Public Comment Closed October 16, 2017

Docket # EPA-HQ-OAR-2012-0788 and FRL-9958-12-OAR

Docket information @ 

What’s at Risk, Talking Points, and What You Can Do

The Trump Administration is considering proposed standards to prevent, monitor and remedy groundwater contamination during and after uranium extraction operations -- standards weaker than originally proposed in 2015.  The proposed standards are intended to protect downgradient groundwater used for drinking water. Radionuclide contamination of downgradient drinking water aquifers has been documented at a number of uranium mines in recent years.  After its original proposal prompted extensive feedback from commenters and discussions with other agencies, EPA issued a revised proposal for comment in January 2017, before the change in administrations.  The revised proposal would significantly weaken the groundwater standards proposed in 2015.  The Trump administration in August extended the comment period on the revised proposal.


The US currently imports more than 85% of the uranium used for power production. Uranium mining is likely to increase over the next decade in response to a renewed interest in nuclear energy in the United States, Asia, Europe, Africa and South America. Globally, there are currently 439 operating reactor units, 36 under construction, 93 in planning and 218 proposed (Yancey, 2008). Within the United States there are 104 operating nuclear reactors which produce about 19% of the US electricity (2007). More than 4000 mines have a history of uranium production in the United States, almost all of these in the western US (Yancey, 2008).    The western United States was the world’s leading producer of uranium during the previous uranium booms in the 1950s and 1970s. The Organisation for Economic Co-operation and Development estimates that the US has about 377,000 tons of uranium reserves - about 6 % of the world’s supply. 

In many deposits, uranium can be recovered by in-situ recovery (ISR) also referred to as in-situ leaching. ISR involves the injection of an oxygenated solution (lixiviant) into ground water which flows through the uranium deposit. Uranium is dissolved into the ground water/ lixiviant solution which is then recovered by extraction wells. The uranium is removed from the “pregnant”solution via ion exchange and processed into yellow cake, a uranium concentrate. The uranium depleted water is then refortified with the lixiviant and re-circulated through the deposit for continued recovery.

Diagram showing injection of chemicals into deep geologic formations and pumpback of the uranium-containing slurry to the surface.
How in-situ leaching works at uranium mines

The percentage of total global uranium production from ISR mines has increased from 16% in 2000 to 47% in 2013.  ISR production in the USA began in Wyoming in 1960s (experimental) and the first commercial mine opened in 1974. Since then more than 30 ISR uranium mines have been permitted. Most currently operating ISR mines in USA began in 1990s and are located in South Dakota, Nebraska, Wyoming, New Mexico and Texas Total annual production typically under 1000 tons. Currently more than 12 ISR facilities are operating in the USA.

The Nuclear Regulatory Commission (NRC) regulates ISR operations. In contrast, conventional uranium mining is regulated by the OSM and individual State mine permitting agencies. The distinction is that NRC is responsible for regulating uranium recovery operations when the ore is processed and chemically treated. This happens in a uranium mill (ore processed from conventional open pit and underground mines) or during in-situ leaching. Therefore the NRC regulates ISR operations, uranium mills and disposal of solid and liquid waste from uranium recovery operations. The NRC has established a process where states can become Agreement States and implement NRC regulations for ISR facilities.  Texas, Colorado and Utah have primacy. NRC regulated ISR facilities in Wyoming, Nebraska and South Dakota.

Contamination Issues from Uranium In-situ Leaching Operations

There are two major environmental issues specific to in-situ uranium mining:

1. Excursions - Roll-front uranium ore bodies often occur with sandstone formations which are typically fresh water aquifers and are protected under the Safe Drinking Water Act. The part of the aquifer that hosts the ore body is typically exempted from protection thru the Underground Injection Control (UIC) regulations. Excursions occur when uranium bearing fluids (lixiviant and groundwater containing uranium) move beyond the mined portion of the ore body and into adjacent un-impacted groundwater. Mining operations are designed to minimize excursions and to mitigate excursions when they happen. Though excursions do happen at numerous ISR facilities, the groundwater contamination is usually local – but can be serious.

