DERR-2024-011663

FIFTH FIVE-YEAR REVIEW REPORT FOR MIDVALE SLAG SUPERFUND SITE SALT LAKE COUNTY, UTAH

Prepared by Utah Department of Environmental Quality Division of Environmental Response and Remediation For U.S. Environmental Protection Agency Region 8 DENVER, COLORADO --------------------------------- Aaron Urdiales, Director Superfund and Emergency Management Division

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Table of Contents
LIST OF ABBREVIATIONS & ACRONYMS .........................................................................................................2 I. INTRODUCTION...................................................................................................................................................3 Site Background .....................................................................................................................................................3 FIVE-YEAR REVIEW SUMMARY FORM ........................................................................................................5 II. RESPONSE ACTION SUMMARY ......................................................................................................................5 Basis for Taking Action OU1 ................................................................................................................................5 Basis for Taking Action OU2 ................................................................................................................................6
Response Actions OU1 ..........................................................................................................................................6 Response Actions OU2 ..........................................................................................................................................8 Status of Implementation OU1 Soils ......................................................................................................................9
Status of Implementation OU2 Soils ......................................................................................................................9 Status of Implementation OU1 and OU2 Groundwater .........................................................................................9 Status of Implementation OU1 and OU2 Riparian Zones ......................................................................................9
IC Summary Table ...............................................................................................................................................10 III. SYSTEMS OPERATIONS/OPERATION & MAINTENANCE ......................................................................10 Groundwater and Surface Water Monitoring .......................................................................................................10 Institutional Controls ............................................................................................................................................11 IV. PROGRESS SINCE THE LAST REVIEW .......................................................................................................12 V. FIVE-YEAR REVIEW PROCESS .....................................................................................................................13 Community Notification, Involvement & Site Interviews ...................................................................................13 VI. Data Review .......................................................................................................................................................13
Groundwater Monitoring .....................................................................................................................................13 Surface Water Monitoring ....................................................................................................................................14 Institutional Controls ............................................................................................................................................14
Site Inspection ......................................................................................................................................................14 VII. TECHNICAL ASSESSMENT .........................................................................................................................14 QUESTION A: Is the remedy functioning as intended by the decision documents? ..........................................14
QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and RAOs used at the time of the remedy selection still valid? .................................................................................................................................15 QUESTION C: Has any other information come to light that could call into question the protectiveness of the
remedy? ................................................................................................................................................................16 VIII. ISSUES/RECOMMENDATIONS ..................................................................................................................17 IX. PROTECTIVENESS STATEMENT .................................................................................................................17 X. NEXT REVIEW ..................................................................................................................................................18 APPENDIX A – REFERENCE LIST ......................................................................................................................19 APPENDIX B – SITE MAPS ..................................................................................................................................21 APPENDIX C – PUBLIC NOTICE .........................................................................................................................24 APPENDIX D – COMMUNITY INTERVIEW SUMMARY REPORTS ..............................................................25 APPENDIX E – COC CONCENTRATIONS IN GROUNDWATER AND SURFACE WATER ........................35 APPENDIX F – SITE INSPECTION PHOTOS ......................................................................................................51 APPENDIX G – SITE INSPECTION CHECKLIST ...............................................................................................56 Tables
Table 1: OU1 Soil Cleanup Levels .............................................................................................................................5 Table 2: OU2 Human Health Risk Based PRGs for Soil ...........................................................................................6 Table 3: Groundwater ACLs ......................................................................................................................................6 Table 4: Summary of Implemented ICs ...................................................................................................................10 Table 5: Protectiveness Determinations/Statements from the 2019 FYR ................................................................12

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LIST OF ABBREVIATIONS & ACRONYMS ACL Alternate Concentration Limits
ARARs Applicable or Relevant and Appropriate Requirements BLL Blood Lead Level BLRV Blood Lead Reference Value
BRA Baseline Risk Assessment CDC Centers for Disease Control CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CERCLIS Comprehensive Environmental Response, Compensation, and Liability Information System CFR Code of Federal Regulations COCs Chemicals of Concern ESD Explanation of Significant Differences EPA United States Environmental Protection Agency ERA Ecological Risk Assessment FYR Five-Year Review ICs Institutional Controls
ICPP Institutional Control Process Plan IHC Intermountain Health Care LEPAC Lead Exposure Prevention and Advisory Committee
LSI Life Systems Incorporated NAAQS National Ambient Air Quality Standards NCP National Contingency Plan
NPL National Priorities List O&M Operation and Maintenance OU Operable Unit PCE Tetrachloroethene ppm Parts per million POA Private Owners Associations PRGs Preliminary Remediation Goals PRP Potentially Responsible Party RAGS Risk Assessment Guidance for Superfund RAO Remedial Action Objective RI Remedial Investigation
ROD Record of Decision RPM Remedial Project Manager SPLP Synthetic Precipitation Leaching Procedure
TCLP Toxicity Characteristic Leaching Procedure UDEQ/DERR Utah Department of Environmental Quality/Division of Environmental Response and Remediation
US&G Upper Sand and Gravel UU/UE Unlimited Use and Unrestricted Exposure WENE Winchester Estates North East WENW Winchester Estates North West WWTP Wastewater Treatment Plant

