Little Elk Creek Watershed: Contaminant Data

Contaminant Data

Clicking on the map opens the full-scale PDF map on the USEPA site.

Information from Fact Sheets prepared by USEPA for individual facilities in the Little Elk Creek Area-Wide Cleanup Program Pilot, indicate that volatile organic compounds are present in groundwater at elevated levels at many of the facilities. Perchloroethylene (PCE), trichloroethylene (TCE), and perchlorate are the primary groundwater contaminants of concern in the area.

Groundwater contaminated with volatile organic compounds (VOCs), such as TCE, may discharge to surface water in Little Elk Creek. VOCs in surface water evaporate into the air and will break down relatively quickly. Thus VOCs generally do not build up in sediment. VOCs also do not accumulate in fish, but low levels have been found in them at some sites (ATSDR, 1997). Fish tissue testing has not been conducted in Little Elk Creek. Low levels of VOCs in groundwater, though a concern for human exposure in drinking water, generally are not a concern in surface water bodies.

Soil contamination includes buried munitions, metals, explosive compounds, pesticides, PCE, and TCE. Soil contamination is generally limited to on-site impacts. Metals, most explosive compounds (e.g., TNT), and pesticides (particularly organochlorine pesticides like DDT) attach strongly to soil particles and generally do not migrate large distances in groundwater. Surface water runoff that discharges to the Little Elk Creek is a strong concern for these contaminants. Thus source control actions at the site should be given a high priority.

In addition to the sites being investigated, there are numerous anthropogenic or non-point sources of these contaminants (metals, polynuclear aromatic hydrocarbon [PAHs], pesticides). Therefore, from a watershed perspective, it is very important to maintain adequate vegetative buffers along the stream that prevent direct runoff of stormwater. Another priority is to promote Low Impact Development (LID) techniques in the watershed that capture and make beneficial use of stormwater runoff rather than channeling stormwater directly to Little Elk Creek through drains or ditches. This also helps protect the stream against flooding and improves water quality by reducing inputs of nutrients and suspended solids.

The Little Elk Creek project team is working to improve the characterization of contaminants in the watershed. USEPA is collecting and mapping data from contaminated sites in the watershed. The majority of the data are about groundwater; there appears to be limited surface water and sediment contaminant data in the watershed. NOAA will continue to evaluate contaminant data as it becomes available.