SALT LAKE CITY (AP) — Utah and U.S. government officials will launch a study this month to determine the extent of mining pollution in Lake Powell on the Utah-Arizona border.
Heavy metals washed into Lake Powell over the decades by flash flooding will be dug up from the river deltas to assess metal concentrations, The Deseret News reported this week.
The study will provide information about how mining affects the lake and the fish that live in it. Researchers will test for levels of arsenic, cadmium, copper, mercury and lead.
The lake is a key part of a water system that provides drinking water to 40 million people in the Southwest.
"This study will help us understand whether human activities such as mining in the San Juan River watershed have impacted or pose a risk to the important recreational, aquatic life and cultural resources of the San Juan River and Lake Powell," said Erica Gaddis, director of the Utah Division of Water Quality.
Gaddis' agency will join the U.S. Geological Society, the National Park Service and the U.S. Bureau of Reclamation on the project.
"This is the first study to collect and characterize sediment through the full thickness of the San Juan and Colorado river deltas," said Scott Hynek, a scientist with the U.S. Geological Survey.
Preliminary findings of the study are expected in 2020.
It comes after the U.S. Environmental Protection Agency accidentally triggered a massive release of wastewater laden with toxic metals at the Gold King Mine in Colorado three years ago. The estimated 3 million gallons of wastewater carrying 540 tons of metals washed into rivers in Colorado, New Mexico and Utah.
Utah has sued the EPA, seeking $1.9 billion after the waste wound up in the San Juan River and at Lake Powell. The state continues to monitor the effects of that spill.