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Decommissioning Projects - United Nuclear Church Rock uranium mines and mill, McKinley County, New Mexico, USA

(last updated 1 Oct 2024)

UNC requests extension of completion date for reclamation of former Church Rock uranium mill site until 2038

[...] the licensee requests changes to the dates in Condition 35 of the license which would extend the projected date from 2019 to 2038 for emplacement of the final radon barrier; extend the projected date for placement of the erosion protection from 2019 to 2038; and to extend the completion of the groundwater corrective actions from 2018 to 2036.
Submit comments by December 2, 2024.
> Federal Register Volume 89, Number 190 (Tuesday, October 1, 2024) p. 79973-79975 (download full text

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> Download: License Amendment Request

, May 14, 2024 (PDF)
> Access Docket ID NRC-2024-0170

Active groundwater remediation at Church Rock uranium mill site no longer makes sense, according to UNC

"In the Southwest Alluvium and Zone 1, the natural systems have functioned as effectively as when active remediation took place. Acidic seepage is being neutralized, resulting in attenuation of metals and radionuclides."
"The Zone 3 pumping system has been declining in performance and has approached the limit of its effectiveness due to declining saturated thicknesses, as predicted."
United Nuclear Corporation (UNC) therefore recommends to implement a No Further Action remedial alternative for the Southwest Alluvium, and to consider terminating extraction pumping from Zone 3.
> Download: Annual Performance Review Report, 2020 Groundwater Corrective Action, Church Rock, New Mexico, United Nuclear Corporation

, Jan. 29, 2021
> Download: Report with revised appendices

, Feb. 18, 2021
> Download: Annual Performance Review Report, 2021 Groundwater Corrective Action, Church Rock, New Mexico, United Nuclear Corporation

, Jan. 30, 2022
> Download: Annual Performance Review Report, 2023 Groundwater Corrective Action, Church Rock, New Mexico, United Nuclear Corporation

, Jan. 30, 2024

Natural attenuation test for remediation of shallow groundwater at former Church Rock uranium mill site successful, almost

"The Southwest Alluvium corrective action pumping system remained idle in 2019. Attenuation via natural geochemical processes has been shown to be at least as effective as pumping. There were no exceedances of current NRC license standards or revised EPA cleanup standards by a hazardous constituent in seepage-impacted water outside the UNC property boundary in 2019."
In the Southwest Alluvium, downgradient Point of Compliance (POC) Monitoring Well GW-3 was the only one showing a continuous increase of uranium, exceeding the NRC license standard of 0.3 mg/L since 2013. It was, however, last sampled on July 7, 2015, since when it could "no longer be accessed due to safety concerns". UNC anyway claims that "Uranium concentrations at this location are not representative of general conditions in the Southwest Alluvium because the water level is very low (beneath the 2-ft minimum specified in the sampling procedure) such that the well no longer provides representative samples."
In Zone 3 and Zone 1 deep aquifers, however, standards for constituents, such as beryllium, nickel, selenium, vanadium, cobalt, among others, were exceeded at a variety of monitoring wells.
> Download: Annual Performance Review Report, 2019 Groundwater Corrective Action, Church Rock, New Mexico, United Nuclear Corporation

, March 28, 2020

Modeling effort fails to analyze water balance of soil covers at selected uranium mill tailings sites

> View here

NRC invites comment on requested extension of date for emplacing final radon barrier and erosion protection at former Church Rock uranium mill site

: However, prior to making a final determination on the UNC's second request to extend the date for emplacing the final radon barrier and the erosion protection, the NRC is providing an opportunity for public participation. Specific comments are requested on the extension of the date for emplacement of the final radon barrier and the erosion protection from December 31, 2014 to December 31, 2019.
Comments should be provided within 30 days of April 30, 2014.
> Federal Register Volume 79, Number 83 (Wednesday, April 30, 2014) p. 24459-24460 (download full text

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> Access Docket ID NRC-2014-0096

United Nuclear requests five-year extension to groundwater corrective actions at Church Rock mill and tailings site

By letter dated Sep. 18, 2013, United Nuclear Corp. requested a five-year extension for the projected completion of groundwater corrective actions and subsequent dates for placement of the final radon barrier and erosion protection.
NRC approved the requested five-year extension for the projected completion of groundwater corrective actions on Nov. 7, 2013.

