East of Hudson Municipal Separate Storm Sewer System

Our East of Hudson (EOH) Watershed has a Municipal Separate Storm Sewer System (MS4) regulated by the New York State Department of Environmental Conservation (DEC). As a regulated MS4, the EOH Watershed is required to comply with the Phase II Stormwater Management Plan. For information about the New York City MS4 program, visit New York City Municipal Separate Storm Sewer System.

EOH Watershed MS4 Reports

The Phase II Stormwater regulations require the EOH Watershed to implement programs and practices to control stormwater runoff that may be polluted. Download the 2024 East of Hudson Watershed MS4 Notice of Intent.

• Download the 2024 East of Hudson Watershed MS4 Interim Report
• Download the 2022-2023 East of Hudson Watershed MS4 Annual Report

For reports from previous years, please visit our Document Portal and search for “East of Hudson Watershed.”

Stormwater in the NYC Watershed

Stormwater from rain or melting snow can pick up and move sediment and a variety of pollutants. For information about stormwater programs, visit Stormwater Management in the New York City Watershed.

Understanding the Phosphorus Issue

In the EOH Watershed, the main pollutant of concern is phosphorus. To learn more about phosphorus, visit Understanding the Phosphorus Issue.

Pollution Prevention Best Practices

Because stormwater transports whatever is left on our lawns and roads, individual actions make a difference in determining the kinds and amounts of pollution.

• Download the Homebuyer’s Guide to Septic Systems
• Download the Homeowner’s Guide to Septic System Best Practices
• Download the Putnam County Septic System Inspection Form
• Download the Stormwater and Proper Construction Designs

You can learn more about pollution prevention practices by visiting the DEC website.

If you observe illegal dumping or discharges into any storm sewers, please call (914) 232-8642 or (845) 334-7185, or email ms4info@dep.nyc.gov.

Visit Stormwater Management and Sewer System for additional information and educational resources.