In 1998, significant portions of Chesapeake Bay and its tidal tributaries within Virginia were identified as not meeting water quality standards and listed as impaired. Areas of the Bay and tidal rivers within Maryland, Delaware and the District of Columbia are also on the federally approved list of impaired waters. The main pollutants causing these impairments are nitrogen, phosphorus and sediment. Despite significant efforts from the Chesapeake Bay Program
, the water quality goals under the Clean Water Act have yet to be met.
Because these Bay waters remained on the impaired waters list, EPA required that a Total Maximum Daily Load (TMDL) be developed. EPA issued the Bay TMDL on December 29, 2010. It was based, in part, on the Watershed Implementation Plans (WIP) developed by the Bay watershed states and the District of Columbia.
The Chesapeake Bay TMDL addresses all segments of the Bay and its tidal tributaries that are on the impaired waters list. As with all TMDLs, a maximum aggregate watershed pollutant loading necessary to achieve the Chesapeake Bay’s water quality standards has been identified. This aggregate watershed loading is divided among the Bay states and their major tributary basins, as well as by major source categories (wastewater, urban storm water, septic, agriculture, air deposition). The TMDL is available on EPA's Chesapeake Bay TMDL website.
Virginia submitted its Phase I Watershed Implementation Plan (WIP) in November 2010, and EPA accepted that plan and included it in the Chesapeake Bay TMDL with minor modifications.
Included in Virginia's WIP I was a proposal to review the James River numeric chlorophyll standard. DEQ will undertake a comprehensive review of the existing James River Site-Specific Numeric Chlorophyll-a Criteria and associated modeling framework for the tidal James River to determine the best scientific basis for the standard. Additional information related to this study is available on the Virginia Water Quality Standards page for Rulemaking Information.
The draft Phase II Watershed Implementation Plan (WIP II) was submitted to EPA in December 2011, and the Phase II WIP was submitted on March 30, 2012.
For information regarding DEQ’s Chesapeake Bay TMDL responsibilities, contact Russ Baxter.