United Nuclear requests relaxed groundwater protection standards at Church Rock mill and tailings site

On April 17, 2012, United Nuclear Corp. sent to NRC a License Amendment Request for Revised Background Standards Based on Updated Background Concentrations.
> Download License Amendment Request April 17, 2012

(PDF)

NRC offers opportunity to request a hearing and to petition for leave to intervene on United Nuclear's requests for relaxed groundwater protection standards at the Church Rock uranium mill and tailings site:
A request for a hearing or petition for leave to intervene must be filed by April 23, 2013.
> Federal Register Volume 78, Number 36 (Friday, February 22, 2013) p. 12365-12368 (download full text )
Note: The ADAMS Package Accession No. given in the FR notice for the license amendment request is incorrect!
> Access Docket ID NRC-2013-0036

NRC approves United Nuclear's requests for relaxed groundwater protection standards at the Church Rock uranium mill and tailings site:
On April 9, 2015, the NRC issued License Amendment No. 52 approving United Nuclear's requests for relaxed groundwater protection standards at the Church Rock uranium mill and tailings site.
> Federal Register Volume 80, Number 78 (Thursday, April 23, 2015) p. 22744-22746 (download full text )
> Download License Amendment No. 52 , April 9, 2015
> Download Technical Evaluation Report , April 2015
> Download Final Environmental Assessment , April 2015

Disposal of contaminated soil from the North East Church Rock Mine site on top of the existing Church Rock uranium mill tailings disposal cell

NRC approves proposed placement of mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: "The adverse environmental impacts of the proposed action, Alternative 1A and Alternative 1B, which each involve the issuance of a license amendment to transfer and dispose approximately 765,000 m³ [1,000,000 yd³] of NECR [Northeast Church Rock] mine waste on top of a portion of the existing tailings impoundment at the UNC Mill Site, would not preclude issuing a license amendment."
> Download: NRC release Jan. 4, 2023

(PDF)
> Federal Register Volume 88, Number 9 (Friday, January 13, 2023) p. 2376-2378 (download full text

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> Federal Register Volume 88, Number 14 (Monday, January 23, 2023) p. 4040 (download full text

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> Download: Environmental Impact Statement for the Disposal of Mine Waste at the United Nuclear Corporation Mill Site in McKinley County, New Mexico, Final Report, NUREG-2243

, NRC Jan. 2023 (26.5MB PDF)
> Download: Public Comments on the Draft Environmental Impact Statement

(1.1MB PDF)
> Download: Record of Decision and License Amendment

, Feb. 15, 2023
> Download: NRC release, Feb. 16, 2023

(PDF)
> Access Docket ID NRC-2019-0026

NRC delays decision on proposed placement of mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: A decision that was expected this month about whether to remove uranium mine waste from an area near a Church Rock community or store it onsite near the community has been delayed for now by the U.S. Nuclear Regulatory Commission.
Area residents have called on federal agencies to have United Nuclear Corporation transport the waste to disposal facilities outside the area.
The NRC and its and staff will continue evaluating a request from United Nuclear Corporation to amend its cleanup plan to transport contaminated soil from its uranium mines and dispose the waste at its mill site. The entire activity would take place next to the Red Water Pond Road Community, an area north of Church Rock. (Farmington Daily June 17, 2022)

In a memorandum issued on Nov. 22, 2022, the NRC lifted the delay.

Navajo reinforce opposition to proposed placement of mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: During an unprecedented out-of-town public meeting held by the U.S. NRC in Gallup, New Mexico, on April 22, 2022, Navajo representatives, including Navajo president Jonathan Nez, Navajo Nation EPA Executive Director Valinda Shirley, and Red Water Pond Road Organization President Edith Hood, reinforced their opposition to the proposed placement of mine waste on top of the reclaimed Church Rock uranium mill tailings deposit.
While U.S. EPA Region 9 Superfund Division Director Michael Montgomery praised the benefits of the waste relocation proposal, the NRC Commissioners present raised deep concerns.
> Watch video recording