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I. INTRODUCTION The purpose of a Five-year Review (FYR) is to evaluate the implementation and performance of a remedy in
order to determine if the remedy is and will continue to be protective of human health and the environment. The methods, findings, and conclusions of reviews are documented in FYR reports such as this one. In addition, FYR reports identify issues found during the review, if any, and document recommendations to address them.
The Utah Department of Environmental Quality, Division of Environmental Response and Remediation (UDEQ/DERR) is preparing this FYR report for the U.S. Environmental Protection Agency (EPA) pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 121, consistent with the National Contingency Plan (NCP)(40 Code of Federal Regulations (CFR) Section 300.430(f)(4)(ii)), and considering EPA policy. This is the fifth FYR for the Midvale Slag Superfund site (Site). The triggering action for this statutory review is the previous FYR completed on 4/8/2019. The FYR has been prepared due to the fact that hazardous substances, pollutants or contaminants remain at the Site above levels that allow for unlimited use and unrestricted exposure (UU/UE).
The Site is 446 acres in size and consists of two operable units (OUs) that will be addressed in this FYR. OU1 encompasses the portion of the Site north of the former slag piles and smelter complex area and includes the
Winchester Estates residential area. OU2 encompasses the former slag piles and smelter complex area. The Site FYR was led by Tony Howes with UDEQ/DERR. Participants included Athena Jones and Josie Nusz,
EPA Remedial Project Managers (RPM); Dave Allison, UDEQ/DERR Community Involvement Coordinator; and Scott Everett, UDEQ/DERR Toxicologist. The review began on 11/9/2023.
Site Background The Site is approximately 12 miles south of Salt Lake City, Utah. The majority of the Site is within Midvale City; however, the northern portion of OU1 extends into Murray City (Figure 1). The Site is bound by 7800 South
Street to the south, the Jordan River to the west, 6400 South Street to the north, and 700 West Street to the east. The Sharon Steel Superfund Site (UTD980951388) is located immediately adjacent to the south of the Midvale Slag Site.
The Site was historically used as a lead and copper smelting facility that operated from the early 1900s to 1958. In addition to lead and copper, the facility produced other metals, including arsenic, cadmium, zinc, gold and silver.
During World War II, substantial tonnages of arsenic trioxide were produced for the United States government to be used as herbicides. Wastes generated from the smelting process were disposed of on-site and impacted groundwater and soil. OU1 is approximately 266 acres in size and includes the Winchester Estates residential area, an abandoned Wastewater Treatment Plant (WWTP), WWTP lagoons, and jurisdictional wetlands. Based on the unique characteristics of OU1 and to facilitate the organization of the remedial investigation (RI), OU1 was divided into the following parcels:
• LR - The southern one-third of OU1.
On January 17, 2024, the EPA issued Updated Soil Lead Guidance for CERCLA sites and RCRA Corrective Action Facilities that lowered recommended regional screening levels for lead-contaminated soil. The EPA and UDEQ/DERR will evaluate how this change may impact the cleanup that was conducted at the Midvale Slag site and determine if additional investigation and/or cleanup is needed. The EPA will share information on planned activities and results as they become available.

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• LF - The west-central portion of OU1 (Site of a small former landfill).
• LG - The area formerly occupied by the abandoned WWTP lagoons, the east-central portion of OU1.
• WENW - The northwestern portion of OU1 that includes the Winchester Estates residential area, bordered to the north by 6400 South Street and to the west by the Jordan River.
• WESE - The southeast portion of Winchester Estates, bordered to the east by 700 West Street. These parcels are depicted in Figure 2. OU2 is approximately 180 acres in size, and the OU2 remedy addressed groundwater, mixed smelter wastes, and slag. For purposes of organizing OU2 materials and their associated environmental effects, the materials were defined as one of the following waste categories:
• Category I: Principal threat wastes that are considered highly mobile, highly toxic, and unacceptable for exposure at the surface under any land-use scenario. Category I wastes contain very high concentrations of chemicals of concern (COCs) and fail toxicity characteristic leaching procedure (TCLP) and synthetic
precipitation leaching procedure (SPLP) tests.
• Category II: Smelter wastes, demolition debris, foundations, and soils with high COC concentrations. Category II wastes are also unacceptable for exposure at the surface under any land-use scenario and fail TCLP and SPLP tests.
• Category III: Contaminated demolition debris, foundations and soils. Category III wastes contain elevated concentrations of COCs and are unacceptable for exposure at the surface under residential-land-use scenarios.
• Category IV: Slag.
Groundwater at the Site is comprised of three distinct hydrogeologic units: an unconfined upper sand and gravel (US&G) aquifer (also referred to as the shallow unconfined aquifer), a confined deep principal aquifer and local/perched groundwater. Wastes generated and disposed of on-site contaminated the US&G aquifer, primarily
with arsenic. The US&G aquifer has also been contaminated by a tetrachloroethene (PCE) plume that passes through the Site and appears to originate from an upgradient, off-site source.
The Site has been developed and is the home of Bigham Junction, which includes a mixed use residential, commercial office and retail area. The Site was deleted from the National Priorities List (NPL) on April 8, 2015.

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FIVE-YEAR REVIEW SUMMARY FORM
II. RESPONSE ACTION SUMMARY
Basis for Taking Action OU1 In 1992 Life Systems Incorporated (LSI), under contract to the EPA and UDEQ/DERR, completed a baseline risk assessment (BRA) for OU1. The BRA found that arsenic, cadmium, and lead in surface soils posed an unacceptable risk to some residents in the Winchester Estates developed area. The BRA also concluded that if the undeveloped portions of OU1 are developed, exposure to surface soils could result in unacceptable health risks depending on the type of land use. The OU1 BRA found no risks associated with groundwater at OU1. The following cleanup levels were established for the OU1 Record of Decision (ROD): Table 1: OU1 Soil Cleanup Levels
Contaminant Cleanup Level (mg/kg)
Current and Hypothetical Residents Hypothetical Future Workers
Arsenic 73 960 Cadmium 49 2,980
Lead 650 --

SITE IDENTIFICATION
Site Name: Midvale Slag
EPA ID: UTD081834277
Region: 8 State: UT City/County: Midvale and Murray/Salt Lake
SITE STATUS
NPL Status: Deleted
Multiple OUs? Yes Has the Site achieved construction completion? Yes
REVIEW STATUS
Lead agency: EPA
Author name: Tony Howes
Author affiliation: UDEQ/DERR
Review period: 11/9/2023 - 4/8/2024
Date of Site inspection: 11/9/2023
Type of review: Statutory
Review number: 5
Triggering action date: 4/8/2019
Due date (five years after triggering action date): 4/8/2024

