Total Maximum Daily Loads of Fecal Bacteria for the Loch Raven Reservoir Basin in Baltimore, Carroll, and Harford Counties, Maryland.

摘要

This document, upon approval by the U.S. Environmental Protection Agency (EPA), establishes a Total Maximum Daily Load (TMDL) for fecal bacteria in the Loch Raven Reservoir watershed (Maryland 8-digit assessment unit MD-02130805). Section 303(d) of the federal Clean Water Act (CWA) and the EPAs implementing regulations direct each state to identify and list waters, known as water quality limited segments (WQLSs), in which current required controls of a specified substance are inadequate to achieve water quality standards. For each WQLS, states are required to either establish a Total Maximum Daily Load (TMDL) of the specified substance that the waterbody can receive without violating water quality standards or demonstrate that water quality standards are being met. The Maryland Department of the Environment (MDE) has identified the tributaries of Loch Raven Reservoir on the States 303(d) List (Category 5 of the Integrated Report of Surface Water Quality in Maryland (Integrated Report)) as impaired by fecal bacteria (listed in 2008) and impacts to biological communities (listed in 2002, 2004 and 2008). The reservoir itself is not listed as impaired by fecal bacteria. The Loch Raven Reservoir and all its tributaries have been designated as Use III-P (Nontidal Cold Water and Public Water Supply). See Code of Maryland Regulations (COMAR) 26.08.02.08J. This document proposes to establish a TMDL for fecal bacteria in the Loch Raven Reservoir watershed that will allow for attainment of the beneficial use designation of water contact recreation. The listings for impacts to biological communities will be addressed in a separate TMDL document. Listings for the impoundment have already been addressed by TMDLs for phosphorus, sediments and mercury, and a WQA for heavy metals. MDE monitored the Loch Raven Reservoir watershed from 2003-2004 for fecal bacteria. A data solicitation for fecal bacteria was conducted by MDE in 2003, and all readily available data from the past five years were considered. To account for portions of subwatersheds located in Pennsylvania (PA), an upstream load allocation (LAPA), determined to be necessary in order to meet MD water quality standards in the MD portion of the watershed, is also included in this TMDL.