A study that sought to identify the sources of fecal pollution of the Concho River in Texas, a water body listed as a 303(d) impaired surface water system for dissolved oxygen and bacteria since 2008, noted that creating a larger baseline of E. coli data and further sampling could help control the contamination.-endpar-
Source Molecular Corporation worked with the Upper Colorado River Authority, which conducted DNA-based sampling in June 2015 on the Concho River. Source Molecular’s laboratory used microbial source tracking (MST) technology to analyze the water samples received. The results of the MST tests were incorporated into the study entitled, “Using Areas of Concentrated E. coli Bacteria to Identify Species Specific Sources in Urbanized Sections of theConcho River, Tom Green County, Texas.”
The study, authored by Darren Seidel and James W. Ward and published in the Angelo State Undergraduate Research Journal, sought to quantify areas of E. coli loading in the Concho River system to further understand local sources of bacteria pollution. It has been established that E. coli loading in the Concho River system fluctuates as the season changes but researchers noted that there are several sites River within the city limits of San Angelo that consistently have very high levels of bacteria.
Ten sites located along highly urbanized sections of the Concho River were sampled 26 times over a year – May 2014 to April 2015. E. coli samples as well as physiochemical parameters were collected. After analyzing the data, researchers identified two sites with very high levels of bacteria. They wanted to test for the presence of Human, Dog, and Bird fecal markers in the water as all three hosts were consistently documented to frequent the areas.
Chuck Brown of the Upper Colorado River Authority sent water samples to Source Molecular on June 22, 2015. All three host analysis came back negative. Researchers noted that there was a massive rainfall between the last sampling period for E. coli and the first DNA sampling, with Tom Green County receiving almost half its total annual rainfall during the period. Thus, the negative results could be due to a natural “flushing” of the surface water system through massive storm water run-off.
Researchers concluded that further sampling of Bacteroides primers/markers at the most contaminated sites is needed in order to know what is polluting the Concho River. When the sources of fecal pollution are identified and a larger baseline of E. coli data at each site is created, watershed managers will be a step closer to controlling the contamination.
Microbial source tracking has been used by water managers as a tool to help them make better decisions when it comes to remediation of water systems and improving water quality. Source Molecular’s MST capabilities are highly advanced, using EPA-patented tests for the detection of Human, Cattle, Chicken and Dog fecal pollution and offering Digital Polymerase Chain Reaction (PCR) technology. Its laboratory can also detect Swine, Gull, Goose, Deer, Elk, Horse, Bird, Beaver and Ruminant fecal bacteria, making it ideal for large MST projects that require testing for a wide range of host sources.
Source Molecular works with various stakeholder groups across the country in the development of Total Maximum Daily Load (TMDL) limits, implementing Best Management Practices (BMPs) and managing stormwater discharges.