Overflow from Superfund Site caused by wet winter

Residents and visitors to Leviathan and Bryant creeks in the eastern Sierra are cautioned to continue to avoid fish from those waters until a toxic overflow from the Leviathan Mine can be fully evaluated.

Pollution from an old sulfur mine on the east slope of the Sierra Nevada about 25 miles southwest of Gardnerville in California began overflowing Thursday into a creek that runs into the East Fork of the Carson River.

The Lahontan Regional Water Quality Control Board said a combination of acid drainage from the Leviathan Mine and rainwater in ponds at the mine started running into Leviathan Creek, and anyone in the remote area, near Markleeville, Calif., should avoid the overflow.

The drainage from the mine, a Sierra Superfund site, is a toxic stew of sulfur, arsenic and dissolved heavy metals such as copper, nickel, aluminum and iron. The mine drainage is flowing into the creek at a rate of about 50 gallons per minute, and the pond overflow is adding a similar amount.

Harold Singer, executive officer of the control board, said the drainage is a result of "the wettest winter in the last 10 years." He said the pollution will continue "for a few days" until crews can set up an emergency treatment system to neutralize the acid mine drainage.