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A lead-clean-up level was not calculated for hypothetical future workers since lead was primarily a concern for children.
Basis for Taking Action OU2 The EPA and UDEQ/DERR completed a BRA in 1994 for OU2. This BRA found that COCs in groundwater and surface and subsurface soil exceeded threshold levels and posed an unacceptable risk to trespassers, future residents and workers. Remedial action was necessary to reduce potential contact, ingestion and inhalation of contaminants to acceptable risk-based levels. The OU2 ROD identified arsenic and lead as the primary COCs for soil since these contaminants were considered to be the main risk drivers for OU2. The following risk-based preliminary remediation goals (PRGs) for soil were identified in the OU2 ROD. Table 2: OU2 Human Health Risk Based PRGs for Soil
Contaminant
Human Health Risk-Based PRGs (mg/kg) Residential Land Use Non-Contact Intensive Contact Intensive Construction Worker Recreational
Arsenic 61 560 50 80 68 Lead 438 2063 430 365 1066 An ecological risk assessment (ERA) was completed for both OU1 and OU2 as part of the 1994 OU2 BRA and found that COCs in sediment and surface water posed little risk to aquatic receptors. However, the ERA found that COC concentrations in riparian area soils could pose a potential threat to aquatic receptors if the soils enter the river.
Investigations completed at the Site indicated that contaminated groundwater in the US&G aquifer discharges to the Jordan River and alternate concentration limits (ACLs), and points of compliance monitoring wells were
established for the US&G aquifer. The ACLs established for the compliance monitoring wells are as follows: Table 3: Groundwater ACLs
Contaminant
Groundwater ACL (µg/L)
Arsenic Cadmium Selenium Antimony 7,000 1,560 900 380 Response Actions OU1 The EPA listed the Site in 1991. Removal actions were completed for OU1 in 1990 and 2001. These removal actions addressed fencing and disposal of drums containing mainly investigation derived wastes.
The OU1 ROD was finalized on April 28, 1995, and addressed soil. The following remedial action objective (RAO) was identified in the ROD:
• Reduce or eliminate exposure to contaminated soils for current or hypothetical residents and hypothetical
future workers.
The components of the remedy selected in the OU1 ROD consisted of the following:
• Excavating the upper 18 inches of native soils at 14 residential yards in the Winchester Estates residential development. The 18-inch depth was considered to be a minimum with confirmatory sampling used to identify areas requiring additional excavation. Clean fill was imported to restore the original grade, and

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each yard restored as closely as possible to its original condition. The wastes, being non-hazardous, were disposed of in a Resource Conservation and Recovery Act (RCRA) Subtitle D landfill or stored at the
Midvale OU2 Site pending remedy selection for OU2.
• Placement of a two-foot thick monolayer soil cover on Parcel WESE (undeveloped southeast portion of Winchester Estates zoned residential). See Figure 2.
• Implementing deed restrictions or other institutional controls (ICs) on Parcel WESE precluding most future excavation that would breach the monolayer soil cover. Any native soils from permitted
excavations must be properly controlled on-site or disposed of in a RCRA Subtitle D landfill.
• Implementing deed restrictions or other ICs on Parcels LR-east, LR-west, LF and LG which prohibit future residential land use without additional property remediation to residential soil cleanup levels.
• Groundwater monitoring at the hydraulically downgradient Site boundary (west and north) for a minimum of five years.
An Explanation of Significant Differences (ESD) was issued in May 1998 and changed two of the OU1 remedy components on the WESE parcel. The two changes were: (1) excavation and relocation of contaminated soils to OU2, instead of placement of a soil cover and (2) elimination of deed restrictions or other ICs for the protection of the permeable soil cover.
As a result of zoning changes and information from additional sampling, a second ESD was issued in February 2006 that clarified certain modifications of the OU1 remedy and consisted of the following:
• Land Use – The ESD allowed for land-use requirements for the undeveloped portion of OU1 to be changed to accommodate multiple land uses as allowed under the new zoning for this area with the
incorporation of the Technical Memorandum for Preliminary Remediation Goals and Decision-Making Process at Midvale Slag OU1, dated March 2005, into the decision-making process. In addition, the Institutional Control Process Plan, Operable Unit No. 1, Midvale Slag Site (ICPP) shall control the
process of implementing institutional controls when needed. The ICPP identified the unrestricted use protocol to achieve unrestricted residential use in a portion of OU1. If this protocol is met, the ICs do not apply.

• Riparian Zone – The Technical Memo and the ICPP addressed requirements for maintaining protectiveness with recreational uses, and those requirements should also be used for the riparian zone. The ROD for OU2 sets out general requirements for the riparian zone. Through the second ESD, the riparian zone remedy came to include some bank stabilization and/or revegetation to minimize Site-
contaminated material from sloughing into the Jordan River. In addition, the ESD identifies several Applicable or Relevant and Appropriate Requirements (ARARs) in the OU2 ROD that would apply to OU1 and anticipated the formation of a riparian stakeholder group.

• Groundwater – The OU1 ROD required semi-annual monitoring of the groundwater in OU1 for a period of five years after the implementation of the remedy. Additional groundwater sampling, however, indicated that a comprehensive groundwater plan for the plume that underlies both OU1 and OU2 would be more effective. As such, the OU2 ROD selected a comprehensive groundwater monitoring plan and
developed RAOs for groundwater that will apply to both OU1 and OU2. In addition, the ESD identified several ARARs selected in the OU2 ROD that will supersede those groundwater ARARs identified in the OU1 ROD.

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Response Actions OU2
Removal actions were completed at OU2 in 1990, 1995 and 1996. These removal actions addressed fencing; well abandonment; disposal of lab chemicals and explosives; and the excavation of contaminated soils and backfilling with clean soils at Butterfield Lumber and the Pioneer Cemetery. The OU2 ROD was finalized on October 29, 2002, and addressed contaminated groundwater, mixed smelter waste, slag and soils. The OU2 RAOs included the following:
• Prevent unacceptable exposure risk to current and future human populations presented by contact,
inhalation or ingestion of contaminated groundwater, smelter materials, associated contaminated materials, and COCs derived from smelter materials and slag.
• Prevent unacceptable exposure risks to current and future ecological receptors presented by contact, ingestion, inhalation, and uptake of smelter materials and slag and associated contaminated materials or COCs derived from smelter materials and slag.
• Provide that the future migration of contaminants from smelter materials and slag, or contaminated materials within slag, is within limits considered protective of groundwater.
• Prevent smelter materials and slag, or contaminated materials within slag, from entering the Jordan River via surface water flow.

• Provide that future migration of COCs into previously uncontaminated portions of the US&G aquifer and into the deep principal aquifer is protective of these aquifers as sources of drinking water.
• Provide that future discharge of contaminated groundwater from the Site to the Jordan River is protective of the aquatic environment and designated use.
• Restore groundwater to beneficial use. The major components of the remedy selected in the OU2 ROD include:
• Excavating and disposing off-site any Category I material and soils in direct contact with this waste.
• Covering Category II and III materials with slag (Category IV material) or with a demarcation layer
consisting of a colored geotextile followed by a vegetative cover. Under commercial/light industrial land use, leaving Category III material uncovered if it is demonstrated that COC concentrations are below the applicable cleanup goals.
• Covering Category IV material with a vegetative cover.
• Providing periodic inspection and long-term maintenance of covers.
• Developing ICs to prevent exposure to contaminated materials (including slag) by placing restrictions on future excavations and reviewing any proposals to change the type of land use at the Site. ICs will also restrict surface water management and irrigation practices to limit infiltration in the plume area.
• Establishing ICs, including expansion of the Sharon Steel Restricted Area, to include the US&G aquifer and requiring buildings constructed over the US&G aquifer PCE plume to install indoor air vapor mitigation systems.