NRC invites comment on Draft Programmatic Agreement on protection of archaeological sites affected by proposed placement of mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: The U.S. Nuclear Regulatory Commission (NRC) is requesting comment on a draft Programmatic Agreement (PA) between the NRC, U.S. Environmental Protection Agency (US EPA), Navajo Nation Tribal Historic Preservation Office (NNTHPO), New Mexico State Historic Preservation Office (NMSHPO), Bureau of Indian Affairs (BIA), and United Nuclear Corporation (UNC). The purpose of this draft PA is to resolve any adverse effects to historic properties identified during consultation for a proposed license amendment application for the UNC Mill Site.
Submit comments by January 21, 2022.
> Federal Register (TBA)
> Download: Draft Programmatic Agreement , Nov. 30, 2021 (PDF)
> Access Docket ID NRC-2019-0026
> Download: Final Programmatic Agreement , Sep. 2022 (616kB PDF)

Navajo President opposes proposed placement of mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: "The Navajo Nation has asked USEPA in the past to require the radioactive uranium waste currently at NECR to be transported to an offsite waste repository away from the Red Water Pond Road Community and other communities in the area. USEPA requires the removal of Principal Threat Waste (PTW), the most toxic or highly mobile waste, to an off-site facility, but the Navajo Nation also asked, and continues to ask, for off-site removal of mine waste exceeding USEPA's "action level" but not qualifying as PTW. This waste remains a threat to human health and the environment, as noted in the DEIS [Draft Environmental Impact Statement] and as discussed above.[...]
The Navajo Nation therefore remains steadfast in its position that all NECR radioactive mine waste registering above USEPA's action level should be removed from the community; simply transporting it to a facility less than one mile away from the reservation boundary, while it technically is removing it from the Navajo Nation, in reality is just taking it from one side of the road to the other. [...]"
> Download: Statement on DEIS for Disposal of NECR Mine Waste at UNC Mill Site , Apr. 12, 2021

DOE drops opposition to proposed placement of mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit:
"Based on the provided information, the Department of Energy (DOE) continues to object to the placement of non-11e.(2) byproduct material mine waste onto the 11e.(2) byproduct material tailings disposal area at the Church Rock Mill Site. This DOE position was previously stated on our letter dated March 9, 2018. DOE believes that any acceptance of and acquiescence to a license amendment request by the current Licensee will most likely aggravate and/or insert an unnecessary risk to DOE's long-term surveillance and maintenance of the site as well as pose a potential increase in the site's life-cycle cost baseline and environmental liability."
(DOE letter to NRC, Oct. 19, 2020 )
"[...] we now believe adequate analysis has been performed demonstrating the solution is technically viable. Moreover, the DOE is willing to accept the transfer of the site as long as the details of the Regulatory oversite [sic!] are established and documented so authorities and responsibilities are clearly defined. [...]"
(DOE letter to NRC, Dec. 11, 2020 )

NRC issues Draft EIS for proposed placement of mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: "[...] The adverse environmental impacts of the proposed action, Alternative 1A and Alternative 1B, which each involve the issuance of a license amendment to transfer and dispose approximately 765,000 m³ [1,000,000 yd³] of NECR [Northeast Church Rock] mine waste on top of the tailings impoundment at the UNC Mill Site, are such that preserving the option for decisionmakers of issuing such a license amendment is reasonable, and that the project should proceed. [...]"
Comments must be filed by October 31, 2021 (comment period reopened).
> Federal Register Volume 85, Number 220 (Friday, November 13, 2020) p. 72706-72707 (download full text )
> Federal Register Volume 85, Number 247 (Wednesday, December 23, 2020) p. 84016-84018 (download full text )
> Federal Register Volume 86, Number 23 (Friday, February 5, 2021) p. 8386-8387 (download full text )
> Federal Register Volume 86, Number 115 (Thursday, June 17, 2021) p. 32285-32287 (download full text )
> Download: NRC News Release, Nov. 17, 2020 (PDF)
> Download: Overview of Draft Environmental Impact Statement , Oct. 2020 (5MB PDF)
> Download: Environmental Impact Statement for the Disposal of Mine Waste at the United Nuclear Corporation Mill Site in McKinley County, New Mexico, Draft Report for Comment , NUREG-2243, NRC, Oct. 2020 (45.1MB PDF)
> Access Docket ID NRC-2019-0026
> Access NRC Facility Info

