ML24334A062

Environmental Assessment for Revised Decommissioning Plan Proposal to Remediate Groundwater at the Cimarron Site in Logan County, Oklahoma

ML24334A062
Person / Time
Site:	07000925
Issue date:	11/29/2024
From:	NRC/NMSS/DREFS/EPMB2
To:
References
Download: ML24334A062 (1)

Text

Environmental Center of Expertise Division of Rulemaking, Environmental, and Financial Support Office of Nuclear Material Safety and Safeguards ML24334A062 Environmental Assessment for Revised Decommissioning Plan Proposal to Remediate Groundwater at the Cimarron Site in Logan County, Oklahoma Cimarron Environmental Response Trust, Licensee Environmental Properties Management, Trustee Docket No. 07000925 License No. SNM-928 November 2024

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i TABLE OF CONTENTS ABBREVIATIONS AND ACRONYMS........................................................................................ vi

1.0 INTRODUCTION

............................................................................................................. 1 1.1 Proposed Action.......................................................................................................... 2 1.2 Purpose of and Need for the Proposed Action............................................................. 2 1.3 Alternative to the Proposed Action............................................................................... 2 1.4 Scope of the Environmental Analysis........................................................................... 2 1.5 Site History.................................................................................................................. 3 1.5.1 Surface Decommissioning Activities..................................................................... 3 1.5.2 Groundwater Considerations in Decommissioning................................................ 3 2.0 PROPOSED ACTION AND ALTERNATIVES.................................................................. 5 2.1 Proposed Action.......................................................................................................... 5 2.1.1 Licensed Areas and Remediation Areas............................................................... 5 2.1.2 Construction and Operation of Groundwater Treatment Facilities......................... 7 2.1.2.1 Construction............................................................................................ 7 2.1.2.2 Groundwater Treatment Operations........................................................ 8 2.1.3 Post-Remediation Monitoring and Dismantlement............................................10 2.1.3.1 Post-Remediation Monitoring.................................................................10 2.1.3.2 Dismantling and Decommissioning the Groundwater Treatment Facility.11 2.1.4 Water Use............................................................................................................12 2.1.5 Air Emissions.......................................................................................................12 2.1.6 Chemical Use......................................................................................................14 2.1.7 Effluents and Wastes...........................................................................................15 2.1.7.1 Radioactive Wastes................................................................................15 2.1.7.2 Nonradioactive Wastes...........................................................................17 2.1.8 Final Status Survey, License Termination, and Subsequent Activities..................17 2.1.9 Permits and Approvals.........................................................................................18 2.2 Alternatives to the Proposed Action............................................................................19 3.0 AFFECTED ENVIRONMENT AND POTENTIAL IMPACTS............................................20 3.1 Land Use....................................................................................................................20 3.1.1 Site Description....................................................................................................20 3.1.2 Historic Site Land Use and Releases from the License........................................21 3.1.3 Surrounding Land Use.........................................................................................23

ii 3.1.4 Potential Land Use Impacts.................................................................................23 3.2 Geology and Soils.......................................................................................................24 3.2.1 Regional Geology................................................................................................24 3.2.2 Site-specific Geology and Soils............................................................................25 3.2.3 Seismic History....................................................................................................29 3.2.4 Potential Geology and Soils Impacts....................................................................29 3.3 Water Resources........................................................................................................30 3.3.1. Surface Water.........................................................................................................30 3.3.1.1.

Affected Environment.............................................................................30 3.3.1.2.

Potential Surface Water Impacts............................................................32 3.3.2. Groundwater...........................................................................................................34 3.3.2.1.

Affected Environment.............................................................................34 3.3.2.2 Contaminant Concentrations..................................................................35 3.3.2.3 Groundwater Use...................................................................................38 3.3.2.4.

Potential Groundwater Impacts..............................................................39 3.4 Climate, Weather, and Air Quality...............................................................................41 3.4.1 Climate and Weather...........................................................................................41 3.4.2 Air Quality............................................................................................................42 3.4.3 Greenhouse Gases and Climate Change.............................................................42 3.4.4 Potential Impacts on Air Quality and from Greenhouse Gas Emissions...............43 3.4.4.1 Potential Impacts on Air Quality..............................................................43 3.4.4.2 Potential Impacts from Greenhouse Gas Emissions...............................44 3.5 Ecological Resources.................................................................................................44 3.5.1 Terrestrial Resources...........................................................................................44 3.5.1.1 Affected Environment.............................................................................44 3.5.1.2 Potential Impacts on Terrestrial Resources............................................47 3.5.2 Aquatic Resources...............................................................................................50 3.5.2.1 Affected Environment.............................................................................50 3.5.2.2 Potential Impacts on Aquatic Resources................................................51 3.6 Public and Occupational Health..................................................................................53 3.6.1 Affected Environment...........................................................................................53 3.6.2 Potential Impacts................................................................................................53 3.6.2.1 Nonradiological Impacts.........................................................................53 3.6.2.2 Radiological Impacts..............................................................................54

iii 3.7 Socioeconomics..........................................................................................................56 3.7.1 Demographic and Socioeconomic Conditions...........................................................56 3.7.2 Potential Socioeconomic Impacts..............................................................................57 3.7.3 Environmental Justice...............................................................................................57 3.8 Historic and Cultural Resources..................................................................................58 3.8.1 Affected Environment...............................................................................................58 3.8.2 Potential Impacts on Historic and Cultural Resources.............................................60 3.9 Visual and Scenic Resources.....................................................................................61 3.9.1 Affected Visual and Scenic Environment.................................................................61 3.9.2 Potential Impacts on Visual and Scenic Resources.................................................61 3.10 Noise..........................................................................................................................62 3.10.1 Noise Levels in the Affected Environment.............................................................62 3.10.2 Potential Impacts from Noise.................................................................................62 3.11 Waste Management....................................................................................................63 3.11.1 Waste Management Facilities and Capacity..........................................................63 3.11.2 Potential Waste Management Impacts.................................................................63 3.12 Transportation and Traffic........................................................................................64 3.12.1 Affected Transportation Environment....................................................................64 3.12.2 Potential Transportation Impacts..........................................................................63 3.13 Cumulative Impacts....................................................................................................67 4.0 CONSULTATION AND COORDINATION......................................................................70 4.1 State Review...............................................................................................................70 4.2 National Historic Preservation Act Section 106 Consultation.......................................70 4.3 Endangered Species Act Section 7 Consultation........................................................71

5.0 CONCLUSION

AND FINDING OF NO SIGNIFICANT IMPACT......................................73 6.0 LIST OF PREPARERS...................................................................................................74

7.0 REFERENCES

...............................................................................................................75 APPENDIX A Cimarron Site Endangered Species Act Determinations

iv LIST OF FIGURES Figure 1-1 Land Use during Operating Years........................................................................ 4 Figure 1-2 Locations of Buildings, Impoundments, and Burial Areas..................................... 4 Figure 2-1 Currently Licensed Subareas............................................................................... 6 Figure 2-2 Proposed Treatment System Layout.................................................................... 7 Figure 3-1 View of a Portion of Cimarron Site from within BA1, in Cimarron River Floodplain.......................................................................................................... 20 Figure 3-2 View of a Portion of Cimarron Site from within the Western Area....................... 21 Figure 3-3 Cimarron Site Subareas A-O............................................................................. 22 Figure 3-4 Generalized Regional Geologic and Hydrogeologic Cross-Section of the Site.................................................................................................................... 26 Figure 3-5 Lithology at the Site........................................................................................... 28 Figure 3-6 Surface Water Features On and Near the Site................................................... 31 Figure 3-7 Floodplain Map.................................................................................................. 32 Figure 3-8 Uranium in the Western Area............................................................................. 35 Figure 3-9 Uranium in Burial Area 1.................................................................................... 36 Figure 3-10 Sitewide Licensed Area, Including Monitoring Wells, Plumes, and Proposed Treatment Systems........................................................................................... 37 Figure 3-11 Water and Oil Wells within a 2-Mile Radius of the Site....................................... 39 Figure 3-12 Areas of Potential Ground Disturbance and Wetland Areas............................... 46 Figure 3-13 Historically Disturbed Areas of the Site, including Grazing and Harvest Areas................................................................................................................. 46 Figure 3-14 Area of Potential Effect, Survey Results, and NRHP-Eligible Resources........... 60 Figure 3-15 Transportation Routes Near the Cimarron Site.................................................. 65 Figure 3-16 Roads on the Cimarron Site............................................................................... 66 Figure 3-17 Aerial View of Commercial and Industrial Facilities Surrounding the Cimarron Site..................................................................................................... 68

v LIST OF TABLES Table 2-1 Emissions During Construction Phase............................................................... 13 Table 2-2 Annual Emissions from Operations.................................................................... 14 Table 3-1 Federal and State Listed Terrestrial Species...................................................... 49 Table 3-2 Federal and State Listed Aquatic Species and Federal Listed Critical Habitat............................................................................................................... 52 Table 3-3 Race, Ethnicity, Income, and Poverty in Logan County and the State of Oklahoma.......................................................................................................... 56

vi ABBREVIATIONS AND ACRONYMS ac acre(s)

BA1 Burial Area 1 BMP best management practices Bq/L becquerel(s) per liter CERT Cimarron Environmental Response Trust CFR Code of Federal Regulations CO2e carbon dioxide equivalent emissions dBA decibel(s)

DEQ Department of Environmental Quality DP decommissioning plan EA environmental assessment ESA Endangered Species Act EPA U.S. Environmental Protection Agency FR Federal Register g

gram(s) gal/min gallons per minute GCRP U.S. Global Change Research Program GHG greenhouse gas ha hectare(s) kg kilogram(s)

L/min liter(s) per minute lb pound(s)

LLRW low-level radioactive wastes MCL maximum contaminant level NAAQS National Ambient Air Quality Standards NRC U.S. Nuclear Regulatory Commission NRHP National Register of Historic Places NSPS New Source Performance Standards OAS Oklahoma Archeological Survey OPDES Oklahoma Pollutant Discharge Elimination System oz ounce(s) pCi/L picocurie(s) per liter PM particulate matter

vii RPP radiation protection plan SHPO State Historic Preservation Office SWPPP stormwater pollution prevention plan Tc-99 technetium-99 WA Western Area WATF Western Area treatment facility WCS Waste Control Specialists

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1.0 INTRODUCTION

On October 7, 2022, Environmental Properties Management, LLC. (EPM) submitted a request to the U.S. Nuclear Regulatory Commission (NRC) for an amendment to special nuclear materials license SNM-928 that would approve EPMs decommissioning plan (DP), revision 3, to treat groundwater contamination at the site. Revision 3 of the DP details EPMs plans to install, operate, and dismantle a groundwater treatment system at the site of the former Cimarron Fuel Fabrication Facility (Cimarron site) in Logan County, Oklahoma (EPM 2022a).

Kerr-McGee Corporation operated a nuclear fuel manufacturing facility on the site from 1966 through 1975. The site has been undergoing decommissioning since 1976, and the only remaining decommissioning action is to address groundwater.

The DP is a revision to a previously approved, 1995 DP that addressed the decommissioning of site structures and soils and relied on monitored natural attenuation to address groundwater contamination. Because groundwater in some portions of the Cimarron site still exceeds NRC release criteria, EPM is proposing in the revised DP to actively remediate groundwater to meet NRC requirements. This DP for groundwater treatment is the third revision but is referred to in this EA simply as the DP.

Decommissioning of this site is being managed by EPM, which is the trustee for the Cimarron Environmental Response Trust (CERT or Trust). The Trust was established in 2011 as part of a bankruptcy settlement agreement with Tronox, Inc. which formerly owned the Cimarron site (Trust Agreement 2011). Although CERT is the licensee on NRC-issued license SNM-928, because EPM will be carrying out the decommissioning activities, this environmental assessment (EA) refers to EPM instead of CERT.

On March 30, 2023, the NRC staff accepted EPMs application for detailed technical review (NRC 2023a) of the amendment to approve the DP. The NRC issued a notice in the Federal Register (FR) on May 25, 2023, providing an opportunity to request a hearing and petition for leave to intervene (88 FR 33932) on the amendment to approve the DP. The NRC received no requests for a hearing or petition for leave to intervene following the notice.

In accordance with title 10 of the Code of Federal Regulations (10 CFR) Part 51, Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions, which implements the National Environmental Policy Act of 1969, as amended (NEPA), EPM submitted an environmental report (ER) in its license amendment application (EPM 2022a). The NRC staff sent EPM a request for additional environmental information on September 6, 2023 (NRC 2023b), and EPM provided responses on November 3, 2023 (EPM 2023a). The NRC staffs environmental review for the proposed approval of the DP is documented in this EA.

The NRC is also conducting a safety evaluation that will be documented separately in a safety evaluation report. The NRC staff sent requests for additional information to support the safety review on October 2 and November 1, 2023 (NRC 2023c, 2023d), and EPM provided responses on November 15 and December 8, 2023 (EPM 2023b, 2023c), respectively. The NRC staffs decision about whether to approve the DP as proposed will be based on the staffs safety and environmental reviews of the DP and EPMs responses to requests for additional information.

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1.1 Proposed Action The proposed federal action is the NRCs approval of EPMs plan for groundwater cleanup activities as described in the DP and in EPMs responses to NRC requests for additional information. EPM proposes to complete decommissioning of the site by reducing the concentration of uranium in groundwater to meet unrestricted release criteria as specified in condition 27 of the license (NRC 2011a). As described in more detail in section 2 of this EA, EPM would install a treatment system to extract and treat groundwater. Treated groundwater would be reinjected to the ground or discharged to the Cimarron River. After groundwater treatment is complete, EPM would conduct monitoring, dismantle the treatment system, and perform a final status survey before requesting NRC license termination.

1.2 Purpose of and Need for the Proposed Action The purpose of the NRCs proposed approval of the revised DP is to allow EPM to conduct groundwater cleanup activities to ensure that the site will comply with NRC decommissioning criteria and standards in 10 CFR Part 20 for protection of the public and the environment.

Groundwater remediation is needed so that the NRC can ultimately release the site for unrestricted use and terminate license SNM-928.

1.3 Alternative to the Proposed Action As an alternative to the proposed approval of the DP, the NRC considered the no-action alternative. Under the no-action alternative, the NRC would not approve the license amendment request if the DP does not meet NRC requirements. If the NRC does not approve the DP, EPM would need to submit a new or revised plan for groundwater remediation. In the meantime, EPM would continue to maintain the site under NRC license. Section 2.2 describes the no action alternative in further detail.

1.4 Scope of the Environmental Analysis To fulfill its obligations under NEPA, the NRC evaluates the radiological and nonradiological environmental impacts associated with approval of the DP. These evaluations involve an assessment of the impacts of the groundwater remediation activities documented in the DP. The NRC staff performed this assessment in accordance with the requirements of 10 CFR Part 51 and staff guidance in NUREG-1748, Environmental Review Guidance for Licensing Actions Associated with NMSS Programs (NRC 2003). The staff reviewed and considered the following documents in the development of this EA: EPMs application (EPM 2022a), EPMs responses to NRC requests for additional information (EPM 2023a, 2023b, 2023c), supplemental information provided by EPM (EPM 2024a, 2024b, 2024c) and previous NRC environmental documents (NRC 1994a, 1999).

This EA assesses the potential impacts of constructing, operating, and decommissioning a groundwater treatment system necessary to meet NRC requirements for unrestricted release of the site from license SNM-928, specifically as it applies to the remaining radiological contamination in the groundwater. Section 2.1.8 of this EA describes final surveys and other actions EPM would take to obtain license termination, as well as further coordination with the State of Oklahoma to address any remaining state requirements.

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1.5 Site History In the 1960s and early 1970s, Kerr-McGee Nuclear Corporation purchased nearly 800 acres (ac) (324 hectares [ha]) of property located at the intersection of Highways 74 and 33, approximately 7 miles (mi) (11 kilometers [km]) south of Crescent, OK, to be used for the construction and operation of manufacturing facilities to produce mixed oxide fuel and uranium fuel. Prior to the purchase, the property was being used for grazing and farming. The fuel manufacturing facilities constructed at the site operated from 1965 until 1975. Between 1970 and 1993, Kerr-McGee held two licenses, one for the production of mixed oxide fuel and one for uranium fuel. Mixed oxide fuel production was halted in 1975, decommissioning activities for that operation were completed in 1993, and the license was terminated. Uranium fuel production was discontinued in 1976. Section 1.2 of the DP, License History, provides more detail about the uranium fuel and mixed oxide fuel manufacturing operations (EPM 2022a).

1.5.1 Surface Decommissioning Activities Since the start of operations, several buildings, collection ponds, sanitary lagoons, storage areas, and burial areas have existed on the site (see figures 1-1 and 1-2). Decommissioning efforts began in 1976 and continued for several decades. Section 1.3 of the DP, Previous Decommissioning Activities, describes in detail the decommissioning of buildings, impoundments, pipelines, and soils through 2011. Section 3.2.2 of this EA describes the past cleanup of site soils.

During these previous decommissioning activities, the site was divided into 15 areas for the purpose of performing final status surveys for buildings, potentially surface contaminated material, and surface and subsurface soils. Beginning in 1996, the NRC determined that certain areas could be released from the NRC license. Section 3.1.2 of this EA provides more detail about these subareas and their licensing status. By the early 2000s, the NRC had released much of the site for unrestricted use. Between 2015 and 2017, the licensee sold several parcels of this released land and now owns approximately 202 ha (500 ac) (EPM 2022a). Of that, 21 ha (52 ac) remain under the license. The radiological status of groundwater was not considered in either the final status surveys or the release of subareas from the license.

1.5.2 Groundwater Considerations in Decommissioning The licensee submitted its first decommissioning plan in 1995, supplementing that plan with additional information over the next several years. One of those submittals was a 1998 groundwater evaluation report, which stated that, based on knowledge of groundwater impact at the time, the licensee believed that active groundwater remediation may not be required to achieve license termination for unrestricted use. In July 1999, the NRC issued license amendment 15 (NRC 1999), approving that decommissioning plan and establishing unrestricted release criteria for groundwater, soil, surface contamination, and exposure. This amendment allowed for monitoring of groundwater with no active remediation (monitored natural attenuation). In 2005, however, after conducting an assessment that natural attenuation had not been effective for groundwater remediation, the licensee applied for approval of an active groundwater remediation system to reduce uranium concentrations in groundwater to unrestricted release criteria (NRC 2005).

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Figure 1-1. Land Use during Operating Years Source: modified from EPM 2022e Figure 1-2. Locations of Buildings, Impoundments, and Burial Areas Source: modified from EPM 2022e

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2.0 PROPOSED ACTION AND ALTERNATIVES This section describes the groundwater remediation activities that would be conducted in accordance with the DP (EPM 2022a) and license conditions. This section also describes the alternative of not approving the DP, referred to as the no-action alternative (section 2.2).

2.1 Proposed Action The NRCs proposed action is to approve EPMs proposal to extract and treat contaminated groundwater before reinjecting it into the ground (when needed to facilitate flushing of remaining contaminated groundwater) or discharging it to the Cimarron River. The proposed groundwater treatment operation would reduce concentrations of uranium in groundwater to 6.7 becquerels per liter (Bq/L) (180 picocuries per liter [pCi/L]), as required in condition 27(b) of license SNM-928 (NRC 2011a). The establishment of this criterion assumed the use of groundwater as a drinking water source and for the raising of produce (plants and livestock) by a resident farmer (EPM 2022a). This NRC limit for uranium in groundwater at the Cimarron site is referred to in this EA as the NRC criterion or derived concentration guideline level (DCGL).

Based on the schedule EPM developed and provided in the DP, the entire groundwater treatment process would take about 16 years. Remediation would be completed in about 12.5 years, followed by about 3 years of groundwater monitoring, dismantling activities, and the development and implementation of the final status survey. After remediation activities are completed and the survey demonstrates that the site meets the NRC criterion, EPM would apply for termination of the license. Details about the schedule and associated activities are provided in section 9 of the DP (EPM 2022c).

The license amendment approving the DP would also authorize the possession of technetium-99 (Tc-99), which is present in the groundwater. Because treatment of the groundwater would likely result in the concentration of Tc-99 in the treatment media, the addition of Tc-99 to the license would allow the licensee to possess and dispose of contaminated material containing both uranium and Tc-99 as low-level radioactive waste.

2.1.1 Licensed Areas and Remediation Areas As discussed in section 1.5, during previous decommissioning activities, the site was divided into 15 subareas based on surface characteristics (subareas A through O). Twelve of the subareas were determined to be non-impacted (subareas A, B, C, D and E) or were removed from the license after remediation (subareas H, I J, K, L, M and O). Subareas F, G, and N remain on the license, comprising 52 ac (21 ha). Figure 2-1 shows the currently licensed areas.

Survey results have shown that these areas are otherwise releasable, but the NRC determined that these subareas would not be removed from the NRC license until sitewide groundwater remediation is complete.

To facilitate planning for the groundwater treatment project, EPM divided the site into two general areas: Burial Area 1 (BA1) and the Western Area (WA). BA1 includes remediation areas BA1-A, where uranium in groundwater exceeds the NRC criterion in two zones (Sandstone B and the Transition Zone), and BA1-B, where uranium in groundwater exceeds the NRC criterion in alluvial material (EPM 2022a). The WA includes remediation area WAA U>DCGL, where

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uranium in groundwater exceeds the NRC criterion in alluvial material; remediation area WU-BA3, the area surrounding the site of former Burial Area #3 in which uranium in groundwater exceeds the NRC criterion; and remediation area 1206-North, the drainage area in which uranium in groundwater exceeds the NRC criterion.

Section 6.3 of the DP describes the proposed modifications to license condition 9, Authorized Place of Use, that would be needed to accommodate groundwater treatment operations on the site. The NRC staffs safety evaluation would result in adding certain areas to the license where:

the concentration of uranium in groundwater exceeds the NRC criterion; extracted groundwater is stored and/or transferred to the treatment facility for treatment; uranium is accumulated in ion exchange resin in groundwater treatment systems; and spent resin and other low-level radioactive waste is stored.

Figure 2-1 shows currently licensed areas and the general locations in the WA and BA1 where groundwater exceeds the NRC criterion. Figure 2-2 shows the proposed layout of the facility.

Figure 2-1. Currently Licensed Subareas Source: modified from EPM 2022f

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Figure 2-2. Proposed Treatment System Layout (Outfall is dotted line extending north to the riverbank.)

Source: modified from EPM 2022e 2.1.2 Construction and Operation of Groundwater Treatment Facilities 2.1.2.1 Construction The entire groundwater remediation facility, including support systems and structures, would occupy less than 4.9 ha (12 ac) of the ~202-ha (~500-ac) property. To prepare the site for construction, EPM would clear and remove vegetation and topsoil to install infrastructure and roads and other surfacing. EPM staff would also install and follow the best management measures specified in a stormwater pollution prevention plan (SWPPP) (EPM 2022d) to reduce soil erosion and minimize the potential for sediment and other pollutants to migrate from the site to the Cimarron River.

Construction would begin with site grading and concrete pouring for equipment pads and a building foundation. The overall facility would consist of extraction and injection trenches, extraction and injection wells, underground and aboveground piping, a permanent building to house the WA treatment process (WA treatment facility or WATF), a Burial Area 1 remediation facility (Burial Area 1 remediation facility or BARF), and other support facilities and measures to reduce dust, erosion, and stormwater runoff (EPM 2022a). Silt fencing would be employed around the downslope sides of any disturbed areas and maintained until permanent vegetation is established. Utility routing and connections for electricity, water (WATF only), and communication services would be installed before the facility construction is complete. EPM would also construct an outfall structure composed of concrete, riprap, and geotextile that would be set back approximately 73 meters (240 feet) from the river to enable a point source discharge of treated groundwater to the river (see figure 2-2) (EPM 2022a). EPM would conduct all construction activities in accordance with an Oklahoma Pollutant Discharge Elimination

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System (OPDES) construction stormwater permit and the associated SWPPP. After construction of the facility, topsoil would be spread over disturbed soil and vegetation would be established.

As described further in section 2.1.4 of this EA, water would be required for dust suppression throughout the construction phase. As described in sections 2.1.5 and 2.1.7, construction activities would generate municipal and construction wastes, potentially contaminated soils, and dust and combustion engine emissions.

