Nevada ranked first nationally in the release of toxic chemicals per square mile in 2017, the most recent year for which data is available, and the state’s mining industry was the reason why.
The industry and state environmental regulators say the federal Environmental Protection Agency’s “Toxics Release Inventory” misleadingly characterizes harmless dirt as toxic material, presenting a distorted report of toxic releases in the state.
But environmentalists counter that mining and state officials understate the threat posed by mining disposal, and the federal reports on toxics releases should not be dismissed lightly.
All five of the top manufacturing facilities generating the most toxic releases that could pose a threat to human health and the environment were mines, according to the U.S. Environmental Protection Agency’s recently released 2019 Toxics Release Inventory (TRI) National Analysis.
Nevada ranked 1st in total releases per square mile and 2nd in total releases overall, with some 148 facilities managing toxic material in 2017, generating 397.7 million pounds of releases, according to the EPA. Alaska is the top state in terms of total releases with about 1.1 billion pounds of waste.
Nevada had a total of 148 facilities managing toxic material in 2017, generating 397.7 million pounds of releases, according to the EPA.
The EPA tallies toxins released into water, air and land. Releases to land was by far the category that put Nevada at the top of the TRI.
Newmont Mining Corp led the state by releasing a combined 230 million pounds of releases from three facilities, more than three times the next biggest polluter in Nevada in 2017. Barrick mines was second statewide, with 75 million pounds released that year.
The federal Toxics Release Inventory tracks more than 21,600 facilities across the country that handle large amounts of toxic chemicals harmful to health or the environment.
The EPA defines toxics releases as potentially harmful chemicals emitted to the air, land and water from manufacturing operations, electric utilities, as well as facilities like hazardous materials landfills that accept certain toxic substances.
JoAnn Kittrell, a spokeswoman for the Nevada Department of Conservation and Natural Resources, said the number of releases can be misleading for Nevada. The figures reported all show the weight of the substances released, not necessarily the potential for impact on human health and the environment. For this reason, heavier wastes like mining refuse often dominate the total release rankings in the EPA’s national analysis.
“While the TRI program provides a big picture indication of toxic releases, there are limitations to the usefulness of the data,” said Kittrell. “The term ‘release’ includes emissions to the air and discharges to water that are regulated by state and federal environmental permits. Since 1998, when mines were required to report moving rock around as a release, even though no toxins are released, Nevada’s number increased dramatically.”
Off-site disposal facilities that are fully permitted and environmentally engineered are counted as releases, said Kittrell, adding that these “inventoried releases do not affect Nevadan’s health and safety.”
Dana Bennett, president of the Nevada Mining Association, said people should keep in mind that the release of these substances do not necessarily pose a risk to the public.
The TRI “compiles numbers that, on face value, may appear alarming to the general public,” Bennett said. “Many of the elements in question are naturally occurring, however, and their release does not necessarily pose a risk to the public. Just as in agriculture and construction, mining moves dirt and rocks from one location to another area that is specifically engineered and secured for processing or disposal, both of which are highly regulated activities. The movement of these materials does not adversely impact the environment or human health, but the movement must be reported to the EPA and listed in the TRI report.”
Bennett added that the report does not take into account the efforts by mine sites to minimize risks of potentially harmful elements to humans, wildlife, and the environment.
While both the Nevada Department of Conservation and Natural Resources and Nevada Mining Association similarly characterized the volume of reported releases as “moving rocks around” John Hadder the director of Great Basin Resource Watch said such a characterization played down the gravity of these “releases.”
“The way the agency makes it sound, it’s nothing. But a lot of that rock is waste rock which has potentially reactive elements that can create drainage that has to be treated. It’s not ignorable,” Hadder said.
A certain amount of excavated rock in mining is not reactive, said Hadder, but a fair amount is, which is the material that can become dangerous to the environment and human health.
For example, most of the ore mined in Nevada is microscopic, requiring a complex chemical process to extract. Much of the mined ore is below the water table so massive pumping is required to keep the mine pit dry. When mining stops, so does pumping, and pits become lakes. These lakes are often contaminated by sulfuric acid runoff, created when rock which hasn’t been exposed for thousands of years is pulled up and, and once exposed, reacts with water and air to create sulfuric acid that dissolves heavy metals such as copper, lead, and mercury. The acid then erodes more rock, creating more sulfuric acid in a chain reaction that can go on for decades, potentially contaminating groundwater and surface water in the process.
“Even if the material mined does not have extractable ore in it, once you uncover that and expose it to the elements—metals like chromium, arsenic— there is the potential they’ll leach out into drainage,” Hadder said. “There is a reason moving rock around is included” in the TRI, he said.
Humboldt County reported more releases than any other county in Nevada with about 160.2 million pounds, nearly all of it coming from the Newmon’s Twin Creeks Mine.
Eureka County had the second highest total in Nevada with about 104.9 million pounds of total releases, most of it originating from Newmont’ Carlin complex.
The purpose of the EPA’s TRI program is to provide the public detailed information about facilities around them and has developed an online searchable database that allows users to search by facility, state, zip code, chemicals released or by industry sector.