Virginia Department of Environmental Quality


Assessment Unit Description: (What's this?)
Waterbody Name:	Thumb Run
Waterbody Type and Size:	RIVER - 6.91 MILES
Waterbody Location:	Segment begins at the confluence of West Branch Thumb Run and East Branch Thumb Run and continues downstream until the confluence with the Rappahannock River.

Assessment Unit:	VAN-E01R_THU01A00
Assessment Category:	EPA Category 4A: Impaired or threatened for one or more designated uses but does not require a TMDL because the TMDL for specific pollutant(s) is complete and US EPA approved.
Impairments:	Fecal Coliform
Sources:	Grazing in Riparian or Shoreline Zones; Livestock (Grazing or Feeding Operations); Runoff from Forest/Grassland/Parkland; Sewage Discharges in Unsewered Areas; Waterfowl; Wildlife Other than Waterfowl
Comments:	Class III, Section 4. DEQ monitoring stations 3-THU004.69, at Route 688 (Leeds Manor Road), and 3-THU006.90, upstream from Route 688. Citizen monitoring stations 3THU-F2-SOS, 3THU-F14-SOS, 3THU-F14-URWP, and 3THU-JMS. Historical Note: This segment was included in Attachment A, Category 1, Part 1 of Virginia's 1998 Part 1A submittal for fecal coliform. Fecal coliform monitoring finds a bacterial impairment, resulting in an impaired classification for the recreation use. A fecal coliform TMDL for the Thumb Run watershed was developed and submitted to the U.S. EPA on April 29, 2002 and approved on May 31, 2002. The sources of fecal coliform bacteria requiring reductions are livestock and wildlife waste delivered directly to the stream, and human contributions from straight pipes. The aquatic life and wildlife uses are considered fully supporting. Citizen monitoring indicates a low probability of adverse conditions for biota. The fish consumption use was not assessed. 2004 TMDL ID for this segment was VAN-E01R-01.