Stormwater Phase II Program

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Stormwater Phase II Program

In response to the 1987 Amendments to the Clean Water Act, the U.S. Environmental Protection Agency (EPA) developed Phase I of the NPDES (National Pollution Discharge Elimination System) Storm Water Program in 1990. Phase I addressed sources of stormwater runoff that had the greatest potential to negatively impact water quality including medium and large municipal separate storm sewer systems (MS4s) and construction activities that disturbed five or more acres of land. The Phase II Final Rule, published in the Federal Register on December 8, 1999, expanded on the Phase I Rule to include NPDES permit coverage for storm water discharges from certain regulated small MS4s and construction activity disturbing between one and five acres of land. Although the Phase II MS4 regulations are generally implemented by municipalities, all public entities that own and maintain a separate storm sewer system, including State Departments of Transportation (DOTs) and other highway departments and authorities, are also bound by the requirements of Phase II.

The City of Yonkers is in the process of implementing a five-year storm water management program (SWMP) for compliance with Phase II. The general framework for the comprehensive SWMP was developed in February 2003, and Notices of Intent (NOI) for Coverage under the Phase II MS4 permit were filed in early March of the same year.

The City of Yonkers completes dozens of maintenance and capital projects each year. Additionally, the City of Yonkers is pursuing alternative methodologies for public education/outreach. Educational brochures will be developed for distribution to promote awareness of stormwater related issues and identify ways that the public can reduce pollution.   The City of Yonkers follows the New York State Standards and Specifications for Erosion and Sediment Control published by NYSDEC (8/2005), and all projects submitting plans under Stormwater Phase II guidelines must be in compliance.  

Municipal Separate Storm Sewer Systems (MS4s) Annual Report

Stormwater runoff gathers a variety of pollutants, which degrade our lakes, rivers, wetland and other waterways. Stormwater management, especially in urban areas, is becoming a necessary step to reduce pollution in our waterways. A new federal regulation, commonly known as Stormwater Phase II, requires permits for stormwater discharges from Municipal Separate Storm Sewer Systems (MS4s) in urbanized areas and for construction activities disturbing one or more acres. Under this new regulation, the City of Yonkers are regulated MS4s.

The City of Yonkers applied for MS4 permit coverage in March and is in the process of implementing a 5-year, system-wide storm water management program (SWMP) for compliance with Phase II.

The SWMP must include the following items:

  • Public education and outreach
  • Public participation
  • Illicit discharge detection and elimination
  • Construction site runoff control
  • Post-construction runoff control
  • Pollution prevention

MS4 Annual Report

          2007-2008 Annual Report
          2008-2009 Annual Report
          2009-2010 Annual Report
          2010-2011 Annual Report
          2011-2012 Annual Report
          2012-2013 Annual Report
          2013-2014 Annual Report
          2014-2015 Annual Report
          2015-2016 Annual Report
          2016-2017 Annual Report
          Stormwater Phase II 2017 Active Locations


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