RESTON, Va. — Sept. 16, 2015 — The U.S. Geological Survey released an interactive mapping tool that predicts concentrations of 108 pesticides in streams and rivers across the U.S., according to a press release.

The resource also identifies streams that are most likely to surpass water quality guidelines for human health or aquatic life, stated the release. People can use the information to design cost-effective monitoring programs.

“Because pesticide monitoring is very expensive, we cannot afford to directly measure pesticides in all streams and rivers,” said William Werkeiser, USGS associate director for water, in the release. “This model can be used to estimate pesticide levels at unmonitored locations to provide a national assessment of pesticide occurrence.”

Based on the Watershed Regression for Pesticides (WARP) statistical model, the tool provides statistics for thousands of streams, reported the release. The model uses information on the physical and chemical properties of pesticides, agricultural pesticide use, soil characteristics, hydrology and climate to estimate concentrations.

“Streams and rivers most vulnerable to pesticides can be assessed,” explained Wes Stone, USGS hydrologist and lead developer of the model, in the release. “For instance, many streams in the Corn Belt region are predicted to have a greater than 50 percent probability that one or more pesticides exceed aquatic-life benchmarks.

The model uses data from USGS monitoring since 1992 that was part of the National Water-Quality Assessment Program, shared the release.

Click here to read the entire release.