The NPDES Phase II Program regulates certain stormwater discharges from three potential sources: municipal separate storm sewer systems, construction activities, and industrial activities.

In the State of Connecticut, the Department of Energy and Environmental Protection (CTDEEP) has implemented the NPDES Phase II Program through the following General Permits:

1.  General Permit for the Discharge of Stormwater from Small Municipal Storm Sewer Systems

The Town of Madison has submitted a registration to the CTDEEP for the General Permit for the Discharge of Stormwater from Small Municipal Storm Sewer Systems (MS4 General Permit), and as required by the permit conditions, has prepared a Town-wide Stormwater Management Plan.

The purpose of the Stormwater Management Plan is to establish, implement, and enforce a stormwater management program that will to the maximum extent practicable, protect surface and groundwater resources from potential impacts from stormwater discharged from roads, parking areas, roof tops and other facilities, and dry-weather illicit flows discharges through the Towns municipal storm sewer system.

The plan includes six minimum control measures that include best management practices intended to reduce or eliminate the discharge of pollutants:

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

Public participation is necessary for the success of the Stormwater Management Plan. Interested citizens are invited to contact the Department of Public Works for further information. Additionally, the public is encouraged to report any illicit discharges to Town storm drainage systems.  Report your concern with the "Report A Concern" button on our homepage.  Users will need to set up a profile with your email address.

A draft copy of the plan can be viewed or downloaded here. 

Town of Madison Stormwater Management Plan Draft for Public Review

2.  General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities

This General Permit authorizes the discharge of stormwater and dewatering wastewaters to surface waters from construction activities on a site, as defined in the General Permit, with a total disturbance of one or more acres of land area on a site, regardless of project phasing.

For construction projects with a total disturbance of between one and five acres, the permittee must adhere to the Towns erosion and sediment control land use regulations, as well as the Connecticut Guidelines for Soil Erosion and Sediment Control, and the Connecticut Stormwater Quality Manual.

For construction projects with a total disturbance greater than five acres, the permittee must file a registration with the CTDEEP and meet the requirements of the General Permit including the preparation of a Stormwater Pollution Prevention Plan that includes erosion and sediment, dewatering wastewater, waste disposal, stormwater runoff, and post construction stormwater controls, inspections of the site, and monitoring of stormwater discharges from the site.

3.  General Permit for the Discharge of Stormwater Associated with Industrial Activity

This General Permit authorizes stormwater discharges from industrial sites.  The Town has submitted registrations to the CTDEEP for this permit for the Department of Public Works Garage Facility and the Bulky Waste Disposal and Recycling Facility, and as required by the permit conditions, has prepared Stormwater Pollution Prevention Plans for both facilities.

These plans set forth procedures and controls related to the management of the operations at these facilities intended to improve the quality of stormwater discharged from the facilities, and reduce or eliminate potential impacts to surface and groundwater resources to the maximum extent practicable.  These plans also include stormwater monitoring requirements for each facility.

The Stormwater Pollution Prevention Plans for these facilities can be viewed or downloaded here:

Bulky Waste Disposal and Recycling Facility

Department of Public Works Garage Facility

Annual Report