Figure 2-2 shows the layout of the proposed facility. Section 3.3.2.4. of this EA provides more information about the installation and operation of groundwater extraction wells and trenches and groundwater injection wells and trenches. Additional details about the construction of wells, buildings, trenches, piping, and other features are provided in section 8 of the DP (EPM 2022a).

Detailed drawings for groundwater extraction, treated water injection, and treated water discharge are provided in appendix I of the DP (EPM 2022b), and design drawings for groundwater treatment are provided in appendix J of the DP (EPM 2022c).

2.1.2.2 Groundwater Treatment Operations Under the proposed DP, groundwater would be extracted using trenches and wells and treated in the WATF to remove uranium. The treated water either would be injected into the ground via wells or trenches or would be discharged to the Cimarron River via an outfall. This section summarizes these operations, and section 8 of the DP describes them in more detail (EPM 2022a). As described further in section 2.1.4, water would be required for dust suppression throughout the operating phase. As described in sections 2.1.5 and 2.1.7, operation of the treatment system would generate municipal wastes, radiological treatment wastes, and dust and combustion engine emissions.

Extraction Contaminated groundwater would be withdrawn through four groundwater extraction wells in the alluvial material in the WA (EPM 2022a) and three wells in the alluvial material in BA1. These wells would maximize the mass of contaminants removed while minimizing the collection and treatment of minimally contaminated groundwater. EPM would also use three groundwater extraction trenches, two in the BA1 area and one in the 1206-North section of the WA. All trenches would be within the 100-year floodplain (EPM 2022a). The trenches would be constructed and maintained according to the SWPPP and the OPDES construction stormwater permit. Groundwater extracted from the WA would be routed to the WATF for treatment, while groundwater extracted from the BA1 would be routed first to the BARF where it would be transferred to the WATF for treatment.

Treatment Groundwater extracted through wells and trenches would be treated to reduce the concentration of uranium in the extracted water to less than the expected OPDES permit discharge limit, with the goal of reducing uranium concentration in groundwater to levels below the NRC criterion (groundwater concentration requirement) of 180 pCi/L (6.7 Bq/L). The untreated, extracted groundwater is expected to contain Tc-99 at less than a quarter of the EPA maximum contaminant level (MCL) of 4 mrem (0.04 mSv) per year (or 900 pCi/L [33.3 Bq/L]), which is also

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less than the NRCs limit of 3,790 pCi/L. Oklahomas limit for beta emitters, including Tc-99, is 50 pCi/L (1.9 Bq/L) (EPM 2022a; ODEQ 2024a).

Treatment for uranium would consist of removal by ion exchange in the WATF in two treatment trains (a train for WA groundwater and a train for BA1 groundwater). Specifically, each resin vessel would contain approximately 1.08 cubic meters (m3) (38 cubic feet [ft3]) of resin that would exchange chlorine ions for uranyl carbonate, thus removing uranium from the groundwater. The anion exchange resin would also remove some of the Tc-99 present in the WATF influent (EPM 2022a). Treated WA water would be split and routed for groundwater injection in the WA or to a tank for storage before discharge into the Cimarron River. Treated BA1 water would be split and routed either to the storage tank for discharge to the river or back to the BARF for injection in BA1.

Injection and Discharge of Treated Groundwater Treated water would be discharged to injection wells, injection trenches, or the Cimarron River.

Delivery of treated groundwater to each of five injection trenches (four in BA1 and one in the 1206-North area of the WA), as well as the monitoring of trench water levels, would be accomplished using an injection well installed within each injection trench, for a total of five injection wells. A portion of each areas treated water would be injected in upgradient areas to flush contaminants downgradient to the extraction trenches and wells. Treated water would be injected into the areas from which it was extracted (e.g., groundwater extracted from BA1 would be reinjected only in BA1).

If the WA and BA1 groundwater extraction systems operate at the expected capacity, 784 liters per minute (L/min) (207 gallons per minute [gal/min]) of water would be delivered to the WATF.

Approximately 136 L/min (36 gal/min) of treated water would be injected to the ground, so 647 L/min (171 gal/min) of treated water would be discharged to the Cimarron River through the outfall. All discharged water would comply with OPDES discharge permit limits, as discussed below. Groundwater injection would be conducted in accordance with Oklahomas underground injection control (UIC) program (EPM 2022a).

The Oklahoma Department of Environmental Quality (DEQ) has indicated that, based on the expected low concentrations of nitrate, Tc-99, and fluoride in treated water, the OPDES permit for discharges to the river would not specify limits for these constituents (ODEQ 2024b). The OPDES permit would contain a limit for uranium of no lower than the MCL of 30 µg/L and no higher than 50 percent of the NRCs effluent standard (i.e., no higher than 100 µg/L) (ODEQ 2024b). While the permit would require effluent pH to remain between 6.5 and 9.0 standard units, EPM has stated that the pH would be maintained between 6.8 and 7.0 (EPM 2024a).

The concentration of uranium in the groundwater influent to the BA1 treatment system train or the WA treatment system train would decrease over time and may decrease below the OPDES permit uranium discharge limit before the NRC criterion for groundwater is achieved in all wells.

In this case, the influent groundwater would not require treatment prior to discharge. EPM could shut down a treatment system either because the NRC criterion for groundwater remediation has been achieved in all wells or because uranium in the combined treatment system influent is below the permitted discharge limit.

November 2024 10 In-Process Monitoring EPM would conduct monitoring during operations to evaluate and optimize the extraction and treatment practices, determine when treatment can be discontinued, and determine when the remediation program is completed and post-remediation monitoring can begin. In-process monitoring would be conducted for the extraction, water treatment, and injection and discharge.

EPM would also conduct remediation monitoring to evaluate progress in achieving the NRC criterion. These monitoring programs are described briefly below:

Groundwater extraction monitoring: real-time recording, logging, and evaluating pumping rates and pressures, groundwater elevations in extraction trenches and wells, and pump run times. Depth to groundwater in monitoring wells would be measured manually. Data would be evaluated periodically to adjust groundwater extraction rates as needed.

Water treatment monitoring: in-line monitoring and sample collection to monitor treatment effectiveness, determine when resin vessels need to be exchanged, verify compliance with NRC possession limits for uranium, and evaluate compliance with requirements for uranium in spent resin and for discharge and injection limits.

Treated water injection and discharge monitoring: real-time recording, logging, and evaluating injection rates and pressures and groundwater elevations in injection wells.

Groundwater elevations in monitoring wells would be measured manually. Data would be evaluated to adjust treated water injection rates as needed. EPM would also monitor the flow rate of water at the point of discharge from the WATF to the line that carries the water to the river outfall, collect samples of discharged water for analysis, and submit monthly reports to DEQ in accordance with the OPDES permit (to be issued).

Remediation monitoring: uranium concentrations obtained through in-process groundwater monitoring would be evaluated for progress toward meeting the NRC criterion and to determine when remediation within the WA or BA1 area should be discontinued.

In-process monitoring programs are described in more detail in section 8.6 of the DP (EPM 2022a).

2.1.3 Post-Remediation Monitoring and Dismantlement When in-process monitoring indicates remediation activities can cease, EPM would begin post-remediation monitoring. Dismantling of the remediation systems would likely overlap in time with post-remediation monitoring.

2.1.3.1 Post-Remediation Monitoring EPM would conduct post-remediation monitoring of groundwater to demonstrate compliance with the NRC criterion. Monitoring well information would provide uranium isotopic mass concentrations, which EPM would convert to activity concentrations based on the level of U-235 enrichment for each remediation area. The activity concentrations would then be evaluated against the NRC criterion of 180 pCi/L (6.7 Bq/L). Post-remediation monitoring would begin when all in-process groundwater monitor wells yield uranium activity concentrations below 180 pCi/L (6.7 Bq/L) for at least three consecutive monitoring events (EPM 2022a).

November 2024 11 In accordance with license condition 27(b), post-remediation monitoring would continue for at least eight consecutive quarters, and the NRC would not terminate the license until total uranium concentrations in all wells have been below the groundwater release criteria for eight consecutive quarterly samples (the past two years). The post-remediation monitoring wells would be located between extraction wells, where the potential for uranium concentration rebound is greatest. If the monitoring well data indicates that the uranium concentration has rebounded above the NRC criterion, EPM would resume remediation and then restart the eight-quarter post-remediation monitoring period (EPM 2022a).

In 2013, the NRC concluded that EPM would not need to remediate Tc-99 because concentrations in groundwater at the time already complied with the NRCs limit of 3,790 pCi/L (140.2 Bq/L) (NRC 2013). The NRC indicated, however, that EPM must conduct post-remediation monitoring for Tc-99 for four consecutive quarters to confirm that concentrations have remained below applicable limits. Since groundwater from three monitoring wells has contained Tc-99 concentrations exceeding the EPA MCL of 900 pCi/L (33.3 Bq/L), EPM would collect samples from these three wells during the first four quarters of post-remediation monitoring (EPM 2022a).

2.1.3.2 Dismantling and Decommissioning the Groundwater Treatment Facility The Trust Agreement states that the Cimarron Trust must ultimately sell, transfer or otherwise dispose or facilitate the reuse of all or part of the Cimarron Trust Assets As such, EPM states that it would keep certain structures or features on the decommissioned site that are likely to enhance the value and desirability of the property (EPM 2023b).

The dismantling of treatment systems, the resin processing system, portions of the groundwater extraction and injection infrastructure, and monitoring wells would begin after post-remediation monitoring demonstrates that uranium and Tc-99 concentrations in groundwater comply with applicable limits. Section 2.1.7 of this EA describes the wastes that would be generated during the proposed action.

Influent and effluent tanks and groundwater transfer equipment would be surveyed to determine whether they meet NRC criteria for unrestricted release. If releasable for unrestricted use, they would be recycled, salvaged, or disposed of as solid waste. If not releasable, they would be packaged and shipped for disposal at a licensed low-level radioactive waste facility (EPM 2022a).

Groundwater extraction wells and monitoring wells in the licensed area would be removed and surveyed for release, and the borings would be plugged in accordance with Oklahoma Water Resources Board (OWRB) regulations. Groundwater extraction sumps would be cut off three feet below grade and the cut-off casing would be surveyed for release. Treated water injection wells and monitoring wells not within the licensed area would be plugged and abandoned in accordance with OWRB regulations (EPM 2022a).

Sections of piping through which groundwater exceeding the NRC criterion was pumped would be removed and surveyed for release. Piping that cannot be practically surveyed would be packaged and shipped for disposal as low-level radioactive waste. Subsurface piping that was not exposed to radioactive material and can be released for unrestricted use would remain in place (EPM 2022a).

November 2024 12 The trenches would be backfilled with previously excavated soil to be flush with the surrounding ground surface. Electric power lines and instrumentation and control wiring would be removed for recycling or disposal as solid waste (EPM 2022a).

Structures or equipment that would remain onsite after decommissioning include the WATF building and ancillary equipment (fencing, concrete foundations, emergency power generator, utilities, security system, etc.), as well as equipment foundations at the BARF (EPM 2022a, 2023b). Section 7 of EPMs responses to NRC requests for additional information (EPM 2023b) and section 8.9 of the DP provide detailed information about materials and equipment that would be removed from the site and materials and equipment that would remain onsite after license termination.

2.1.4 Water Use Logan County would provide potable water during construction, operation, and, to a lesser extent, decommissioning of the groundwater treatment systems. During construction, water would be taken from hydrants near the property. During operations and decommissioning, water would be provided directly to the permanent WATF (EPM 2023a).

During construction, potable water would be used as needed for dust suppression. Quantities used for this purpose would vary based on weather conditions during construction. During a 2017 pilot test, water use for dust suppression varied from 0 L (0 gal) to 60,567 L (16,000 gal) per day. The maximum daily water use of 121,133 L (32,000 gal) occurred when large water tanks were filled for the construction of an extraction trench (EPM 2023a). Water would likely be required in reduced amounts for the same purpose during decommissioning.

During operation, potable water would be needed for sanitary purposes, for sluicing new resin into the vessels, and for sluicing spent resin out of the vessels. During new resin sluicing, approximately 3,028 L (800 gal) of potable water would be used to add new resin to the ion exchange vessel. Potable water would be recirculated as necessary to sluice the required quantity of resin into the vessel and to minimize the use of potable water (EPM 2023a). After spent resin is removed, approximately 1,514 L (400 gal) of potable water would be needed to clean and flush the vessel and piping. This process would occur initially every five weeks, decreasing in frequency as the concentration of uranium in extracted groundwater decreases (EPM 2023a).

2.1.5 Air Emissions Most emissions from the proposed action would be generated during the construction phase.

The expected sources of emissions for the construction and operational phases are summarized below, and tables 2-1 and 2-2 provide the estimated quantities of these emissions.

Emissions from Construction The construction phase is estimated to take less than one year and would require about 24 workers driving to and from the site daily and operating trucks and equipment on the site. During this phase, emissions would be generated from standard earthmoving machinery such as backhoes and bulldozers, hauling equipment such as water trucks, hand tools, and temporary

November 2024 13 generators needed to construct the remediation and treatment infrastructure. These machines and equipment would be used on unpaved roads around the site and on paved roads to and from the site. Additional vehicles traveling to and from the site would include passenger vehicles, pickup trucks, tractor trailers, dump trucks, and concrete trucks.

Emissions information for construction activities is presented in table 2-1. The table shows that fugitive dust (particulate matter or PM), referred to as PM10 and PM2.51, would be generated by traffic on paved and unpaved roads and during earthmoving activities. As discussed further in section 3 of this EA, EPM would control fugitive dust by following a dust control plan, using dust suppression measures, limiting vehicle speeds on site, and stabilizing soil stockpiles. These mitigation measures are not factored into the estimates in table 2-1. Tailpipe emissions such as nitrogen oxides, carbon monoxide, volatile organic compounds, and sulfur dioxide, would be generated by vehicles and equipment moving onsite and traveling to and from the site.

Table 2-1. Emissions During Construction Phase (estimated <1 year, tons)

Description Nitrogen oxides Carbon monoxide Volatile organic compounds PM10 PM2.5 Sulfur dioxide Carbon dioxide equivalent emissions Construction engine emissions 5.67 4.93 1.42 0.36 0.36 0.71

~400 Tailpipe emissions 8.21 23.00 1.59 0.71 0.51 0.15

~1,141 Dust from earthmoving activitiesa n/a n/a n/a 18.54 3.86 n/a n/a Dust from unpaved roadsb n/a n/a n/a 65.79 6.58 n/a n/a Dust from paved roadsc n/a n/a n/a 6.97 1.71 n/a n/a Total emissions, rounded 14 28 3

92 13

<1

~1,541 (1,398 metric tons)

Source: EPM 2023a, Table 5-1 a Up to 25,230 m3 (33,000 yd3) of soil would be excavated during earthmoving and construction activities.

b Distances traveled on unpaved roads would range from 3 to 5 mi (4 to 8 km) per day for each vehicle.

c Distances traveled to and from the site on paved roads would be approximately 60 mi (96 km) for each vehicle.

Emissions from Operations The operations phase is expected to last about 12.5 years and would require two daily workers.

During this time, the main sources of air emissions would be from equipment used to operate the treatment system. Table 2-2 provides sources and estimates of the quantities of emissions generated during groundwater treatment operations. The primary source would be a forklift used to move materials (resin, waste, drums, etc.). Fugitive dust (PM10 and PM2.5) would be generated by traffic on paved and unpaved roads. EPM would employ dust suppression 1 Particles are defined by their diameter for air quality regulatory purposes. Those with a diameter of 10 microns or less (PM10) are inhalable into the lungs and can induce adverse health effects. Fine particulate matter is defined as particles that are 2.5 microns or less in diameter (PM2.5).

November 2024 14 measures to reduce emissions below those presented in table 2-2. Tailpipe emissions would be generated by vehicles moving within and traveling to and from the site. Combustion emissions from a forklift and the two emergency generators would be similar in nature to the tailpipe emissions from vehicles.

Table 2-2. Annual Emissions from Operations (tons/year)

Description Nitrogen oxides Carbon monoxide Volatile organic compounds PM 10 PM 2.5 Sulfur dioxide Carbon dioxide equivalent emissions Equipment engine emissionsa 1.61 1.47 0.40 0.10 0.10 0.20

~115 Tailpipe emissionsb 0.05 0.03 0.00 0.00 0.00 0.00

~2 Emergency generatorsc 1.89 1.11 0.19 0.07 0.07 0.03

~313 Dust from unpaved roadsb n/a n/a n/a 2.07 0.08 n/a n/a Dust from paved roadsb n/a n/a n/a 0.00 0.00 n/a n/a Total emissions, rounded

~4

~3

<1

~2

<0.5

<0.5 430 (390 metric tons)

Source: EPM 2023a, Table 5-1 a The forklift would operate on average 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> per day, 5 days per week.

b Distances traveled to and from the site on paved roads would be approximately 5 mi (8 km) per day for commuters (two workers) and less frequent trips for maintenance activities. Onsite traffic along gravel roads would include occasional trucks providing replacement supplies, commuter vehicles, occasional material deliveries, and maintenance vehicles. In addition, waste resin and general trash would be transported to appropriate waste facilities for disposal.

c Two emergency generators (30 kilowatt and 528 kilowatt) are assumed to operate up to 500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> per year each.

Emissions from Dismantlement Dismantling the groundwater treatment facility would involve activities that are similar to construction operations but reduced. About 12 workers would be onsite daily during this phase (half the workers needed during construction). Emissions from dismantling the facility would be less than emissions for construction because the WATF building would not be removed and less excavation work would be needed (e.g., injection wells would be plugged, clean piping would remain in place). However, for bounding purposes, the NRC assumes the emissions from dismantling and decommissioning the groundwater treatment facility would be the same as the emissions from construction.

2.1.6 Chemical Use During all phases of the proposed action, only a few chemicals would be used and stored onsite to support construction, operations, and maintenance of the facility and equipment. Operations and maintenance activities would use up these chemicals and thus disposal would not be needed. Section 2.1.7 describes the wastes that would be generated throughout the proposed

November 2024 15 action. EPM anticipates that pest and weed control activities would be conducted by a licensed vendor, and no pesticides or herbicides would be stored on-site (EPM 2023a).

Hydrochloric acid, the only hazardous chemical associated with groundwater remediation, would be used at a rate of about 132 L/day (35 gal/day) to adjust the pH of the influent to the treatment systems. Hydrochloric acid would be stored in and delivered to the influent lines from a 5,000-gal (18,927-L), double-walled tank located next to the WATF building. The tank would be refilled approximately every 3 months by a chemical delivery truck (EPM 2022a). A scrubber would capture vapors from the hydrochloric acid tank.

Up to 200 gal (757 L) of diesel fuel would be stored for possible use in two emergency generators. Other consumable materials that would be used are maintenance chemicals, ion exchange resin, and nonhazardous inorganic absorbent to process spent resin. The ion exchange systems are designed to produce water that can be discharged to the Cimarron River without the addition of chemicals. Treated water that is injected back into the ground may need further treatment to prevent mineral scaling and fouling of the injection system and subsurface formation.

2.1.7 Effluents and Wastes This section describes the types and quantities of wastes that would be produced throughout the proposed action, from construction through demobilization of the groundwater treatment facilities. The potential impacts from waste management are discussed in section 3.11.

2.1.7.1 Radioactive Wastes The proposed action would generate low-level radioactive wastes (LLRW). The primary radioactive waste stream would be spent ion exchange resin removed from the uranium treatment systems. In addition, treatment operations would generate LLRW waste gloves, maintenance equipment, disposable sampling devices, and other tools or materials that would have contact with licensed material and could exceed release criteria but would not be practical to survey. Other LLRW would be generated as a result of dismantling the treatment systems and disposing of the piping network. Additionally, some potable water from the domestic water supply would be used to sluice (i.e., rinse) the spent resin out of the resin vessel. Because the water would be in contact with the resin it would become process water that would be routed back to the water ion exchange system and then further filtration (EPM 2022a).

The NRC has adopted a waste classification system for LLRW based on its potential hazards, and has specified disposal and waste form requirements for each of the general classes of waste: classes A, B, and C. The classifications are based on the key radionuclides present in the waste and their half-lives. In general, Class A wastes have the least stringent requirements for waste form, stability, and disposal methods, and Class C wastes have the most stringent requirements. All solid radioactive waste resulting from the proposed action would be Class A waste.

Spent Anion Resin Each resin vessel would contain approximately 750 kilograms (kg) (1,653 pounds [lb]) of resin.

The maximum estimate of uranium in the influent groundwater indicates that no resin vessel would accumulate greater than 450 grams (g) (15.9 ounces [oz]) of U-235. The resin would be

November 2024 16 dewatered, and an inert, inorganic absorbent would be added to make sure the mixture contains no free liquid and would not produce free liquid during transportation. The resin waste mixture would contain 1 g (0.04 oz) resin for every 2 kg (4.4 lbs.) of absorbent material so that the waste could be classified as Class A, fissile exempt LLRW. The NRC anticipates that each anion resin exchange would generate between 1.1 and 1.4 m3 (40 and 50 ft3) of waste after the spent resin is blended with the absorbent material. The blended waste would be packaged in 55-gallon (208-L) drums (or other suitable, DOT-approved containers) for storage and eventual transport (EPM 2022a).

During the first year of operation, as many as ten exchanges may occur, yielding between 11.3 and 14.2 m3 (400 and 500 ft3) of LLRW. Drums of processed resin waste would be loaded onto pallets and strapped together. Each pallet of drums would be stored in the spent resin storage area located in the southern portion of the WATF until it is shipped. Although the generation of LLRW would likely decrease over time as uranium concentrations in the groundwater decline, the NRC staff assumes that approximately 14.2 m3 (500 ft3), less than 85 drums, per year would be generated over the approximate 12.5 years of pumping operations (EPM 2022a). EPM would ship the waste to the EnergySolutions facility in Clive, Utah, or to the Waste Control Specialists (WCS) facility in Andrews, Texas for disposal as Class A, fissile exempt, LLRW (EPM 2022a).

Potentially Contaminated Materials Tubing, filters, and other materials that contact groundwater only after treatment would be disposed of as solid waste. Similarly, single use in-line filters and tubing used to collect samples from monitoring wells would also be disposed of as solid waste. This material would be stored in a designated area of the WATF (EPM 2022a).

Material that cannot be practically surveyed to demonstrate that it is releasable for unrestricted use (e.g., tubing or in-line filters that repeatedly contact untreated water) would be segregated from other solid waste for disposal. EPM would package and ship this material to a licensed facility for disposal as Class A LLRW. The NRC estimates this waste would be less than 15 percent of the total volume of radioactively contaminated waste (EPM 2022a).

Contaminated Soils License condition 27(c) specifies the unrestricted release criteria for soils and soil-like materials.

The criterion for enriched uranium is 30 pCi/g (1.1 Bq/g) and the criterion for depleted uranium is 35 pCi/g (1.3 Bq/g) (NRC 2011a). Subsurface soils would be excavated during such ground-disturbing activities as installation of injection and extraction trenches, monitoring wells, and trenches for piping and utilities. EPM would conduct gamma surveys over the excavated soils to identify any hot spots (i.e., activity detected at levels greater than twice background) and, if needed, sample these soils to better characterize the area (EPM 2022a). EPM would not excavate any area of the site known to have soils at depths greater than 1.2 m (4 ft) that exceed a net 30 pCi/g (1.1 Bq/g) uranium (EPM 2022a).

EPM would also survey any soil-like material (e.g., crushed asphalt) encountered to identify any elevated gamma counts. Material with elevated gamma counts would be removed, segregated, and sampled for laboratory analysis. If the material is not releasable, it would be packaged and disposed of as LLRW (EPM 2022a).

