City of Austin Watershed Protection and Development Review Department
Doi
Abstract
This 2004 summary of findings highlights the most common water quality impairments found in Waller Creek.The Texas Water Quality Inventory (305(b) report) is prepared by the Texas Commission on Environmental Quality (TCEQ) and submitted to the U.S. Environmental Protection Agency (USEPA) biennially in accordance with Section 305(b) of the Clean Water Act (CWA). For the 2004 report, a “target assessment” was conducted that included evaluation of a limited number of waterbodies, resulting in little overall change in assessment results. The table below summarizes Austin area impairments and concerns as compared to that of 2002.
Water bodies noted on the 303(d) list as "impaired" are those that do not support their designated uses in the Texas Surface Water Quality Standards (30 TAC 307), and for which existing water quality controls are not adequate. "Concerns" are also identified where the uses are met but elevated pollutants with indirect impacts are identified or limited data are available. Assessments are based on the prior five years of water quality data collected by the TCEQ and cooperating agencies under approved quality assurance guidelines. City of Austin Watershed Protection and Development Review Department (WPDRD) staff have been working for several years to ensure City water quality monitoring data is incorporated into the TCEQ assessments through the Clean Rivers Program administered by the Lower Colorado River Authority (LCRA). The 2002 and 2004 assessments included creeks based on City data that otherwise would not have been assessed. Both impairments and concerns were identified for water bodies in the Austin area. For water bodies where a priority impairment is identified, a Total Maximum Daily Load (TMDL) study may be required by TCEQ to determine the maximum pollutant load that can be borne by the water body without violating water quality standards. The pollutant load is allocated among the sources in the watershed, and any actions necessary to restore and maintain designated uses of the water body are determined. An ongoing bacteria TMDL study of Onion Creek is anticipated to result in delisting due to LCRA monitoring results. An upcoming bacteria TMDL study of Gilleland Creek may also result in delisting or modifications to permit limits of several wastewater treatment plants in the area. A primary focus at this time in the Austin area is the appropriate biological monitoring and establishing a baseline for aquatic life use supported. In addition, elevated toxins in sediments and nutrients in water are focus areas for WPDRD monitoring. These pollutants are currently addressed only as “secondary concerns” by TCEQ because no regulatory criteria have been adopted. In addition, statewide screening levels for these constituents have not been exceeded sufficiently to make them priorities for TCEQ to pursue in the Austin area. However, monitoring results for these parameters have been used in masterplanning and program targeting by the City.Waller Creek Working Grou
