Regulators announced Thursday that new monitoring at five of Nevada's largest mines has shown three kinds of mercury are coming out of smokestacks, including a gaseous form that can find its way into fish.
The findings tell the Nevada Division of Environmental Protection what kinds of pollution control technology to require at the mines, said agency spokesman Dante Pistone.
The monitoring program is the first of its kind in the country and requires mines to work with a third party to test the emissions coming out of their equipment.
Tests found the presence of an oxidized, vaporous form of mercury, but further tests are needed to determine how much.
"The oxidized form is the most reactive form, the form that is deposited more locally. That's the one that could potentially make it into Nevada waterways," Pistone said.
The Assembly this week unanimously approved AB115, which would
require higher fees of mining companies to pay for two new positions at NDEP to regulate mercury emissions. The proposal has support from Gov. Jim Gibbons, Pistone said.
Nevada is the nation's top gold producer, producing 78 percent of the total amount mined in the country. The state produces 12 percent of the world's gold. The calculated value of gold produced in Nevada was $3.8 billion last year, up about $750 million from 2005.
In February, the NDEP announced its first enforcement action against a mine accused of violating new pollution standards. NDEP Administrator Leo Drozdoff said that announcement was made in part to emphasize the state means business about controlling mercury pollution.
The new rules require mines that release significant amounts of mercury to install scrubbers and similar technology to control smokestack emissions.
Mercury is released into the atmosphere during roasting and other refining procedures used to extract gold from ore. A neurotoxin, the substance is of particular danger to children and developing fetuses.
(Copyright 2007 by The Associated Press. All Rights Reserved.)