The Municipal Separate Storm Sewer System (MS4) refers to a collection of structures designed to gather stormwater from municipal sources and discharge it into local streams and rivers. These structures include retention basins, ditches, roadside inlets and underground pipes. 

MS4 is separate from the sanitary sewer system and private septic systems that treat household wastewater. If you are seeking information about preventing stormwater pollution on private property, please see the Conservation Department.  

Interested in learning more about the Town's current version of the MS4 permit, please click here and you will be redirected to the Environmental Protection Agency's (EPA) Massachusetts Small MS4 General Permit webpage.

Stormwater runoff is the leading cause of water pollution in New England. It may threaten drinking water or impact water quality keeping residents from safely swimming and fishing in local ponds, lakes and oceans. Each year, as part of its MS4 permit, Dedham is required to update and revise its Stormwater Management Plan to meet the requirements of our permit. 

Each permit year the Town is required under our MS4 permit to publish our draft SWMP for public review and comment. Please find below a draft copy of the Town's Year 7 SWMP. Please submit any comments to jmammone@dedham-ma.gov before July 18, 2025.

DRAFT FOR PUBLIC COMMENT: Year 7 SWMP - Report - Appendices A-J - Appendices K-M

The following documents are available for download (PDF): 

Year 6 SWMP: Dedham Final SWMP - June 2024 - Report - Appendices A-J - Appendices K-M

Year 5 SWMP: Dedham Final SWMP - June 2023 - Report - Appendices A-J - Appendices K-M

Year 4 SWMP: Dedham Final SWMP - June 2022

Year 3 SWMP: Dedham Final SWMP - June 2021

Year 2 SWMP: Dedham Final SWMP - June 2020

Year 1 SWMP: Dedham Final SWMP - June 2019

Town of Dedham Annual MS4 Stormwater Reports

Stormwater discharges from municipal sources are regulated under the National Pollutant Discharge Elimination System. For more information, see Stormwater Discharges from Municipal Sources. The Town of Dedham submits to EPA an annual report detailing the Town's progress in addressing stormwater. You can download those reports below (PDF):

Phosphorous Source Identification Report (PSIR)

As part of our obligations under the MS4 permit, Dedham was required by the end of Year 4 to develop a PSIR for the portion of Mother Brook that exists within the Town due to its impairment for total phosphorous. The following PSIRs are available for for download below (PDF) and will be updated each permit year as necessary

Phase II PSIR - June 2023

PSIR - June 2022

Phosphorous Control Plan (PCP)

Each permit year the Town is required under our MS4 permit to publish our draft PCP for public review and comment. Please find below a draft copy of the Town's Year 7 PCP. Please submit any comments to jmammone@dedham-ma.gov before August 1, 2025.

YEAR 7 PCP - DRAFT FOR PUBLIC COMMENT - Report 

Dedham is one of many communities in the Charles River Watershed where the EPA approved a Total Maximum Daily Load (TMDL) for nutrients, specifically phosphorous (P). As such, the EPA has required communities that are under the TMDL through its MS4 permit, to develop a PCP designed to reduce the amount of P in our local stormwater discharges to the Charles River and its tributaries. Below is the latest version of the Town's PCP which will be updated each permit year as necessary.

PCP - Year 7

PCP - Year 6

Stormwater Pollution Prevention Plans (SWPPP)

As part of the minimum control measure for Good Housekeeping and Pollution Prevention for Municipal Operations, the MS4 permit requires regulated communities to develop and implement a written Stormwater Pollution Prevention Plan (SWPPP) for all permittee-owned or operated maintenance garages, public works yards transfer stations and or other waste handling facilities where pollutants are exposed to stormwater. The following SWPPPs are available for for download below (PDF) and will be updated each permit year as necessary:

DPW Facility SWPPP - April 2020

Illicit Discharge Detection & Elimination Plan (IDDE)

As part of our MS4 Permit, the Town is required to implement an IDDE program to systematically find and eliminate sources of illicit discharges to its MS4 and implement procedures to prevent such discharges. The MS4 Permit defines illicit discharge as "any discharge to a municipal separate storm sewer that is not composed entirely of stormwater except discharges pursuant to a NPDES Permit (other than the MS4 Permit) and discharges resulting from fire-fighting activities. Below is the latest version of the Town's IDDE Plan (PDF) which will be updated each permit year as necessary:

Town of Dedham Illicit Discharge Detection & Elimination Plan - June 2019

Street Sweeping Schedule Map

Available for download is a copy of our street sweeping schedule for the Town.

Street Sweeping Schedule Map - June 2022

Miscellaneous Informational Flyers

The informational flyers below range from information on yard waste to pet waste and what residents can do with these items to improve the quality of our waterways. These flyers are available for download for personal use or to be distributed (PDF):

• NSP 2024 General Mailer
• NSP Septic Postcard - Year 6
• Year 6 - Dedham - Septic Smart Mailer
• Fall 2022 Yard Waste Flyer
• Summer 2022 Townwide Mailer
• 2022 Stormwater Pollution Prevention Guide Mailed to All Industrial Properties 
• Summer 2021 Townwide Mailer
• Annual 2020 Pet Waste Flyer
• Summer 2020 Townwide Mailer
• Fall 2020 Yard Waste Flyer

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