Navajo community unhappy with EPA's plan for relocation during proposed reclamation work at Church Rock uranium mill tailings deposit: The village of Red Water Pond Road sits in the southeast corner of the Navajo Nation, a tiny speck in a dry valley surrounded by scrub-covered mesas. Many families have lived here for generations. The federal government wants to move them out.
In what might seem a cruel echo of history, officials are relocating residents to the city of Gallup, about a half-hour away, and surrounding areas. This echo is nuanced, however. The village sits amid a Superfund site loaded with uranium mine waste. Mitigation has been delayed for decades, along with remedies for hundreds of other abandoned uranium mines across the tribe's lands that boomed during the Cold War.
The Environmental Protection Agency aims to haul away thousands of truckloads of the radioactive waste over the next seven years. Residents do not want to stay during that work, but many fear losing their way of life if they are uprooted and unmoored from rural roots and traditions. They have countered the agency's plan with another solution: construction on a nearby mesa of an off-grid, solar-powered community designed by an architecture group at the University of New Mexico.
The EPA had rejected the idea but is facing new pressure from lawmakers and community members to reexamine it. (Washington Post Jan. 18, 2020)

NRC announces opportunity to request a hearing and to petition for leave to intervene on proposal to place mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: On September 24, 2018, United Nuclear Corporation (UNC) requested an amendment to its reclamation plan for its Uranium Mill site near Gallup, New Mexico. UNC is a wholly owned indirect subsidiary corporation of the General Electric Company (GE). This amendment, if granted, would allow construction of a repository for mine-impacted soil. This mine waste would be removed from the Northeast Church Rock Mine Site and transported to be placed in the repository, located on and beside the existing Tailings Disposal Area.
A request for a hearing or petition for leave to intervene must be filed by May 13, 2019.
> Download: NRC news release March 18, 2019 (PDF)
> Federal Register Volume 84, Number 49 (Wednesday, March 13, 2019) p. 9148-9150 (download full text )
> Access Docket ID NRC-2019-0026

NRC invites comments on scoping for EIS on proposal to place mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit: The U.S. Nuclear Regulatory Commission (NRC) received a license application by letter dated September 24, 2018, from United Nuclear Corporation (UNC). By this application, UNC is requesting authorization to amend its license (SUA-1475) to excavate approximately 1 million cubic yards (CY) of mine spoil from the Northeast Church Rock Mine Site and dispose of it at the existing mill site in Church Rock, New Mexico (the proposed action). The NRC staff will prepare an EIS to document the potential environmental impacts from the proposed action and reasonable alternatives. As part of the EIS development process, the NRC is seeking comments on the scope of its environmental review.
Comments must be filed by April 19, 2019.
> Download: NRC release Feb. 14, 2019 (PDF)
> Federal Register Volume 84, Number 27 (Friday, February 8, 2019) p. 2935-2937 (download full text )
> Access Docket ID NRC-2019-0026

United Nuclear requests licence amendment to place mine waste repository on top of reclaimed Church Rock uranium mill tailings deposit "[...] Proposed activities at the site include construction of a Repository for mine-impacted soil and debris on the licensed mill tailings disposal area. Mine waste will be removed from the Northeast Church Rock Mine Site (based on defined cleanup standards), transported to and placed in the Repository, located on the existing tailings disposal area. The Repository design includes specific procedures for protection of the existing radon barrier over the mill tailings and an erosion-resistant, evapotranspirative (ET) cover over the mine waste. Stormwater controls will be added in the immediate vicinity of the Repository and to the Pipeline Arroyo. [...]
The Repository layout includes a design capacity of 1,033,500 cubic yards [790,167 m³] of mine waste with the ability to accommodate variations in the mine waste volume between about 955,000 cubic yards and 1,110,000 cubic yards."
> Download: UNC Application for License Amendment, US NRC Source Material License SUA-1475 , Sep. 24, 2018
> Download: Safety Evaluation Report Rev. 1 , Dec. 2022 (PDF)

Pre-Design Studies released for proposed disposal of contaminated soil from the North East Church Rock Mine site on top of the existing Church Rock uranium mill tailings disposal cell:
> Access related documents (Oct. 31, 2014)

Pre-Design Studies Work Plans released for proposed disposal of contaminated soil from the North East Church Rock Mine site on top of the existing Church Rock uranium mill tailings disposal cell:
Northeast Church Rock Mine Site Removal Action, Pre-Design Studies Work Plan, Northeast Church Rock Mine Site, August 16, 2013:
> Download: Part 1 · Part 2 · Part 3 · Part 4 · Part 5 · Part 6

Northeast Church Rock Mine Site Removal Action, Pre-Design Studies Work Plan, Church Rock Mill Site, August 16, 2013:
> Download: Part 1 · Part 2 · Part 3

