United States Nuclear Regulatory Commission - Protecting People and the Environment

Rio Algom – Lisbon Valley

This site description was provided by the cognizant Agreement State, and the U.S. Nuclear Regulatory Commission (NRC) makes no claim regarding the validity of the information provided. See our Site Disclaimer for more information.

1.0 Site Identification

Type of Site: Uranium Recovery
Location: San Juan County, UT
License No.: UT1900481
Docket No.:
License Status:  

2.0 Site Status Summary

Uranium mining and milling occurred at the Site from 1972 to 1989. Two tailings impoundments were operated during mining. The former Lisbon Valley Uranium Mill has been decommissioned and was done under NRC oversight. Rio Algom has been the only licensee and operator for the former Mill site. It is believed that the site was decommissioned using a concentration-based criteria in accordance with 40 CFR 192.12(a), 192.32(b)(2), and 192.41. However, the DWMRC is waiting for the licensee to submit a closure report to confirm this assumption. Rio Algom is in the process of revisiting the groundwater modeling to re-establish new ACLs for uranium. Seepage of tailings water from the impoundments was the source of uranium contamination in the groundwater. The existing ACLs were approved by the NRC before the State of Utah became an Agreement State.

3.0 Major Technical or Regulatory Issues

On February 7, 2011, an enforcement action was taken against Rio Algom for exceeding the Target Action Levels for uranium in wells RL-1 and EF-8 for two consecutive sampling events. Rio Algom is in the process of revising the ACLs for uranium. The revised ACLs must be approved by the DWMRC before the licensee can return to compliance. Another option available to the DWMRC is to require the licensee to remediate the aquifer to meet the Utah GWQS for uranium (30 μg/L). This is something the DWMRC is considering if the licensee fails to submit a closure report in the near future.

Page Last Reviewed/Updated Thursday, August 23, 2018