Stormwater Discharges from Municipal Sources
Overview
- Community Solutions for Stormwater Management: A Guide for Voluntary Long-Term Planning
- Stormwater Discharges from Transportation Sources
- Proposed National Rulemaking to Strengthen the Stormwater Program
- National Menu of Best Management Practices (BMPs) for Stormwater
- Stormwater Maintenance
Polluted stormwater runoff is commonly transported through municipal separate storm sewer systems (MS4s), and then often discharged, untreated, into local water bodies.
An MS4 is a conveyance or system of conveyances that is:
- owned by a state, city, town, village, or other public entity that discharges to waters of the U.S.,
- designed or used to collect or convey stormwater (e.g., storm drains, pipes, ditches),
- not a combined sewer, and
- not part of a sewage treatment plant, or publicly owned treatment works (POTW).
To prevent harmful pollutants from being washed or dumped into specific types of MS4s, operators might be required to obtain NPDES permits and develop stormwater management programs (SWMPs).
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Phase I MS4s |
Phase II MS4s |
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Issued in 1990, the Phase I regulation requires medium and large cities or certain counties with populations of 100,000 or more to obtain NPDES permit coverage for their stormwater discharges.
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Issued in 1999, the Phase II regulation requires regulated small MS4s in urbanized areas, as well as small MS4s outside the urbanized areas that are designated by the permitting authority, to obtain NPDES permit coverage for their stormwater discharges.
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NPDES permits for regulated MS4s require permittees to develop a SWMP, which describes the stormwater control practices that will be implemented consistent with permit requirements to minimize the discharge of pollutants from the sewer system. |
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Developing an MS4 Program
Owners/operators of regulated municipal separate storm sewer systems (MS4s) are required to develop, implement, and enforce a stormwater management program (SWMP). The focus of the SWMP is to describe how the MS4 will reduce the discharge of pollutants from its sewer system and addresses these program areas:
- Construction Site Runoff Control
- Illicit Discharge Detection and Elimination
- Pollution Prevention/Good Housekeeping
- Post-Construction Runoff Control
- Public Education and Outreach
- Public Involvement/Participation
- Program Effectiveness
- Total Maximum Daily Loads
Use the guidance and references on this page to help you develop your SWMP.
- Construction Site Runoff Control
Include a program in your SWMP to reduce pollutants in stormwater runoff to your MS4 from construction activities that disturb ≥ 1 acre of land.
- Construction Fact Sheets.
- The Menu of BMPs for Construction Site Runoff Control —Describes best management practices (BMPs) for MS4s and construction site operators to address stormwater runoff from active construction sites.
- Developing Your Stormwater Pollution Prevention Plan: A Guide for Construction Sites —Provides guidance for construction site operators, including SWPPP templates and a sample inspection form.
- Illicit Discharge Detection and Elimination (IDDE)
Stormwater and certain authorized types of uncontaminated non-stormwater are the only discharges that should enter your MS4. Illegal dumping and connections can result in illicit discharges of non-stormwater wastes like car oil and sanitary waste into it. Include a program in your SWMP to detect and eliminate illicit discharges to your system.
- Illicit Discharge Detection and Elimination —Describes BMPs for identifying and eliminating illicit discharges and spills to storm drain systems.
- IDDE Fact Sheets
- IDDE Guidance Manual —Outlines practical, effective IDDE techniques for MS4s. Electronic resources associated with the manual:
- Outfall Reconnaissance Inventory (ORI) Form(2 pp, 112 K)
- ORI Database - Use to record and manage ORI data (Note: You must download the file to edit it)
- Hotspot Site Investigation Form
- Chemical Mass Balance Model (CMBM) Setup - Executable file for sophisticated technique used to differentiate among flow types at outfalls with blended flows
- CMBM Sample Input File(1 pg, 18 K) - CMBM Sample Input File
- Hotline Tracking Form(2 pp, 84 K)
- IDDE Supporting Materials – Provides methods for detecting illicit discharges, identifying sources, quantifying discharges, and examples of what communities are doing to fix problems.
- Methods for Detection of Inappropriate Discharges to Storm Drainage Systems: Background Literature and Summary of Findings
- Source Verification of Inappropriate Discharges to Storm Drainage Systems
- Quantification of Escherichia Coli and Enterococci levels in Wet Weather and Dry Weather Flows
- Inappropriate Discharge Detection and Elimination: What Phase I Communities Are Doing to Address the Problem
- Pollution Prevention/Good Housekeeping
Minimizing the potential pathways for contaminants carried in runoff is a key way to control pollutant discharges from MS4s. Include a program to prevent or reduce pollutant runoff from municipal operations into the storm sewer system.