November 2024 17 The 1206-North drainage area is unique in that it is the only area in which excavation and disposition of sediment would be conducted as a groundwater remediation strategy. Soils at the 1206-North drainage area (see figure 2-2) would be excavated, mixed with excess soils generated during trench excavation, and placed in a soil laydown area. EPM would then establish a 10-m (32.8-ft) grid over the laydown area and collect soil samples. For each 10-m (32.8-ft) sample that yields less than 30 pCi/g (1.1 Bq/g) total uranium above background, the material within that grid would be considered in compliance with the 30 pCi/g (1.1 Bq/g) criterion. Should a sample from a grid location exceed 30 pCi/g (1.1 Bq/g) above background, samples would be collected from the same depth on a 5-m (16.4 ft) grid surrounding that sample to determine whether the average activity over a 100 m2 (1,076 ft2) area complies with the license criterion. If the average activity for the 10-m grid (32.8-ft) sample and the four surrounding 5-m (16.4 ft) grid locations is less than the license criterion, the material within that grid would be considered in compliance with the license criterion. Should any grid/depth interval exceed the license criterion, that material would be excavated, placed in drums with absorbent material, and disposed of as LLRW (EPM 2022a).

Liquid Effluent All liquid effluent would contain licensed material at concentrations below the NRC effluent limits listed in Appendix B of 10 CFR part 20 and would meet OPDES permit requirements. As such, no liquid radioactive waste would be generated by groundwater treatment operations. The treated groundwater either would be reinjected into the ground in accordance with the State of Oklahomas underground injection control program or would be discharged to the Cimarron River in accordance with the OPDES permit (EPM 2022a).

2.1.7.2 Nonradioactive Wastes The proposed action would generate nonradioactive hazardous, municipal, and demolition wastes. Municipal solid waste would consist of typical trash, such as food waste, paper, glass, cardboard, and plastic. Construction waste would include concrete, sheetrock, metal, and excess piping (EPM 2023a).

Operation of the ion exchange system would by its nature generate very little waste. In addition to general plant trash, waste generated during operations would consist of empty absorbent bags and empty absorbent drums (EPM 2022a, 2023a).

As part of dismantlement and decommissioning, approximately 4,536 kg (10,000 lb) of well piping, steel tanks, and general equipment would be disposed of as construction debris. All steel tanks and equipment would be surveyed for release and salvaged (EPM 2022a, 2023a).

2.1.8 Final Status Survey, License Termination, and Subsequent Activities In accordance with condition 27(b) of the license, EPM would need to demonstrate that the total uranium concentrations in all wells have been below the groundwater release criterion for eight consecutive quarterly samples (the past two years). After all dismantlement and decommissioning activities are complete, EPM would submit a final status survey plan for NRC approval. The final status survey would include the groundwater and surface areas involved in the groundwater treatment system. Post-remediation monitoring would provide the data needed to demonstrate that groundwater complies with the NRC groundwater criterion. Section 15 of the DP provides more detail on final status surveys that would be conducted for the influent tank

November 2024 18 and influent pump foundations, the ion exchange and spent resin area, the LLRW storage area, and the instrument sample/package room (EPM 2022a).

EPM would submit a request for the termination of license SNM-928 after the final status survey report and residual dose model meet NRC requirements. License termination would be a separate licensing action requiring another safety and environmental review.

The proposed action would sufficiently reduce potential exposure to the public from radiological contaminants of concern to meet NRC requirements and would allow the site ultimately to be released from the NRC license. The proposed remediation may not reduce the concentration of radiological or non-radiological contaminants below the state limits. The Oklahoma DEQ plans to work with EPM during and after decommissioning to further address groundwater concentrations of Tc-99 (if needed), fluoride, and nitrate. After NRC license termination, the Oklahoma DEQ would likely impose restrictions on future use of the property, including restricting the use of groundwater for drinking or irrigation (ODEQ 2024a).

2.1.9 Permits and Approvals EPM would need to obtain certain permits or approvals from state and local agencies, primarily for activities in natural areas of the site, including the 100-year floodplain, that would generate stormwater runoff, sedimentation, and a point source discharge to the Cimarron River. These and other permits or approvals are identified below.

Wetlands and Floodplain EPM would obtain Nationwide Permit 7 wetlands permit for outfall structures and associated intake structures. This permit would be needed for the construction of a discharge structure set back from the river, as well as a dispersion ditch at the riverbank. However, EPM does not expect to perform construction or route piping through wetlands (EPM 2023a).

EPM would file a floodplain development application with the Logan County Floodplain Administrator. The estimated 100-year flood elevation is approximately 290 m (951.0 ft) above mean sea level. EPM would stage equipment and material outside of the 100-year floodplain during construction activities (per Floodplain Development Permit requirements) (EPM 2023a).

Stormwater Construction projects that will disturb greater than 1 ac (0.4 ha) of land are issued a certificate of permit coverage under the Oklahoma DEQ General Permit OKR10, which authorizes construction-related stormwater discharges into State waters. EPM would update the SWPPP and submit a notice of intent to the Oklahoma DEQ to be covered under the stormwater permit (EPM 2023a).

Discharges to Cimarron River EPM would obtain an OPDES permit from the Oklahoma DEQ for discharges of treated groundwater to the Cimarron River. The outfall would be set back approximately 73 m (240 ft) from the riverbank, and a manmade dispersion ditch would be located adjacent to the river (EPM 2024a).

November 2024 19 Air Emissions As described in section 2.1.5 of this EA, EPM would have two diesel generators available for use in emergencies. These generators would be subject to Subpart IIII of the Oklahoma New Source Performance Standards (NSPS). Oklahoma has established a permit-by-rule for facilities that require permits for emergency engines that are subject to emissions standards under the NSPS. The emergency generator engines would need to be permitted but can be permitted through the emergency engine permit-by-rule (EPM 2023a).

Underground Injection EPM would work with the Oklahoma DEQ to ensure the reinjection of treated groundwater is conducted in accordance with the State underground injection control requirements for class V wells (wells for the injection of nonhazardous fluids).

2.2 Alternatives to the Proposed Action The NRC staff considered the no-action alternative. Under the no-action alternative, the NRC would not approve the DP or the license amendment request if, as proposed, the DP would not ensure that NRC requirements would be met. EPM would need to prepare a new DP that meets NRC requirements, and site maintenance activities would continue in the meantime. The NRC staff assumes that the preparation of another plan, NRC staff review, and implementation of cleanup would require an additional 2 to 4 years (beyond the timeframe for the current proposal). During that time, the site would remain largely in its present condition, except that groundwater contaminants would continue to migrate and disperse, potentially approaching the Cimarron River. Because the eventual plan to decommission would require the NRC staff to review and approve a newly DP for groundwater remediation, the impacts from no action ultimately would be similar to the impacts described in this EA, albeit delayed. The no-action alternative is not evaluated further in this EA.

In 1999, the NRC approved natural attenuation as a method to reduce groundwater contamination to acceptable levels (EPM 2022a). However, after several years of monitoring groundwater migration and contaminant concentrations, the licensee determined, and the NRC confirmed, that this process was not effective and that active remediation would be necessary (NRC 2005). This decision led to the present proposal to pump, treat, and discharge or reinject groundwater. The NRC staff has determined that natural attenuation is not a reasonable alternative, and it is not evaluated further in this EA.

November 2024 20 3.0 AFFECTED ENVIRONMENT AND POTENTIAL IMPACTS This section describes the current environmental conditions at the site and presents the NRC staffs evaluation of the potential environmental impacts of the proposed action. As stated in section 2.2, the NRC staff has determined that the no action alternative of not approving the DP would result in EPMs submitting another groundwater remediation plan for NRC review. This would result in further delay of groundwater remediation.

3.1 Land Use This section describes current land uses on the site, previous releases of land from licensee ownership, surrounding land uses, and the potential land use impacts of the proposed action.

3.1.1 Site Description The Cimarron site is located across the Cimarron River from and south of Cimarron City, Oklahoma in Logan County. The currently-owned property is in Sections 1, 2, 11 and 12, Township 16N, Range 4W of the Indian Meridian along the southern bank of the Cimarron River about 1 km (0.5 mi) north of the Oklahoma State Highways 33 and 74 intersection and 40 km (25 mi) north of Oklahoma City, Oklahoma. Figures 3-1 and 3-2 show representative areas of the site.

Figure 3-1. View of Portion of Cimarron Site within BA1, in Cimarron River Floodplain (Stakes show monitoring well locations.)

Source: EPM 2024b

November 2024 21 Figure 3-2. View of Portion of Cimarron Site within Western Area.

Source: NRC staff, 2022.

The property is approximately 202 ha (500 ac) and consists of upland prairie, rolling hills, manmade ponds, and forest, with some unpaved roads and no buildings. The northern property boundary is along the Cimarron River, which migrates and thus has shifted the property line slightly over time. Approximately 21 ha (52 ac) of the site remain under the NRC license.

Remaining buildings from the Kerr McGee operation are on an adjacent property that the licensee no longer owns. These are the former emergency response building (which the licensee is leasing for use as office space), former warehouse, and former mixed oxide fuel fabrication building. The warehouse and mixed oxide fuel fabrication buildings would not be used to support the proposed groundwater remediation activities. The office space would be used until the lease terminates 12 months after replacement offices are provided in the WATF (EPM 2023a).

3.1.2 Historic Site Land Use and Releases from the License The Cimarron site was used to manufacture fuel for nuclear reactors from 1965 to 1975. Prior to construction of the facility, much of the property was used for grazing and farming and continued as such throughout construction, operation, and decommissioning of the facility.

During the construction and operation of the nuclear fuel manufacturing processes, there were several buildings, collection ponds, sanitary lagoons, storage areas, and burial areas on the site. Figures 1-1 and 1-2 show the former features and land uses at the site. As described in section 1.5 of this EA, decommissioning efforts began in 1976. In 2011, CERT became the licensee and assumed responsibilities for the Cimarron site, including completion of the decommissioning activities. Until 2015, the licensee owned nearly 324 ha (800 ac) of property, including property located west of Highway 74 and south of the current property line.

During decommissioning, the site was divided into three areas that included both affected and unaffected areas. These general areas were further subdivided into 15 areas, labeled subarea A through subarea O (figure 3-3). Beginning in 1996, the NRC determined that certain subareas

November 2024 22 could be released for unrestricted use from the NRC license. Other subareas were released from the license after decommissioning and confirmation through surveys that the subareas met NRC requirements. Decommissioning activities and resulting surveys addressed buildings, potentially surface-contaminated material such as concrete slabs and pavement, and surface and subsurface soil. Overall, by the early 2000s, much of the site had been released by NRC for unrestricted use (EPM 2022a). Below is a list of the license amendments that resulted in release of subareas:

License amendment 13, issued in April 1996, released subareas A, B, C, D, and E.

License amendment 16, issued in April 2000, released subareas J and O.

License amendment 17, issued in April 2001, released subareas H, I, L, and M.

License amendment 18, issued in May 2002, released subarea K.

Final status surveys and confirmatory surveys have confirmed that subareas G and N are releasable for unrestricted use, but the NRC determined that these areas should not be released until groundwater remediation is complete. Because groundwater exceeds license criteria in subarea F, this area also cannot be released for unrestricted use until groundwater remediation is complete (NRC 2011b).

After release from the NRC license, several parcels of land were sold. In 2015, Cimarron Holdings, LLC purchased approximately 9.7 ha (24 ac) of land in portions of subareas H, I, K, and L. Industrial operations were conducted in two of the former processing buildings until early 2020, at which time operations were discontinued.

Also in 2015, approximately 47.3 ha (117 ac) of the western half of subarea E and all of subarea J were sold to Snake Creek Ranch, Inc. (EPM 2022a). Although this area is currently fallow, future land use may be for grazing and ranching (EPM 2022a).

Approximately 56.7 ha (140 ac) of property containing most of subarea A was sold to Cimarron Holdings LLC in November 2017. The land was used and will continue to be used by a third party to grow grass for cattle feed (EPM 2022a).

The current office building (former emergency response building) being leased by the CERT is on a small portion of subareas E and I [less than 0.4 ha (1 ac)].

November 2024 23 Figure 3-3: Cimarron Site Subareas A-O (Blue and yellow highlight complex boundaries.)

Source: modified from EPM 2022e 3.1.3 Surrounding Land Use Located near the intersection of Highways 33 and 74 is a small commercial development with a service station/convenience store, a building housing several shops, a storage facility, and an oil and gas production facility. A golf course is located within 1.6 km (1 mi) of the southeastern corner of the site. There are a few small towns within 16 km (10 mi), with the largest being the City of Guthrie, located 14 km (9 mi) east of the site. Farmsteads and houses are scattered throughout the area, with the nearest homes located approximately 0.8 kilometer (0.5 mile) away and less than 100 people living within 1.6 km (1 mi) of the site (EPM 2022a). The area is primarily rural with rolling hills and incised drainages. Vegetation in the area consists of native grasses and various stands of trees along and near the Cimarron River and associated drainages.

3.1.4 Potential Land Use Impacts Section 2.1.2 of this EA describes the activities that would be conducted to construct and operate the proposed groundwater treatment system. The groundwater remediation infrastructure associated with achieving the unrestricted release criterion for uranium in groundwater (i.e., the criterion in license condition 27(c) of 180 pCi/L [6.7 Bq/L] total uranium)

November 2024 24 would be contained within approximately 4.9 ha (12 ac) of the property and concentrated in the following areas:

The WA groundwater extraction infrastructure would consist of groundwater extraction wells and a groundwater extraction trench on approximately 1.6 ha (4 ac) in subarea H, and a treated water injection trench in subarea M.

Impacted groundwater would be transferred from subarea H to the treatment facility (new WATF building) that would occupy less than 0.8 ha (2 ac) in portions of subareas I and N.

BA1 groundwater extraction and treated water injection infrastructure would consist of three groundwater extraction wells, two groundwater extraction trenches, four treated water injection trenches, and a small groundwater management facility, altogether occupying approximately 1.6 ha (4 ac) in portions of subareas C and F.

Contaminated groundwater would be piped from BA1 to the water treatment facility and treated water would be piped from the treatment facility back to BA1 through subareas F, C, G, O, and N; the piping would occupy less than 0.2 ha (0.5 ac).

During treatment operations, most of the piping infrastructure associated with the groundwater remediation would be buried, resulting in minimal land surface impacts. Once treatment operations are complete the piping would be removed, if necessary, and disposed of accordingly (EPM 2022a).

After groundwater remediation is complete, the 202 ha (500-ac) property owned by the CERT may be sold. Portions of the site that include the WATF building would likely be used for commercial purposes and the remaining property would likely be used for grazing and farming (EPM 2022a). The Trust Agreement (Trust 2011) requires that EPM provide for the disposition of the property and termination of the CERT, with the property releasable for unrestricted use, farming, grazing, commercial/industrial, or recreational use (EPM 2022a).

Because the amount of land that would be under the NRC license during the proposed action is relatively small, and because the land would be released for unrestricted use after NRC-licensed activities are complete, the NRC staff concludes that land use impacts from the proposed action would not be significant. Section 2.1.8 of this EA describes the potential actions that could occur after the land is released from the NRC license, including actions that may be required by the State of Oklahoma.

3.2 Geology and Soils This section describes the regional geologic features, site geology and soils, the regions seismic history, and the potential impacts of the proposed action on geology and soils.

3.2.1 Regional Geology The bedrock geology of Logan County is composed of predominately Permian-age clastic sedimentary rocks of the Garber-Wellington Formation. The lithology of the Garber Sandstone and underlying Wellington Formation, which comprise the Garber-Wellington Formation,

November 2024 25 includes lenticular channel and sheet-flood sandstones interbedded with shales and mudstones with a combined thickness of approximately 305 m (1,000 ft) (EPM 2022a). The two formations have similar water bearing properties and are often treated as a single mappable formation and grouped into a single hydrostratigrahic unit, the Garber-Wellington Aquifer (figure 3-4) (Wood and Burton 1968).

The Cimarron site area is part of the Nemaha Uplift of Central Oklahoma. The Nemaha Uplift, also called the Nemaha Ridge, consists of north-northwest trending normal faults and anticlinal structures. During the Permian period, when the Garber-Wellington Formation was deposited, Central Oklahoma was part of the eastern shelf of a shallow marine sea. The sandstones and shales of the Garber-Wellington Formation were deposited as part of a westward-advancing marine delta fed by numerous streams flowing to the west and northwest. Thus, the sands of the Garber-Wellington Formation are often sinuous and discontinuous and exhibit the rapid lithologic changes typical of a deltaic channel and overbank depositional system (floodplain deposits). Sand accounts for 35 percent to 75 percent of the Garber-Wellington Formation (USGS 1977).

Although there is bank erosion along streams and the Cimarron River, there is no evidence of subsidence, karst terrain, or active landslides (EPM 2002a). The heavy vegetation throughout the area mitigates floodplain and upland erosion. Agricultural fields in the area, however, are subject to sediment erosion during heavy precipitation events. There are no man-made geologic features such as mines and quarries in the vicinity of the site (EPM 2022a).

3.2.2 Site-specific Geology and Soils Like that of Logan County, the stratigraphy at the Cimarron site is dominated by the Garber-Wellington Formation. The Garber Formation is exposed along the escarpment that borders the Cimarron River, whereas the Wellington Formation is not exposed within the site boundary.

Onsite, the Wellington Formation consists of approximately 293 m (960 ft) of red shale with several thin siltstone beds. The Garber Formation consists primarily of sandstone layers separated by relatively continuous siltstone and mudstone layers (figure 3-5). The Garber sandstones can be divided into the following three basic sandstone units separated by two relatively continuous mudstone layers:

Sandstone A is the uppermost sandstone unit, generally red-brown to tan in color and up to 11 m (35 ft) in thickness. The bottom of this sandstone unit occurs at an elevation of approximately 290 to 296 m (950 to 970 ft) above mean sea level (amsl).

Mudstone A is a red-brown to orange-brown, sometimes tan mudstone and claystone that separates Sandstones A and B. It ranges from 1.8 to 6.1 m (6 to 20 ft) thick.

Sandstone B is the second sandstone unit, underlying Mudstone A, and similar in color and sedimentary features to Sandstone A. It is found at elevations between 282 and 291 m (925 and 955 ft) amsl and is up to 9.1 m (30 ft) thick.

November 2024 26 Figure 3-4. Generalized Regional Geologic and Hydrogeologic Cross-Section of the Site Source: modified from EPM 2022e Mudstone B consists of mudstone and claystone separating Sandstone B and Sandstone C. It is similar in color to Mudstone A and ranges from 1.8 to 4.3 m (6 to 14 ft) thick.

Sandstone C is the lowermost sandstone in the Garber-Wellington Formation, similar in color and sedimentary features to the overlying sandstones. This unit varies in thickness from 3 to 7.6 m (10 to 25 ft) at the site to at least 30.5 m (100 ft) thick regionally.

The Cimarron River floodplain alluvium consists of sand and silt, developed by the erosion of the Garber Formation from the escarpment bordering the river on the south, as well as material transported to the floodplain from upstream within the river system. This alluvium contains many buried channels that reflect both transport of the alluvial materials northward toward the river from the escarpment and meandering of the main river channel. Near the present river channel, buried oxbow meanders are likely to be present. Near the escarpment, any buried channels are likely the continuation of present drainages incised into the escarpment sandstones. The alluvium is about 9.1 to 12 m (30 to 40 ft) thick. The river has carved a floodplain nearly 0.8 km (0.5 mi) wide at the site. The erosional escarpment is evident in the western half of the site and rises over 9.1 m (30 ft) above the floodplain in areas. To the east, the escarpment is present only as a shallow slope.

November 2024 27 Previous Cleanup of Site Soils Nuclear fuel manufacturing operations resulted in the contamination of site soils through the uses of such features as impoundments and burial areas (see figures 1-1 and 1-2). Specifically, soils from three previous burial areas were excavated, and soils with concentrations of uranium above NRC requirements for unrestricted release were shipped offsite for disposal. After NRC and Oklahoma DEQ review and approval as reflected in license condition 23, approximately 12,799 m3 (16,740 yd3) of stockpiles or excavated soils with an average concentration between 35.7 and 45 pCi/gram (1.3 and 1.7 Bq/g) and a total activity of 0.98 curies were placed in BA4 (EPM 2022a. This area was subsequently covered with at least 4 feet (1.3 m) of soil followed by several inches of topsoil and then vegetated (EPM 2022a). The NRCs safety evaluation report for this action states, The contaminated soil in question contains only low concentrations of uranium, slightly above the concentrations (above 30 pCi/g [1.1 Bq/g]) for which no special disposition is required, and there are no other significant radioactive or toxic contaminants (NRC 1994b). The NRCs 1999 EA for the initial version of the decommissioning plan included a conservative assessment of the dose that a resident farmer would receive from living on the site, growing and consuming food, and drinking water from an onsite well with concentrations of uranium at the proposed release limit of 180 pCi/L (6.7 Bq/L). The EA concluded that, even when assuming no soil and vegetative cover is in place, the total dose from these pathways would be less than 10 mrem per year (0.1 mSv/yr) (NRC 1999). An NRC confirmatory survey in 2002 concluded that exposure rate measurements, soil sample analysis results, and alpha and beta measurements were all below applicable NRC release criteria and that subarea N met NRC criteria for unrestricted use (NRC 2002). License condition 23(b) requires the licensee to place a note in the deed regarding the presence of BA4 and to install and maintain permanent markers at the corners of the disposal cell. These actions have been completed (EPM 2022a).

Section 1.3 of the DP (EPM 2022a) describes the decommissioning of site soils, subsurface soils, and buildings. Surveys have confirmed all surface areas meet NRC requirements for unrestricted release. However, the NRC determined that areas currently under the NRC license (subareas F, G, and N) cannot be released until groundwater remediation is complete.

November 2024 28 Figure 3-5. Lithology at the Site Source: modified from EPM 2022e

November 2024 29 3.2.3 Seismic History As part of an NRC evaluation of seismicity east of the Rocky Mountains, the Nemaha Uplift, also called the Nemaha Ridge, was identified as an area with a moderately high seismic risk classification (NRC 1983). The Nemaha Uplift extends from Oklahoma to Nebraska and is approximately 668 km (415 mi) long. The Nemaha Uplift has been mapped using data gathered from over 20,000 wells, revealing a complex fault pattern dominated by several discontinuous uplifts.

The USGS interactive Quaternary fault map/database (USGS 2021) does not identify any Quaternary surface faults in the vicinity of the site that have had movement in the last 1.6 million years. The nearest Quaternary fault is the Meers fault, located approximately 145 km (90 mi) southwest of the site. At the site, the uppermost groundwater aquifers include the Quaternary-age floodplain alluvium (i.e., unconsolidated) along the Cimarron River and the Permian-age Garber Formation (Sandstones A, B, and C). However, groundwater flow in the Quaternary-age floodplain alluvium and the Permian-age Garber-Wellington Formation is not affected by the Nemaha Uplift and interpreted faults at and in the vicinity of the site (EPM 2022a).

From 2009 through 2021, 3,098 earthquakes with a magnitude of at least 3.0 were recorded. Of those, 97 had a magnitude between 4.0 and 5.0, and 4 earthquakes had magnitudes between 5.0 and 5.8 (maximum) (USGS 2023). The scientific community largely agrees that the increase in seismic activity within this area was due to injection of wastewater from oil and gas production activities, and in this case into the Arbuckle Formation. In 2013, the Oklahoma Corporation Commissions Oil and Gas Conservation Division established a 38,850 km2 (15,000 mi2) area of interest (inclusive of the site) where regular reporting of disposal volumes was required.

Total injection volumes were reduced within the area of interest to comply with directives to reduce injection volumes or to shut down disposal wells (EPM 2022a).

3.2.4 Potential Geology and Soils Impacts Prior to excavating the trenches, EPM would remove 10 to 15 cm (4 to 6 in) of soil (i.e., topsoil) from the ground surface and stockpile the topsoil nearby. In addition, an access trench may be needed to provide a level working surface for the excavator and to enable the excavator to reach the required maximum trenching depths (up to 7.6 m [25 ft] below ground surface). EPM would excavate trenches to a minimum width of 0.6 m (2 ft) using a tracked excavator. Soil removed as part of this process would be stockpiled near the trenches, but separately from stockpiled topsoil. To reduce soil loss, best management practices (BMPs) would be implemented (including placement of silt fencing, erosion control blankets, etc.) around the downslope sides of the stockpiles (EPM 2022a).

Excavated rock would be stockpiled separately from topsoil and soil removed during trench excavation. A portion of the excavated rock would be stockpiled for further use as backfill where possible. Not all of the excavated rock would be reused because gravel fill would be needed instead as part of the remediation process. Any excess excavated rock would be mixed with native onsite soils (EPM 2022a).

