Following a rain or snow event, stormwater flows through yards, down driveways, over streets, and into catch basins. Catch basins are the grates on the sides of streets and they connect to the storm drain system, which conveys the water, untreated, into our local waterways, including Boston Harbor and the Charles, Neponset, and Mystic Rivers.

As stormwater travels into the catch basins, it flushes pesticides, fertilizers, pet waste, trash and debris, automotive fluids, motor oil, and other pollutants into the storm drain system. As these pollutants enter local waterways, they can be harmful to water quality and the environment.

All Boston residents play a role in reducing and preventing stormwater pollution.

For Residents

Learn what pollutants are commonly found on our streets and how to prevent them from entering the storm drains. Also learn what to do with used motor oil, gasoline, antifreeze, cleaning agents, pesticides, and paint.

BWSC's stormwater system collects rainwater and snowmelt from rooftops and pavement and discharges this runoff, without treatment, into the nearest receiving water. As stormwater runs over the ground, it picks up pollutants and debris that have been carelessly or illegally deposited onto our streets or directly into the storm drains. These pollutants include used motor oil, gasoline, antifreeze, cleaning agents, pesticides or fertilizers and paint. Debris commonly found in storm drains include pet waste, cigarette butts, yard clippings, and sand. In addition, car washing and lawn watering can also contribute to the pollution of the waterways. 

Here are some things you can do to prevent pollutants from entering the storm drains:

  • Never pour any hazardous materials into a storm drain. This includes used motor oil, gasoline, antifreeze, cleaning agents, pesticides or fertilizers and paint. For proper disposal of these items, go to the City of Boston’s Department of Public Works website
  • Sweep up and remove litter and sand from sidewalks and driveways to prevent these materials from being carried into storm drains by stormwater runoff or snowmelt. Dispose of these materials in the trash
  • Collect leaf litter and yard clippings and donate them to a local community garden for use as compost
  • Use landscaping fertilizers and pesticides sparingly or not at all. Landscaping chemicals should not be applied when rain is forecasted
  • Clean up outdoor spills using dry methods such as sweeping, applying absorbent towels or spreading cat litter. If not hazardous, place the material in the trash. If hazardous, dispose of the material at one of the City of Boston’s drop off sites
  • Never hose down a spill into the storm drain. If you must hose down an area, direct the runoff towards a grassy landscaped area.Detergents and chemical cleaners should not be used to wash sidewalks or driveways
  • If you see a storm drain that is clogged with debris, report it to BWSC for cleaning
  • Reduce exposure to household chemicals by using non-toxic alternative cleaners

For Businesses

Business owners have a responsibility for all pollutants leaving their property, including contaminated stormwater which enters the storm drain. Common pollutants generated by businesses such as automotive and food and beverage establishments include used motor oil, antifreeze, fertilizers and pesticides, sand, dirt, litter, paint, cooking oil and cigarette butts.

Some of these suggestions include:

  • Proper disposal of all pollutants. If you are unsure as to how to dispose of certain material, consult the manufacturer or contact the Massachusetts Hazardous Waste Hotline for Businesses at 617-292-5898
  • Provide neighborhood amenities. Place trash receptacles in highly visible areas, including receptacles for cigarette butts
  • Keep public areas clean. Sweep outdoor areas and dispose of debris into the trash and not into a storm drain. Hose down areas and direct the runoff away from the storm drain
  • Dispose of leaf litter into the trash and not into a storm drain
  • Maintain solid waste containers. Locate these containers away from storm drains. Have the container cleaned on a regular basis and store adequate spill equipment on-site to clean up spills and releases
  • Disposal of wash water. Never pour wash water onto a parking lot or into storm drains. Wash water should be disposed of into a janitorial sink or a floor drain that is properly connected to the sanitary sewer system
  • Installation and disposal for restaurant owners. Install and maintain grease traps and properly dispose of cooking oil. Never pour grease or cooking oil into sinks, floor drains, or into a storm drain

For Construction Sites

As stormwater flows over a construction site, it picks up pollutants that are transported into the drainage system.

Owners, developers or general contractors are responsible for stormwater management on their construction sites. Stormwater runoff is rain or snowmelt that cannot be absorbed by the soil and instead washes off the surface of the land. As stormwater flows over a construction site, it picks up pollutants that may be transported into nearby receiving waters such as rivers or the harbor.

To avoid this pollution, a construction site may require permits from federal, state and local authorities. Visit the Stormwater Permits for Construction page to determine if you need a stormwater discharge permit or other permits for your construction activity.

Construction Stormwater Permits