EPA issues Record of Decision for disposal of contaminated soil from the North East Church Rock Mine site on top of the existing Church Rock uranium mill tailings disposal cell:
> Download: Record of Decision, United Nuclear Corporation Site, McKinley County, New Mexico, Surface Soil Operable Unit , U.S. Environmental Protection Agency, Region 6, March 29, 2013 (17.9MB PDF)

EPA plans to place approximately 1.4 million short tons of contaminated soil from the North East Church Rock Mine site on top of the existing Church Rock uranium mill tailings disposal cell:
> View here

Navajo Nation President declares anniversary of Church Rock uranium tailings spill as "Uranium Legacy Remembrance and Action Day"

Navajo Nation President Ben Shelly has declared Saturday (July 16) as "Uranium Legacy Remembrance and Action Day." The proclamation was issued to commemorate the 32nd anniversary of a uranium tailings spill near Church Rock, N.M., as well as six decades of impacts from uranium mining on the reservation. Elected officials and other community leaders planned to gather in the Church Rock area Saturday morning for a prayer and a march to the site of the July 16, 1979 spill.
That day, millions of gallons of acidic water poured into the north fork of the Rio Puerco after an earthen uranium tailings dam failed. Within days, contaminated tailings liquid was found 50 miles downstream in Arizona. (The Republic July 16, 2011)

Revised Site-Wide Supplemental Feasibility Study released for Church Rock mill and tailings site

> Download: Revised Site-Wide Supplemental Feasibility Study (SWSFS) for the Church Rock mill and tailings site, April 2011: Part 1

· Part 2 (Tables)

· Part 3 (Fig. 1 - 12)

· Part 4 (Fig. 13 - Appendix G)

United Nuclear chasing three cows, this time...

During an environmental inspection performed on Oct. 27, 2009, United Nuclear's maintenance worker had to chase 3 cows out of the fenceline area of its reclaimed Church Rock tailings; the damage of the fenceline was repaired.
(Semi-Annual Effluent and Environmental Monitoring Report, Second Half of 2009 (July thru December), Feb. 24, 2010)

Failed groundwater cleanup at Church Rock is nothing but administrative problem, UNC says

In the Executive Summary (dated Jan. 28, 2010) of the 2009 Groundwater Corrective Action Annual Review Report for UNC's Church Rock uranium mill tailings site, UNC contractor Chester Engineers maintains that

"UNC believes that the main requirements for achieving closure of corrective action are largely administrative in nature for the Southwest Alluvium and Zone 1."

According to UNC, compliance can easily be achieved, if EPA and NRC issue the requested waivers and alternate concentration limits.

Navajo president reaffirms tribal ban on uranium mining to mark 30th anniversary of Church Rock uranium mill tailings spill

The leader of the Navajo Nation marked the 30th anniversary of a massive uranium tailings spill by reaffirming the tribe's ban on future uranium mining. Speaking in Navajo and English, President Joe Shirley Jr. addressed about 100 people who made a seven-mile walk Thursday (July 16) to the site of the July 16, 1979 spill and to the land of Navajo ranchers who live near another contaminated site.
What Shirley called "the largest peacetime accidental release of radioactive contaminated materials in the history of the United States" occurred when 94 million gallons of acidic water poured into the north fork of the Rio Puerco after an earthen uranium tailings dam failed. Within days, contaminated tailings liquid was found 50 miles downstream in Arizona. (Los Angeles Times July 16, 2009)

Failed groundwater cleanup at Church Rock: United Nuclear Corp. points at EPA

In a letter dated May 20, 2009, UNC's parent company General Electric presents its view of the "Technical Impediments to Site Closure" of its Church Rock Mill Site to the NRC: in summary, the reason for the site groundwater not complying with the remediation goals is not UNC's inability/incapability to reach them, but EPA's unwillingness to relax them.
Thank you, UNC, for this "strong statement."

United Nuclear chasing horse, again...

During an environmental inspection performed on Oct. 31, 2008, United Nuclear's inspector had to chase a horse out of the fenceline area of its reclaimed Church Rock tailings; the damage of the fenceline was repaired.
(Semi-Annual Effluent and Environmental Monitoring Report July thru December, 2008; Feb. 25, 2009)

United Nuclear requests further relaxed groundwater standards at Church Rock uranium mill and tailings site

On Dec. 15, 2008, United Nuclear Corporation (UNC) requested "an amendment to Source Materials License SUA-1475, Condition 30. B., to apply Alternate Concentration Limits (ACLs) to two point-of-compliance (POC) wells within the Zone 1 hydrostratigraphic unit."