EPM would conduct and document inspections throughout the proposed action until vegetation is established and soil retention installations (best management measures) are removed. If

November 2024 30 during biweekly inspections EPM observes evidence of sediment migration or damage to existing soil retention installations, EPM would improve or put in new installations (EPM 2022a).

Any rupture due to seismic activity would have the potential to impact surface soils and near surface geologic material. Although seismic activity is not expected to generate unacceptable stresses on the piping network, due to the inherent inability of traditional buried piping systems to resist lateral movements, seismic design considerations would be incorporated. EPM proposes to use piping materials such as high-density polyethylene and polyvinyl chloride piping for the surface and subsurface because these materials are more flexible and durable than standard alternatives (EPM 2022a). Sections 2.1.7 and 3.11 of this EA (waste management) provides additional information on how radiological soil contamination would be evaluated and managed.

The proposed action (installation, operation, and demobilization of groundwater remediation systems) would have a temporary impact on geology and soils. Impacts would occur from the temporary removal, storage, and replacement of soils onsite. The potential for ruptured piping to contaminate soil would be mitigated by the use and monitoring of high-density polyethylene or polyvinyl chloride piping material. Therefore, the NRC staff concludes that impacts on geology and soils would be temporary and not significant.

3.3 Water Resources This section describes the surface water features at and near the site, groundwater characteristics, and the potential impacts of the proposed action on surface water and groundwater. Water use for the proposed action is described in section 2.1.4.

3.3.1. Surface Water 3.3.1.1. Affected Environment The Cimarron River is a perennial gaining river (i.e., groundwater discharges into the river) that flows east for approximately 1,123 km (698 mi) from northeastern New Mexico to Keystone Lake in Oklahoma, west of Tulsa, where it joins the Arkansas River. The Cimarron River runs along the northern boundary of the site (figure 3-6). Because the river is fed by groundwater, the river base flow is highest in the winter months when groundwater tables experience reduced evapotranspiration and lowest in the late summer when groundwater tables are lower. There are no stream gauges at the site, so no site-specific river flow rate has been measured. The Guthrie gauge is located approximately 16 km (10 mi) east of the site. From 1990 to 2017, this gauge measured an average annual flow rate between 8.13 cubic meters per second (m3/s) to 104.6 m3/s (287.1 to 3695 cubic feet per second [cfs]) (USGS 2023).

EPM estimated annual 7-day average low flow rates in the river using the SWToolbox, a GIS interface and hydrological statistics tool developed by the U.S. Geological Survey, for the Crescent and Guthrie gauges, which are just upstream (west) and 16 km (10 mi) east of the site, respectively. The annual 7-day average low flow rate for the Guthrie gauge from October 1983 to July 2022 was 1.28 m3/s (45.1 cfs), while the Cresent gauge was estimated to be 1.24 m3/s (43.6 cfs) for the same period (EPM 2022a).

November 2024 31 Figure 3-6. Surface Water Features on and near the Site Source: EPM 2022e The U.S. Geological Survey compiled flood statistics for the Cimarron River through 2001 (USGS 2001). The study found that peak flow ranged from a discharge of 756 m3/s (26,700 cfs) during a 2-year flood to a discharge of 6,711 m3/s (237,000 cfs) during a 500-year flood. Floods typically occur from May to June or in October, often due to heavy rainfall upstream and west of the site. A 100-year flood would flood the entire alluvial valley but would not impact the upland areas of the Cimarron site (figure 3-7). The Federal Emergency Management Agency has classified the alluvial valley adjacent to the site as Zone A. Zone A areas are subject to inundation by 100-year flood events (EPM 2022a).

Several small streams and ponds in the area feed into the river (figure 3-6). Cottonwood Creek is 11.3 km (7 mi) south of the site and flows northeast through Guthrie, downstream of the site.

Gar Creek is less than 0.8 km (0.5 mi) east and downstream of the site, while Cox Creek is directly west and upstream of the site. Indian Springs and a small pond at Crescent Spring are north of the site across the Cimarron River. Most other surface waters near the site are ephemeral and only flow in response to heavy rains.

November 2024 32 Figure 3-7. Floodplain Map Source: B&M 2024 There are two manmade ponds on the site, referred to as West Pond and East Pond. Both ponds are roughly 293 m (960 ft) above mean sea level. The East Pond has a spillway to control maximum pool elevation, while the West Pond has two 76.2-cm (30-in) corrugated steel culverts. Both ponds have a negligible impact on flooding at the site as both ponds are small, and the flow of the ephemeral streams that feed them is small compared to the Cimarron River.

The ponds are above the groundwater elevation in Sandstone B. Pond evaporation rate in central Oklahoma is estimated to be up to 76.2 cm (30 in) per year (Grant 1989).

There are no major domestic uses of surface water in the area, as the surface water is of generally poor natural quality and potable water is provided by groundwater wells north of the area (EPM 2022a). Any surface water use in the area around the site is not impacted by current site conditions because all remaining contamination is in the groundwater within the site boundary.

3.3.1.2. Potential Surface Water Impacts Sections 2.1.2.1 and 2.1.2.2 of this EA describe the proposed construction and operations that would result in discharges to the Cimarron River and create stormwater runoff. To limit the potential impacts of sediment migration on local surfaces waters, especially during construction,

November 2024 33 EPM would use BMPs (best management practices, such as silt fencing and other erosion controls) as stipulated in the SWPPP that would accompany the OPDES stormwater permit and would also use an erosion and sediment control plan. If the NRC approves EPMs DP, EPM would update the SWPPP that was prepared for a 2017-2018 pilot test to reflect the full-scale operation of the proposed cleanup (EPM 2022d).

During operations, treated water would be injected back into groundwater systems or discharged into the Cimarron River through outfall 001 (shown on figure 2-2) (EPM 2022a). All water discharged into the river would comply with OPDES permit limits and would have chemical properties similar to the groundwater naturally discharging into the river (EPM 2022a).

The OPDES permit is expected to limit the daily maximum concentration of uranium in the discharge to between 30 µg/L and 100 µg/L (ODEQ 2024b). Additionally, the permit would require the pH of the discharged water to be between 6.5 and 9.0. EPM expects to discharge approximately 647 L (171 gal) of water per minute, or 0.38 cubic feet per second, to the river, adding to the existing flow of at least several hundred cubic feet per second. For comparison, 171 gpm is less than 0.2 percent of the average annual flow rate for the Cimarron River at the Guthrie gauge 16 km (10 mi) east of the site for any year between 1990 and 2017 (USGS 2023). The treated water would be periodically sampled to confirm compliance with the OPDES permit.

The OPDES permit is not expected to include a limit for Tc-99 specifically because the extracted groundwater would contain concentrations of Tc-99 at less than the effluent limit of 60,000 pCi/L (2220 Bq/L) in 10 CFR Part 20 Appendix B, which the State has adopted (EPM 2022a; ODEQ 2024a, 2024b). The State has not set a drinking water limit for Tc-99, although the EPA limit for Tc-99 in drinking water is 900 pCi/L (33.3 Bq/L) (4 millirem per year). Gross-beta, which includes Tc-99, would be monitored to ensure total beta emissions remain below the state limit for beta emissions in drinking water of 50 pCi/L (1.9 Bq/L) (ODEQ 2024a). As described in section 3.3.2.4 of this EA and in section 8.6.3 of the DP, if Tc-99 is present in extracted groundwater, it would be found at very low concentrations and some (if not all) would be captured by the resin. Therefore, the NRC staff concludes that Tc-99 would likely be present only in very low levels in the treated water that would be discharged to the river. Tc-99 levels would likely be nondetectable in the river water (well below the EPA drinking water limit).

The flow rate to Outfall 001 would be recorded, and samples of treated water being discharged would be collected for laboratory analysis on a biweekly basis or as otherwise specified in the OPDES permit. Discharge monitoring reports would report this data to the Oklahoma DEQ on a monthly basis in accordance with the OPDES discharge permit (EPM 2022a).

Small amounts of runoff could impact surface waters, such as runoff from vehicle washing, water used for dust suppression, condensate from compressors or air conditioning, and water used for landscape irrigation. BMPs outlined in the SWPPP and the erosion and sediment control plan would limit the impacts from these activities on surface waters at the site. All structures and materials storage areas would be placed in the upland areas of the site, above the base flood elevation, to prevent damage to materials or accidental release of contaminants into floodwaters. As discussed in section 2.1.6, the proposed action would not require large quantities of materials. All materials would be stored in accordance with the SWPPP.

In summary, water discharges to the river would comply with the OPDES permit, sediment and stormwater runoff would be controlled using BMPs as stipulated in the SWPPP, and materials would be stored above the floodplain to prevent contact with floodwaters. Therefore, the NRC

November 2024 34 concludes that the potential impacts from the proposed action on surface waters would not be significant.

3.3.2. Groundwater 3.3.2.1. Affected Environment Groundwater at the site flows north toward the Cimarron River, which acts as a groundwater drain in this area of central Oklahoma. The site is underlain by the Permian-age Garber-Wellington Aquifer. Recharge of the Garber-Wellington Aquifer near the site has been estimated at about 10 percent of annual precipitation (USGS 1977). Due to naturally poor water quality, no site groundwater is used for drinking water or irrigation (EPM 2022a).

The Garber Formation can be split into three separate water-bearing zones, Sandstones A, B, and C, which are interspersed with mudstone layers (see EA section 3.2.2 and figure 3-5).

Sandstone A is generally unconfined with semi-confined areas overlying mudstone and shale.

Sandstones B and C are deeper than Sandstone A and are confined or semi-confined, depending on the overlying mudstone. Sandstone A is recharged by local precipitation and discharges through seeps into escarpments in the Cimarron River floodplain. The deeper Sandstones B and C typically flow north to northwest toward the Cimarron River. Sandstone B is recharged through precipitation infiltrating the shallow groundwater unit recharge zone and from upgradient flow. Sandstone B flows north to northwest toward the alluvial and transition zones. Sandstone C is regionally controlled with flow predominantly north toward the river. Flow in the alluvium is north toward the river.

Sandstone B is the uppermost water-bearing unit at BA1. The groundwater in the area originates as precipitation or from upgradient flow toward the Cimarron River. The groundwater flows across a buried escarpment into a former drainage channel filled mostly with silts and clays into the floodplain alluvium. Once the groundwater exits the Transition Zone, it enters a sandy alluvial material with a very low hydraulic gradient. Flow in the Transition Zone is north toward the Cimarron River. Average groundwater flow in the area is approximately 0.18 m (0.6 ft) per day in Sandstone B, decreasing after it reaches the alluvium to 9.1x10-3 m (0.03 ft) per day (EPM 2022a).

Sandstone A is the uppermost water-bearing unit for the western upland area of the site. The groundwater originates as precipitation infiltrating the shallow groundwater unit recharge zones.

There are two small local drainages for the groundwater in Sandstone A just west of uranium waste pond #1 and BA3 (figure 1-2). The water becomes an ephemeral shallow surface channel created by groundwater seepage from both east and west of the channel when the water table is high, such as from a storm. The channel flows north to northwest toward the floodplains of the river. Groundwater in Sandstone A typically flows toward this channel or north to the Cimarron River with an average velocity of approximately 0.37 m/day (1.2 ft/day) (EPM 2022a).

Groundwater in Sandstones B and C are present approximately 30 feet below the groundwater in Sandstone A in the western upland. The deeper groundwater flows north toward the Cimarron River. Due to the presence of the mudstone units, there is little vertical hydraulic conductivity between the lower and upper sandstone units (Grant 1989).

November 2024 35 3.3.2.2 Contaminant Concentrations Data is collected from 212 active monitoring wells at the site, many of which have never yielded groundwater exceeding the release criterion for uranium (EPM 2022a). Groundwater in eleven of the monitoring wells in the WA, however, have yielded results that exceed the criterion of 180 pCi/L (6.7 Bq/L), which is roughly 123 µg/L for the WA (since the uranium in impacted areas of WA groundwater has an average enrichment of 2.7 percent U-235). Data from these areas indicate that uranium concentrations in groundwater range from 0.63 to 875 µg/L with an average of 47.2 µg/L (EPM 2022a). Figure 3-8 shows the range of uranium concentrations in the WA.

Similarly, groundwater in 32 monitoring wells in BA1 exceeds 201 µg/L, which is the concentration that would comply with the NRC criterion of 180 pCi/L (6.7 Bq/L) (and 1.3 percent average enrichment of uranium in BA1 groundwater) (EPM 2022a). Data from these areas of BA1 indicate that uranium concentrations in groundwater range from 1.24 to 3,516 g/L with an average of 412 g/L. Figure 3-9 shows the range of uranium concentrations in BA1.

Figure 3-8. Uranium in the Western Area Source: EPM 2022a

November 2024 36 Figure 3-9. Uranium in Burial Area 1 Source: EPM 2022a

November 2024 37 Figure 3-10. Sitewide Licensed Area, Including Monitoring Wells, Plumes, and Proposed Treatment Systems (Areas proposed to be brought under license outlined in red.)

Source: EPM 2024b

November 2024 38 Tc-99 concentrations in groundwater sitewide since 2004 have been below 3,000 pCi/L (111 Bq/L) and thus are below the NRC limit2 for unrestricted release of 3,790 pCi/L (140.2 Bq/L)

(NRC 2013). The NRC staff previously determined that Tc-99 remediation at the site is not necessary. Four monitoring wells have Tc-99 concentrations above the EPA-established drinking water MCL of 900 pCi/L (33.3 Bq/L). The Oklahoma DEQ plans to work with EPM to address Tc-99 concentrations in groundwater during and after decommissioning (ODEQ 2024a).

Fluoride concentrations in groundwater in the WA range from 0.175 to 48.90 mg/L, with an average of 3.1 mg/L. There is no known fluoride contamination in BA1. The NRC does not regulate fluoride since it is not a radioactive contaminant. The Oklahoma DEQ has established a criterion of 4 mg/L based on the EPA MCL for fluoride in drinking water (EPM 2022a). The Oklahoma DEQ plans to work with EPM to address fluoride concentrations in groundwater during and after decommissioning (ODEQ 2024a).

Nitrate concentrations in groundwater in the WA range from 0.028 to 1006 mg/L, with an average of 71.5 mg/L. There is no known nitrate contamination in BA1. The NRC does not regulate nitrate because it is not a radioactive contaminant. The Oklahoma DEQ has established a criterion of 22.9 mg/L of nitrate for the Cimarron site (EPM 2022a), which accounts for background nitrate levels that exceed the EPA MCL for nitrate in drinking water.

The presence of elevated nitrate levels is due at least in part to the widespread use of fertilizers for agricultural activities in the area. The State criterion of 22.9 mg/L is based on analysis of samples from wells located upgradient of any previous operations or waste disposals. The Oklahoma DEQ plans to work with EPM to address nitrate concentrations in groundwater during and after decommissioning (ODEQ 2024a).

3.3.2.3 Groundwater Use The Logan County Rural Water District provides potable water for the site from a system that provides up to 1,892,706 L (500,000 gal) of water per day in the peak summer months. Above the peak summer load, this supply system has the capacity to supply at least another 378,541 L (100,000 gal) per day (EPM 2023a). Figure 3-11 shows the locations of oil, gas, and water wells around the site. Domestic water wells are either on the north side of the Cimarron River or south and southeast (upgradient) of the site.

2 The NRC limit is based on the 1982 International Commission on Radiological Protection (ICRP) Publication 30, Limits for Intakes of Radionuclides by Workers, and a 4 millirem per year (mrem/yr) dose limit for beta emitters in drinking water established by the EPA.

November 2024 39 Figure 3-11. Water and Oil Wells within a 2-Mile Radius of the Site Source: modified from EPM 2022e 3.3.2.4. Potential Groundwater Impacts Groundwater remediation is necessary to comply with NRC license termination criteria based on the use of groundwater by a resident farmer for drinking water or raising of produce (livestock or plants). The NRC criterion for total uranium in groundwater is established in license condition 27(b) at 180 pCi/L (6.7 Bq/L) (NRC 2011a).

Under the proposed action, a total of seven groundwater extraction wells would be screened in the alluvial material. Four wells would be screened in the alluvial material in the WA, and three wells would be screened in the alluvial material in BA1 (EPM 2022a). Extraction well screens would be installed to span the vertical area of uranium concentrations above the MCL within the saturated thickness of the aquifer, and no well screen top would extend above 5 ft (1.5 m) below the ground surface. Extraction wells would be designed to maximize the mass of uranium removed during remediation efforts while minimizing the collection and treatment of minimally contaminated groundwater. This design should reduce the time required to meet the NRC groundwater criterion for groundwater.

Three groundwater extraction trenches would be installed, two in the BA1 and one in the WA.

One of these trenches was constructed during the 2017/2018 pilot test in the BA1 transition zone and is approximately 56 m (184 ft) long. Another trench would be constructed in the BA1 transition that would be approximately 61 m (200 ft) long. A third trench would be installed in the transition zone in the 1206-North area north of the Western Alluvial Area. This trench would be

November 2024 40 approximately 84 m (275 ft) long. All trenches would be within the 100-year floodplain (EPM 2022a).

After being extracted, the groundwater from each area (BA1 and WA) would be pumped to the WATF for treatment. The influent from each area would be treated separately. A portion of the treated water would be injected in upgradient sandstone units and transition zone units to flush contaminants downgradient to the extraction trenches and wells. Any treated water for injection would be injected into the same area from which it was extracted (e.g., groundwater extracted from BA1 would be reinjected only into BA1).

EPM would install five injection wells for the proposed action, four in the BA1 area and one in the WA. One of these injection wells was installed during the pilot test at the southern end of BA1 (upgradient from the extraction well). Two wells would be installed north of the first injection trench in BA1, such that they are south southwest and west of the extraction trenches, respectively. Another well would be installed between the two extraction trenches to reduce the potential for an unsaturated zone between the two extraction trenches. This well would be in the transition zone while the other three trenches would inject treated water into Sandstone B. One well would be installed in the 1206-North area east of the 1206 Drainage and would inject treated water into Sandstone A.

During operations, EPM would monitor groundwater quality using a series of wells within and surrounding the injection and extraction trenches and wells to verify that the injected water moves within the contaminated zones or area and is captured for treatment (EPM 2023c). The remaining (not reinjected) treated water from BA1 and WA would be combined and discharged into the Cimarron River, which is the natural destination of the local groundwater.

No treated water would be discharged to onsite reservoirs, as the OPDES permit would not authorize discharge to the onsite reservoirs. The treated water released into the river would be chemically similar to groundwater currently discharging into the river, but with lower concentrations of uranium (EPM 2022a).

The treatment system is designed to remove uranium from the water to meet NRC standards for unrestricted release of the site. EPM estimates that to meet the NRC criterion, the treatment system would remove roughly 589 kg (1,298 lb) of uranium from BA1 and 271 kg (598 lb) of uranium from the WA (EPM 2022a). The treatment system is not designed to reduce the concentration of the other known contaminants of concern: nitrate, fluoride, or Tc-99. The Oklahoma DEQ plans to work with EPM to address nitrate, fluoride, and Tc-99 concentrations in groundwater during and after the completion of NRC-approved decommissioning activities (ODEQ 2024a). Concentrations of nitrate, fluoride, and Tc-99 in the extracted, untreated groundwater influent are expected to be below state discharge limits and therefore the Oklahoma DEQ does not anticipate including specific OPDES permit limits for these constituents (ODEQ 2024b).

Some Tc-99 would likely be collected by groundwater treatment activities. Data from the pilot test indicated that each resin bed would collect an estimated 1.26 nanograms per liter (ng/L) of Tc-99 from the treated groundwater (EPM 2022a). Based on the Tc-99 specific activity (1.7110 pCi/g), this would be approximately 20.52 pCi/L (0.76 Bq/L) of Tc-99 per resin bed. Four monitoring wells have measurable Tc-99 concentrations above the EPA MCL of 900 pCi/L (33.3

November 2024 41 Bq/L). Because the proposed action would result in removing Tc-99, the groundwater treatment would reduce Tc-99 concentrations in groundwater.

Treated water would have a uranium concentration below the drinking water MCL. Any treated water with uranium concentrations above the MCL would be treated again until the concentration drops below the MCL and the water can be reinjected or discharged to the river (EPM 2022a).

EPM would work with the Oklahoma DEQ to ensure the reinjection of treated groundwater is conducted in accordance with Oklahomas underground injection control program. EPM would submit monthly reports to the DEQ describing the quantity of treated water injected into each injection trench (EPM 2022a).

Groundwater treatment operations would improve the quality of groundwater at the site.

Uranium contamination in the groundwater would decrease below the NRC criterion and would gradually return to concentrations near or at natural levels for the area. The proposed action could have impacts on the site shallow groundwater flow system (flow rate or direction),

although such impacts would be minor and temporary, ending shortly after remediation activity ceases. Therefore, the NRC staff concludes that the proposed action would not have significant adverse impacts on groundwater and would have beneficial impacts on groundwater quality.

Impacts on Groundwater Supply The Rural Water District provides potable water from four groundwater wells north of the Cimarron River. Although the groundwater from the site is feeding into the river, the NRC staff does not expect site groundwater to have any impact on these wells. Wells south of the site would not be affected by site conditions because groundwater flow at the site is generally north or east toward the Cimarron River.

Due to naturally poor water quality, no site groundwater is used for drinking water or irrigation (EPM 2022a). As discussed in section 2.1.4, EPM would use a few hundred gallons of water per day (supplied by the County) for sanitary purposes. In addition, resin bed sluicing operations would require less than 5,678 L (1,500 gal) of water, initially every five weeks. The frequency of resin reloading would depend on the amount of uranium extracted and would decrease over time as uranium concentrations decrease (EPM 2023a). The NRC staff concludes that this amount of water would not significantly affect the regional water supply.

3.4 Climate, Weather, and Air Quality This section describes the regional climate, weather patterns, air quality, and climate change patterns, as well as the proposed actions potential impacts on air quality and from greenhouse gas (GHG) emissions.

3.4.1 Climate and Weather The Cimarron site is in central Oklahoma within the States Central climate division and is approximately 16 km (10 mi) north of Oklahoma Citys northern suburbs (OCS 2014). Climate conditions in the state vary dramatically from the arid, high-elevation western borders to the eastern borders with humid states in the Mississippi River valley (GCRP 2023). The Oklahoma

November 2024 42 City area is temperate and humid, with frequent variations in weather seasonally, except during consistently hot and humid summer months. From March to early June, the area is affected by both warm, moist air from the Gulf of Mexico and cold, dry air from Canada. Winters are typically cool and relatively dry, though highly variable. Periods of extreme cold are infrequent, and those lasting more than a few days are rare (OCS 2003).

According to the Oklahoma Climatological Survey, between 1991 and 2020, Logan County experienced an average of 14 days per year with temperatures above 37.8 degrees Celsius (°C)

(100 degrees Fahrenheit [°F]) and 87 days per year with a low temperature below 0°C (32°F)

(OCS 2023). The mean annual temperature in the area is about 15 degrees C (59 degrees F).

Annual rainfall in Logan County is about 76 to 102 centimeters (30 to 40 inches) per year (GCRP 2018). Floods of major rivers and tributaries, such as the Cimarron River occur most frequently during the spring and autumn months associated with greatest rainfall. On average, thunderstorms occur about 45 to 55 days per year, peaking in late spring and early summer.

The Oklahoma City area has a very active severe weather season from March through June.

Located in the center of Tornado Alley, the area is prone to frequent and severe tornadoes, as well as severe hailstorms and occasional derechos.3 Tornadoes can occur any time of year but are most frequent between April and June. Between 1950 and 2010, approximately 56 tornadoes were recorded in Logan County (OCS 2023).

Drought is a recurring part of Oklahoma's climate cycle. Because almost all of Oklahoma's usable surface water comes from precipitation within the state's borders, drought in the state is tied almost entirely to local rainfall patterns (OCS 2003).

