Pathogen TMDLs for Planning Segments 4G Reaches Segments, AR11010009-902, AR11010012-016, AR11010012-015, AR11010012-014, AR11010012-011, AR11010012-010, AR11010012-008, AR11010012-003.

摘要

This report presents total maximum daily loads (TMDLs) for fecal coliform and Escherichia coli (E. coli) for 8 stream reaches in the Strawberry River Basin in northern Arkansas. These stream reaches were included on the Arkansas Department of Environmental Quality (ADEQ) 2004 Section 305(b) Report (ADEQ 2004a) as not supporting their designated use of primary contact recreation. The suspected sources of contamination and causes of impairment from the 303(d) listing are shown below in Table 1. The TMDLs in this report address the impairments due to pathogens and were developed in accordance with Section 303(d) of the Federal Clean Water Act and the Environmental Protection Agencys (EPA) 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 standard 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 (NPS), 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.