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• Developing and implementing a surface water and groundwater monitoring program (applicable to both OU1 and OU2) to assess whether applicable surface water and groundwater quality criteria are being met.
• Stabilizing the banks of the Jordan River and/or possible revegetation to minimize Site contamination from sloughing off into the Jordan River.
An ESD was issued in October 2013 that clarified the final remedial goals and cleanup standards for the contaminated portion of the US&G aquifer and identified: (1) the RAO regarding beneficial use of this aquifer as a drinking water source; and, (2) ACLs established for COCs in groundwater in lieu of standards that would have
otherwise been suitable ARARs. These changes were as follows:
• The ACLs established for arsenic, cadmium, selenium and antimony, the COCs in the 2002 OU2 ROD, are the final, applicable groundwater standards for those contaminants in the US&G aquifer.
• Restoration of the contaminated portion of the US&G aquifer to beneficial use as a drinking water source is not an RAO for the OU1 and OU2 remedies.
Status of Implementation OU1 Soils The excavation of soils and importation of clean fill for 14 residential yards located in the WENW Parcel was conducted in 1996. The excavation of contaminated soil on the WESE Parcel and relocation to OU2 was conducted in 1998. The remedial action for OU1 is complete, and the final Remedial Action Report was signed in
March 1999. Land-use restrictions for soils within OU1 Parcels LR-east, LR-west, LF, and LG have been established as an IC
Ordinance that is enforced by Midvale City. The ICs in this Ordinance are based upon the Institutional Control Process Plans for OU1 of the Midvale Slag Site. Status of Implementation OU2 Soils Remedial action activities for OU2 soils were completed in August 2007. During the remedial action, Category I wastes were not encountered; therefore, excavation and off-site disposal was not necessary. Category II and III wastes were covered with a demarcation layer of either slag or geotextile material, and the slag and geotextile material were covered with soil and vegetation. Land-use restrictions for OU2 soils have been established under the IC Ordinance that is enforced by Midvale City. Status of Implementation OU1 and OU2 Groundwater A groundwater monitoring system consisting of 30 monitoring wells was installed in December 2008. Two monitoring wells, MW-501s and MW-501i, were properly abandoned in September 2020 as recommended in the previous 2019 FYR Report. UDEQ/DERR performs routine groundwater and surface water monitoring and sampling to ensure (1) discharges to the Jordan River are protective of the aquatic environment; (2) groundwater
COCs do not migrate into the deep principal aquifer and uncontaminated portions of the US&G aquifer; and (3) groundwater COC concentrations remain below established ACL values. Groundwater use at OU1 and OU2 is restricted by the Salt Lake Valley Groundwater Management Plan and Midvale City IC Ordinance.
Status of Implementation OU1 and OU2 Riparian Zones
Riparian zone bank stabilization and revegetation was completed in July 2011. This work included laying back the steep riverbanks, installing benches, and vegetating the benches and banks to prevent erosion and the potential sloughing of contamination into the Jordan River.

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IC Summary Table
Table 4: Summary of Implemented ICs
Media, engineered controls, and areas that do not support UU/UE based on current conditions
ICs Needed
ICs Called for in the Decision Documents
Impacted Parcel(s) IC Objective
Title of IC Instrument Implemented and Date (or planned)
Soils Yes Yes OU1/OU2
Requires
procedures to prevent unacceptable human exposure to contaminants that remain on Site,
restricts irrigation practices to limit infiltration in the plume area, ensures protection, maintenance and
improvement of covers that have been constructed at the Site
Midvale Municipal Code Chapter 8.10
Institutional Controls Ordinance for Bingham
Junction, Jordan Bluffs and designated Rights-
of way June 26, 2007
Groundwater Yes Yes OU1/OU2
Prohibits the installation of groundwater wells
and requires vapor mitigation measures for residential buildings constructed above the groundwater PCE plume
Midvale Municipal Code Chapter 8.10 Institutional
Controls Ordinance for Bingham Junction, Jordan Bluffs and designated Rights-of way June 26, 2007
Groundwater Yes Yes OU1/OU2 Restricts the transfer of water rights into the Site
Utah Department of Natural Resources,
Division of Water Rights, Salt Lake Valley Groundwater Management Plan June 25, 2002
III. SYSTEMS OPERATIONS/OPERATION & MAINTENANCE
Groundwater and Surface Water Monitoring
The 2004 Groundwater and Surface Water Monitoring and Sampling Plan prepared by CDM, under contract to the EPA, established the plan for monitoring at the following groundwater and surface water locations:

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• Seven monitoring well pairs, designated MW-701 through MW-707, were established to monitor
groundwater conditions within, immediately below and adjacent to the contaminated portion of the
US&G Aquifer, at points representative of discharge to the Jordan River.
o Shallow wells are designated with an "s" (e.g., MW-701s), and deeper wells are designated with
an "i" (e.g., MW-701i).
o Monitoring wells MW-702s through MW-706s are shallow wells placed in the contaminated
portion of the US&G Aquifer used for assessing ACL exceedances. The wells MW-702i through
MW-706i are paired, intermediate-depth wells placed in the underlying uncontaminated portion
of the US&G Aquifer. These paired wells, at different depths, allow for evaluation of downward
migration of contaminants and calculation of hydraulic gradients.
o Paired monitoring wells MW-701s and MW-701i and paired monitoring wells MW-707s and
MW-707i were established as locations for assessing lateral migration of the plume.
• Paired monitoring wells MW-601s and MW-601i and MW-602s and MW-602i were established as points of assessment to monitor the downward migration of contamination within the plume core.
• Paired monitoring wells MW-501s and MW-501i through MW-507s and MW-507i were established to monitor changes in the uncontaminated portion of the US&G aquifer that may indicate lateral migration.
• Surface water monitoring location SW-202 was established as a point of compliance to ensure that surface Water quality criteria is not exceeded in the Jordan River. Surface water monitoring location SW-201 was also established to measure conditions upstream of the discharge of the contaminated groundwater from the US&G Aquifer. UDEQ/DERR performs annual groundwater and surface water monitoring and sampling under a cooperative agreement with the EPA. In March 2018, the EPA completed a groundwater optimization study that recommended reducing the number of wells sampled on an annual basis. UDEQ/DERR and the EPA
implemented this recommendation in May 2018 and began monitoring and sampling 12 monitoring wells and two surface water locations during even numbered years and monitoring and sampling all 28 monitoring wells and two surface water locations during odd numbered years. Reports summarizing the results of each groundwater and
surface water monitoring and sampling event are prepared by UDEQ/DERR and submitted to the EPA. Institutional Controls
ICs outlining procedures for ensuring protection, maintenance and improvement of covers that have been constructed at the Site are enforced through a Midvale City Ordinance. Requirements and responsibilities for
enforcing the ICs are as follows: City of Midvale Responsibilities
1. Periodic inspection of covers and final barriers on the Site. 2. Prohibit new groundwater wells without prior consent of the EPA, UDEQ, and the State Engineer. 3. Repair covers and final barriers if the Private Owners Associations (POA) or landowner is unresponsive. The city will enforce repair and collection of costs. 4. Review of Site plan applications and issuance of final Site plan approval. 5. Review of road-cut permit applications and issuance of permits. 6. Review of intrusive activity plans and issuance of final approval. 7. Periodic inspections during initial Site development and post-development construction to ensure compliance with construction permits, including air quality monitoring plans. 8. Oversight of landscaping activities of POA (or similar entity). 9. Verification that private covenants and deed restrictions for developments include the requirements of the
Ordinance relating to landscaping and excavation. 10. Review irrigation plans for non-residential development with Source Areas and issue approval for such plans.

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11. Review the request for a Certificate of Occupancy to determine whether the final depth of surface cover meets or exceeds the approved depth.
U.S. EPA and UDEQ Responsibilities 1. Review of procedures and protocols for testing excavated materials and issuance of final approvals. 2. UDEQ has general oversight responsibilities for operations and maintenance (O&M) of the remedy. 3. The EPA reviews and approves Five-Year Reviews.
Landowner/POA Responsibilities
1. Maintenance and repair of covers on their property. 2. Review, approve and oversee the implementation of irrigation plans in residential areas. 3. Establish conditions, covenants and restrictions which include the creation of POAs to oversee compliance with applicable excavation and grading restrictions.
4. Prepare and submit all plans and requests for approvals as required by the Midvale Ordinance. Hire a Special Inspector to oversee residential development projects. IV. PROGRESS SINCE THE LAST REVIEW
This section includes the protectiveness determinations and statements from the last five-year review, as well as the recommendations from the last five-year review and the current status of those recommendations. Table 5: Protectiveness Determinations/Statements from the 2019 FYR
OU # Protectiveness Determination Protectiveness Statement
1 Protective The remedy at OU1 is protective of human health and the environment.
2 Protective The remedy at OU2 is protective of human health and the
environment.
Sitewide Protective Because the remedial actions at both OUs are protective, the
Site is protective of human health and the environment.
There were no issues identified or recommendations made in the last FYR.
Recommendations made under other findings in the previous 2019 FYR Report that did not affect current and/or future protectiveness have been addressed as follows:
• Monitoring wells MW-501s and MW-501i were abandoned in September 2020;

• Analyses of PCE and its degradation byproducts were eliminated in May 2018;

• Annual groundwater and surface water monitoring and sampling of select monitoring wells and two
surface water locations began in May 2018;

• The collection of annual groundwater samples from 12 monitoring wells MW-505s, MW-505i, MW-
507s, MW-507i, MW-601s, MW-601i, MW-602s, MW-602i, MW-701s, MW-701i, MW-706s, MW-
706i, and two surface water samples SW-201 and SW-202 began in May 2018; and

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• The biennial (every two years) collection of groundwater and surface water samples from all monitoring wells and two surface water locations began in May 2019. V. FIVE-YEAR REVIEW PROCESS
Community Notification, Involvement & Site Interviews A public notice was made available by a newspaper posting (Appendix C) in the Midvale City Journal, on
2/5/2024, stating that there was a five-year review and inviting the public to submit any comments to the EPA and UDEQ/DERR. The results of the review and the report will be made available at the Site information repository located at UDEQ/DERR, 195 North 1950 West, 1st Floor, Salt Lake City, Utah, and at http://eqedocs.utah.gov.
The results of the review and the report will also be made available on the EPA’s Site profile page at http://www.epa.gov/superfund/midvale-slag.
UDEQ/DERR conducted community interviews with individuals knowledgeable about the Site. Individuals that were interviewed included personnel with the Midvale City Engineering Division, Salt Lake County Parks Division, Intermountain Health Care (IHC) - Supply Chain Fulfillment Center, CHG Healthcare headquarters building – Gardner Company, and Winchester Estates Mobile Home Park. None of the interviewees expressed any health or environmental concerns. Reports summarizing the interviews are included in Appendix D. VI. Data Review
Groundwater Monitoring As discussed previously, the current groundwater monitoring system at the Midvale Slag Site consists of co-located wells at 14 locations, for a total of 28 wells, and two surface water sampling locations (Figure 3). Each well pair consists of one shallow monitoring well screened in the upper interval of the US&G aquifer and one
intermediate monitoring well screened at a lower interval within the US&G aquifer. The monitoring system is divided into four groups and consists of upgradient, downgradient, plume core and ACL (point of assessment) monitoring wells. COC concentrations in samples collected within the last five years from each monitoring well are provided in Appendix E. Based on a review of data found in the annual groundwater monitoring and sampling reports prepared over the
last five years, the following general conclusions can be made:
• Horizontal groundwater flow direction is toward the northwest and Jordan River.
• COC concentrations in the shallow ACL (point of assessment) monitoring wells MW-702s through MW-706s did not exceed their respective ACL value.
• Stable or low COC concentrations in the intermediate ACL (point of assessment) monitoring wells MW-702i through MW-706i indicate that COCs are not migrating downward.

• Arsenic levels in the plume core monitoring well MW-601i have increased over the period of the last five years, thus indicating that contamination may be migrating downward.
• COC concentrations are stable and well below ACLs in paired monitoring wells MW-701s and MW-701i and MW-707s and MW-707i, and the plume is not migrating to uncontaminated portions of the US&G aquifer.

