The Clean Water Act and Sligo Creek

The federal Clean Water Act requires that Maryland establish water quality standards for its waters, monitor them, and describe their quality to the U.S. Environmental Protection Agency in what is known as a 305(b) report. This is submitted on April 1st of every even numbered year. As part of the 305(b) report, it must make a list of those waters that do not meet water quality standards. This is known as the 303(d) list.

For those waterbodies on the 303(d) list, Maryland is required to make priority rankings, establish Total Maximum Daily Loads (TMDLs) of pollutants that would enable the waterbody to meet the water quality standards, solicit public comment, and have the E.P.A. approve the 303(d) list and TMDLs (see the Maryland Department of the Environment TMDL page).

Sligo Creek is designated as a Use I water meaning it should allow for water contact recreation and the protection of nontidal warmwater aquatic life. Because it has been found in surveys to have deficient levels of aquatic life, Sligo Creek has been judged to be biologically impaired. This is a record of Sligo Creek’s being listed on Maryland’s 303(d) lists.

Sligo Creek Listings in Maryland’s 303(d) Lists of Category 5 (Impaired) Waters

Year Maryland’s 303(d) List Impairment Priority Data Sources for Impairment Listing
2006 Maryland’s 2006 303(d) List – *Draft*, pages 196-197 Biological Low 2000 Green, Passmore, and Childers ♠

1997 Maryland Biological Stream Survey Site MO-P-269-203-97

2004 Maryland’s 2004 303(d) List, pages 141-142 Biological Low 2000 Green, Passmore, and Childers, ♠

1997 Maryland Biological Stream Survey Site MO-P-269-203-97

2002 Maryland’s 2002 303(d) List, pages 37-38 Biological Low 2000 Green, Passmore, and Childers, ♠

1997 Maryland Biological Stream Survey Site MO-P-269-203-97

♠ 2000 Green, Jim, Passmore, Maggie, and Childers, Hope. A Benthic Macroinvertebrate Survey of Non-tidal Tributaries of the Anacostia River.
U.S. Environmental Protection Agency, Wheeling, West Virginia and Signal Corporation, Wheeling, West Virginia. July 28, 2000.♣ Maryland Biological Stream Survey Site MO-P-269-203-97Map showing both above sites

History of Public Comments Made to Maryland Regarding Sligo Creek’s Listing as an Impaired Water

As noted above, Maryland must solicit public comments about the waters it names to its 303(d) lists. The comment period for the Anacostia watershed’s 2006 listing ended in January 2006. According to the MDE it is expected that the comment period for the 2008 report will probably start in the latter part of 2007, and there will be an opportunity at that time to comment on Sligo Creek’s status.


Up to this point, there is no record of comments made specifically about Sligo Creek’s listing as a biologically impaired water. However, in the Comment Response Document for the 2004 303(d) List (page 9) a comment was made about the Anacostia watershed being listed as a low priority for nutrient, sediment, and biological impairments. Sligo Creek is part of the Anacostia watershed and is listed as being biologically impaired, so it has always been rated as low priority. Here is an excerpt from the comment and the MDE response.

Comment: “6. Anacostia TMDLs. The Anacostia River suffers from serious pollution problems, described in Kingman Park Civic Assn. v. EPA, 84 F .Supp.2d 1 (D.D.C. 1999), and “has been bestowed with the dubious distinction of being one of the ten most polluted rivers in the country.” Id. 4. Maryland, whose borders encompass over 80% of the Anacostia Watershed, bears substantial responsibility for water quality standard violations both within its own parts of the watershed and in the downstream reaches of the River that flow through the District of Columbia. To date, however, while the District of Columbia has prepared several TMDLs, Maryland has prepared none. Moreover, far from indicating any urgency about shouldering its responsibilities for the Anacostia, MDE’s draft 2004 list characterizes the Anacostia as “low” priority for nutrients, sediments, and biological impairments, and “medium” priority for toxics. At meetings in the District of Columbia on TMDL issues, MDE staff have been evasive when asked when MDE will prepare TMDLs for their portion of the watershed. MDE’s failure to prepare TMDLs for the Anacostia violates the Clean Water Act, which required TMDLs to have been established long ago, 303(d), and also demonstrates a lack of commitment on the part of MDE do its share to clean up this long-abused river.”

MDE Response: “In order to identify Maryland’s pollutant loads in the Anacostia River and provide defensible solutions to bacterial reductions, MDE has initiated several watershed scale monitoring programs. First, from November 2002 to November 2003, MDE collected bacteria information for enumeration and bacteria source tracking. The objective of the study is to characterize the Anacostia Maryland 12-digit scale subwatersheds and identify relative sources of bacterial contamination. MDE also selected the Anacostia and surrounding watersheds bacteria source tracking results to be part of the first completed on the Western Shore. The results are to be available in Spring 2004. In a second monitoring effort, MDE has collaborated with USGS and Prince Georges County, in an innovative monitoring study to estimate loads from both the Northeast and Northwest Branches. MDE has committed extensive resources to assessment of the Anacostia and innovative monitoring to assist in TMDL development. These initiatives demonstrate a strong commitment to the Anacostia watershed with the goal of identifying scientifically defensible solutions to the elevated bacterial levels in the Anacostia River.”

Status of Maryland Developing a TMDL Addressing Sligo Creek’s Biological Impairment

According to the Maryland Department of the Environment, they are now in the process of developing a methodology to first identify the likely stressor (e.g. sediment, nutrient, etc.) that is causing the impact to the stream biology. They are receiving technical assistance from the University of Maryland and are coordinating with Maryland Department of Natural Resources on the development of the stressor identification methodology.

However, Maryland’s schedule for the development of TMDLs within the next year or so does not include TMDLs for biological impairments.