"Health and Environmental Protection
Standards for Uranium and Thorium
Mill Tailings"
United States
Environmental Protection
Agency
Notice of Proposed Rulemaking
About the Standards
The current regulations, "Health and Environmental Protection
Standards for Uranium and Thorium Mill Tailings" (40 CFR
192), set standards to protect public health, safety and the
environment from radiological and nonradiological hazards
associated with uranium and thorium ore processing and its
wastes. EPA issued the standards under the legal authority
of the Uranium Mill Tailings Radiation Control Act of 1978
(UMTRCA). The standards were originally issued in 1983 and
last revised in 1995-
Why is EPA proposing changes?
In the years since the rule was originally issued, in-situ recovery
(ISR) has become the prominent method of uranium extraction
in the U.S. The current regulations do not explicitly address the
alteration of ground water that occurs during the ISR process.
EPA is proposing to add a new Subpart to 40 CFR 192 that will
establish ground water restoration and monitoring requirements
at ISR facilities. EPA is also proposing to correct a few outdated
references and make minor changes to correct typographical errors.
Oxygenated water pumped
into injection well
\AMer containing mobilized uranium
pumped out of production well to
processing plant
Monitoring wells
Monitoring
well
To plant
Production
well 4
Figure 1: ISR Extraction Process for Uranium
United States Environmental Protection Agency | Office of Radiation and Indoor Air (6608T)
EPA-402-F-13-051 | October 2014
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Measured
ground water
concentration
Restoration
Goal
Time
Figure 2: ISR Phases and Proposed Monitoring Requirements
In-situ recovery (ISR) and ground water
In the ISR process, fluids are injected into an ore-bearing
aquifer to mobilize uranium. Extraction wells then collect the
ground water, which is processed at the surface to obtain the
uranium. The fluids injected to mobilize uranium also mobilize
minerals and metals like arsenic and lead, and change the
chemistry of the aquifer from its original state. Ground water
from the altered aquifers could migrate (an "excursion") over
time and contaminate nearby ground water.
What is proposed for ISR Facilities?
The proposed new Subpart of 40 CFR 192 would establish
ground water restoration goals and monitoring requirements at
ISR facilities. Specific provisions of the new Subpart include:
Requirements to characterize background ground water
chemistry: The proposed rule describes how ISR facilities are to
characterize ground water chemistry before beginning uranium
recovery operations.
Requirements to meet restoration goals for 13 constituents:
The proposed rule would require compliance with whichever
standard is most protective from the Safe Drinking Water
Act (SDWA), the Resource Conservation and Recovery
Act (RCRA), or UMTRCA for each of 13 ground water
constituents. The 13 ground water constituents are: arsenic,
barium, cadmium, chromium, lead, mercury, selenium, silver,
nitrate (as nitrogen), molybdenum, radium, total uranium and
gross alphaparticle activity. If the water in the aquifer meets
the ground water standards before ISR operations begin, it
would have to be restored to meet them again after operations
have stopped. If the constituent concentrations already exceed
standards before operations begin, the operator would have to
restore the ground water chemistry to original, pre-operational
concentrations. If background concentrations or ground water
protection standards cannot be achieved, ISR operators can
request an Alternate Concentration Limit (ACL), provided
that they meet certain criteria and conditions.
Requirements for long-term stability monitoring:
The proposed rule would require ISR operators to monitor
ground water for 30 years after demonstrating that the ground
water chemistry has been restored and is stable. Under this
proposal, the 30-year monitoring period could be shortened
if monitoring data and geochemical modeling show that the
ground water chemistry has been restored, has remained stable
for at least three consecutive years, and is likely to remain stable
into the future. Statistical analyses would have to demonstrate
ground water stability at a confidence level of 95 percent.
How You Can Participate
Rulemaking starting the day of its publication in the Federal Register. Be sure to identify your submission by Docket ID No. EPA-HQ-OAR-2012-0788.
notice. You can download the text at: http://www.epa.gov/radiation/laws7192.html
United States Environmental Protection Agency | Office of Radiation and Indoor Air (6608T) EPA-402-F-13-051 | October 2014
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