Total Maximum Daily Loads (TMDLs) and Stormwater
You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.
- Introduction
- Resources for Developing Stormwater-Source TMDLS
- Other Stormwater Resources
- Contact Information
Introduction
Throughout the U.S. there are thousands of waters listed for impairments from stormwater sources. The most common pollutants coming from stormwater sources include sediment, pathogens, nutrients, and metals. These impaired waters need a Total Maximum Daily Load (TMDL), which identifies the total pollutant loading that a waterbody can receive and still meet water quality standards, and specifies a pollutant allocation to specific point and nonpoint sources. The TMDL is implemented via the National Pollutant Discharge Elimination System (NPDES) stormwater permitting system. States and EPA Regions have used a variety of methods to develop stormwater-source TMDLs during the past decade. With the expansion of NDPES Stormwater regulations to smaller municipalities and smaller construction activities, there has been increasing demand for more detailed quantification of stormwater allocations in TMDLs that are more useful for implementation in NDPES permits.
Resources for Developing Stormwater-Source TMDLs and Implementing in NPDES Permits
TMDL-Stormwater Examples:
Total Maximum Daily Loads with Stormwater Sources: A Summary of 17 TMDLs (PDF) (59 pp., 600K), July 2007, EPA 841-R-07-002. This document summarizes 17 TMDLs that have been developed for stormwater-source pollutants in 16 states, representing a range of pollutants, models used, and different allocation and implementation methods.
Total Maximum Daily Loads and National Pollutant Discharge Elimination System Storm Water Permits for Impaired Water Bodies: A Summary of State Practices (PDF) (111 pp, 1.2MB), Sept. 15, 2007. This EPA report summarizes information on TMDL-stormwater practices in 10 states, provides specific TMDL and permit language, and identifies some specific technical and programmatic challenges.
TMDL-Stormwater Permit Case Studies:
These two case studies describe activities linking stormwater-source TMDLs currently being developed with applicable stormwater permits:
- The DuPage River and Salt Creek (Illinois) Case Study (2004) (PDF) (12 pp., 282K)
- The Minnehaha Creek Watershed District (Minnesota) Nine Lakes TMDL (2005) (PDF) (12 pp., 209K)
Innovative TMDLs using Surrogates for Stormwater Pollutants
Three states in EPA Region 1 have developed TMDLs using impervious cover and flow as surrogates for stormwater-source pollutants in streams listed for biological impairment.
Impervious Cover:
Barberry Creek, Maine, Total Maximum Daily Load (PDF) (41 pp., 2.7MB), July 2006
A Total Maximum Daily Load Analysis for Eagleville Brook, Mansfield, Connecticut (PDF) (43 pp., 617K), Feb. 8, 2007
Hydrology:
Total Maximum Daily Load to Address Biological Impairment in Potash Brook (VT05-11) Chittenden County, Vermont (PDF) (29 pp., 1.1MB) , Oct. 2006
TMDL-Stormwater Technical Resources:
Establishing Total Maximum Daily Load (TMDL) Wasteload Allocations (WLAs) for Storm Water Sources and NPDES Permit Requirements Based on Those WLAs (PDF) (6 pp., 235K) - Robert H. Wayland, III and James A. Hanlon -- Nov. 22, 2002, US EPA, Office of Water This memo clarifies existing EPA regulatory requirements for, and provides guidance on, establishing wasteload allocations (WLAs) for storm water discharges in total maximum daily loads (TMDLs) approved or established by EPA.
An Approach for Using Load Duration Curves in the Development of TMDLs (PDF) (74 pp., 3.3MB), Aug. 2007, EPA-841-B-07-006. This document shows how duration curves can be used for developing TMDLs and includes one case study.
Options for Expressing Daily Loads in TMDLs (PDF) (62 pp., 970K), June 22, 2007. This draft document provides technical options for developing daily load expressions in TMDLs calculated using time frames greater than daily allocations (e.g., annual, monthly, seasonal).
Stressor Identification Guidance Document:EPA 822-B-00-025. USEPA, Washington, DC. This document provides a formal process to identify stressors causing biological impairments in aquatic ecosystems and a structure for organizing the scientific evidence supporting the conclusions.
CADDIS.An online application that helps scientists and engineers in the Regions, States and Tribes find, access, organize, use and share information to conduct causal evaluations related to stressor identification in aquatic systems.