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• Stable or low concentrations in paired monitoring wells MW-501s and MW-501i through MW-507s and MW-507i indicate that COC concentrations are not migrating laterally to uncontaminated portions of the US&G aquifer.
The 2004 Groundwater and Surface Water Monitoring and Sampling Plan recognized that plume concentrations would increase for at least 100 years; however, excessive or rapid increases in concentrations may indicate a change in conditions that could influence the downgradient monitoring wells that are assessed against ACLs. Arsenic levels in monitoring well MW-601i have increased, thus indicating that COC concentrations may be migrating downward within the plume core; however, COCs in the downgradient ACL (point of assessment) wells have remained stable and well below ACLs. UDEQ/DERR will continue to perform annual groundwater
monitoring and sampling in order to evaluate COC levels throughout the plume. UDEQ/DERR and the EPA will continue to evaluate arsenic levels in MW-601i. Surface Water Monitoring Surface water samples are collected from the Jordan River at two monitoring locations at the Midvale Slag Site (Figure 3). COC concentrations in samples collected within the last five years from each sample location and surface water quality criteria for the Jordan River are provided in Appendix E. A review of the COC levels in surface water over the last five years shows concentrations are stable and well below levels that would have an adverse impact on aquatic life.
Institutional Controls
Individuals associated with Midvale City who were interviewed included the City Engineer and the Superfund Site Coordinator. The City Engineer indicated that development and compliance with ICs have proceeded smoothly since remedial activities were completed at the Site in 2007 and that there were only two small vacant
parcels left to develop. During the community interviews, individuals with IHC and Gardner Company were interviewed. IHC owns and operates a supply chain fulfillment center at the Site and Gardner Company owns an office building at the Site that it leases to CHG Health Care. Both IHC and Gardner Company were aware of the ICs enforced by Midvale City. IHC completed an expansion of their supply chain fulfillment center within the last five years. Construction activities related to the expansion were coordinated with Midvale City and complied with ICs.
Site Inspection The inspection of the Site was conducted on 11/9/2023. In attendance were UDEQ/DERR Section Manager Wes Sandlin, UDEQ/DERR Project Manager Tony Howes, and UDEQ/DERR Community Involvement Coordinator Dave Allison. The purpose of the inspection was to assess the protectiveness of the remedy.
The group toured the Site, observed construction related to the expansion of the IHC Supply Chain Fulfillment Center, inspected monitoring wells and the Jordan River riparian zone, and noted general Site conditions. Photographs of the Site taken during the inspection are provided in Appendix F and the completed Site inspection
checklist is included in Appendix G. VII. TECHNICAL ASSESSMENT
QUESTION A: Is the remedy functioning as intended by the decision documents? Question A Summary:
The remedies at both OU1 and OU2 are functioning as intended by the decision documents.

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The excavation of contaminated soils from OU1 eliminated exposure to contaminated soils for current or
hypothetical future residents and hypothetical future workers. Removal of OU2 Category I wastes was not necessary since these wastes were not encountered during the response action. The cover constructed over OU2 wastes is in place and continues to prevent exposure. Data from routine groundwater monitoring show that COCs are below their respective ACL values. An analysis of the trends in all groundwater wells also shows the contaminated groundwater plume is stable. Relatively stable contaminant trends in all wells also support that the plume is not migrating to uncontaminated portions of the US&G aquifer or the deep principal aquifer. An analysis of surface water sampling results indicates that the contaminant concentrations remain at levels that do not have an adverse impact on the aquatic environment. Riverbank stabilization and revegetation of the OU1 and OU2 riparian zones remain intact and prevent the erosion
and potential sloughing of contamination into the Jordan River. Midvale City enacted and enforces an IC Ordinance for both OUs. The IC Ordinance identifies procedures for the
management and disposal of soils and requires permits and a special inspector to certify that construction activities comply with ICs. The IC Ordinance also provides for the maintenance and repair of the cover to ensure future protectiveness and prohibits the installation of groundwater wells. In addition to the IC Ordinance,
groundwater use at the Site is restricted under the Salt Lake Valley Groundwater Management Plan, which restricts the transfer of water rights into the Site. Vapor intrusion concerns identified in the OU2 ROD for the Midvale Slag Site have been addressed through Midvale City’s IC Ordinance which requires vapor mitigation measures for residential buildings constructed above the groundwater PCE plume. QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and RAOs used at the time of the remedy selection still valid? Question B Summary: The clean-up numbers for OU1 and OU2 were derived from the exposure assumptions and toxicity data in the OU1 (1992) and OU2 (1994) BRAs for the Midvale Slag Superfund Site and the OU1/OU2 Ecological Risk
Assessment (1994). There have been changes to the exposure assumptions and toxicity information since those documents were issued.
When the Site Risk Assessments were conducted (1992-1994) the risk models used a 10 ug/dl blood lead level (BLL). This soil lead screening level was established so that a typical child or similarly exposed group of children would have an estimated probability of no more than 5 percent of exceeding a BLL of 10 micrograms per deciliter
(µg/dL). The 10 µg/dL BLL target concentration is based (in part) on the 1991 Center for Disease Control’s (CDC) blood lead “level of concern.” In 2012, CDC accepted the recommendations of its Advisory Committee on Childhood Lead Poisoning Prevention that the “level of concern” be replaced by a reference value based on the 97.5th percentile of the National Health and Nutrition Examination Survey-generated BLL distribution in children 1-5 years old (i.e., 5µg/dL). In 2021, the CDC updated its Blood Lead Reference Value (BLRV) from 5 µg/dL to 3.5 µg/dL in response to the Lead Exposure Prevention and Advisory Committee (LEPAC) recommendations. On January 17, 2024, the EPA issued Updated Soil Lead Guidance for CERCLA sites and RCRA Corrective Action Facilities that lowered recommended regional screening levels for lead-contaminated soil. In accordance with the guidance, these new screening levels will be used to determine whether further investigation is warranted and whether additional response actions are necessary for the remedy to remain protective.
Additionally, the OU1 and OU2 BRAs and Ecological Risk Assessment were developed prior to the EPA’s Risk Assessment Guidance for Superfund (RAGS) Part F (2009), and therefore, the exposure assumptions for the