On Apr. 27, 2009, NRC informed UNC of its intent to hold the License Amendment Request in abeyance until after the completion and submittal of the comprehensive Site Wide Supplemental Feasibility Study (SWSFS) requested by the U.S. Environmental Protection Agency (EPA). The EPA has directed UNC, to develop the SWSFS, in light of the existing remedy's ineffectiveness in improving groundwater quality.

U.S. EPA opposes United Nuclear's request to halt groundwater treatment at Church Rock uranium mill tailings site

"The U.S. Environmental Protection Agency (EPA) has concerns regarding the United Nuclear Corporation's (UNC's) August 15, 2007 License Amendment request under Source Materials License SUA-1475 (License) for the permanent discontinuance of corrective action in the Southwest Alluvium. As you know, EPA has directed UNC to perform a site-wide supplemental feasibility study (SFS) at the UNC Church Rock Superfund site (Site) to evaluate other remedial alternatives for ground water and support future EPA decision-making. [...]
Currently, the cleanup standards for TDS and sulfate are being exceeded for the Southwest Alluvium, as well as Zone 1 and Zone 3 of the Upper Gallup Sandstone Formation. The SFS is intended to develop, screen, and analyze other alternatives that shall attain (or support a waiver of) those standards. [...]
Additionally, as part of the ongoing SFS, UNC has been directed to review the cleanup criteria established by EPA in the 1988 Record of Decision and assess the appropriateness of changing some of those criteria to reflect newly promulgated federal and state standards and health-based criteria for ensuring the continued protectiveness of the remedy. The assessment will include the new federal Maximum Concentration Limit (MCL) for uranium of 30 micrograms per liter (µg/L), promulgated under the Safe Drinking Water Act. The current uranium standard established by the NRC in the License is 300 µg/L. The uranium concentrations measured in the seepage-impacted areas of the Southwest Alluvium are currently at or below the current NRC standard of 300 µg/L. However, they would exceed the 30 µg/L MCL if selected by EPA as an ARAR for the CERCLA remedy. [...]"
(U.S. EPA letter to NRC, February 12, 2008, emphasis added)

Flood event downs fence at Church Rock uranium mill tailings site

A major flood event had occured on Aug. 6, 2007, which damaged or downed the perimeter fenceline on UNC's Sec. 36 and Sec. 2 property areas on 200 and 700 feet, respectively.
(Environmental Inspection Aug. 31, 2007; in: United Nuclear Corporation: Second Half - July thru December, 2007, Semi - Annual Effluent and Environmental Monitoring Report, Feb. 26, 2008)

Flood event downs fence at Church Rock uranium mill tailings site; UNC chasing cattle...

Major flood events had occured on July 10 and 11, 2006, which damaged or downed the perimeter fencing on UNC's Sec. 36 and Sec. 2 property areas on 100 and 420 feet, respectively.
Daily surveillance was done to keep out livestock and 8 heads of cattle was chased on July 21, 2006.
(Environmental Inspection July 31, 2006; in: United Nuclear Corporation: Semi-Annual Effluent and Environmental Monitoring Report from July to December, 2006, Feb. 26, 2007)

Pilot study to improve groundwater restoration at Church Rock uranium mill tailings site by injection of alkalinity unsuccessful

The pilot study was conducted between October 2006 and February 2007 to evaluate the use of alkalinity injection wells to enhance the ongoing remediation of Zone 3.
The injection and extraction rates observed during the pilot study were not the expected rates, and the total amount of cumulative extraction was considerably lower than calculated. As a result, the estimated travel time between the injection wells and extraction wells became prohibitive with respect to pore volume extraction rates, and the pilot test was terminated.
The lower than expected K values, extremely low injection well efficiency, and negligible yield from 4 of the 5 extraction wells may be attributed to alteration of the Zone 3 aquifer minerals by the acidic leachate that comprises the groundwater plume.
Based on information presented above, it would take 10 times longer to accomplish remedy goals than was hypothesized. Using what might have been envisioned as an approximate 5 year remedy enhancement could actually take 50 years or more.
(United Nuclear Corporation, In-Situ Alkalinity Stabilization Pilot Study Report, UNC Church Rock Site, Gallup, New Mexico, June 2007)

