WILLARD -- A drainage system constructed to intercept contaminated groundwater seeping into Willard Bay appears to be working, a state official says.
"Our latest sample results indicate that contaminant levels both within and outside the shoreline booms are decreasing," Walt Baker, director of the state Division of Water Quality, said in a prepared statement.
"Levels outside the booms (in Willard Bay) are not at concentrations that pose a threat to human health or wildlife."
Continued trace levels of diesel-related hydrocarbons in surface-water samples last week suggested to DWQ scientists that groundwater flowing into the bay had been contaminated by the spill.
However, since the installation of the drain, levels of contaminants have decreased, DWQ officials said in the statement. DWQ anticipates reductions in trace contaminant levels will continue over time.
Groundwater contamination from the Chevron Corporation pipeline leak will not jeopardize Willard Bay State Park's drinking water, which is supplied by the city of Willard, said the DWQ statement.
Preliminary assessments by the Utah Department of Environmental Quality and Department of Health suggest that fish from Willard Bay will likely be safe to eat.
DWQ is considering sampling of fish for diesel-related contamination to support this finding.
Monitoring wells will be constructed to evaluate the extent of groundwater contamination over the long term.
"We will continue to vigorously sample Willard Bay waters to monitor the level of contaminants," Baker said. "Protecting the park's water quality is priority."
The leak was discovered March 18 in the pipeline that extends from Salt Lake City to Burley, Idaho.
The spill and ensuing cleanup has prompted the closure of Willard Bay's north marina until at least early June, said Utah State Parks Director Fred Hays.
About 20,000 gallons of fuel have been collected from the site, while about 2,800 gallons remain unaccounted for, Baker said.
A dam built by beavers is credited with initially stopping the fuel from flowing into Willard Bay. Six beavers have been recovered from the site and are being treated for fuel exposure at the Wildlife Rehabilitation Center of Northern Utah in Ogden.