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inhalation exposure pathway were conducted differently. The exposure metric that was used in the RODs and the BRA used inhalation concentrations that were based on ingestion rate and body weight (mg/kg-day). The updated
methodology uses the concentration of chemical in the air, with the exposure metric of micrograms per cubic meter (ug/m3). The inhalation pathway for the site COCs, Arsenic and Lead, is minor compared to the soil ingestion pathway which is the major risk factor at the Site. The OU2 ROD indicated that if conditions develop that are inconsistent with the Site conceptual model and/or the assumptions used to calculate groundwater ACLs, then the protectiveness of the remedy would need to be reevaluated. These conditions could consist of one or more of the following:
• COCs are detected in point-of-assessment wells established outside of the present plume boundaries.
• Hydrologic data indicates that the flow direction (vertical and/or horizontal) in or near the contaminated
portion of the US&G aquifer has changed significantly.
• Hydrologic data indicate that the contaminant plume no longer discharges to the Jordan River.
The 2004 Groundwater and Surface Water Monitoring and Sampling Plan established paired monitoring wells MW-701s and MW-701i and paired monitoring wells MW-707s and MW-707i (Figure-3) as the primary
locations for assessing lateral migration of the plume. A review of data found in the annual groundwater monitoring reports prepared over the last five years shows there
are no significant changes in groundwater flow direction (vertical or horizontal) and groundwater continues to flow to the Jordan River. COC concentrations detected at points of assessment are stable and well below ACLs. Based on this information, the assumptions used to calculate the ACL values remain valid. QUESTION C: Has any other information come to light that could call into question the protectiveness of the remedy? On January 17, 2024, the EPA issued Updated Soil Lead Guidance for CERCLA sites and RCRA Corrective Action Facilities that lowered recommended regional screening levels for lead-contaminated soil. In accordance with the guidance, these new screening levels will be used to determine whether further investigation is warranted and whether additional response actions are necessary for the remedy to remain protective.

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VIII. ISSUES/RECOMMENDATIONS

Issues and Recommendations Identified in the Five-Year Review:

OU(s): Site-wide Issue Category: Remedy Performance
Issue: On January 17, 2024 EPA issued Updated Soil Lead Guidance for CERCLA sites
and RCRA Corrective Action Facilities that lowered recommended regional screening levels for lead-contaminated soil.
Recommendation: In accordance with the guidance, use new screening levels to
determine whether further investigation is warranted and whether additional response actions are necessary for the remedy to remain protective.
Affect Current Protectiveness Affect Future Protectiveness Party Responsible Oversight Party Milestone Date
Yes Yes EPA EPA 4/9/2027
IX. PROTECTIVENESS STATEMENT

Protectiveness Statement
Operable Unit: 1 Protectiveness Determination: Protectiveness Deferred Addendum Due Date: 4/9/2027
Protectiveness Statement:
A protectiveness determination of the remedy at OU1 cannot be made at this time until further information is obtained. Further information will be obtained by applying the 2024 Updated Soil Lead Guidance for CERCLA
sites and RCRA Corrective Action Facilities and using the lowered screening levels to determine whether further investigation is warranted and whether additional response actions are necessary for the remedy to remain
protective. It is expected these steps could take approximately 36 months to complete, after which a protectiveness determination will be made using the information received through application of the 2024 Updated Soil Lead
Guidance for CERCLA sites and RCRA Corrective Action Facilities.

Protectiveness Statement
Operable Unit: 2 Protectiveness Determination: Protectiveness Deferred Addendum Due Date: 4/9/2027
Protectiveness Statement:
A protectiveness determination of the remedy at OU2 cannot be made at this time until further information is obtained. Further information will be obtained by applying the 2024 Updated Soil Lead Guidance for CERCLA
sites and RCRA Corrective Action Facilities and using the lowered screening levels to determine whether further investigation is warranted and whether additional response actions are necessary for the remedy to remain
protective. It is expected these steps could take approximately 36 months to complete, after which a protectiveness determination will be made using the information received through application of the 2024 Updated Soil Lead
Guidance for CERCLA sites and RCRA Corrective Action Facilities.

Sitewide Protectiveness Statement
Protectiveness Determination: Protectiveness Deferred Addendum Due Date: 4/9/2027

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Protectiveness Statement: A protectiveness determination of the remedy at the Midvale Slag site cannot be made at this time until further
information is obtained. Further information will be obtained by applying the 2024 Updated Soil Lead Guidance for CERCLA sites and RCRA Corrective Action Facilities and using the lowered screening levels to determine
whether further investigation is warranted and whether additional response actions are necessary for the remedy to remain protective. It is expected these steps could take approximately 36 months to complete, after which a
protectiveness determination will be made using the information received through application of the 2024 Updated Soil Lead Guidance for CERCLA sites and RCRA Corrective Action Facilities.
X. NEXT REVIEW
The next five-year review report for the Midvale Slag Superfund Site is required five years from the completion
date of this review.

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APPENDIX A – REFERENCE LIST AECOM, 2020, Letter Report Summarizing MW-504 s/i Repair and MW-501 s/i Abandonment Activities
Midvale Slag Site Midvale, Utah, 15p. SEMS# 100014815 CDM, 2004, Midvale Slag Superfund Site Midvale, Utah Groundwater and Surface Water Monitoring Plan
September 2004 Technical Report, 300p. SEMS# 2035272 Life Systems Inc., 1992, Baseline Risk Assessment-Human Health Evaluation, Midvale Slag Superfund Site, Operable Unit 1, Midvale, Utah. SEMS# 89448 Office of Superfund Remediation and Technology Innovation Environmental Protection Agency, 2009, Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for Inhalation Risk Assessment), 68p. https://semspub.epa.gov/work/HQ/140530.pdf United States Environmental Protection Agency, 1994, Engineering Evaluation/Cost Analysis at the Midvale Slag Operable Unit No. 2 (0U2) Superfund Site Midvale, Utah Volume 2 Baseline Risk Assessment Report,
619p. SEMS# 89767 United States Environmental Protection Agency, 1995, EPA Superfund Record of Decision: Midvale Slag (O.U.
1), Midvale, UT 4/28/1995, 98p. SEMS# 90224 United States Environmental Protection Agency, 1998, Explanation of Significant Differences for the Midvale
Slag Operable Unit One Superfund Site Winchester Estates Southeast Parcel, 4p. SEMS# 89253 United States Environmental Protection Agency, 2002, Midvale Slag Superfund Site Operable Unit 2 Midvale, Utah, Record of Decision, October 2002, 273p. SEMS # 2003421 United States Environmental Protection Agency, 2003, First Five-Year Review Report for Midvale Slag
Superfund Site Midvale, Salt Lake County, Utah CERCLIS ID: UTD081834277, 122p. SEMS# 1064962 United States Environmental Protection Agency, 2004, Midvale Slag Superfund Site Midvale, Utah RD/RA Consent Decree, Institutional Control Process Plan Operable Unit No. 1 Midvale Slag Site Midvale, Utah, p.560. SEMS# 1055083 United States Environmental Protection Agency, 2006, Explanation of Significant Differences Midvale Slag
Superfund Site Midvale, Utah Operable Unit #1, 9p. SEMS# 1052312
United States Environmental Protection Agency, 2008, Ready for Reuse Determination Midvale Slag Superfund Site, 103p. SEMS# 1570715 United States Environmental Protection Agency, 2008, Second Five-Year Review Report for Midvale Slag Superfund Site CERCLIS ID: UTD081834277 Midvale Salt Lake County, Utah, 74p. SEMS# 1092844
United States Environmental Protection Agency, 2013, Explanation of Significant Differences Midvale Slag, Operable Units 1 & 2 Midvale, UT, 11p. SEMS# 1272367
United States Environmental Protection Agency, 2014, Final Close-Out Report Midvale Slag Superfund Site, 13p. SEMS# 1558757

