Citation:

Glassmeyer, S, E. T. Furlong, D. W. Kolpin, J. D. Cahill, S. D. Zaugg, S. L. Werner, L. B. Barber, AND D D. Kryak. WHAT GOES UP MUST COME DOWN: A LAGRANGIAN STUDY OF POTENTIAL CHEMICAL IDICATORS OF FECAL CONTAMINATION DOWNSTREAM FROM WASTEWATER PLANTS. Presented at Society of Environmental Toxicology and Chemistry, Portland, OR, November 14-18, 2004.

Impact/Purpose:

The objectives of this task are to evaluate a large suite of chemical compounds for their correlation with the concentration of indicator microbes, and determine their ability to monitor water quality in source and finished waters as a surrogate for traditional methods of human fecal contamination.

Description:

In earlier studies, we have determined that pharmaceuticals and other compounds found in household wastewater (such as surfactants, disinfectants, and scenting agents) are present in the effluent from wastewater treatment plants, and persist downstream from the facilities. To obtain a better understanding of the fate of these compounds, two wastewater dominated watersheds, Four Mile Creek in Ankeney, IA and Boulder Creek near Boulder, CO, were investigated using a Lagrangian sampling scheme. Prior to sampling, a dye tracer was released in each stream to determine the time it takes for the water to reach different points downstream. With this time of travel information, water was collected at the predetermined downstream points so that the same parcel of water was analyzed at all locations. This sample collection design allows for a better understanding of the processes that can remove the compounds from the stream, such as photodegradation, sorption onto particulates, and volatilization. Additionally, the kinetics of the combined removal processes can be approximated, so the average lifetime of each of these compounds in the watershed can be calculated. At each of the sample sites, a water sample was collected and field filtered. Two different samples were extracted using solid phase extraction, and analyzed using liquid chromatography/ mass spectrometry (pharmaceuticals) and gas chromatography/ mass spectrometry (wastewater compounds); between the two methods, there are over 85 analytes. The samples were also analyzed for two indicator bacteria, E. coli and enterococci. For most compounds, the concentration profiles were as expected: absent or very low concentrations in the upstream samples, with a noticeable increase in the effluent, and a decline in the downstream samples. The information gathered in this project will help determine which of these compounds might be useful as tracers of human fecal material. Disclaimer: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

Record Details: