Polluted street runoff entering this catch-basin will be transported to a tributary of the Neponset River in in just a few minutes by the storm drain system, with almost no treatment to remove pollutants.

Polluted runoff from roadways, parking lots and other impervious surfaces, also know as “stormwater pollution” is the largest remaining pollution source affecting the Neponset and its tributaries. With many square miles of existing pavement that pre-date modern requirements to intercept and clean-up polluted runoff before dumping it into streams, stormwater is a problem that affects every community in the watershed.

The Neponset Watershed Association has recently partnered with 12 of the 14 communities in the Neponset Valley, and our regional planning agency the Metropolitan Area Planning Council, to propose a regional collaborative that would work across town lines to curb stormwater pollution.

The collaborative will include the communities of Canton, Dedham, Foxborough, Medfield, Milton, Norwood, Randolph, Sharon, Stoughton, Walpole, Westwood, and the Boston Water and Sewer Commission.

In Massachusetts, municipalities own and manage a large share of the paved areas that contribute to stormwater pollution, and they also take the lead role in regulating privately owned parking lots, driveways, and other sources of contaminated runoff. Because of this dual role, effective stormwater pollution efforts by Neponset Valley communities will be absolutely critical to achieving the Watershed Association’s goal of reducing stormwater pollution so that area streams can be restored to meet “fishable-swimmable” water quality standards.

The Watershed Association’s volunteer water testing data show that almost all areas of the watershed now meet fishable-swimmable standards during dry weather, thanks to efforts to eliminate sources of domestic and industrial sewage that once entered the river and its tributaries. But during wet weather, when streams are flooded with untreated runoff from parking lots and roadways, water quality standards are violated almost everywhere in the watershed.

All of the participating communities, with the exception of Boston which is participating as a technical adviser, are facing significant new mandates to address stormwater pollution, as the US Environmental Protection Agency prepares to issue more stringent municipal stormwater permits.

The focus of the Neponset Valley Regional Stormwater Collaborative will be improving the effectiveness and reducing the cost of efforts to comply with the new mandates. Because the new EPA stormwater permits will require similar work across all communities, there are significant opportunities for cost savings and quality improvements through the economy of scale that comes with a regional approach, rather than having every community re-create the same work using its own consultants or staff.

To help fund the first year of the collaborative’s work, the group is seeking grant funding from the Commonwealth’s Community Innovation Challenge Grant program and each participating community will also contribute $5,000 toward completing the first year’s work plan.

If the group’s grant application is successful, the goals for the first year will be to:

• Formalize the Collaborative structure and develop work plans for future years
• Develop an integrated, region-wide outreach and education campaign to inform residents, commercial and industrial property owners, and developers about the problem of stormwater pollution and steps they can take to prevent or reduce the problem.
• Analyze the drainage collection infrastructure in each community to identify what steps communities will need to take at each of their drainage outfalls to comply with the new permit and prepare some of the key planning documents that will be required.
• Evaluate local stormwater bylaws as well as zoning and other rules in each community and identify changes which may be required or beneficial to help reduce polluted runoff at non-municipal sites.
• Prepare a preliminary evaluation and ranking of publicly-owned parcels that many be suitable for the installation of new measures to intercept and clean-up polluted runoff before it enters local streams and wetlands.
• Assemble a variety of model policies and procedures required to comply with the “good housekeeping” provisions of the new municipal stormwater permit.
• Evaluate options for creating a regional database that would make it possible for communities to track whether local developers are keeping up with requirements to perform ongoing maintenance of stormwater pollution control infrastructure.
• Conduct a pilot project in two communities to use the forthcoming MAPC Stormwater Financing Toolkit to evaluate the likely cost of complying with new municipal stormwater permit requirements and evaluate a variety of options for financing those costs.

To learn more about this project, please contact Ian Cooke, Executive Director at the Neponset River Watershed Association, or Julie Conroy, Senior Environmental Planner at the Metropolitan Area Planning Council.