3.4.2 Air Quality Under the Clean Air Act, the EPA has established National Ambient Air Quality Standards (NAAQS) for six criteria pollutants: nitrogen dioxide, sulfur dioxide, carbon monoxide, lead, ozone, and PM. The EPA designates areas of attainment and nonattainment with respect to meeting NAAQSs. Areas for which there are insufficient data to determine attainment or nonattainment are designated as unclassifiable. Areas that were once in nonattainment, but are now in attainment, are called maintenance areas; these areas are under a 10-year monitoring plan to maintain their attainment designation status. States have primary responsibility for ensuring attainment and maintenance of the NAAQSs. For the purpose of planning and maintaining ambient air quality with respect to the NAAQSs, the EPA has developed air quality control regions (AQCRs), which are intrastate or interstate areas that share a common airshed.

Logan County is in the EPAs Central Oklahoma Intrastate Air Quality Control Region (region 184) (40 CFR 81.47). The State of Oklahoma, including Logan County, is in attainment for all criteria pollutants (ODEQ 2023).

3.4.3 Greenhouse Gases and Climate Change Gases found in Earths atmosphere that trap heat and play a role in the climate are collectively termed GHGs. These GHGs include carbon dioxide (CO2), methane, nitrous oxide, water vapor, and fluorinated gases, such as hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.

Earths climate responds to changes in concentrations of GHGs in the atmosphere because 3 A derecho is a large, fast-moving complex of thunderstorms with powerful straight-line winds that cause widespread destruction.

November 2024 43 these gases affect the amount of energy absorbed and heat trapped by the atmosphere.

Increasing concentrations of GHGs in the atmosphere generally increase Earths surface temperature. Atmospheric concentrations of CO2, methane, and nitrous oxide have significantly increased since 1850. For instance, since 1850, CO2 concentrations have increased by almost 50 percent (GCRP 2023).

In 2009, the Commission provided guidance to the NRC staff on addressing GHG issues in environmental reviews. That guidance directed the NRC staff to include consideration of carbon dioxide and other greenhouse gas emissions in its environmental reviews for major licensing actions under the National Environmental Policy Act (NRC 2009).

In 2023 the U.S. Global Change Research Program (GCRP) published its most recent report regarding the state of climate change in the nation (GCRP 2023). Information in this section is drawn from both the 2023 and the 2018 GCRP reports. The Cimarron site is in the geographic area defined in the GCRP report as the Southern Great Plains. The impacts of climate change throughout the Southern Great Plains include an increase in the intensity and frequency of drought, flooding, and severe storms, as well as rising air and water temperatures. These precipitation patterns influence water availability and aquatic habitats such as lakes, rivers, springs, and streams, which can affect the availability of food and water for wildlife and conditions for native vegetation to thrive.

Increased aridity (or dryness) is projected for the Southern Great Plains with climate change, due to enhanced evapotranspiration and depleted soil moisture associated with increased temperatures. As happened during past droughts, future drought conditions that decrease surface water availability would likely lead to an increase in the use of groundwater. The Oklahoma Water Plan projects that water use in Oklahoma is likely to increase over the next 50 years, with the greatest increase (by 63 percent) projected for energy use (GCRP 2018).

Groundwater is essential around the Cimarron site and more generally near and west of Interstate 35, with aquifers primarily supporting agricultural production and public water supply.

Although governments have created reservoirs, the Southern Great Plains region experiences some of the countrys worst water shortages, and these are projected to increase in intensity and duration (GCRP 2023).

Annual average temperatures in Oklahoma increased by 0.3°C (0.6°F) from 1900 to 2020, with the greatest warming during the winter months (GCRP 2018, 2023). Also, during that period, Oklahoma experienced increases of greater than 30 percent in the frequency of days with 2 or more inches (5 cm) of precipitation. In contrast, from 2010 to 2022, Oklahoma experienced 69 months of severe to exceptional drought conditions. Air temperatures in Oklahoma are projected to be historically unprecedented by the end of the century, with the number of extreme heat days (above 37.8°C [100°F]) per year projected to increase by 20 to 50 days.

3.4.4 Potential Impacts on Air Quality and from Greenhouse Gas Emissions 3.4.4.1 Potential Impacts on Air Quality The proposed action would result primarily in emissions from the combustion engines of earthmoving equipment, trucks, and cars. Equipment, worker vehicles, and truck shipments would emit criteria pollutants and GHGs. Construction and dismantlement operations and truck

November 2024 44 traffic would cause fugitive dust emissions. EPM would prepare a dust control plan in accordance with applicable County or State requirements (EPM 2022a).

Oklahoma requires a permit when emergency backup generators are installed because the generators are subject to Subpart IV of the NSPS. EPM would need to secure an air quality permit from the Oklahoma DEQ for the emergency generators. Because Oklahoma has established a permit-by-rule for facilities that are subject to permitting due to the construction (installation) or operation of an emergency engine subject to an NSPS, the two emergency generators could be permitted through the permit by rule (EPM 2023a).

Emissions from construction would be localized and temporary, decreasing significantly after about a year, when construction of the facility is complete. Emissions during operations would be minimal, resulting from employee vehicles, emergency generators, delivery trucks and other trucks, and maintenance vehicles. Emissions during dismantlement of the system would be similar to construction emissions, though substantially less because of the reduced level of activity. These emissions also would be localized and temporary, lasting less than one year.

Therefore, the NRC staff concludes that the potential impacts on regional air quality from the proposed action would not be significant.

3.4.4.2 Potential Impacts from Greenhouse Gas Emissions Section 2.1.5 of this EA discusses potential air emissions from the proposed action, and the carbon dioxide equivalent emissions (CO2e) are presented in tables 2-1 and 2-2. As illustrated in the tables, the proposed action would result in about 1,398 metric tons (about 1,541 tons) of CO2e from construction activities (projected to take less than a year) and about 390 metric tons (430 tons) of CO2e per year over 12.5 years from operating the groundwater treatment system and associated activities. In addition, the NRC staff conservatively estimates that dismantlement and decommissioning activities would generate another 1,398 metric tons (about 1,541 tons)

CO2e. Over 16 years from the start of construction until the end of post-remediation monitoring, the proposed action would generate about 480 metric tons (529 tons) annually.

Under 40 CFR Part 98, facilities must report emissions annually to the EPA if they emit 25,000 metric tons (27,558 tons) or more per year of CO2e. The 480 metric tons (529 tons) CO2e expected from the proposed action annually is far below the EPAs reporting threshold. Given that GHG emissions from the proposed action would be localized, temporary, and well below the EPAs reporting threshold, the NRC staff concludes that the proposed actions impacts resulting from GHGs would be minimal and not significant.

3.5 Ecological Resources This section addresses terrestrial resources and aquatic resources, describing the site environment, special status species of plants or animals (such as endangered species), and the potential impacts of the proposed action on these species or their habitats.

3.5.1 Terrestrial Resources 3.5.1.1 Affected Environment The Cimarron Site has three areas or types of terrestrial habitats: riparian, floodplain, and

November 2024 45 upland. The riparian area is located along the south bank of the Cimarron River at the north property boundary. The area includes a mature stand of phreatophyte (deep-rooted) tree species, including cottonwood and salt cedar, with an understory of wildrye, Western wheat, and sea oat grasses. The existing Cimarron River floodplain is bounded by the south side of the river and the bluffs. This area has a general mixture of native grasses, as well as tree and shrub species, including Johnson grass, wildrye, bermudagrass, soap berry, cottonwood, Eastern red cedar, black willow, and cottonwood. The upland area has a well-established stand of generally native tallgrass prairie species, including big bluestem, Indiangrass, switchgrass, little bluestem, and sideoats grass, along with a diverse group of forbs and wildflowers. This area has been historically mowed for hay (EPM 2022a).

Figure 3-12 shows where wooded areas exist in relation to planned areas of disturbance. EPM conducted a qualitative assessment of the wooded areas and documented the presence of Siberian elm, eastern red cedar, Kentucky coffeetree, black willow, fragrant sumac, bur oak, and green ash (EPM 2023a). Figure 3-12 also shows wetland areas on the site, most notably surrounding two manmade ponds and along the northern border of the site adjacent to the Cimarron River. Figure 3-13 shows areas of the site that have been used for cattle grazing or grass harvesting.

Federally Listed Terrestrial Species Protected under the Endangered Species Act The U.S. Fish and Wildlife Service (FWS) administers the Endangered Species Act of 1973 (ESA) and manages the protection of and recovery effort for listed terrestrial and freshwater species. Using the FWS Information for Planning and Consultation (IPaC) database, the NRC staff generated a species list in April 2024 and updated that list on November 11, 2024 (FWS 2024a). The only difference between the two lists is that the November list no longer contains the tricolored bat. On May 7, 2024, the NRC submitted information to the Oklahoma Ecological Services Field Office of the FWS that describes the Federal action area, the proposed groundwater remediation project, the listed threatened and endangered species, and the NRC staffs determinations of the projects potential effects on listed and candidate species (NRC 2024b, appendix A to this EA). On June 28, 2024, the Oklahoma Ecological Services Field Office responded by email concurring with the NRCs effects determinations (FWS 2024b).

Table 3-1 lists and provides summary information about the terrestrial species identified as potentially being present in the action area. These species are the tricolored bat, piping plover, rufa red knot, whooping crane, and monarch butterfly. No critical habitats are located in the vicinity of the Cimarron site for terrestrial species (FWS 2024a).

State Listed Protected Terrestrial Species The Oklahoma Department of Wildlife Conservation (ODWC) identified the same Federally listed, terrestrial species as the NRC staffs search results, as noted in table 3-1. In addition, the State identifies the tricolored bat as a species of greatest conservation need. The Oklahoma DEQ submitted questions to EPM in a letter dated August 21, 2024, including a question about the status of bat roost locations as potential or confirmed (ODEQ 2024c). EPM responded that the roost locations are potential locations (EPM 2024c). The Oklahoma DEQ responded by letter dated September 16, 2024, approving EPMs responses to the DEQs questions (ODEQ 2024d). Section 3.5.2.2 discusses DEQ questions pertaining to aquatic species.

November 2024 46 Figure 3-12. Areas of Potential Ground Disturbance and Wetland Areas Source: B&M 2024 Figure 3-13. Historically Disturbed Areas of the Site, Including Grazing and Harvest Areas Source: EPM 2022a

November 2024 47 Bald and Golden Eagle Protection Act and Migratory Birds Treaty Act Under the Bald and Golden Eagle Protection Act of 1940 and the Migratory Birds Treaty Act of 1918, native birds must be protected from project-related impacts. Any activity resulting in take of migratory birds, including eagles, is prohibited unless otherwise permitted by the FWS. In addition, Executive Order 13186, Responsibilities of Federal Agencies to Protect Migratory Birds, obligates Federal agencies to minimize the effects of their activities or authorized activities on migratory birds. No bald eagles, golden eagles, or eagle nests have been observed at the site (EPM 2023a). Further, the IPaC report (FWS 2024a) indicates that there are no bald eagles, golden eagles, or migratory birds of concern in the vicinity of the project area.

3.5.1.2 Potential Impacts on Terrestrial Resources The proposed action would involve construction of a new outfall to the Cimarron River, installation and operation of a groundwater pumping and treatment system (piping, trenches, and two buildings for treating the groundwater), and subsequent effluent discharges to the river.

To construct and operate the groundwater treatment system, approximately 15.5 ha (38.3 ac) of forested area would be cleared or potentially disturbed, with the majority of the clearing likely occurring in Spring 2025 (EPM 2024a). These activities would consist of clearing and removing native grasses and topsoil, trees, and shrubs as needed to install infrastructure and support features (e.g., to control runoff) and to improve roads. EPM would remove trees and shrubs using standard earthmoving machinery and estimates that no more than 2,000 mature trees would be removed. Two mature bur oak trees would need to be removed, and three potential bat roost trees may need to be removed (EPM 2023a). If potential roost trees need to be cleared and that cannot be accomplished prior to March 31, 2025, EPM would conduct a survey to identify and mitigate potential impacts on bats.

Noise from construction and earthmoving would last less than one year (and would be similar but reduced for the decommissioning phase). During the 12-13 year operations phase, noise would be minimal and limited to occasional vehicles and pump skid systems, similar to the present noise levels at the site.

The new outfall would be constructed approximately 73 m (240 ft) from the river, and a dispersion ditch would carry discharges to the river. Outfall and dispersion ditch construction would disturb less than 0.04 ha (0.1 ac) of riparian habitat, and construction activities would be confined to areas along the banks above the ordinary high-water mark. EPM anticipates disturbing less than 0.2 ha (0.5 ac) of riparian vegetation (EPM 2024a). EPM confirmed with the Tulsa District of the U.S. Army Corps of Engineers that the proposed design of the treatment system, with one outfall to the Cimarron River, would be covered by Nationwide Permit 7 for outfall structures and associated intake structures (EPM 2023a).

EPM would apply for a stormwater permit that requires an updated SWPPP, similar to the plan developed for the 2017 pilot project (EPM 2022d). EPM would implement best management measures as outlined in the SWPPP (e.g., installing silt fencing and erosion control blankets) during earthmoving activities, while trenches and other features are in place that could result in sediment runoff, and until vegetation is established where needed. For example, the SWPPP would require vegetative buffers for land-disturbing activities within an ARC corridor: a buffer of at least 30.5 m (100 ft) would be required along perennial and intermittent streams and a 15.2-m (50-ft) buffer would be required along ephemeral streams and drainages.

November 2024 48 EPM would sod, seed, or mulch disturbed areas within the site where construction has terminated, applying seed in accordance with Oklahoma Department of Transportation Commission specifications. Any fertilizer would be applied at the appropriate time of year and would not be applied before heavy rains, in stormwater conveyance channels, or on frozen ground. All local, State, and Federal requirements regarding fertilizer application would be followed (EPM 2022d). Herbicides would only be used around manmade surfaces (e.g., to prevent the growth of weeds in concrete cracks). Large areas of the site that have been mown for hay for several decades would continue to be mowed.

As described above and in the NRCs determinations of effects on protected species (NRC 2024b), the proposed action could affect ecological resources at the site, including some areas vegetated with trees, shrubs, and grasses. The area of the 202-ha (500-ac) site that would be disturbed totals approximately 15.5 ha (38 ac). The site is almost entirely undeveloped and covered with vegetation, as described in section 3.5.1.1. The proposed action would leave most of the site unaffected or would result in minor or temporary impacts, such as noise during construction and decommissioning. The NRC staff concludes that the proposed actions effects on terrestrial resources at the site would not be significant. As described in the NRCs ESA effect determinations outlined in the consultation email to the FWS (NRC 2024b, appendix A),

the staff has determined further that the project is not likely to adversely affect threatened or endangered terrestrial species (see table 3-1).

November 2024 49 Table 3-1. Federal and State Listed Terrestrial Species Species Federal Status State Status Description Effect Conclusion tricolored bat*

(Perimyotis subflavus) n/a Species of greatest conservation need Flying mammal.

May affect, not likely to adversely affect.

piping plover*

(Charadrius melodus)

Threatened n/a Shorebird.

May affect, not likely to adversely affect.

rufa red knot*

(Calidris canutus rufa)

Threatened n/a Shorebird.

May affect, not likely to adversely affect.

whooping crane*

(Grus americana)

Endangered n/a Shorebird.

May affect, not likely to adversely affect.

monarch butterfly*

(Danaus plexippus)

Candidate n/a Insect.

May affect, not likely to adversely affect.

• More detailed information, including the NRC ESA determinations, is provided in the consultation information provided to the FWS (see appendix A to this EA, NRC 2024b).

November 2024 50 3.5.2 Aquatic Resources 3.5.2.1 Affected Environment The Cimarron site is bordered on the north by the Cimarron River, which is a federally-designated aquatic resource of concern (EPM 2022d). In this area, the river is relatively shallow and sandy, dominated by run and riffle components. It contains relatively little pool habitat, little aquatic vegetation, and a riparian corridor with salt cedars and eastern cottonwood. Coursing through natural mineral deposits, salt plains, and saline springs, the Cimarron River is mineral-rich and feeds into the Arkansas River.

Two onsite ponds created by earthen dams constructed in the 1960s contain water year-round, but the ephemeral streams that supply water to the ponds are dry in the summers, and the water level in the ponds typically lowers during the summer (EPM 2022a). Figure 3-6 shows the surface water features on the site. The ponds are palustrine unconsolidated bottom wetlands and have a surrounding or nearby riparian area or palustrine emergent wetlands. The riparian woodlands include dogwood species, eastern cottonwood, and eastern red cedar. One large wetland observed on the site includes dogwood species, eastern cottonwood, and eastern red cedar. Herbaceous wetland vegetation includes pinkweed and spike-rush, among many other species (EPM 2023).

Federally Listed Aquatic Species Protected under the Endangered Species Act The FWS and the National Marine Fisheries Service (NMFS) jointly administer the Federal Endangered Species Act of 1973 (ESA). The FWS manages the protection of and recovery effort for listed freshwater species, and the NMFS manages the protection of and recovery effort for listed marine and anadromous species.

Table 3-2 lists the threatened and endangered aquatic species and critical habitats identified for the action area. These species are the peppered chub and the Arkansas River shiner, and critical habitat has been designated for both species. The NRCs May 7, 2024, consultation information in appendix A of this EA describes in detail the proposed projects potential effects on these listed threatened and endangered aquatic species and their critical habitats. On June 28, 2024, the Oklahoma Ecological Services Field Office responded by email concurring with the NRCs effects determinations (FWS 2024b).

State Listed Protected Species Two species of fish, the blackside darter and the longnose darter, are special status species in Oklahoma. The blackside darter is a small fish in the perch family with a yellowish-olive body color and rectangular blotches along each side. Blackside darters were likely uncommon in Oklahoma historically. While its range in Oklahoma is limited (southeastern Oklahoma), the fish is widespread in several eastern states in the Mississippi River drainage. This species most likely prefers streams with high water quality and substrates containing a mix of gravel and larger cobble (rock) (ODWC 2023b).

The longnose darter is a small, slender member of the perch family with an elongated head and snout, yellowish body color, and dark vertical blotches on each side. In Oklahoma, this fish is currently found in one creek along the eastern border of the state. This species occupies

November 2024 51 streams and rivers with high water quality and a mixture of gravel and larger cobble substrate (ODWC 2023c).

3.5.2.2 Potential Impacts on Aquatic Resources EPM would discharge treated groundwater either by injection to the ground or as a discharge to the Cimarron River. The outfall for discharges to the river would be set back approximately 73 m (240 ft) from the riverbank, with a dispersion ditch extending from the outfall to the river. Treated water would discharge at a maximum rate of 852 L/min (225 gal/min) and a design rate of 651 L/min (172 gal/min). EPM does not anticipate making any changes to instream flow, banks, or other habitat features directly associated with the Cimarron River. The area of riparian vegetation that would be permanently impacted is less than 0.5 acre (EPM 2024a).

As described in the NRCs ESA effect determinations located within the consultation package (appendix A to this EA, NRC 2024b), the Cimarron River is designated critical habitat for two species of fish, the peppered chub and the Arkansas River shiner. When discharging treated groundwater to the Cimarron River, EPM would abide by relevant Federal and State regulations, including conditions in the OPDES permit. The proposed action would increase the rate of flow in the river by up to 1.2 percent, based on a low-flow rate in the river of 71,923 L/min (19,000 gal/min) and a maximum discharge rate of 852 L/min (225 gal/min) (EPM 2024a). The discharge water would be adjusted for pH to fall within 6.8 to 7.0 and would meet NRC standards in 10 CFR Part 20, as well as discharge standards in the OPDES permit (EPM 2022a). The discharge limit for uranium would be between 30 µg/L and 100 µg/L(ODEQ 2024b). The Oklahoma DEQ does not expect that the OPDES permit will need to specify limits for Tc-99, fluoride, or nitrate.

Effluents would not affect conductivity or dissolved oxygen and would not be heated.

The proposed action would not result in impacts to the two onsite ponds or site wetlands. EPM would obtain Nationwide Permit 7 wetlands permit for outfall structures and associated intake structures. This permit would be needed for the construction of the discharge structure and the dispersion ditch at the riverbank (EPM 2023a).

Based on the information above, the NRC staff concludes that the proposed actions effects on the aquatic environment would not be significant. The water discharged to the river would be treated water that meets drinking water standards for uranium and Tc-99. The maximum discharge would be about 1 percent of the total river flow at low flow conditions. The proposed action would not affect wetlands or the onsite ponds. As shown in table 3-2 and further described in the NRCs consultation package (NRC 2024b), the NRC staff has determined that Federal and State threatened or endangered species of fish would not be affected because they are not present in the river. The proposed action is not likely to destroy or adversely modify designated critical habitat for the Arkansas River shiner and for the peppered chub (NRC 2024b). In its August 21, 2024, letter to EPM, the Oklahoma DEQ asked whether an aquatic field survey would be needed for aquatic species (ODEQ 2024c). EPM responded that a field survey is not required by the FWS and that the two species of fish are presumed to be extirpated from the Cimarron River (EPM 2024c). In its response to EPM, the Oklahoma DEQ approved EPMs response to this question (ODEQ 2024d).

November 2024 52 Table 3-2. Federal and State Listed Aquatic Species and Federal Listed Critical Habitat Species Federal Status State Status Description Effects Conclusion Arkansas River shiner*

(Notropis Girardi)

Threatened Critically imperiled/

Endangered Fish. Not present in action area No effect.

Arkansas River shiner critical habitat*

Designated n/a Overlaps with action area.

Not likely to destroy or adversely modify.

Peppered chub*

(Macrhybopsis tetranema)

Endangered n/a Fish. Not present in action area.

No effect.

Peppered chub critical habitat*

Designated n/a Overlaps with action area.

Not likely to destroy or adversely modify.

Blackside darter (Percina maculate) n/a Imperiled/

Threatened Fish. Not present in action area.

No effect.

Longnose darter (Percina nasuta)

Under review Critically imperiled/

Endangered Fish. Not present in action area.

No effect.

• More detailed information is in the consultation information provided to the FWS (NRC 2024b).

November 2024 53 3.6 Public and Occupational Health 3.6.1 Affected Environment All site decommissioning activities have been completed except for groundwater remediation.

Present site activities consist of property maintenance and groundwater investigations related to the proposed groundwater treatment plan described in the DP. There are no measurable amounts of contaminants above background levels on the land surface sitewide. Section 3.3.2 of this EA describes the groundwater conditions at the site. Due to naturally poor water quality, no site groundwater is used for drinking water or irrigation; thus, there is no current exposure pathway for the radioactive material in the groundwater (EPM 2022a), no occupational radiological exposure approaching NRC limits in 10 CFR 20.1201, and no known public exposure from the site. Nonradiological hazards to workers are minimal from current site operations (groundwater investigations and site maintenance).

The licensee has a radiation protection plan (RPP) that the NRC initially approved in license amendment 15 in July 1999. EPM updates the RPP annually, and the most recent version is included as appendix M of the DP (EPM 2022g). The RPP establishes the processes for implementing air monitoring, calculating exposures, providing respiratory protection, and controlling contamination as needed during decommissioning to ensure the protection and safety of workers and the public. Currently, no air monitoring or respiratory protection requirements apply at the site, as there is no identified pathway for radiation exposure.

3.6.2 Potential Impacts 3.6.2.1 Nonradiological Impacts Nonradiological impacts may occur during construction, operation, and dismantlement of the groundwater remediation system. EPM would control fugitive dust by following a dust control plan, using dust suppression measures, limiting vehicle speeds on site, and stabilizing soil stockpiles. Any ground disturbing activities related to the placement of piping for the groundwater treatment system would follow local and state license requirements for soil erosion and stormwater runoff to prevent accidental contamination spread and ensure worker safety (EPM 2022d). To avoid the risk of a fire at the site, combustible materials such as gasoline or diesel fuel would be properly stored in accordance with applicable ordinances. EPM would also develop and implement a fire protection plan in accordance with Occupational Safety and Health Administration standards.

The treated groundwater that would be discharged into the Cimarron River would be less contaminated than the untreated groundwater, which would naturally discharge into the river without intervention. The non-radiological contaminants (nitrate and fluoride) would not be treated during the proposed action and would thus remain largely unaffected by the proposed action. Discharges of treated groundwater to the river must comply with any OPDES permit or other Oklahoma DEQ requirements for nitrate, fluoride, and Tc-99, and the OPDES permit limit for uranium, which the DEQ expects to set no lower than 30 µg/L and no higher than 50 percent of the NRCs effluent standard (i.e., no higher than 100 µg/L) (ODEQ 2024b). The Oklahoma DEQ has stated that it will work with EPM to address Tc-99, nitrate, and fluoride concentrations in groundwater during and after decommissioning (ODEQ 2024a).