- Pollution Prevention/Good Housekeeping Fact Sheets —Describes BMPs that can be used to prevent pollution from entering MS4s.
- Pollution Prevention/Good Housekeeping for Municipal Operators
- Municipal Pollution Prevention/Good Housekeeping Practices Manual Exit —Focuses on control and reduction of stormwater pollution and addresses local subwatershed restoration goals and objectives.
- Deriving Reliable Pollutant Removal Rates for Municipal Street Sweeping and Storm Drain Cleanout Program in the Chesapeake Bay Basin —Provides information to support pollutant removal efficiencies for Phase I and II communities in the Chesapeake Bay watershed.
- Post-Construction Runoff Control
Managing stormwater after construction activities end is a key part of the SWMP. Include a program to reduce pollutants from new development and redevelopment projects that disturb ≥ 1 acre of land.
- Post-Construction Fact Sheets
- Post-Construction Stormwater Management in New Development & Redevelopment
- Managing Stormwater in Your Community: A Guide for Building an Effective Post-Construction Program Exit — Provides practical guidance and downloadable tools that can help with program implementation.
- Managing Urban Runoff — Provides technical information on controlling urban nonpoint source pollution.
- Incorporating Environmentally Sensitive Development into Municipal Stormwater Programs — Discusses encouraging or requiring low impact development (LID) practices to meet stormwater goals.
- Urban Stormwater Retrofit Practices Manual Exit — Highlights practices that capture and treat runoff before it is delivered to water bodies.
- Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices — Compares the economic viability of LID practices and traditional stormwater management design practices.
- Monitoring to Demonstrate Environmental Results: Guidance to Develop Local Stormwater Monitoring Studies Using Six Example Study Designs (PDF) — Provides study designs for MS4 communities to use to assess their local stormwater programs.
- Green Infrastructure – Provides information on green infrastructure practices that use vegetation, soils, and natural processes to manage water and create healthier urban environments.
- Stormwater Wet Pond and Wetland Management Guidebook —Discusses inspection and maintenance practices at existing ponds and wetlands.
- Public Education and Outreach
An informed and knowledgeable community is crucial to the success of your SWMP. Implement a public education program on the impacts of stormwater that includes steps to reduce pollutants in stormwater runoff.
- Public Outreach Fact Sheets
- Public Education & Outreach in the Menu of BMPs
- Getting In Step: A Guide for Conducting Watershed Outreach Campaigns —Describes tools for developing and implementing an effective outreach plan.
- Getting In Step: Engaging and Involving Stakeholders in Your Watershed —Describes tools for effectively identifying, engaging, and involving stakeholders throughout a watershed.
- Nonpoint Source (NPS) Outreach Toolbox —Provides educational materials and other useful links for educating the public on NPS or stormwater runoff.
- Public Involvement/Participation
The public can provide you with valuable input and assistance in developing, implementing, updating, and reviewing your SWMP. Include efforts to reach out and engage all economic and ethnic groups in your public participation program.
- Program Effectiveness
Provide measurable goals in your SWMP so you can evaluate the program’s effectiveness and make adjustments as necessary. As part of the program, compile a report on program progress that includes things like the status of compliance with permit conditions, results of any information collected and analyzed, summaries of planned stormwater activities, and any changes that have been made.
- Evaluating the Effectiveness of Municipal Stormwater Programs
- Three Keys to BMP Performance: Concentration, Volume, and Total Load
- Measurable Goals Guidance for Phase II Small MS4s —Designed to help operators of small MS4 comply with the measurable goals permitting requirements.
- Total Maximum Daily Loads
Know whether your storm drain system discharges to an impaired water body or a water body with an approved Total Maximum Daily Load (TMDL). Include a process in your SWMP for addressing the TMDL if necessary.
- Understanding Impaired Waters and Total Maximum Daily Load (TMDL) Requirements for Municipal Stormwater Programs —Discusses how to determine if your MS4 discharges to an impaired water body and how to upgrade your SWMP to address the TMDL.