U.S. EPA releases Update on Ground Water Cleanup at Church Rock uranium mill tailings site

> Download Update on Ground Water Cleanup, United Nuclear Corporation Church Rock Superfund Site, Church Rock, McKinley County, New Mexico, May 2006 (1.1M PDF - U.S. EPA Region 6)

United Nuclear granted relaxed radium groundwater standard at Church Rock uranium mill tailings site

On Sep. 30, 2005, United Nuclear filed a License Amendment Request for Changing the Ground Water Protection Standard for Radium at its Church Rock uranium mill tailings site: "The proposed revision accounts for the fact that the current site standard lies well within the background concentration ranges for radium-226 and 228 in the Southwest Alluvium and Zone 1. The proposed revision incorporates a statistical testing procedure to objectively determine if the combined radium concentration is attributable to the occurrence and migration of seepageimpacted water or if it is within the normal and expected background distribution."
On Feb. 22, 2006, United Nuclear submitted a revised license amendment request and technical analysis report.
On July 26, 2006, NRC staff issued a related Environmental Assessment and Finding of No Significant Impact.
> Federal Register: August 2, 2006 (Volume 71, Number 148) p. 43822-43823 (download full text

)
On Aug. 9, 2006, the NRC issued the requested license amendment.

United Nuclear intends to inject alkalinity into aquifer to improve groundwater restoration at Church Rock uranium mill tailings site

Given that the currently pursued groundwater restoration scheme of removal and evaporation apparently cannot meet the remedial objectives, United Nuclear now plans to inject alkalinity into the aquifer to enhance remediation of the Zone 3 groundwater at the Church Rock uranium mill tailings site.

"This Pilot Study will evaluate the use of alkalinity injection wells to enhance the ongoing remediation of Zone 3 in addition to using extraction wells alone at the United Nuclear Corporation (UNC) Church Rock Site (site) located in Gallup, New Mexico. This Pilot Study has been prepared on behalf of UNC by Blasland, Bouck & Lee, Inc. (BBL).
The planned studies will test the injection of alkalinity-rich groundwater from an unimpacted part of the Southwest Alluvium into the Zone 3 aquifer. The injected water (hereinafter referred to as "fixiviant") will then flow through the Zone 3 formation to recovery wells where the fixiviant will be pumped to the surface for treatment and disposal. Theoretically, injection of the alluvium groundwater (i.e., fixiviant) into Zone 3 would effect the following changes:
1. The pH of the Zone 3 groundwater would increase;
2. Groundwater migration of target Zone 3 groundwater constituents of concern (such as cadmium, cobalt, nickel, radium-226/228, Th-230 and gross-alpha) would be reduced or eliminated via changes in aqueous/solid partitioning and precipitation reactions as a result of the increased pH conditions; and
3. Groundwater and fixiviant withdrawn by the extraction wells would recover uranium (and other chemical species) in solution, which could then be handled via the existing evaporation system.
The specific pilot study described herein will be conducted to assess the effectiveness of this proposed remedial approach. In addition, information obtained from the pilot study will be used to prepare a full-scale design, if groundwater remediation via injection is deemed a viable and effective remedy for the Zone 3 aquifer."
(UNC Church Rock Site In-Situ Alkalinity Stabilization Pilot Study, October 2005)

United Nuclear chasing horse, this time...

During an environmental inspection performed on Jun. 28, 2005, United Nuclear's inspector had to chase a horse out of the fenceline area of its reclaimed Church Rock tailings, though no damage of the fenceline could be observed.
(Semi-Annual Effluent and Environmental Monitoring Report from January to June 30, 2005)

United Nuclear yet again chasing cattle...

United Nuclear's fence problems at its reclaimed Church Rock tailings area are continuing. During environmental inspections performed in the second half of 2004, United Nuclear's inspector once again had to chase cattle out of the perimeter fence line:
Sep. 24, 2004: Chased two bulls out of the fenced tailings area
Oct. 26, 2004: Chased three bulls out of the east perimeter area
(Semi-Annual Effluent and Environmental Monitoring Report from July to December, 2004).

New Church Rock tailings fence line seriously damaged during floodings

A new 48'' field fence that had been installed in place of the previous barbed wire fence line to prevent further livestock entry, was damaged and downed a few weeks after installation during a major flood event on Sep. 9, 2003. (Semi-Annual Effluent and Environmental Monitoring Report from July to December 2003; Feb. 11, 2004)

United Nuclear again chasing cattle...

