1/28/11
A state and federal effort to sample wells has found that the groundwater it tested in Humboldt and Del Norte counties is particularly clean. Scientists from the U.S. Geological Survey and the North Coast Regional Water Quality Control Board on Thursday outlined their preliminary results at a meeting held at the Humboldt Bay Municipal Water District. The state and federal programs sampled 58 wells in Humboldt, Del Norte, Mendocino, Lake and Napa counties, among thousands of wells tested statewide between 2004 and 2011. The sampling falls under the USGS National Water Quality Assessment program and the State Water Resources Control Board's Groundwater Ambient Monitoring Assessment Program. The programs aim to determine the status of groundwater quality, how it changes and how natural and human factors affect groundwater quality. The programs tested for a wide range of elements, nutrients, volatile compounds, pesticides and pharmaceuticals, as well as naturally occurring radioactive isotopes that can help scientists understand the age of groundwater. It also measured pollutants at much lower levels than state health detection standards. Preliminary results show the Humboldt and Del Norte county wells to be free of most measured pollutants, or are at very low levels. USGS scientist Tim Mathany said there were no pesticides detected in the groundwater sampled there, one of the few areas in the country where that's true. In inland areas to the south of the North Coast region, where there is more agricultural land, the survey turned up some pesticides, he said. There were only very low levels of inorganic constituents like heavy metals on the Humboldt and Del Norte coast, and none were above health-based benchmarks. A complete report is expected this spring.