2. A more serious issue is the failure to meet post-closure groundwater restoration goals. Groundwater restoration is required by NRC regulations even though an aquifer is exempted from protection through a UIC permit. At ISR facilities, impacted groundwater (regulated constituents) must be restored to baseline quality, applicable State groundwater quality standards or alternative concentration limits (ACLs). Various treatment methodologies are utilized by the industry. Post mining GW monitoring is required to demonstrate compliance and “stabilization.” At many ISR facilities restoration standards for a small group of parameters (mainly metals, including uranium and radium) are too often not achieved after initial restoration efforts. Metals are mobilized by in-situ recovery and can reach dissolved concentrations that exceed applicable groundwater protection standards;  restoration methods (including active treatment) have not been as effective as necessary to prevent exceedance of standards. This commonly results in the approval of alternative concentration limits for the problematic metals. Once ACLs are approved, the risk of contaminated groundwater migrating down-gradient beyond the aquifer exemption boundary into groundwater used for drinking water is increased and – in fact - has happened.

EPA Groundwater Protection Rule

In January 2015, the EPA proposed new Health and Environmental Protection Standards under the Uranium Mill Tailings Radiation Control Act (UMTRCA).1 The proposed standards were aimed at improving ground water protection at uranium mines using in-situ recovery facilities).

As most uranium ore in the USA is now mined using in-situ leaching methods it is critically important to restore impacted groundwater to acceptable standards. The 2015 rule was important in that was aimed at preventing contamination of downgradient groundwater used for drinking water. Radionuclide contamination of downgradient drinking water aquifers (USDWs) has been documented at a number of in-situ uranium mines in recent years. The revised proposal issued in January 2017 significantly weakens the groundwater protection regulations proposed in January 2015.

The new standards proposed by EPA in 2015 included the following key provisions:

  1. Requirements for consistent characterization of baseline water quality. Selection of background concentration values are often too subjective and determined with too little data.
  2. Requirements to meet restoration goals for 13 specific constituents (arsenic, barium, cadmium, chromium, lead, selenium, ,NO3, radium, total uranium, gross alpha radioactivity, mercury, silver and molybdenum).                      
  3. Applicable standards for regulated contaminants will be the most protective from from the three statutes that set standards for drinking water.2  If standards are already exceeded before operations begin, alternative concentration limits are established.
  4. Requirements for long-term (30 years) stability monitoring UNLESS
    1. Monitoring data demonstrate restoration to standards
    2. Statistical analyses demonstrates stability for 3 consecutive years
    3. Geochemical modeling indicates stability and no re-mobilization

 Suggested Talking Points

1. Reducing groundwater monitoring requirements following mine closure from 30 years to 6 years will allow contamination to continue with no responsible party to monitor or remediate the contamination.

2. Mining companies should be held to clear drinking water protection standards, even when requesting an alternative concentration limit. The proposed "best practicable active restoration" test is vague, leading to extensive agency time evaluating proposals with inconsistent outcomes. 

3. It is critical to establish a scientifically adequate baseline characterization before mining activities begin. At a minimum, baseline characterization should include one full year of monitoring to account for seasonal variation. The proposed rule would allow for monitoring of less than one year- a blatant attempt to reduce monitoring costs for the industry at the expense of public health.

4. Well construction standards are vague, with no related guidance on sampling methods. Clear standards should be established to support adequate baseline characterization. 

5. The 2015 proposal requires operational and post-closure monitoring inside and outside of the aquifer affected by uranium in-situ mining. This monitoring is critical to ensure that down-gradient drinking water aquifers are not contaminated by mining activities, and should be retained. 

6. The rule should retain require that the list of 13 specific contaminants identified in the 2015 proposal be met during restoration. 

7. The re-proposed rule improperly extends the time period for facilities to take corrective action when operations have resulted in contamination to the aquifer, putting drinking water aquifers at further risk.

8. The re-proposed rule eliminates the requirements for public participation when setting alternative concentration limits. Public participation in rulemaking - including alternative concentration limits - is a fundamental right and must be retained.

What You Can Do

It would be great if well-reasoned, fact-based comments were enough to win the day, but in today’s deregulatory environment, raising the political stakes of regulatory rollbacks is crucial to stopping or slowing them down.  For rules that are particularly important to you, please consider taking one or more of the following steps, too.

  • Write to your members of Congress and other elected officials.  Let them know your concerns and ask them to weigh in with the agency proposing the rollback.
  • Write letters to the editor and even op-eds in your local papers.
  • Organize or participate in letter-writing campaigns.
  • Join or organize demonstrations.
  • Talk to your friends, colleagues and neighbors and encourage them to comment and otherwise join in this effort.  Voicing your concerns on social media can be a very effective way to spread the word.

Links for More Information

Electronic link to proposed rule

In-situ Leach Uranium Mining

EPA: Technical analysis of the January 2017 re-proposal



140 CFR part 192

2 Safe Drinking Water Act, Resource Concentration and Recovery Act, Uranium Mill Tailings Control and Reclamation Act

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