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The Neponset Stormwater Partnership (NSP) is a regional group managed by the Neponset River Watershed Association (NepRWA) that is committed to reducing water pollution and complying with federal pollution reduction requirements.

How much do you know about lawn fertilizer?

There is an environmental impact to fertilizer use. Improperly applied fertilizer can easily wash into local waterways through storm drain systems and cause problems in local streams and ponds.

Click here to learn more about smart lawn care.

Be smart about lawn care!

If you must use fertilizer, plan responsibly.

  • Do not use fertilizer with phosphorus unless you get a soil test. Phosphorus pollution is such a problem in Massachusetts that it is illegal to apply phosphorus-containing fertilizer without a soil test stating it is necessary.
  • Test your soil at least once every 3 years to learn what your lawn needs to be healthy. UMass Amherst offers a convenient soil testing option.
  • Make sure the pH of your lawn is in the acceptable range (this stat will be shown on your soil test). If the pH is too high or low, the plants will not be able to absorb the nutrients, regardless of how much you apply.
  • Choose organic or slow-release fertilizers whenever possible. This allows for a slow, sustained release of nutrients after application rather than a heavy, all-at-once dose.
  • Test homemade compost prior to application so you know the actual nutrient content of the material. Knowing the content will allow you to calculate an acceptable application rate. Unfortunately, UMass no longer tests compost, but they direct to their colleagues at Penn State and the University of Maine for these services.

The #1 cause of water pollution in the Neponset River Watershed is polluted stormwater runoff.

Polluted stormwater happens when bacteria, chemicals, and trash get washed into storm drains from impervious surfaces, like streets, driveways, parking lots; industrial sites, and construction sites.

After the polluted runoff enters our storm drains, it empties — untreated — into local streams and ponds and affects our drinking water resources, swimming, boating, fishing, wildlife, and fish habitats.

The Neponset Stormwater Partnership (NSP) is a regional cooperation and resource-sharing program in the Neponset Watershed that was formed to help reduce the water quality problems caused by polluted stormwater runoff.

NSP partners include the towns of Avon, Canton, Dedham, Foxborough, Medfield, Milton, Norwood, Quincy, Randolph, Sharon, Stoughton, Walpole, and Westwood, along with the Metropolitan Area Planning Council (MAPC).

Learn more about polluted stormwater.

Read below to learn how you can help to reduce stormwater pollution in your community.


Make simple changes around your home. Limit lawn chemical use and always pick up after your dog!


Maintain the area around your property and follow guidelines to reduce contaminants.


Protect your business and your clients by installing construction site stormwater best management practices.


Take steps to reduce or eliminate the cause of polluted runoff to minimize the risk of costly clean-ups.

Report a Problem. Ask a Question.

Seen dumping in a storm drain? Spotted pollution in a waterway? Have a stormwater question?

Email us at stormwater@neponset.org, or give us a call at 781-575-0354 x 300. If we can’t solve the problem or answer the question on the spot, we will relay it to the appropriate agency for further action.

The NSP is Managed by NepRWA

The Neponset Stormwater Partnership is managed by the Neponset River Watershed Association (NepRWA), a non-profit grass-roots organization founded in 1967, with a mission to protect and restore the natural resources of the Neponset River, its tributaries, and surrounding watershed lands for the benefit of present and future generations.

You can learn more about NepRWA and the programs they manage at neponset.org

For more information about the NSP, contact NepRWA Managing Director for Community Resilience, Kerry Snyder, snyder@neponset.org (781) 575-0354 x300