TMDL Model Evaluation and Research Needs (2005) (PDF) (403 pp., 10.82MB), This document provides a comprehensive review of available models for developing TMDLs.
These short fact sheets for state permitting authorities, municipalities and others describe developing and implementing stormwater management programs and linkage to TMDLs:
- Understanding Impaired Waters and TMDLs for Municipal Stormwater Programs (PDF) (5 pp., 634K), Jan. 2008, EPA 833-F-07-009
- Evaluating the Effectiveness of Municipal Stormwater Programs (PDF) (6 pp., 350K), Jan. 2008, EPA 833-F-07-010
- Incorporating Environmentally Sensitive Development Into Municipal Stormwater Programs (PDF) (7 pp., 431K), Jan. 2008, EPA 833-F-07-011
- Funding Stormwater Programs (PDF) (5 pp., 354K), Jan. 2008, EPA 833-F-07-012
Other Stormwater Resources
EPA Sites
Nonpoint Source Urban Web Site. Provides technical information on control of urban nonpoint source pollution.
Stormwater Program. Contains technical and regulatory information on the NPDES Stormwater program and provides stormwater outreach materials.
Stormwater Discharges from Construction Activities. Provides general information and guidance for construction activities.
Stormwater Discharges from Industrial Facilities. Provides general information and guidance for industrial facilities.
Stormwater Discharges from Municipal Separate Storm Sewer Systems (MS4s) Program. Includes permit requirements and guidance for MS4s.
Urban Stormwater BMP Performance Tool. Provides easy access to more than 220 studies assessing the performance of over 275 best management practices (BMPs) .
Managing Wet Weather with Green Infrastructure. Summarizes common Green Infrastructure approaches and key resources for research, funding and partnerships.
Bioassessment and Biocriteria. Hosts introductory, technical and guidance documents on the use of biological assessments and data.
Contact Information
If you have questions about stormwater-source TMDLs, you may send an e-mail to swtmdl-ow@epa.gov and someone on the EPA Headquarters TMDL-Stormwater Team will get back to you.
EPA Headquarters TMDL-Stormwater Team
- Chritine Ruf (ruf.christine@epa.gov)
- Menchu Martinez (martinez.menchu-c@epa.gov)
- Dean Maraldo (maraldo.dean@epa.gov)
- Jamie Fowler (fowler.jamie@epa.gov)
- Jack Faulk (NPDES Permits) (faulk.jack@epa.gov)
- Jenny Molloy (NPDES Permits) (molloy.jennifer@epa.gov)
- Robert Goo (Nonpoint Source) (goo.robert@epa.gov)
EPA Regional Office TMDL Contacts
- Region 1: Steve Winnett (winnett.steven@epa.gov)
- Region 2: Antony Tseng (tseng.antony@epa.gov)
- Region 3: Mary Kuo (kuo.mary@epa.gov)
- Region 4: William Melville (melville.william@epa.gov)
- Region 5: Dean Maraldo (maraldo.dean@epa.gov)
- Region 6: Curry Jones (jones.curry@epa.gov)
- Region 7: Bruce Perkins (perkins.bruce@epa.gov)
- Region 8: Jim Ruppel (ruppel.jim@epa.gov)
- Region 9: Peter Kozelka (kozelka.peter@epa.gov)
- Region 10: Laurie Mann (mann.laurie@epa.gov), Dave Ragsdale (Ragsdale.Dave@epa.gov)
EPA Regional Office NPDES Stormwater Contacts
- Region 1: Thelma Murphy (murphy.thelma@epa.gov)
- Region 2: Sergio Bosques (bosques.sergio@epa.gov)
- Region 3: Paula Estornell (estornell.paula@epa.gov)
- Region 4: Mike Mitchell (mitchell.michael@eps.gov)
- Region 5: Bob Newport (newport.bob@epa.gov), Brian Bell (bell.brianc@epa.gov)
- Region 6: Brent Larsen (larsen.brent@epa.gov)
- Region 7: Mark Matthews (matthews.mark@epa.gov)
- Region 8: Gregory Davis (davis.gregory@epa.gov)
- Region 9: Eugene Bromley (bromley.eugene@epa.gov)
- Region 10: Misha Vakoc (vakoc.misha@epa.gov)