Technical Analysis of the 2017 Re-proposal for Uranium Mining Groundwater Standards


1. The 2017 re-proposal significantly weakens the protections in the 2015 proposed rule. The re-proposed rule reduces the post closure monitoring requirements from 30 years to a total of 6 years (three years for “initial” stability monitoring and 3 additional years for “long-term” stability monitoring). Given the commonly occurring failure to achieve initial restoration goals, utilizing the current approaches to restoration, and subsequent reliance on Alternative Concentration Limits (ACLs), it is clear that at many ISR mines water quality stability may not be achieved for many years. it is irresponsible to allow the use of groundwater fate and transport models to “demonstrate” stability in lieu of empirical monitoring data. At a minimum quarterly monitoring should be required after the six-year period.

2. Prior to requesting an ACL the mining company must use “best practicable active restoration.”  However there is no definition or explanation as to what this means. Also under the re-proposed rule the “regulatory agency would consider a list of factors when considering setting an ACL ( the list is included in Section II A. 2 of the FR notice). The list is long and exhaustive and, while including critical factors, will require a significant effort by the regulatory agency and is likely to be incomplete with no consistent approach.

3. Duration of pre-operational monitoring and changes to well completion requirements: the changes in the re-proposed rule would significantly weaken the  requirements aimed at assuring that an adequate baseline characterization is completed. Adequate establishment of baseline is a problem. The re-proposed rule allows for baseline monitoring to occur for less than a year in areas where “temporal variations are not expected to occur”. This does not conform with hydrologic reality – even confined aquifers have seasonal variability regarding recharge, potentiometric surface levels and water chemistry. It seems perfectly reasonable to require at least one full year of baseline data to establish that there is “no seasonal variation”. This is just an attempt to reduce monitoring costs for the industry.

4. The re-proposed rule states that “EPA believes that sufficient monitoring should be completed to ensure that all perturbations associated with well construction are resolved prior to establishing background concentrations” and “EPA requires the sampling frequency to be sufficient to ensure statistically valid background levels are not influenced by well construction.” The well construction problems refer to the introduction of oxygen (which helps mobilize uranium) during monitoring well construction. This proposed revision introduces too much vagueness and provides no guidance on how to conduct sampling to “ensure statistically valid background levels are not influenced by well construction.”  This will be a complicated procedure and will rely far too much on the discretion of State agency staff. The end result will be a less rigorous determination of baseline water quality conditions which will impact the establishment of post-closure restoration standards.

5. The re-proposed rule eliminates the requirement to do operational and post-closure monitoring both inside and outside the boundaries of the exempted aquifer. However, the re-proposed rule is very unclear as to where post- closure compliance monitoring should occur. The proposed change in definition of point of exposure, in combination with what is likely to be an increase in ACL requests, certainly increases the risk of post-closure down-gradient groundwater contamination.

6. The re-proposed rule will eliminate the requirement to monitor and establish standards for all constituents listed in Table 1 of 40 CFR part 192, subpart F. Instead facilities would only be required to monitor and establish standards for the listed constituents that are present or could be affected by the ISR operation.  What is meant by “identified as present or affected by operations in the groundwater”? No guidance or definition.

7. The re-proposed rule establishes a corrective action approach to deal with exceedances of standards during operation (excursions) and post-closure restoration and stability. It further extends the time frame for implementing corrective action. Given the fact that once an excursion has been detected, groundwater outside the production zone has already been impacted, this provision allows for too much time to meet standards and will result in a higher risk to down-gradient groundwater.

8. This re-proposed rule does not require a public participation process in the request/ agency approval process for ACLs. This is a serious omission given the current use of ACLs and the expected increase in ACL requests. The NRC was considering a requirement that all ALCs must be approved by the NRC, which would trigger a public participation process. It is unknown if this is true.