November 2024 54 EPM would follow Federal and State worker safety and health requirements during construction, operation, and decommissioning of the groundwater treatment facility. After NRC-required treatment is complete and the license is terminated (in a separate licensing action), the site would remain under EPM control and State oversight, with continued NRC involvement as a beneficiary of the Trust until the Trust is terminated. The Oklahoma DEQ would likely impose restrictions on future use of the property, including restricting the use of groundwater for drinking or irrigation. Therefore, the NRC staff concludes that potential nonradiological impacts from the proposed action on occupational and public health and safety would not be significant.

3.6.2.2 Radiological Impacts Licensees are required to comply with NRC regulations that limit doses to the public in 10 CFR Part 20, Subpart D, Radiation Dose Limits for Individual Members of the Public. In addition, licensees must comply with NRC limits for radioactive materials in effluents in 10 CFR Part 20 Appendix, Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for Release to Sewerage. Because the Cimarron site is being decommissioned for eventual release from the NRC license, the site must also meet requirements in license condition 27.

Occupational Exposure The proposed action involves concentrating uranium in anion resin, to be packaged and transported offsite for disposal at a licensed facility (EPM 2022a). The removal of uranium from the pumped groundwater is a passive system that would not require regular onsite personnel exposure. EPM estimates that workers would be in close proximity to the contaminated anion resin less than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> per week. The exposure rate for workers at a distance of 30 cm (12 in) from the resin beds was estimated to be less than 30 µR/hr (0.026 mrem/hr) (EPM 2022a).

Assuming 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of exposure at 30 cm (12 in) per day for a full-time worker, the estimated annual dose would be approximately 62,400 µR (54.7 mrem), well below the occupational regulatory limit of 0.05 Sv (5,000 mrem) in 10 CFR 20.1201. An annual dose of 62,400 µR (54.7 mrem) is conservative because it assumes a daily 8-hour exposure rate, but the actual exposure rate would be less than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> a week.

When resin beds are replaced, the lead vessel would be transported by forklift to the spent resin handling area, where it would be washed. The resin would be dewatered and then blended with inert absorbent material. The process would not require any worker to be near the uranium-contaminated resin for extended periods. Spent resin would be stored in 55-gallon (208-L) drums in the southern portion of WATF until the drums are shipped for disposal at an approved off-site waste disposal facility. Spent resin storage and handling is discussed in further detail in section 2.1.7 of this EA. All operating procedures for the treatment facility, packaging, and shipping of spent resin would be conducted in accordance with the as low as reasonably achievable (ALARA) principle as described in the RPP (EPM 2022g).

Airborne radioactive contamination is unlikely because the contaminated material would consist primarily of ion exchange resin, PPE, tubing, and water. Resin particles would be too large to become airborne particulates (about 600 microns), and all processing and packaging would be done within containment. The RPP for the Cimarron site would require air sampling during resin unloading and packaging to confirm airborne radioactivity is below NRC limits. EPM would use passive area radiation monitoring using thermoluminescent dosimeters or optically stimulated

November 2024 55 luminescent dosimeters to verify no individual receives a dose beyond 10 percent of the occupational limits in 10 CFR Part 20 (EPM 2022g). If individual monitoring is shown to be necessary based on area monitoring, EPM would provide workers with personal dosimeters as outlined in section 6.5 of the RPP. Respiratory protection would be required if a workers intake exceeds 40 DAC-hours in a week. If the potential intake for workers exceeds 2 percent of the annual limits on intake, the Radiation Safety Officer would perform an investigation to determine whether internal exposure monitoring is required (EPM 2022g). No worker is expected to receive a total effective dose equivalent of more than 100 mrem (1 mSv) per year from the proposed action (EPM 2022a).

Public Exposure The regulation in 10 CFR 20.1301 establishes 1 mSv/yr (100 mrem/yr) as the limit for total effective dose equivalent to individual members of the public. The NRC requires that the licensee demonstrate compliance, by measurement or calculation, to show either that the highest dose to an individual member of the public from sources under the licensees control does not exceed the regulatory limits, or that the annual average concentrations of radioactive material released in gaseous and liquid effluents do not exceed levels specified in 10 CFR Part 20, Appendix B, Table II, at the unrestricted area boundary.

License condition 27(c) lists the unrestricted release criteria for facilities, equipment, and soil or soil-like material. The unrestricted release of soils and soil-like material requires an average dose of 10 µR/hr (0.01 mrem) above background at 1 m (3.3 ft), with a maximum of 20 µR/hr (0.02 mrem) above background at 1 meter (3.3 feet) for any 100 m2 (1,070 ft2) area of the site (EPM 2022a). The soil buried at the disposal cell designated BA4 is below these dose requirements but some of that soil exceeds the total enriched uranium concentration limit in license condition 27(c) of 30 pCi/g (1.1 Bq/g). BA4 was approved by NRC and the Oklahoma DEQ in 1994 to be used as an onsite disposal area for contaminated soils. The uranium concentrations range from 30 pCi (1.11 Bq) to 100 pCi (3.7 Bq) per gram in a total of 12,804 m3 (452,186 ft3) of soil in three ditches inside the disposal cell. All contaminated soil was covered with 1.2 to 1.8 m (4 to 6 ft) of clean cover soil followed by topsoil that was seeded with vegetation (EPM 2022a). The onsite disposal cell was closed and all post-closure monitoring and notification required in license condition 23(b) are complete (notification in the deed and permanent markers at the corners of the disposal cell). Section 3.2.2 of this EA describes the resident farmer dose assessment the NRC completed in 1999 for this area and the NRCs inspection report that concluded the area was releasable from the license. The proposed action would not include unearthing any portion of the disposal cell. Any soil or soil-like material that may be unearthed during decommissioning operations that has radiation levels exceeding unrestricted release criteria would be removed and shipped as low-level radioactive waste to an appropriate waste disposal site. Because the unrestricted release criteria require that a full-time resident farmer receive a dose no greater than 1 mSv/yr (100 mrem/yr), the NRC staff does not expect any radiological health impact to the public from unearthed soil during operation or decommissioning of the proposed treatment system.

If an accidental release of radioactive material were to occur during operation, it would likely be associated with the leakage of pretreated, contaminated water from the treatment system tanks or piping. To reduce the chances of a release, all tanks and pipes would be monitored regularly during operation, as outlined in the RPP, and would be drained before any replacement or before removal during decommissioning. Combustible or flammable materials, such as diesel fuel, would be stored away from the treatment system to avoid affecting radiologically

November 2024 56 contaminated materials in the event of an accidental fire. Potentially contaminated combustibles at the site would include personnel protective clothing, rags and towels used for site cleanup, and other small items. The radioactivity contained in these materials would not be sufficient to result in a measurable release of radiation in the event of a fire (EPM 2022a).

Because EPMs proposed DP, if approved, would require compliance with NRC requirements for protecting public health and safety during all phases of the proposed action, as described in the paragraphs above, the NRC staff concludes that radiological impacts on public health and safety from the proposed action would not be significant.

3.7 Socioeconomics This section describes the demographic characteristics of the area around the Cimarron site and the potential socioeconomic impacts from the proposed action, including environmental justice considerations.

3.7.1 Demographic and Socioeconomic Conditions EPM currently has a very small workforce of about three employees at the Cimarron Site (EPM 2023a). EPM paid Logan County $479 for property taxes in 2023 (Logan County 2023).

According to the 2020 U.S. Census Bureau decennial census, Logan Countys population was 49,555 (USCB 2023). There are four census block groups within a 6.4 km (4 mi) radius of the Cimarron site whose combined population was 5,517 people in 2020 (EPA 2023). The population of Logan County is projected to be 56,322 by 2045 (Chiappe 2023), which covers the period until license termination in 2043. The Greater Guthrie Chamber of Commerce website provides a listing of several agricultural and farm businesses in the area that employ seasonal or temporary workforces (Greater Guthrie Chamber of Commerce 2023). Oil and gas field operations within 3.2 km (2 mi) of the site likely also employ temporary workers (EPM 2022a).

Table 3-3 presents 2022 U.S. Census estimates for race, ethnicity, median income, and individuals in poverty in Logan County and the State of Oklahoma.

Table 3-3 Race, Ethnicity, Income, and Poverty in Logan County and the State of Oklahoma Category Logan County (expressed as percent unless otherwise denoted)

State of Oklahoma (expressed as percent unless otherwise denoted)

White alone(a) 82.8 73.0 Black or African American(a) 7.4 7.9 American Indian and Alaska Native(a) 3.8 9.5 Asian(a) 0.7 2.6 Native Hawaiian and other Pacific Islander(a) 0.1 0.3 Persons reporting two or more races(a) 5.1 6.7 Persons of Hispanic or Latino origin(b) 8.1 12.1 White, non-Hispanic(a) 76.3 63.4

November 2024 57 Table 3-3, Continued Race, Ethnicity, Income, and Poverty in Logan County and the State of Oklahoma Category Logan County (expressed as percent unless otherwise denoted)

State of Oklahoma (expressed as percent unless otherwise denoted)

Percent minority 23.7 36.6 Median household income, 2018-2022

$80,565

$61,364 Individuals below poverty level 12.0 15.7 (a) Includes persons reporting only one race.

(b) Hispanics may be of any race, so are also included in applicable race categories.

Source: U.S. Census website: https://www.census.gov/quickfacts/fact/table/OK,logancountyoklahoma/PST045222 3.7.2 Potential Socioeconomic Impacts During construction, which should take less than one year, EPM would need to increase the number of workers at the site. The number of construction workers would range from two workers to as many as 24 workers. During remediation and monitoring, the number of workers would vary, generally between two and three operations and maintenance and health physics personnel. Demobilization (decommissioning) of the remediation systems would require about 12 workers for approximately 11 months (EPM 2022a, 2023a). Based on the number of people living in the region, an additional 24 workers (at most) would not noticeably increase the demand for housing, utilities, or public services. There would be no noticeable effect on temporary and seasonal workforces in the region or on their commutes.

CERTs current tax payments ($479 in 2023) are not significant compared to the total amount of property taxes collected in Logan County. If portions of the site are released from the license in the future, there would be no noticeable change in the county tax revenue generated from the site. For these reasons, the NRC staff does not anticipate related changes to or impacts on the local economy. Therefore, the NRC staff concludes that the socioeconomic impacts from the proposed action would not be significant.

3.7.3 Environmental Justice Executive Order (EO) 12898 (59 FR 7629), Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations, directs Federal agencies to identify and address the disproportionately high and adverse human health or environmental effects of their actions on minority and low-income populations. Although independent agencies, such as the NRC, were only requested rather than directed to comply with the EO, NRC Chairman Ivan Selin, in a letter to the President, indicated that the NRC would endeavor to carry out the measures set forth in the EO and the accompanying memorandum as part of the NRCs efforts to comply with the requirements of NEPA. In 2004, the Commission issued its Policy Statement on the Treatment of Environmental Justice Matters in NRC Regulatory and Licensing Actions (69 FR 52040).

In 2022, the estimated percentage of minority populations in each of the four block groups located within the 6.4-km (4-mi) radius of the Cimarron site did not exceed 50 percent of the total block group population or the corresponding county or state percentage by more than 20

November 2024 58 percentage points (see table 3-3). In the 2020 decennial Census, 23.7 percent of the population within the 6.4-km (4-mi) radius identified themselves as minority.

In addition, in 2022, the estimated percentage of low-income populations in each of the four block groups did not exceed 50 percent of the total block group population or meaningfully exceed corresponding state or county percentages. However, in 2020, two of the four census block groups had percentages of low-income households and individuals with poverty levels exceeding the percentages for Logan County and the State of Oklahoma by more than 20 percentage points. This included the block group where the Cimarron site is located.

Furthermore, the Council on Environmental Quality (CEQ) identifies the Cimarron site census tract as both overburdened and underserved (CEQ 2023).

The Cimarron site is approximately 500 ac (202 ha) and provides a large buffer area around the limited proposed action activities that would occur on 12 ac (4.9 ha). The proposed action would result in beneficial impacts on groundwater and result in temporary impacts on air quality and from noise during the construction and dismantlement phases. The NRC staff does not expect that people offsite would experience impacts except potentially for a limited amount of temporary noise and dust. EPM must meet NRC requirements for public health, as described in section 3.6.2.2 of this EA.

Based on this information and the analysis of human health and environmental impacts in this environmental assessment, the NRC concludes that minority and low-income populations near the Cimarron site would not experience significant or disproportionate and adverse human health and environmental effects from the proposed action.

3.8 Historic and Cultural Resources The National Historic Preservation Act of 1966, as amended (NHPA), requires Federal agencies to consider the effects of their undertakings on historic properties, and the proposed groundwater remediation activities are an undertaking that could potentially affect historic properties. As stated in the act, historic properties are any prehistoric or historic district, site, building, structure, or object included in or eligible for inclusion in the National Register of Historic Places (NRHP). This includes cultural resources, sites, or artifacts that may be associated with Native American tribes.

This section describes the known historic and cultural resources on and in the vicinity of the site and the potential impacts of the proposed action on known resources. Section 4 of this EA describes the NRCs consultation with the Oklahoma State Historic Preservation Office (SHPO),

the Oklahoma Archeological Survey (OAS), and Federally-recognized Native American tribes.

3.8.1 Affected Environment The site is situated on approximately 500 acres (202 ha) along the south bank of the Cimarron River. Prior to the construction of the facility, much of the property was used for grazing and farming. In 1965, the Cimarron Fuel Fabrication Site was established to enrich uranium fuel for use in nuclear power plants, while large areas of the site continued to be used for grazing, farming, and harvesting grass for cattle. Fuel fabrication continued until 1975 and then decommissioning activities began. Figures 1-1 and 1-2 show the areas of the site that have been used for the facility or for agricultural purposes over the last several decades.

November 2024 59 The proposed groundwater remediation project would disturb areas of the site needed for groundwater remediation infrastructure, including two buildings, aboveground and underground piping, wells, trenches, and utilities (as described in section 2 of this EA). The area of potential effect (APE) is approximately 214.5 ha (530 ac), comprising the Cimarron site (licensed areas and areas released from the license) and the adjacent 10 ha (25 ac) that were formerly part of the site but are now owned by Kalidy LLC and Craftair Industries.

At the request of the Oklahoma Archeological Survey (OAS 2019), EPM conducted a cultural resources survey in May 2020 and produced a report that describes the resources identified and provides determinations of eligibility for listing on the NRHP (B&M 2020). The survey identified seven standing historic structures and no archaeological resources. Section 6 of the survey report contains detailed descriptions of the seven resources and their respective NRHP-eligibility determinations. The NRC staff provided these eligibility recommendations to the SHPO and the OAS, and the SHPO and OAS agreed with the NRCs recommendations and determinations (SHPO 2023; OAS 2023). These resources are depicted on figure 3-14 and briefly described below:

Resource 01/01a: Mixed Oxide Fuel Fabrication building and associated cooling plant -

This building (Resource 01) was used from 1970 until 1975 for the production of plutonium-containing nuclear fuel. This resource is on the adjacent 10-ha (25-ac) property that is no longer part of the Cimarron site.

Resource 02: Warehouse #4 - This warehouse was used to support nuclear fuel manufacturing operations until 1975. After 1975, the building was used for other industrial purposes as described in section 6.1.3 of the survey report. This resource is on the adjacent property that is no longer part of the Cimarron site.

Resource 03: Emergency Response Building - This building served as an emergency response station during the nuclear manufacturing facilitys operating years. This resource is on the adjacent property that is no longer part of the Cimarron site.

Resources 04, 05, and 06: Abandoned Diesel Pumps - These abandoned diesel pumps were used to pump water from the Cimarron River to the facility and are located at the northwest corner of the property along the south bank of the Cimarron River.

Resource 07: A Mid-twentieth Century Corral and Associated Wire Fence - This resource consists of three pens connected to a hallway or corridor and is described further in section 6.1.6 of the survey report.

Resources 01/01a, 02, 03, 04, 05, and 06 maintain historic associations with a facility important in the nuclear history of the United States sand are eligible for listing on the NRHP. Resource 07 is not eligible because it does not have any known historical associations important to local or national history, is not distinctive in form or design, and is not part of an archeological site (NRC 2023e; SHPO 2023).

November 2024 60 Figure 3-14. Area of Potential Effect, Survey Results, and NRHP-Eligible Resources Source: B&M 2020 3.8.2 Potential Impacts on Historic and Cultural Resources As described in section 2 of this EA and as shown on figure 3-14, all proposed ground disturbance would occur in areas away from the identified historic resources. To ensure the protection of any unknown resources that EPM may encounter during excavation and other ground-disturbing activities, and consistent with SHPO recommendations to preserve the visual quality of the resources associated with the former fuel fabrication facility (SHPO 2023), the NRC would add a condition to license SNM-928 that would require the following:

If archaeological artifacts are discovered during ground-disturbing activities, EPM must cease all work within 15 m (50 ft) of the discovery and secure the location against further disturbance. EPM must notify the NRC, SHPO, and OAS of the discovery before the close of business the next working day after the discovery. If human remains, funerary objects, sacred objects, or objects of cultural patrimony are encountered, EPM must cease all activities within 15 m (50 ft) of the discovery and secure the location. EPM must notify the NRC, SHPO, and OAS within one working day.

Upon completion of the groundwater remediation project, and except for the permanent WATF building and associated utilities and ancillary equipment, the site must be

November 2024 61 returned to pre-construction condition. For example, for any monitoring wells not required to remain in place by the Oklahoma DEQ, concrete pads must be removed, filled, and revegetated. This is to ensure that the project has no lasting visual effect on the NRHP-eligible properties.

Based on this information and the addition of the license condition, the NRC staff concludes that the proposed action is not likely to adversely affect identified historic resources. With the license condition in place, the NRC staff also concludes that EPM would prevent or mitigate disturbance to resources that may be encountered during excavation activities.

3.9 Visual and Scenic Resources This section describes the visual environment around the site and the potential visual impacts of the proposed action.

3.9.1 Affected Visual and Scenic Environment The site is in a rural area of Logan County, Oklahoma consisting mostly of cultivated land. The landscape is a mix of low, rolling hills and grasslands interspersed with riparian areas around streams. As described in section 3.1.2 there are a few small towns in the vicinity with some farmsteads and houses scattered throughout the area (EPM 2022a).

No buildings remain within the current site boundary, and the site is a mix of grasslands and forested areas. On land adjacent to the current site boundary, the MOFF building, emergency response building, and warehouse still stand. Prior to the sale of portions of the site, these remaining buildings and surrounding pavement had been deteriorating. The sale of the land resulted in the repair of fences and gates west of Highway 74, the renovation of the buildings, the repair of pavement, and improved fencing and gating of the site (EPM 2022a).

3.9.2 Potential Impacts on Visual and Scenic Resources EPM conducted a viewshed analysis to establish the areas in which the structures associated with the proposed action (i.e., groundwater remediation) could be viewed and also provide an inventory of sensitive receptors. The viewshed analysis used ArcGIS to incorporate all publicly available data representing Federal, state, and local parks, the NRHP, tribal-owned lands, wildlife recreational areas, federal and state-owned lands, and scenic rivers to produce a 32 km (20 mi) viewshed model (EPM 2022h). A total of 52 sensitive receptors (24 local parks and 28 National Register of Historic Places sites) were identified. The closest sensitive receptor is over 9.6 km (6 mi) away.

Structures to be built for the proposed action would be neutral in color consistent with pre-engineered industrial buildings. Structures would be placed on upland areas above the flood plain of the Cimarron River, with nearby surrounding riparian vegetation providing a natural visual screen. Of the proposed new buildings, the tallest structure would be no more than 15 m (49 ft) above the current ground level (EPM 2022h).

Because visual effects are inversely proportional to distance, the NRC anticipates that the visual effects of the proposed structures would be minimal at distances greater than 8 km (5 mi). In

November 2024 62 addition, because the proposed structures would be located next to riparian areas, some of the visual impacts would be blocked by vegetation. The neutral colors of the structures would further reduce visual impacts. Although there are roadways located within the viewshed area, any potential visual impact to passing motorists would be temporary. Therefore, the NRC staff concludes that the proposed action would have no significant visual impacts to sensitive or other receptors.

3.10 Noise This section describes noise levels in the surrounding environment and the potential noise impacts from the proposed action.

3.10.1 Noise Levels in the Affected Environment The Cimarron site is situated in a rural area. The nearest resident is at the southeast boundary of the site, separated by a dense forested area. There are no schools, hospitals, prisons, motels, or hotels in the immediate vicinity of the site. Therefore, noise receptors are minimal.

EPMs contractor Burns and McDonnell conducted a noise survey, measuring ambient sound levels at six representative noise-sensitive receiver locations. At these locations the ambient sound levels varied from a low of 34.8 decibels (dBA) during the midnight measurements to a high of 67.8 dBA during the morning measurements (EPM 2022a). For reference, a quiet residential area experiences noise levels at around 40 dBA, while freeway traffic may generate around 70 dBA (CHC 2023).

The State of Oklahoma does not have applicable state-wide noise regulations and has delegated the authority to the individual counties and cities. The site is in an unincorporated area of Logan County near Cimarron City and the City of Guthrie. Logan County does not have any noise regulations applicable to the site, and the cities' noise ordinances would not be applicable to the site because it is located outside each citys limits. Neither the City of Guthrie nor Cimarron City establish numerical noise limits in their city ordinances (EPM 2022i).

3.10.2 Potential Impacts from Noise In 1974, as required by the Noise Control Act of 1972, the EPA published Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety, which established the EPA recommended guideline for outdoor activity in residential areas. This guideline is a day-night average sound level of 55 dBA or less, which is equivalent to a 24-hour period sound level of 48.6 dBA (EPA 1974). Due to the absence of local noise regulations and consistent with the EPA guidance, EPM established a design goal of 48.6 dBA for surrounding noise sensitive receivers (EPM 2022a).

For the survey report, Burns and McDonnell conservatively assigned all sound emitting equipment a sound pressure level of 85 dBA at 0.9 m (3 ft) horizontally (EPM 2022a). During the construction and demobilization phases, the greatest sources of noise would be from construction and earthmoving equipment, ranging from 80 to 90 dBA. Reduced noise during operations would primarily be emitted by pump skids located outside of the water treatment building. The extraction and treatment of groundwater, and the subsequent injection and/or discharge of treated water would not produce noise that can be heard by neighbors (EPM

November 2024 63 2022a). Individuals working onsite would not be exposed to sound levels that would require hearing protection. The overall sound levels experienced by neighboring properties would be the combination of sound from equipment associated with the proposed action and existing ambient sound. The site has a significant elevation change, which scatters and absorbs the sound waves (EPM 2022i). Vegetation throughout the site would also effectively absorb sound from project activities.

Based on the noise level modeling, there would be no significant increases to ambient sound levels at off-site receptor locations. The largest increase over the quietest measured background ambient sound level would be approximately 1 dbA (EPM 2022i). As stated above, noise from the proposed action would remain below the goal of 48.6 dBA at the surrounding noise-sensitive receptors (EPM 2022i). Therefore, the NRC staff concludes that the impacts from increased noise as the result of the proposed action would not be significant.

3.11 Waste Management This section describes the capacity of available waste management facilities that would be receiving wastes from the proposed action, as well as the potential impacts from waste generation and disposal. Section 2.1.7 of this EA describes the wastes and effluents that would be generated during the proposed action.

3.11.1 Waste Management Facilities and Capacity Class A LLRW and nonradioactive solid wastes would result from the proposed action. The management of LLRW and nonradioactive wastes would be subject to non-NRC Federal and State regulations, permits, licenses, notifications, and approvals, including those for hazardous waste generation and disposition. Class A LLRW would be transported to the Clive, Utah, EnergySolutions facility, which has an overall LLRW capacity of 6,670,051 m3 (235,550,619 ft3)

(EnergySolutions 2015), or to the Andrews, Texas, WCS facility, which has a licensed disposal capacity of 736,238 m3 (26,000,000 ft3) (WCS 2022). Nonhazardous municipal waste and construction and demolition recyclables and waste would be transported for disposal at the Guthrie Landfill, located approximately 14 km (9 mi) from the site (EPM 2023).

