(2018) Pearson Creek - Wastewater Exfiltration Sources
Pearson Creek is located in east Springfield, Missouri and is on the state’s 303(d) list of impaired waters for E. coli bacterial contamination. Pearson Creek consistently exceeds the Missouri Department of Natural Resources (MDNR) water quality standards for Whole Body Contact Recreation (WBCR) Class-A designation of 126 MPN/100 mL from both urban and rural nonpoint pollution sources.
It is known that leaking sanitary sewer infrastructure can release pollutants including bacteria, phosphorus, and nitrogen to surface waters, and water quality surveys have been used successfully to pinpoint the locations of exfiltrating wastewater to streams during base flow conditions.
To better understand the influence of exfiltrating wastewater on water quality trends in Pearson Creek and to identify areas within the sewer system that may need maintenance, the City of Springfield, Missouri contracted with the Ozarks Environmental and Water Resources Institute (OEWRI) at Missouri State University to use a water quality survey to locate potential points of exfiltration of sewage from leaking sewer lines. The purpose of this study is to quantify variations in wastewater specific indicators at base flow along a 9.7 km segment of Pearson Creek beginning at the confluence with the James River going upstream to State Highway YY (Division St.).
- Perform a source risk assessment using GIS analysis of the segment to locate sewer line crossings, inflowing tributaries, local springs, faults and other geologic features, and permitted point discharges;
- Collect field-based temperature (T), dissolved oxygen (DO), pH, and specific conductivity (SC) and water quality samples to be analyzed in the laboratory for total phosphorus (TP), total nitrogen (TN), chloride (CL), and E. coli concentrations at equally spaced stream locations throughout the study reach; and
- Make specific recommendations to the City of Springfield and its engineers regarding site prioritization based on results from this exfiltration risk assessment.
The City of Springfield, Missouri