Resources
Long-Term Stormwater Planning
- Community Solutions for Stormwater Management: A Guide for Voluntary Long-Term Planning - Guide to assist states and local governments in developing and implementing effective long-term stormwater plans. This document describes how to develop a comprehensive long-term community stormwater plan that integrates stormwater management with communities' broader plans for economic development, infrastructure investment and environmental compliance.
Permit Resources
- MS4 Permits – Compendium of Clear, Specific and Measurable Permitting Examples – Features examples from existing MS4 permits of clear, specific, and measurable requirements.
- Summary of State Stormwater Standards — Describes each state's regulatory program and performance standard for post-construction discharge from newly developed and redeveloped sites.
- Revisions to the November 22, 2002 Memorandum “Establishing Total Daily Load (TMDL) Wasteload Allocations (WLAs) for Stormwater Sources and NPDES Permit Requirements Based on Those WLAs” – Updates EPA’s 2002 memorandum on establishing TMDL wasteload allocations for stormwater sources.
- MS4 Permit Improvement Guide — Guide to assist permit writers in strengthening MS4 stormwater permits.
- Municipal Separate Storm Sewer System (MS4) Program Evaluation Guidance — This guide is primarily for use by NPDES authorities to evaluate the quality of Phase I and Phase II MS4 programs, for permit compliance, technical assistance, and other purposes. It can be used for comprehensive program evaluations, or for certain components. It can also be used by MS4 program managers to evaluate their own programs.
- Total Maximum Daily Loads (TMDLs) and Stormwater — Provides information on waters listed for impairments from stormwater sources.
- TMDLs to Stormwater Permits Draft Handbook
- Integrated Municipal Wastewater and Wastewater Planning — An integrated planning process can identify a prioritized critical path to achieving the water qualtiy objectives of the Clean Water Act by identifying efficiencies in implementing competing requirements that arise from separate wastewater and stormwater projects.
- NPDES Compliance Monitoring Strategy — This strategy outlines inspection and compliance goals for the entire NPDES program, including stormwater. It places increased emphasis on wet weather issues, particularly stormwater sources, and sets ambitious targets for audits and inspections of Phase I and II MS4s, construction sites, and industrial facilities.
- Urbanized Area Maps for NPDES MS4 Phase II Stormwater Permits — Includes links to maps based on 2010 urbanized areas and the 2000 urbanized areas.
Fees and Funding
Federal Government and Stormwater Fees
- Federal Government Obligations to Pay Stormwater Fees — On January 4, 2011, President Obama signed into law "An Act to Amend the Federal Water Pollution Control Act to clarify Federal responsibility for stormwater pollution," Pub. L. No. 111-378, 124 Stat 4128 (2011) to clarify that reasonable service charges payable by federal agencies, as described in section 313(a), include certain stormwater assessments.
- Memorandum Clarifying that New Legislation Provides for Stormwater Fees to be Paid from Current Lump-sum Appropriations — On March 18, 2011, the Department of Justice/Office of Legal Counsel released a memorandum to clarify that language in section 313(c)(2)(B) of the Clean Water Act contained in new legislation obligating federal agencies to pay stormwater managements fees does not impose a specific appropriation requirement. Stormwater assessments are payable from annual—including current—lump-sum appropriations.
Funding Sources and Resources
- Clean Water State Revolving Fund (CWSRF) — This page describes funding options for a wide variety of water quality projects.
- Nonpoint Source (319) Grant Program — This page describes grant money that is available under section 319 of the Clean Water Act to states, territories, and Indian Tribes to support activities as part of an approved nonpoint source management program.
- Catalog of Federal Funding Sources for Watershed Protection — This searchable database provides information on financial assistance sources (grants, loans, cost-sharing) available to fund a variety of watershed protection projects.
- Water Infrastructure and Resiliency Finance Center — This page serves as a resource to communities for improving their wastewater, drinking water, and stormwater systems, particularly through innovative financing and increased resiliency to climate change.
Fact Sheets and Guidance
- Funding Stormwater Programs — This fact sheet for municipalities provides information on alternatives for funding their stormwater programs.
- Guidance for Municipal Stormwater Funding — This document was developed in January 2006 by the National Association of Flood and Stormwater Management Agencies (NAFSMA) under a grant provided by EPA to provide funding guidance for stormwater utilities.
Training and Webcasts
EPA provides webcasts for stormwater professionals on the minimum control measures as well as joint EPA-Federal Highway Administration (FHWA) webcasts on transportation stormwater management.