3.11.2 Potential Waste Management Impacts The NRC anticipates that operation of the groundwater treatment system would generate 11.3 and 14.2 m3 (400 and 500 ft3) of LLRW annually. Although the generation of LLRW would likely decrease over time as the quantity of contaminated groundwater decreases, the NRC staff assumes for this EA that approximately 14.2 m3 (500 ft3) per year would be generated over the approximate 12.5 years of pumping operations (EPM 2022). The total volume of LLRW from the proposed action would account for less than 1 percent of the capacity of either the EnergySolutions or the WCS facility.

The use of pre-engineered building materials during construction and the use of an ion exchange system would result in generating very little nonradioactive solid waste. Upon dismantling of the treatment facility equipment, components that can be practically surveyed for unrestricted release would be surveyed. If the equipment can be demonstrated to be releasable, it would be disposed of at the Guthrie Landfill, located about 14 km (9 mi) from the site. The

November 2024 64 proposed action would generate a total of approximately 4,536 kg (10,000 lb) of nonradioactive nonhazardous waste, which includes approximately 4 kg (9 lb) per worker per year. Less waste would be generated during the operations phase than during the construction and decommissioning phases (EPM 2023a). The NRC staff does not anticipate that waste from the proposed action would create a significant burden on the existing nearby landfill facilities. The NRC staff assumes that Logan County and other local governments monitor and plan as appropriate to ensure that future disposal capacity will meet regional needs.

Hazardous wastes generated during the proposed action would include incidental wastes created by maintenance activities, such as rags with waste solvents or oils. Any hazardous wastes would be disposed of appropriately as required by State and local regulations.

The NRC staff expects that EPM would continue to adhere to applicable local, State, and Federal requirements regarding nonradioactive waste generation, handling, and disposal.

Likewise, the staff expects that EPM would comply with State requirements for the management and disposal of LLRW. Based on these expectations and the availability of disposal capacity for both LLRW and nonradioactive wastes, the NRC staff concludes that the potential impacts of waste management would not be significant.

3.12 Transportation and Traffic 3.12.1 Affected Transportation Environment Transportation routes around and on the Cimarron site are shown on figures 3-15 and 3-16. The site is located northeast of the intersection of state highways 74 and 33 in a rural area with light to moderate traffic, depending on the time of day. Cimarron City, with a population of less than 200 people, is directly to the north (across the river) and east of the site. The closest major airport is Will Rogers World Airport in Oklahoma City, which is situated about 56.3 km (35 mi) south of the site.

Figure 3-15 shows the unpaved, dirt and gravel roads that traverse the site. Workers would access the site from the entrance along State Highway 74 (EPM 2022a), which is on the neighboring property. EPM has been granted unrestricted access to this entrance.

November 2024 65 Figure 3-15. Transportation Routes near the Cimarron Site Source: Google Maps, accessed 12/28/2023

November 2024 66 Figure 3-16. Roads on the Cimarron Site Source: Google Maps, accessed 12/28/2023 3.12.2 Potential Transportation Impacts Improvements to unpaved roads in the licensed area would be needed to provide essential access to planned facilities on the Cimarron site. No traffic or road infrastructure improvements outside of the licensed area would be needed (EPM 2022a). Most likely, the primary roadways used for commuting workers, equipment and supply shipments, and any produced-waste shipments would be Highway 74 to and from the Oklahoma City metropolitan area or Highway 33 through Guthrie (EPM 2022a).

During the remediation construction phase and demobilization phase, workers would drive personal vehicles and commercial trucks, tractor trailers, and concrete trucks to and from the site regularly. Earthmoving equipment and heavy machinery, such as bulldozers, forklifts, backhoes, scrapers, generators, would be brought to the site and left for several months (less than one year) until construction or demobilization is completed. During the operations phase, consumable materials including hydrochloric acid, ion exchange resin, fuel, and vehicle maintenance supplies would be delivered to the site by trucks or tractor trailers. Municipal solid waste generated at the site would be transported routinely, but not daily, during the life of the project. Removing post-construction and demolition waste (e.g., wellfield pipes and appurtenances) from the site during the demobilization phase would require transportation similar to that needed for the remediation construction and installation phase.

November 2024 67 The construction and demobilization phases would have the greatest transportation needs. The NRC anticipates that for both phases (each of which would last less than one year), no more than 24 workers would be needed. During the operations and monitoring phases, only two to three people would be needed daily. Traffic volume on offsite roads would be higher during construction and demobilization than during operations and monitoring. Because all phases of the proposed action would require a very small workforce, the NRC staff concludes that the increased traffic impacts on local roads from all phases of the proposed action would not be significant. The NRC expects that EPM would comply with all regulations and requirements for transport of waste and materials.

3.13 Cumulative Impacts The CEQ regulations that implement NEPA define cumulative effects as effects on the environment that result from the incremental effects of the action when added to the effects of other past, present, and reasonably foreseeable actions regardless of what agency (Federal or non-Federal) or person undertakes such other actions. Cumulative effects can result from individually minor but collectively significant actions taking place over a period of time (40 CFR 1508.1). The NRC staff evaluated whether cumulative environmental effects could result from the incremental effects of the proposed action when added to the effects of other past, present, or reasonably foreseeable actions in the area.

As described throughout this EA, the groundwater at the site is contaminated with uranium, Tc-99, fluoride, and nitrate as a result of past Kerr-McGee nuclear fuel manufacturing activities.

If the proposed action is approved, then the groundwater treatment system would be installed to extract, treat, and reinject or discharge treated groundwater to the Cimarron River. When the groundwater treatment is complete, EPM would need to demonstrate that the site complies with the NRC criterion for uranium in the license, as well as NRC standards for the protection of public health and safety and the environment. The NRC would subsequently release the site from the NRC license (in a separate licensing action).

Most of the land in the vicinity of the Cimarron site is used for agricultural, ranching, and grazing. In addition, surrounding the site there are several facilities and various types of industries. Because the proposed action is groundwater remediation, the information in this section discusses activities, projects, and facilities that have the potential to impact groundwater near the site and thus could contribute to an additive impact when coupled with the proposed action.

There are 17 industrial or commercial facilities in the vicinity of the site (figure 3-17) (EPM 2023a). Several of the facilities in the area are related to oil and gas production. These oil and gas related sites contain either production, saltwater disposal (private and commercial disposal),

or abandoned wells (EPM 2023a). Production fluids associated with oil and gas production have the potential to impact the groundwater. Industry practice is to store produced fluid in aboveground storage tanks prior to transport either via pipeline or truck, and the potential for groundwater contamination is associated with a rupture of the containment berm prior to transport. In the case of the facilities near the site, a containment failure could release produced fluids downstream into Pawnee Creek which eventually flows into the Cimarron River approximately 0.4 km (0.25 mi) upstream from the site (EPM 2023a).

November 2024 68 Figure 3-17. Aerial View of Commercial and Industrial Facilities (red outlines) surrounding the Cimarron Site (blue outline)

Source: EPM 2023a The Riverside Gas & Grill contains a gasoline and diesel fueling station, a convenience store with a fast-food restaurant, and a small strip mall. Since the station stores fuel in underground tanks, there is a potential for groundwater contamination. However, no tank leaks have been reported or identified (EPM 2003a). Given how fuel is stored, the tanks and supply lines contain leak detection systems as an early alert system. Should unanticipated tank leaks develop, the contaminant plume could migrate toward the western portion of the Cimarron site (EPM 2023a).

The adjacent, 10-ha (25-ac) property (formerly part of the site) now owned by Kalidy, LLC, contains a building that was formerly the former mixed oxide fuel fabrication facility (EPM 2023a). Past operations at this facility contributed to the present groundwater contamination.

Currently, the facility is unoccupied and is available for lease (EPM 2023a).

Past and current agricultural activities have resulted in elevated nitrate levels in shallow groundwater, which add to the nitrate contributed by the Cimarron site (EPM 2022a). For example, a nearby golf course may be impacting groundwater as the result of the use of lawn fertilizers and pesticides. Surface runoff from the site could enter a small creek that leads to a

November 2024 69 freshwater pond near the eastern boundary of the site. This pond discharges to the Cimarron River through a spillway (EPM 2023a).

If approved, the proposed action would result in groundwater being remediated for uranium to NRC regulatory standards that are protective of human health and the environment; thus, there would be an overall beneficial effect. The Tc-909 concentrations in groundwater currently meet NRC requirements. As described above, the NRC staff does not expect that other facilities in the area are affecting groundwater, except for nitrate contributions from agricultural practices.

With continued monitoring (e.g., for leaking underground storage tanks), these facilities are not likely to impact groundwater. The NRC staff has determined that the effects of the past operation of the Kerr-McGee site on groundwater are noticeable, and that uranium concentrations would be reduced through implementing the proposed action to treat groundwater to meet NRC requirements. In addition, the Oklahoma DEQ would work with EPM during and after the proposed action to address nitrate, fluoride, and Tc-99 concentrations in groundwater.

November 2024 70 4.0 CONSULTATION AND COORDINATION 4.1 State Review The NRC provided the draft EA in June 2024 to the Oklahoma Department of Environmental Quality for review and comment (NRC 2024e). The Oklahoma DEQ provided clarifying comments regarding the States role during and after the NRC-licensed decommissioning activities to further ensure public health and safety at the site, clarification regarding OPDES permit limits, clarification regarding State Tc-99 limits in wastewater discharges and in groundwater, and corrections (ODEQ 2024a, 2024b). This EA reflects changes the NRC staff made to address these State comments.

This EA also reflects factual and clarifying edits the staff made in response to EPM comments and suggestions (EPM 2024b), where appropriate.

4.2 National Historic Preservation Act Section 106 Consultation In June 2019, the NRC staff sent letters to 21 tribes offering consultation on this project (NRC 2019b), following the letters with telephone calls to tribes who did not respond by letter or email.

The tribes the NRC contacted are:

Muscogee Creek Nation Caddo Nation Tonkawa Tribe of Oklahoma Alabama-Quassarte Tribal Town United Keetoowah Band of Cherokee Indians in Oklahoma Absentee-Shawnee Tribe of Indians of Oklahoma Seminole Nation of Oklahoma Ottawa Tribe of Oklahoma Seneca-Cayuga Nation Wyandotte Nation Fort Sill Apache Tribe Iowa Tribe of Oklahoma Wichita and Affiliated Tribes Pawnee Nation of Oklahoma Ponca Tribe of Oklahoma Shawnee Tribe of Oklahoma Otoe-Missouria Tribe Delaware Nation Thlopthlocco Tribal Town Osage Nation Cheyenne and Arapaho Tribes In response to this invitation, four tribes (Muscogee Creek Nation, Caddo Nation, Tonkawa Tribe of Oklahoma, and Alabama-Quassarte Tribal Town) expressed their preference to be updated on project activities but did not request formal consultation. Thirteen tribes did not respond to NRC communications and four tribes (Delaware Nation, Thlopthlocco Tribal Town,

November 2024 71 Osage Nation, Cheyenne and Arapaho Tribes) indicated that either the project is out of their area or they prefer to be notified only in the event of an inadvertent discovery. In June 2023 (NRC 2023f), the NRC staff sent updates by email to all the tribes except for those four who indicated they do not wish to be contacted further or only in the event of a discovery. In the update emails, the NRC staff described recent project activities, provided the cultural resources survey report, and identified next steps in the NRCs environmental review process. In response to this update, the Caddo Nation requested no further updates. In August and September 2024, the NRC staff published information from this EA about the historic and cultural resources aspects of the Cimarron site (NRC 2024c) and requested comments from the tribes on this information (NRC 2024d). In response, the Shawnee Tribe stated that the project is out of their area of interest and the Alabama-Quassarte Tribal Town reaffirmed their preference to continue receiving updates. The NRC received no comments from tribes on the published information.

In April 2019, the NRC initiated consultation with the Oklahoma SHPO and the Oklahoma Archeological Survey (OAS) under Section 106 of the National Historic Preservation Act (NRC 2019). In response, the SHPO stated that the SHPO would defer to the OASs opinion regarding the need for a cultural resources investigation (SHPO 2019). The OAS indicated that an archaeological field inspection was indeed necessary (OAS 2019). In May of 2020, Burns &

McDonnell Engineering Company, Inc., conducted a field survey of the site (B&M 2020). On September 29, 2022, the NRC staff sent letters to the SHPO and the OAS enclosing the survey report and providing NRHP-eligibility determinations (NRC 2023e). The OAS responded on November 3, 2023, concurring with the NRCs conclusions and deferring to the SHPO regarding historic properties (OAS 2023). The SHPO responded on November 6, 2023, concurring with the NRCs recommendations (SHPO 2023). The SHPO also requested the NRCs agreement that, after completion of the proposed action, the Cimarron site would be revegetated and left in a state that would not detract from the visual quality of the NRHP-eligible buildings. The SHPO stated that the NRCs consultation would be complete upon providing this agreement. After informally consulting with the SHPO on the content of a proposed license condition to address the SHPOs concerns, the NRC sent a letter to the SHPO dated April 6, 2024, describing the proposed license condition and closing out the Section 106 process (NRC 2024a).

As mentioned above, the NRC published information about this undertaking on the NRCs Cimarron Project website for public review and comment in August 2024 (NRC 2024c). The NRC received no comments on this information.

4.3 Endangered Species Act Section 7 Consultation Federal agencies may fulfill their obligations to consult with the Services under ESA Section 7 in conjunction with the interagency cooperation procedures required by other statutes, including NEPA (50 CFR 402.06(a)). In such cases, the Federal agency should include the results of the ESA Section 7 consultation in the NEPA document (50 CFR 402.06(b)). The NRC considers this EA and associated correspondence with the FWS (NRC 2024b) to fulfill its obligations under ESA Section 7.

Upon receipt of EPMs DP, the NRC staff considered whether any federally listed or proposed species or designated or proposed critical habitats may be present in the action area (as defined at 50 CFR 402.02) for the proposed action. As discussed in section 3.5 of this EA, the NRC staff concluded that the proposed action may affect but is not likely to adversely affect the piping plover, rufa red knot, whooping crane, and monarch butterfly. The NRC staff concluded

November 2024 72 that the proposed action would not affect the peppered chub or Arkansas River shiner. The NRC staff further concluded that the proposed action may modify, but is not likely to adversely modify, critical habitat for the peppered chub and the Arkansas River shiner. On May 7, 2024, the NRC staff provided its assessment and effects determinations to the FWS for review and concurrence (see appendix A to this EA). On June 28, 2024, the FWS provided its concurrence with the NRCs determinations (FWS 2024b).

November 2024 73

5.0 CONCLUSION

AND FINDING OF NO SIGNIFICANT IMPACT The NRC has prepared this EA as part of its review of EPMs request to remediate groundwater at the Cimarron site. Based on its review, in accordance with the requirements of 10 CFR Part 51, the NRC has determined that amendment of NRC license SNM-928 to approve the licensees DP would not significantly affect the quality of the human environment.

During its review of the DP and supplemental information, the NRC staff concluded that construction, operation, and decommissioning of the proposed groundwater remediation system would have a beneficial impact on groundwater quality and would not have significant impacts on land use, visual and scenic resources, the geologic environment, surface water resources, air quality, noise, socioeconomic conditions, public and occupational health, transportation, and waste generation and management. The NRC staff concluded, after consultation with the Oklahoma SHPO and Oklahoma Archaeological Survey and receiving input from Native American tribes, that the proposed action would not cause effects on resources that are eligible for listing on the NRHP and that no tribal cultural resources have been identified or are known to exist on the site. In consultation with the Oklahoma Ecological Services Field Office of the FWS and the Oklahoma DEQ, the NRC staff concluded that the proposed action (1) may affect but is not likely to adversely affect terrestrial threatened or endangered species, (2) would not affect the aquatic threatened or endangered species (fish), and (3) may modify but is not likely to adversely modify critical habitat for the two species of fish. Finally, the staff found that the proposed decommissioning activities would not have disproportionate and adverse human health and environmental effects on minority and low-income populations living near the Cimarron site.

As explained in this EA, the proposed action would result in the remediation of uranium to concentrations required by the NRC, specified in license condition 27(c). In addition, the proposed action would result in the removal of some Tc-99 from groundwater, but the concentrations of Tc-99 in groundwater are already below the NRC limit. The Oklahoma DEQ has stated that it plans to work with EPM during and after the proposed action to further address Tc-99, nitrate, and fluoride. After groundwater remediation for uranium is complete and the license is terminated, EPM would need to follow any controls that may be established by the Oklahoma DEQ for future land use or groundwater use. Due to naturally poor water quality, no site groundwater is used for drinking water or irrigation (EPM 2022a).

Based on this assessment, in accordance with 10 CFR 51.31, the NRC concludes that the proposed action does not warrant the preparation of an environmental impact statement, and, pursuant to 10 CFR 51.32, a finding of no significant impact is appropriate.

November 2024 74 6.0 LIST OF PREPARERS This EA was prepared by the NRC staff.

Contributor Education, Years of Experience Christine Pineda BA Sociology, Env. Studies minor MS Environmental Sciences and Policy 23 years of professional experience Marla Morales BA Geology MS Geology License-Professional Geoscientist - States of Virginia and Texas Shipley Group NEPA Certificate 17 years of environmental site analysis and evaluations Isaac Johnston BA Marine Science PhD Environmental Engineering and Earth Sciences 2 year professional experience Amy Minor BA Environmental Studies Duke NEPA Certificates 23 years of environmental site analysis and evaluations

November 2024 75

7.0 REFERENCES

References used in the preparation of this EA are publicly available - either online or through the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html. To begin a search in ADAMS, select Begin WBA Search. The ADAMS accession number is provided for references in ADAMS.

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November 2024 77 EPM (Environmental Properties Management). 2022b. Cimarron Environmental Response Trust Facility Decommissioning Plan - Rev 3, Appendix I, Remediation Infrastructure Design. Kansas City, Missouri. October 7, 2022. ML22285A208, ML22285A210, ML22307A307.

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Kansas City, Missouri. Prepared November 2017. ML22285A139, ML22307A296.

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Prepared June 26, 2017. ADAMS Accession No. ML22285A153.

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November 2024 78 Comments on Draft Environmental Assessment. Kansas City, Missouri. July 3, 2024.

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EPM (Environmental Properties Management). 2024c. Response to Questions re: Bat and Aquatic Habitat Assessments. Kansas City, Missouri. August 27, 2024. ML24240A050.

FWS (U.S. Fish and Wildlife Service). 2024a. Letter from FWS to NRC re: List of threatened and endangered species that may occur in your proposed project location or may be affected by your proposed project. IPaC Report. November 11, 2024. ML24316A009.

FWS (U.S. Fish and Wildlife Service). 2024b. Email from Oklahoma Ecological Services Field Office to NRC re: Request for Concurrence with ESA Determinations for Cimarron Site Decommissioning Plan (Consultation Code 2023-0113658). June 28, 2024. ML24219A232.

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[for Burial Area 4]. Washington, D.C. November 4, 1994. ML092660294 (letter) and ML092660295 (license).

November 2024 79 NRC (U.S. Nuclear Regulatory Commission). 1999. Documents Supporting Amendment No. 15 to License No. SNM-928 for the Cimarron Facility. Washington, D.C. ADAMS Package:

ML092680913. Environmental Assessment (July 29, 1999): ML092680912. Safety Evaluation Report (August 20, 1999): ML092680911. License Amendment 15 (August 20, 1999):

ML092680909.

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Washington, D.C. September 18, 2002. ML022610647.

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NRC (U.S. Nuclear Regulatory Commission). 2005. Letter to Cimarron regarding the need to submit a license amendment request for approval of active groundwater remediation.

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21. Washington, D.C. February 14, 2011. ML110270373.

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NRC (U.S. Nuclear Regulatory Commission). 2019a. Letters to the OK SHPO and OK Archeological Survey re: Notification and Request for Consultation Regarding Environmental Properties Managements Proposed Decommissioning Activities for the Former Cimarron Fuel Fabrication Facility. Washington, D.C. April 18, 2019. ML19093A049.

NRC (U.S. Nuclear Regulatory Commission). 2019b. Letters to Tribes re: Request for Consultation Regarding Environmental Properties Management's Proposed Decommissioning Activities for the Former Cimarron Fuel Fabrication Facility. Washington, D.C. June 11, 2019.

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NRC (U.S. Nuclear Regulatory Commission). 2023a. Letter to Bill Halliburton re: Acceptance Review of License Amendment Request for Special Nuclear Material License SNM-928, Cimarron Environmental Response Trust Cimarron Facility. Washington, D.C. March 30, 2023.

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November 2024 80 NRC (U.S. Nuclear Regulatory Commission). 2023b. Letter to Bill Halliburton re: Request for Additional Information for the Environmental Assessment of the Decommissioning Plan for the Cimarron Site Near Crescent, Oklahoma. Washington, D.C. September 6, 2023. ML23230B217.

NRC (U.S. Nuclear Regulatory Commission). 2023c. Letter to Bill Halliburton re: Request for Additional Information for the Safety Evaluation of the Decommissioning Plan for the Cimarron Site Near Crescent, Oklahoma (Docket Number: 70-925). Washington, D.C. October 2, 2023.

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NRC (U.S. Nuclear Regulatory Commission). 2023d. Letter to Bill Halliburton re: Request for Additional Information for the Safety Evaluation of the Decommissioning Plan for the Cimarron Site Near Crescent, Oklahoma (Docket Number: 70-925) [re: criticality safety]. Washington, D.C. November 1, 2024. ML23289A185.

NRC (U.S. Nuclear Regulatory Commission). 2023e. Letters to the Oklahoma SHPO and Oklahoma Archeological Survey re: Recommendations of Eligibility for Historic Properties at the Former Cimarron Fuel Fabrication Facility. Washington, D.C. October 10, 2023. ML20336A207.

NRC (U.S. Nuclear Regulatory Commission). 2023f. Email Updates to Tribes re: Cultural Resources Survey of Cimarron Site. Washington, D.C. June 2023. ML23268A032.

NRC (U.S. Nuclear Regulatory Commission). 2024a. Letter to Oklahoma SHPO Closing Out Section 106 Consultation Related to Cimarron Site. Washington, D.C. April 6, 2024.

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NRC (U.S. Nuclear Regulatory Commission). 2024b. Email to FWS re: Request for Concurrence with ESA Determinations for Cimarron Site Decommissioning Plan (Consultation Code: 2023-0113658). Washington, D.C. May 7, 2024. ML24122A742.

NRC (U.S. Nuclear Regulatory Commission). 2024c. Cimarron Site Decommissioning Plan Environmental Assessment Documentation Pertaining to Section 106 of the National Historic Preservation Act. Washington, D.C. August 23, 2024. ML24236A704.

NRC (U.S. Nuclear Regulatory Commission). 2024d. Emails to Tribes Requesting Comment on the Historic and Cultural Resources Sections of the Environmental Assessment. Washington, D.C. August and September 2024. ML24316A014.

NRC (U.S. Nuclear Regulatory Commission). 2024e. Email to State of Oklahoma Requesting Review of Draft Environmental Assessment for the Decommissioning Plan and Proposal to Remediate Groundwater at the Cimarron Site in Logan County, Oklahoma. Washington, D.C.

May 31, 2024. ML24316A012.

OAS (Oklahoma Archeological Survey). 2019. Letter to NRC re: OAS FYI 9-1807 Decommissioning Activities for former Cimarron Fuel Fabrication Facility. Norman, Oklahoma.

May 23, 2019. ML19311C325.

OAS (Oklahoma Archeological Survey). 2023. Letter to NRC re: OAS FY24-0035 Phase I Cultural Resources Survey of the Cimarron Environmental Response Trust Property. Norman, Oklahoma. November 3, 2023. ML23335A149.

November 2024 81 OCS (Oklahoma Climatological Survey). 2003. The Climate of Oklahoma. Derek Arndt. Norman, Oklahoma. January 1, 2003. https://cig.mesonet.org/climateatlas/doc60.html. Accessed December 14, 2023.https://cig.mesonet.org/climateatlas/doc60.html. Accessed December 14, 2023.

