Abstract |
This report presents a total maximum daily load (TMDL) for siltation/turbidity for Lake Frierson in northeast Arkansas. This lake was included on the Arkansas Department of Environmental Quality (ADEQ) draft 2004 Arkansas 303(d) list (ADEQ 2005a) and the final 2004 Arkansas 303(d) list (EPA 2006) as not supporting the designated use of aquatic life. The sources of contamination and causes of impairment from the 2004 303(d) listing are shown in Table 1.1. The TMDL in this report was developed in accordance with Section 303(d) of the Federal Clean Water Act and EPA's regulations in 40 CFR 130.7. The purpose of a TMDL is to determine the pollutant loading that a waterbody can assimilate without exceeding the water quality standards for that pollutant and to establish the load reduction that is necessary to meet the standard in a waterbody. The TMDL is the sum of the wasteload allocation (WLA), the load allocation (LA), and a margin of safety (MOS). The WLA is the load allocated to point sources of the pollutant of concern. The LA is the load allocated to nonpoint sources, including natural background. The MOS is a percentage of the TMDL that takes into account any lack of knowledge concerning the relationship between pollutant loadings and water quality. |