The Patuxent River Lower basin is located on Maryland’s Western Shore in Prince George’s, Charles and Calvert Counties, MD. The restricted shellfish harvesting area in the mainstem of the Patuxent River Lower Basin is addressed in this report. The Patuxent River has a length of approximately 71 km and a width ranging from 500 m upstream to 2.4 km at the mouth, where it flows east directly into the Chesapeake Bay. The restricted shellfish harvesting area in the mainstem of the Patuxent River Lower Basin has a drainage area of 91,966.5 acres (372.2 km2). The length of the restricted area is approximately 20 km.
Patuxent River Lower Basin (basin number 02131101) was identified on the State’s 303(d) List submitted to U.S. Environmental Protection Agency (EPA) by the Maryland Department of the Environment (MDE) as impaired by nutrients (1996), sediments (1996), bacteria (1996/1998/2004), toxics – chlorpyrifos (water) (2002), and the non-tidal portion of the basin for impacts to biological communities (2002/2004). In addition, an impoundment within the watershed, Lake Lariat, was listed as impaired by metals – methylmercury (2002). Recent monitoring data show that the applicable water quality criteria for fecal coliform are being met in the restricted shellfish harvesting area in the mainstem of the Patuxent River Lower basin. As a result, TMDLs of fecal coliform are not necessary to achieve water quality standards in this restricted shellfish harvesting area. Barring the receipt of any contradictory data, this report will be used to support the bacteria listing change for the restricted shellfish harvesting area in the mainstem of the Patuxent River Lower Basin from Category 5 (“waterbodies impaired by one or more pollutants and requiring a TMDL”) to Category 2 (“surface waters that are meeting some standards and have insufficient information to determine attainment of other standards”) when MDE proposes the revision of Maryland’s 303(d) list for public review in the future. TMDLs of fecal coliform have been completed for other tidal shellfish harvesting areas in the basin in 2004 and 2005. A TMDL for the metals listing was completed in 2002 for Lake Lariat. The listings for other impairments will be addressed separately at a future date.
Although the waters of the restricted shellfish harvesting area in the mainstem of the Patuxent River do not display signs of fecal coliform impairments, the State reserves the right to require additional pollution controls in the watershed if evidence suggests that fecal coliform from the basin is contributing to downstream water quality problems.
Water Quality Analysis of Fecal Coliform for the Restricted Shellfish Harvesting Area in the Mainstem Patuxent River Lower Basin in Prince George's, Charles, and Calvert Counties, Maryland
(Concurrence May 15, 2007)
EPA's Decision Letter
Comment Response Document
Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3818.
1800 Washington Boulevard, Baltimore, MD 21230