OCS (Oklahoma Climatological Survey). 2014. Map of Oklahoma Climate Divisions. Norman, Oklahoma.https://climate.ok.gov/index.php/climate/map/map_of_oklahoma_climate_divisions/oklah oma_climate. Accessed December 13, 2023.

OCS (Oklahoma Climatological Survey). 2023. Climate of Oklahoma. Norman, Oklahoma.

https://climate.ok.gov/index.php/site/page/climate_of_oklahoma. Accessed December 15, 2023.https://climate.ok.gov/index.php/site/page/climate_of_oklahoma. Accessed December 15, 2023.

ODEQ (Oklahoma Department of Environmental Quality). 2023. Past Air Data. Norman, Oklahoma. https://www.deq.ok.gov/air-quality-division/ambient-monitoring/past-air-data/#:~:text=Below%20are%20data%20summaries%20for,available%20on%20our%20NAAQ S%20page. Accessed December 15, 2023. https://www.deq.ok.gov/air-quality-division/ambient-monitoring/past-air-data/#:~:text=Below%20are%20data%20summaries%20for,available%20on%20our%20NAAQ S%20page. Accessed December 15, 2023.

ODEQ (Oklahoma Department of Environmental Quality). 2024a. State of Oklahoma Comments on Draft EA for Cimarron Site Decommissioning Plan for Groundwater Remediation. Oklahoma City, Oklahoma. August 2, 2024. ML24218A172.

ODEQ (Oklahoma Department of Environmental Quality). 2024b. Letter to NRC re: NPDES Permit Discharge Limits. Oklahoma City, Oklahoma. October 11, 2024. ML24309A252.

ODEQ (Oklahoma Department of Environmental Quality). 2024c. Letter to EPM from Oklahoma DEQ re: Bat Habitat and Aquatic Habitat Assessment Reports for Cimarron Site. Oklahoma City, Oklahoma. ML24316A010.

ODEQ (Oklahoma Department of Environmental Quality). 2024d. Letter from the Oklahoma DEQ to EPM Approving EPM Responses to Questions re: Bat Habitat and Aquatic Habitat Assessments for the Cimarron Site. Oklahoma City, Oklahoma. ML24316A008.

ODWC (Oklahoma Department of Wildlife Conservation). 2023b. Blackside Darter.

https://www.wildlifedepartment.com/wildlife/field-guide/fish/blackside-darter. Accessed December 21, 2023.

ODWC (Oklahoma Department of Wildlife Conservation). 2023c. Longnose Darter.

https://www.wildlifedepartment.com/wildlife/field-guide/fish/longnose-darter. Accessed December 21, 2023.

SHPO (Oklahoma State Historic Preservation Office). 2019. Letter to NRC re: File #1578-19

[Former File #2295-18]; CERT License Amendment for the Cimarron Fuel Facility Decommissioning Plan for Groundwater Remediation, Logan County, Oklahoma. Oklahoma City, Oklahoma. May 8, 2019. ML19311C323.

November 2024 82 SHPO (Oklahoma State Historic Preservation Office). 2023. Letter to NRC re: File #0107-24;

[Former File #2562-20]; U.S. Nuclear Regulatory Commission Proposed Cimarron Fuel Fabrication Plant Project in Cimarron City Vicinity, Logan County, Oklahoma. Oklahoma City, Oklahoma. November 6, 2023. ML23335A148.

Trust Agreement. 2011. Environmental Response Trust Agreement (Cimarron). February 14, 2011. ML110450212.

USCB (U.S. Census Bureau). 2022. QuickFacts, Oklahoma; Logan County, Oklahoma.

Available at https://www.census.gov/quickfacts/fact/table/OK,logancountyoklahoma/PST045222, accessed 18 December 2023.

USCB (U.S. Census Bureau). 2023. Table P1, Race, for Logan County. Available at https://data.census.gov/table?q=P1&g=050XX00US40083, accessed December 18, 2023.

USGS (U.S. Geological Survey). 1977. Preliminary Appraisal of the Garber-Wellington Aquifer, Southern Logan and Northern Oklahoma Counties. Carr, J.E. and M.V. Marcher. US Geological Survey. OFR 77-278. Reston, Virginia. May 1977. https://pubs.usgs.gov/publication/ofr77278 USGS (U.S. Geological Survey). 2001. Flood Frequency Estimates and Documented and Potential Extreme Peak Discharges in Oklahoma. Robert L. Tortorelli and Lan P. McCabe.

Oklahoma City, Oklahoma. 2001. https://pubs.usgs.gov/wri/wri014152/pdf/wri014152.pdf USGS (U.S. Geological Survey). 2021. U.S. Quaternary Faults Interactive Map. Accessed December 26, 2023.

<https://usgs.maps.arcgis.com/apps/webappviewer/index.htsml?id=5a6038b3a1684561a9b0aa df88412fcf>

USGS (U.S. Geological Survey). 2023. USGS Surface-Water Annual Statistics for the Nation.

Accessed January 2024. https://waterdata.usgs.gov/nwis/annual.

Wood and Burton. 1968. Ground-Water Resources of Cleveland and Oklahoma Counties, Oklahoma. Oklahoma Geological Survey Circular 71. Wood, P.R., and Burton, L.C., Norman, Oklahoma.

WCS (Waste Control Specialists). 2022. Facilities. Andrews, Texas.

<https://www.wcstexas.com/about/our-facilities/facilities/> (Accessed 4 January 2024)

Appendix A

U.S. Nuclear Regulatory Commission ESA Effect Determinations for Cimarron Environmental Response Site Decommissioning Plan Species or Critical Habitat Federal Status Habitat in Action Area Rationale for Determination ESA Effect Determination tricolored bat (Perimyotis subflavus)

Proposed endangered Habitat

present, recent survey Tricolored bats may roost or forage within the Cimarron action area in onsite wetlands, adjacent edges of active or old agricultural field and pastureland, and riparian woodlands with dogwood species, eastern cottonwood, and eastern red cedar. The bats primarily roost in deciduous hardwood trees, among pine needles, and in eastern red cedar (FWS 2023a).

On September 26, 2023, Burns & McDonnell conducted a habitat assessment for the tricolored bat (EPM 2024). A wildlife biologist conducted a desktop review and field survey using U.S. Fish and Wildlife Service (FWS) approved methods for Indiana and northern long-eared bat surveys. Three potential roost trees (PRT) were identified: PRT-1, PRT-2, and PRT-3. These are defined as trees at least three inches in diameter at breast-height with sloughing bark, cracks, crevices, or hollows. PRT-1 and PRT-3 are unlikely to be preferred habitat for the tricolored bat due to the current mortality stages of the trees. PRT-2 is a standing, dead green ash with exfoliating bark. There are no caves or bridges present on the site.

The proposed action would involve construction of a new outfall to the Cimarron River, groundwater pumping and treatment, and subsequent effluent discharges to the river. In connection with these activities, the licensee would clear approximately 38.8 acres of vegetation, including forested area containing the PRTs within the Cimarron site, in spring of 2025 to support installation of trenches, wells, piping, and other infrastructure. In Oklahoma, winter tree clearing is November 16th through March 1st. If any of the PRTs require removal, the licensee would remove the trees prior to March 31, 2025, when tricolored bats are hibernating and least likely to be present on site. The licensee states that if the clearing of PRTs cannot be accomplished prior to March 31, 2025, then it would conduct an emergent survey to identify and mitigate potential impacts. The emergent survey would involve visual observation of the PRTs from one hour prior to sunset until one hour after sunset for each PRT to document the presence or absence of the tricolored bat. If no bats are present, the PRTs would be removed within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of the emergent surveys (EPM 2024). These protocols will ensure that tricolored bats are not adversely affected by tree clearing and other construction-related disturbances and that potential impacts would not rise to the level where take might occur. With respect to other disturbances caused by the proposed action, such as noise and general human activity, tricolored bats, if present in the action area, have already acclimated to this type of activity because Cimarron is an established industrial-use site.

Thus, these types of disturbances during the decommissioning period would not cause additional behavioral changes in bats to a degree that could be meaningfully measured, detected, or evaluated, or that would reach the scale where take may occur. The proposed action would also not increase collision hazards, such as those associated with tall structures or vehicles.

May affect but is not likely to adversely affect

The NRC staff finds that all potential effects on the tricolored bat resulting from the proposed action would be insignificant or discountable. Therefore, the NRC staff concludes that the proposed action may affect but is not likely to adversely affect the tricolored bat.

piping plover (Charadrius melodus)

Threatened Habitat present, no recent surveys The piping plover is typically present in Oklahoma during migration from March to May and from July to September. The Cimarron River in the action area flows along the northern border of the Cimarron site. It is relatively shallow and sandy, dominated by run and riffle components, and contains relatively little pool habitat, aquatic vegetation, or riparian. Piping plovers have not been observed in the action area, although habitat, such as sandy beaches or mudflats, is likely to be present along riverbanks (EPM 2023). Suitable habitat within the action area is not of high-quality for piping plovers and would only constitute temporary stopover habitat during migration.

The proposed action would involve construction of a new outfall to the Cimarron River, groundwater pumping and treatment, and subsequent effluent discharges to the river. The licensee will construct the new outfall (Outfall 001) approximately 240 feet from the river (EPM 2024), However, the discharge would not terminate at the Cimarron River (EPM 2024). Instead, the licensee would construct a dispersion ditch adjacent to the river. Outfall and dispersion ditch construction would disturb less than 0.1 acre of riparian habitat, and construction activities would be confined to areas along the banks above the ordinary high-water mark (EPM 2024). The licensee anticipates disturbing less than 0.5 acres of riparian vegetation in total (EPM 2024). As described above for the tricolored bat, 38.8 acres of forested vegetation would also be cleared for trenches, wells, piping, and other infrastructure. The licensee would seek required permits from the U.S. Army Corps of Engineers for construction activities and would follow associated permit conditions and best management practices to minimize impacts to the environment, such as erosion and sedimentation. The licensee would also revegetate disturbed areas following construction.

Once the outfall is in use, the licensee will discharge up to 225 gallons per minute (gpm) of treated groundwater from the outfall to the Cimarron River. These effluent discharges could potentially increase the flow rate of the Cimarron River in the action area by up to 1.2 percent (EPM 2024). However, the licensee will also construct a dispersion ditch adjacent to the site, which will reduce the potential for increased turbidity and sedimentation within the river. The licensee will adjust the pH of effluent to 6.8-7.0 before it is discharged and will abide by relevant Federal and State regulations, including the Oklahoma Department of Environmental Quality (ODEQ)-issued Oklahoma Pollutant Discharge Elimination System (OPDES) permit (EPM 2024). Effluents could cause localized increases in turbidity.

However, measurable or detectable impacts to water quality are unlikely due to the treatment of water prior to discharge, effluent limitation within the OPDES permit, and localized nature of any increases in turbidity.

Other potential stressors that piping plovers could experience from the proposed action include noise; behavioral changes, such as avoidance of vehicles, machinery, and general human activity; collisions with site structures and vehicles; and effects related to herbicide application. If present in the action area, piping plovers have already acclimated to these types of stressors because Cimarron is an established industrial-use site. Thus, these types of activities during the decommissioning period would not cause behavioral changes in May affect but is not likely to adversely affect

piping plovers to a degree that could be meaningfully measured, detected, or evaluated, or that would reach the scale where take may occur. The proposed action would also not increase collision hazards. The licensee would apply any herbicides on the site in accordance with labeled uses and U.S. Environmental Protection Agency requirements.

The NRC staff finds that all potential effects on the piping plover resulting from the proposed action would be insignificant or discountable. Therefore, the NRC staff concludes that the proposed action may affect but is not likely to adversely affect the piping plover.

rufa red knot (Calidris canutus rufa)

Threatened Habitat present, no recent surveys The rufa red knot has a nonbreeding migration range that includes Oklahoma, though according to the Oklahoma Department of Wildlife Conservation, ideal foraging habitat is limited and fewer than five birds are reported in the state annually (ODWC 2023a). Rufa red knots have not been observed within the action area (EPM 2023). Suitable habitat within the action area is not of high-quality for the rufa red knot and would only constitute temporary stopover habitat during migration.

The impacts that red knots could experience from the proposed action are identical to those described above for the piping plover. For the same reasons as identified for the piping plover, the NRC staff finds that all potential effects on the rufa red knot resulting from the proposed action would be insignificant or discountable. Therefore, the NRC staff concludes that the proposed action may affect but is not likely to adversely affect the rufa red knot.

May affect but is not likely to adversely affect whooping crane (Grus americana)

Endangered Habitat present, no recent surveys Whooping cranes may occur in the action area from April through October during migration to wintering grounds in Florida. Whooping cranes have not been observed in the action area (EPM 2023). However, this species has been known to land on sites in central Oklahoma with features like those in the action area, including shallow wetlands, sandbars, shorelines of shallow rivers, and agricultural fields near water (ODWC 2023b).

The impacts that whooping cranes could experience from the proposed action are identical to those described above for the piping plover. For the same reasons as identified for the piping plover, the NRC staff finds that all potential effects on the whooping crane resulting from the proposed action would be insignificant or discountable. Therefore, the NRC staff concludes that the proposed action may affect but is not likely to adversely affect the whooping crane.

May affect but is not likely to adversely affect Arkansas River shiner (Notropis girardi)

Threatened Habitat present, no recent surveys The FWS considers the Arkansas River shiner to be extirpated from the Cimarron River (70 FR 59808). For this reason, the NRC staff concludes that the proposed action would have no effect on the Arkansas River shiner.

No effect Arkansas River shiner critical habitat Designated Habitat present, no recent surveys FWS established critical habitat for the Arkansas river shiner in 2005 to include the Cimarron River (70 FR 59808). The last known capture of this species occurred in 2004 where eight individuals were collected near Guthrie, Oklahoma (70 FR 59808). As stated above, the FWS considered this species to be extirpated from the Cimarron River.

The FWS established seven primary constituent elements (PCEs) essential for the conservation of the species (70 FR 59808). These are:

Not likely to destroy or adversely modify

(1) A natural, unregulated hydrologic regime complete with episodes of flood and drought or, if flows are modified or regulated, a hydrologic regime characterized by the duration, magnitude, and frequency of flow events capable of forming and maintaining channel and instream habitat necessary for particular Arkansas River shiner life-stages in appropriate seasons; (2) A complex, braided channel with pool, riffle (shallow area in a streambed causing ripples), run, and backwater components that provide a suitable variety of depths and current velocities in appropriate seasons; (3) A suitable unimpounded stretch of flowing water of sufficient length to allow hatching and development of the larvae; (4) Substrates of predominantly sand, with some patches of silt, gravel, and cobble; (5) Water quality characterized by low concentrations of contaminants and natural, daily and seasonally variable temperature, turbidity, conductivity, dissolved oxygen, and pH; (6) Suitable reaches of aquatic habitat, as defined by primary constituent elements 1 through 5 above, and adjacent riparian habitat sufficient to support an abundant terrestrial, semiaquatic, and aquatic invertebrate food base; and (7) Few or no predatory or competitive non-native fish species present.

The proposed action would have no effect on PCE 1, 2, 3, 4, or 7.

With respect to PCE 5 and 6, the proposed action would involve construction of a new outfall to the Cimarron River, groundwater pumping and treatment, and subsequent effluent discharges to the river, all of which have the potential to affect this PCE. Construction impacts are described above for the piping plover. Notably, construction would take place within the riparian zone of the Cimarron River established in the FWSs final rule designating Arkansas River shiner critical habitat (77 FR 59808). As indicated there, the licensee would abide by relevant local, State, and Federal permits for construction and effluent discharges and would follow best management practices for construction and revegetation of disturbed areas.

When discharging effluent to the Cimarron River, the licensee will abide by relevant Federal and State regulations, including conditions set forth in the OPDES permit, when discharging effluents to the Cimarron River (EPM 2024). Effluents would not affect conductivity, dissolved oxygen, and would not be heated. The licensee will adjust the pH of effluent to 6.8-7.0 before it is discharged (EPM 2024). Effluents could cause localized increases in turbidity.

However, this could represent a beneficial impact to the critical habitat because the Arkansas River shiner prefers turbid and moving water (FWS 2018).

Because all activities associated with the proposed action would require permits that would ensure that impacts to the aquatic environment are minimized, measurable or detectable impacts to PCE 5 and 6 within the action area are unlikely. Accordingly, the NRC staff finds that all potential effects on Arkansas River shiner critical habitat resulting from the proposed action would be insignificant or discountable. Therefore, the NRC staff concludes that the proposed action is not likely to destroy or adversely modify critical habitat of the Arkansas River shiner.

peppered chub (Macrhybopsis tetranema)

Endangered Habitat present, no recent surveys The FWS states that the peppered chub is not currently present in the Cimarron River (FWS 2018). For this reason, the NRC staff concludes that the proposed action would have no effect on the peppered chub.

No effect peppered chub critical habitat Designated Habitat present, no recent surveys The FWS designated critical habitat for the peppered chub in 2022 to include the Cimarron River (87 FR 11188). The last observed occurrence of the peppered chub in the Cimarron River resiliency unit was in 2011 (87 FR 11188). As stated above, the FWS considers the species to no longer be present in the Cimarron River. The FWS established five physical or biological features (PBFs) essential for the conservation of the species (88 FR 11188).

These are:

(1) Unobstructed river segments greater than 127 river miles (rmi) in length that are characterized by a complex braided channel and substrates of predominantly sand, with some patches of silt, gravel, and cobble; (2) Flowing water with adequate depths to support all life stages and episodes of elevated discharge to facilitate successful reproductions, channel and floodplain maintenance, and sediment transportation; (3) Water of sufficient quality to support survival and reproduction, which includes, but is not limited to, the following conditions: (i) water temperatures generally less than 98.2 degrees Fahrenheit; (ii) dissolved oxygen concentrations generally greater than 3.7 parts per million (ppm); (iii) Conductivity generally less than 16.2 milli siemens per centimeter; (iv) pH generally ranging from 5.6 to 9.0, and (v) sufficiently low petroleum and other pollutant concentrations such that reproduction and/or growth is not impaired; (4) Native riparian vegetation capable of maintaining river water quality, providing a terrestrial prey base, and maintaining a healthy riparian ecosystem; (5) A level of predatory or competitive, native or nonnative fish present such that any peppered chub populations resiliency is not affected.

Not likely to destroy or adversely modify

The proposed action would have no effect on PBF 1, 2, and 5. With respect to the impacts on PBF 3 and 4, the impacts that the peppered chub critical habitat could experience from the proposed action are identical to those described above for the Arkansas River shiner critical habitat. Because all activities associated with the proposed action would require permits that would ensure that impacts to the aquatic environment are minimized, measurable or detectable impacts to PBF 3 and 4 within the action area are unlikely.

Accordingly, the NRC staff finds that all potential effects on peppered chub critical habitat resulting from the proposed action would be insignificant or discountable. Therefore, the NRC staff concludes that the proposed action is not likely to destroy or adversely modify critical habitat of the peppered chub.

monarch butterfly (Danus plexippus)

Candidate Habitat present, no recent surveys Monarchs in Oklahoma belong to the eastern migratory population, which breeds in the central and eastern United States and southern Canada and winters in Mexico (ODWC 2023c). Monarchs are associated with prairie, meadow and grassland habitats. Milkweed provides a habitat for the development of monarch eggs and larvae (OKState 2024). The most common species of milkweed located in central Oklahoma is green antelopehorn milkweed (Asclepias viridis) and is considered the most important host plant for the species.

Green antelopehorn blooms from April to June and disperses seeds in July (OKState 2024).

The licensee reports no known occurrences of the monarch butterfly within the action area.

However, the licensee has conducted no ecological surveys to assess the species presence or the suitability of onsite habitat. Given the proximity of known milkweed occurrences adjacent to the site, the NRC conservatively assumes that milkweeds could occur on site and the action area may provide larval habitat. Otherwise, monarchs may be occasionally present when moving between transitory areas of more suitable habitat.

As described above for the tricolored bat, 38.8 acres of forested vegetation would also be cleared for trenches, wells, piping, and other infrastructure. The licensee would seek required permits from the U.S. Army Corps of Engineers for construction activities and would follow associated permit conditions and best management practices to minimize impacts to the environment, such as erosion and sedimentation. Historically, the action area has been mowed for hay and it is anticipated that weed control will be contracted out to a licensed vendor (EPM 2023). Milkweed is not known to occur onsite; it has the potential to occur on site in grasslands and open areas given its occurrence in central Oklahoma. Herbicides would only be applied according to labeled uses in developed and manicured areas on the site. Clearing and removal of native grasses, topsoil, trees, and shrubs will be removed using standard earthmoving machinery (EPM 2023).

Green antelopehorn, the milkweed important to central Oklahoma, is known to regrow and bloom following disturbances from vegetation clearing (OKState 2024). The licensee would revegetate disturbed areas following construction. The contractor must submit its seeding plan and mixture to Burns & McDonnell for approval prior to restoration activities (EPM 2022). Monarchs would only have the potential to occur in the action area seasonally and infrequently, making the likelihood of occurrence low.

May affect but is not likely to adversely affect

All the potential effects on the monarch butterfly resulting from the proposed action would be insignificant or discountable. Therefore, the NRC staff concludes that the proposed action may affect but is not likely to adversely affect the monarch butterfly.

References 70 FR 59808. October 13, 2005. U.S. Fish and Wildlife Service. Endangered and Threatened Wildlife and Plants ; Final Designation of Critical Habitat for the Arkansas River Basin Population of the Arkansas River Shiner (Notropis girardi); Final Rule. Federal Register 70:59808-59846.

87 FR 11188. February 28, 2022. U.S. Fish and Wildlife Service. Endangered and Threatened Wildlife and Plants; Endangered Species Status for Peppered Chub and Designation of Critical Habitat. Federal Register 87:11188-11220.

(EPM) Environmental Properties Management, LLC. November 3, 2023. Letter from Bill Halliburton re: Response to September 6, 2023, Request for Additional Information. ADAMS No. ML23319A252.

(EPM) Environmental Properties Management, LLC. March 29, 2024. Burns & McDonnell; Cimarron Environmental Response Trust Bat Habitat and Aquatic Habitat Assessment Reports. ADAMS No. ML24089A260.

(EPM) Environmental Properties Management, LLC. 2022. Cimarron Environmental Response Trust Facility Decommissioning Plan - Rev 3, Appendix B, Stormwater Pollution Prevention Plan. Kansas City, Missouri. November 2017. ADAMS Nos. ML22285A139 and ML22307A296.

(FWS) U.S. Fish and Wildlife Service. 2022. Species Status Assessment Report for the Arkansas River Shiner (Notropis girardi) and Peppered Chub (Macrhybopsis tetranema) https://www.regulations.gov/document/FWS-R2-ES-2019-0019-0033 (FWS) U.S. Fish and Wildlife Service. 2023a. Environmental Conservation Online System, Tricolored bat (Perimyotis subflavus). Available at

<https://ecos.fws.gov/ecp/species/10515> (accessed December 20, 2023).

(FWS) U.S. Fish and Wildlife Service. 2024a. FWS to NRC, List of threatened and endangered species that may occur in your proposed project location or may be affected by your proposed project. IPaC Report. April 18, 2024. ADAMS No. ML24109A283.

(ODWC) Oklahoma Department of Wildlife Conservation. 2023a. Rufa Red Knot. Available at <https://www.wildlifedepartment.com/wildlife/field-guide/birds/rufa-red-knot> (accessed November 6, 2023).

(ODWC) Oklahoma Department of Wildlife Conservation. 2023b. Whooping Crane. Available at <https://www.wildlifedepartment.com/wildlife/field-guide/birds/whooping-crane> (accessed November 6, 2023).

(ODWC) Oklahoma Department of Wildlife Conservation. 2023c. Monarch. Available at <https://www.wildlifedepartment.com/wildlife/field-guide/invertebrates/monarch> (accessed November 8, 2023).

(OKState) Oklahoma State University. 2024. Monarch Conservation in Oklahoma and the southern Great Plains. Available at

<https://monarch.okstate.edu/> (accessed April 19, 2024).