United Nuclear still has problems with the fences at its reclaimed Church Rock tailings area. During environmental inspections performed in the first half of 2003, United Nuclear's inspector again had to chase cattle out of the perimeter fence line: he chased 6 cows and 9 burros on Jan. 16, and one cow and one calf on June 30, 2003.
(Semi-Annual Effluent and Environmental Monitoring Report from January to June 2003; Aug. 15, 2003)

United Nuclear chasing cattle...

During environmental inspections performed in 2002, United Nuclear's inspector had to chase cattle out of the perimeter fence line of the reclaimed Church Rock tailings area: he chased 6 herds of cattle on July 31 and "1 bull" (!) on August 27, 2002.
(Semi-Annual Effluent and Environmental Monitoring Report from July to December 2002; Feb. 19, 2003)

United Nuclear wants to halt groundwater treatment at Church Rock site

On November 4, 2002, United Nuclear's contractor Earth Tech, Inc., submitted a technical impracticability (TI) evaluation [!!] to support a request for a TI waiver for sulfate and total dissolved solids (TDS).

"Based on the results of the test, United Nuclear Corporation (United Nuclear) believes that sufficient data have been collected to demonstrate that natural attenuation mechanisms are more beneficial than the current corrective action at controlling the quality of groundwater for all key constituents of concern. Therefore, United Nuclear requests a decision from the agencies that the Southwest Alluvium system can be shut down permanently."

> View extension of groundwater plumes and proposed areas for institutional controls

(Fig. 7-1 from Second Five-Year Review Report for the United Nuclear Corporation Ground Water Operable Unit Church Rock, McKinley County, New Mexico, September 2003, US EPA Region 6)

On Feb. 13, 2004, EPA submitted its comments on UNC's Final Report and Technical Impracticability Evaluation, finding that the data provided by UNC is insufficient to support the conclusion that natural attenuation were more beneficial than the current groundwater corrective action.

Church Rock tailings cover deteriorates prematurely

Following a site visit on June 13, 2002, the U.S. DOE, in a letter dated July 3, 2002, notified the U.S. NRC of a number of concerns regarding early deterioration observed at the site:

A large amount of sediment had been deposited in the on-pile channels and in the other diversion channels.
The slopes of the diversion berm appeared to be in a deteriorated condition caused by erosion and sloughing.
Some rocks in the jetty along Pipeline Arroyo had been displaced.
A gully had occurred on the side slope of the tailings pile at the southern end.
Some differential settlement was noted in several areas on the top cover.
Biointrusion of the cell cover was visible.

Based on these observations, DOE feels that "significant annual maintenance at the Church Rock site will be required. [...] annual maintenance costs will be in the $10,000 to 20,000 per year range. These costs will be above and beyond what is normally required to maintain long-term care of a disposal site."

Environmental Protection Agency Meeting with United Nuclear Corporation, April 22, 1998

"On April 22, 1998, a representative from the Division of Waste Management participated in an Environmental Protection Agency (EPA) Meeting with United Nuclear Corporation (UNC), New Mexico Environmental Department, and the Navajo Nation. The purpose of the Meeting was to discuss the EPA's draft five-year review of corrective action at UNC's Churchrock uranium mill site. UNC's Churchrock site is a Nuclear Regulatory Commission-licensed superfund site currently undergoing corrective action for a groundwater plume that developed from leachate generated by a uranium tailings impoundment. UNC provided its comments on the draft as well as its plans for site closure. The regulatory agencies provided comments on the tentative closure plans, and discussed options available to UNC for site closure including Alternate Concentration Limits and Technical Infeasiblity waivers." (NRC Weekly Information Report for the Week Ending May 1, 1998)

NRC FINES UNITED NUCLEAR $100,000 FOR FAILING TO SET ASIDE FUNDS FOR DECOMMISSIONING CHURCH ROCK URANIUM MILL

(Feb 14, 1997) "The Nuclear Regulatory Commission staff has proposed a fine of $100,000 against United Nuclear Corporation, of Gallup, New Mexico, for failing to properly comply with a January 1992 order to set aside $16.4 million needed to decommission and decontaminate the Church Rock uranium mill site near Gallup." [NRC Region IV Press Relase 97/10]
> View Notice of Violation EA 93-170

> View background information on Uranium Mill Tailings Management - USA

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