Draft Environmental Impact Statement for Roca Honda Mine

Chapter 3. Affected Environment and Environmental Consequences
related disease. Uranium mining is more strongly associated with obstructive lung disease and
radiographic pneumoconiosis in Native Americans than in Hispanics and non-Hispanic whites.
Obstructive lung disease in Hispanic and non-Hispanic white miners is mostly related to cigarette
smoking. Native Americans have the highest prevalence of radiographic pneumoconiosis, or lung
disease caused by dust in the lungs, and are less likely to meet criteria for compensation. This
disease can be caused by coal dust, silica, or other sources as well; in coal miners it is known as
“black lung disease.”
Mining History of New Mexico
Because there was very little regulatory framework in place during the earlier (pre-1990s) round
of uranium mining, New Mexico has been left with what is referred to as a legacy of
environmental contamination from these activities (NMBGMR). According to a University of
Michigan study, mining began in earnest in the Southwest United States after World War II, when
atomic weapons were being developed. Escalation of the Cold War between the United States and
the Soviet Union sent workers to uranium mines to mine the ore for processing into nuclear
weapons. More than 15,000 people have mined uranium or worked in ore processing mills in the
Southwest since the 1940s. Some 13 million tons of uranium were mined while the mines were in
operation. The Vanadium Corporation of America and Kerr-McGee Corporation were the
principal owners of these mines.
Mine Types
Uranium mines are generally one of three types: open pit, underground hard rock mines, or in situ
leach mines. Open pit and underground hard rock mines can process (mill) the ore onsite, or
instead can ship the ore offsite for processing. In situ leach, processes would leach the uranium
out of rock in place, far underground, by pumping chemicals from the surface into the
underground ore deposit and bringing uranium to the surface in solution for further processing.
The overall footprint and potential for exposure and contamination is generally less with an
underground mine, because it is generally smaller in scope and works with a more confined ore.
This is especially true if processing is done offsite, which is what would occur with the Roca
Honda Mine. Other factors affecting health risk potential include the presence or absence of
groundwater, mine depth, and waste rock overall contamination and handling and characteristics.
Ore Processing
Ore can be processed (milled) onsite with either mine type. Open pit and underground mines can
also haul ore to a treatment (milling) facility where it is exposed to acid to leach out the mineral.
Surface exposure of ore to water and chemicals is referred to as a heap leach process. This
process can be done at the mine or at offsite processing facilities. Ore can also be processed in
situ using acids or other chemicals to leach out the mineral in place, far underground, and then
pump the leachate to the surface to recover the uranium. The advantage of the in situ leach
process is lower worker exposure, potentially lower recovery costs, and the elimination of a waste
tailings pile. Disadvantages include potential groundwater contamination and the possibility of a
permanently contaminated underground area upon completion, although surface areas are
generally less affected.
DEIS for Roca Honda Mine, Cibola National Forest 437