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United States Environmental Protection Agency, 2014, Third Five-Year Review Report Midvale Slag Superfund Site Salt Lake County, Utah CERCLIS ID:UTD081834277, 122p. SEMS# 1278900
United States Environmental Protection Agency, 2015, National Oil and Hazardous Substances Pollution Contingency Plan National Priorities List: Deletion of the Midvale Slag Superfund Site (notice of intent), Vol. 80, No. 24, F.R. 6496 (February 5, 2015) United States Environmental Protection Agency, 2015, National Oil and Hazardous Substances Pollution Contingency Plan National Priorities List: Deletion of the Midvale Slag Superfund Site (Final Rule), Vol. 80, No. 67, F.R. 18780 (April 8, 2015) United States Environmental Protection Agency Office of Land and Emergency Management, 2024, Update Residential Soil Lead Guidance for CERCLA Site and RCRA Corrective Action Facilities, 10p.
https://www.epa.gov/system/files/documents/2024-01/olem-residential-lead-soil-guidance-2024_signed_508.pdf
Utah Department of Environmental Quality Division of Environmental Response and Remediation, 2019, Annual Groundwater and Surface Water Monitoring and Sampling Report Midvale Slag Superfund Site Midvale City, Utah, May 2019, 634p. SEMS# 1930749
Utah Department of Environmental Quality Division of Environmental Response and Remediation, 2020, Annual Groundwater and Surface Water Monitoring and Sampling Report Midvale Slag Superfund Site Midvale City, Utah, June 2020, 455p. SEMS# 100014819 Utah Department of Environmental Quality Division of Environmental Response and Remediation, 2021, Annual Groundwater and Surface Water Monitoring and Sampling Report Midvale Slag Superfund Site Midvale City, Utah, May 2021, 384p. SEMS# 100014820 Utah Department of Environmental Quality Division of Environmental Response and Remediation, 2022, Annual Groundwater and Surface Water Monitoring and Sampling Report Midvale Slag Superfund Site Midvale
City, Utah, June 2022, 459p. Utah Department of Environmental Quality Division of Environmental Response and Remediation, 2023, Annual Groundwater and Surface Water Monitoring and Sampling Report Midvale Slag Superfund Site Midvale City, Utah, May 2023, 124p. SEMS# 100014813

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APPENDIX B – SITE MAPS

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APPENDIX C – PUBLIC NOTICE

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APPENDIX D – COMMUNITY INTERVIEW SUMMARY REPORTS Midvale Slag Superfund Site
Five-Year Review
Interview of Local Agencies

Site Name: Midvale Slag Superfund Site
EPA ID: UTD081834277
January 22, 2024
Type of Contact: Teleconference Call

Contact Made By: Dave Allison and Tony Howes,
UDEQ-DERR
Persons Contacted
Name: Keith Ludwig, P.E. City Engineer
Billie Smathers, Site Coordinator
Organization: Midvale City - Engineering Division
Address:
Midvale City Hall
7505 S Holden St
Midvale, UT 84047
Phone Number: [phone]

1. Is your organization/department aware of the Midvale Slag Superfund Site and the actions
underway to address environmental contamination? Keith Ludwig, P.E. City Engineer, for the
Midvale City Engineering Division since 1999 and throughout the Midvale Slag Site cleanup and
redevelopment of Bingham Junction (Operable Units 1&2). Billie Smathers is the current Midvale City
Site Coordinator and was hired in May 2018, primarily to oversee the development construction work
at the former Midvale Slag Superfund Site area now known as Bingham Junction. The Midvale City
Engineering Division is responsible for implementing the Institutional Control Process Plans, local
zoning, building, road and excavation permits, engineering design guidelines, residential
requirements, and controls on water management and groundwater use.

2. What’s your overall impression (your general sentiment) of the actions performed at the Midvale
Slag Superfund Site? Ludwig and Smathers said that since the cleanup finished in 2006 and 2007 the
development of the Site has progressed smoothly. There are only two small vacant parcels left to
even develop at the nearly 450-acre Site, Ludwig said. Developers are well aware of the Site history,
haven’t communicated any issues over the years, and have been great to reach out to Midvale when
building at the Site. Existing tenants also haven’t had any issues with construction activities as well.
Smathers and Ludwig said Bingham Junction is well managed and development has been a non-issue
with the cleanup of Midvale Slag.

3. Does your office conduct routine communications and/or activities (Site visits, inspections,
reporting activities, participation in meetings, etc.) for the Midvale Slag Superfund Site? If so,
please briefly summarize the purpose and results of these communications and/or activities over
the past several years. Other than communicating with developers and contractors as projects arise,
Smathers and Ludwig said there are no regular formal reporting tasks. As permit requests are
submitted to the City and found to be involved on the Site, Smathers will reach out to
developers/contractors to make sure everything falls in line with the institutional controls in place.
Smathers also communicated throughout the life of the project depending upon what their project
needs are.

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4. Are you aware of any community concerns regarding the Midvale Slag Superfund Site or its
operation and administration? If so, please give details. Ludwig or Smathers could not recall any
health or environmental community concerns over the last five years from businesses or residents.

5. Over the past five years, have there been any complaints, violations, or other incidents (e.g.,
vandalism, trespassing, or emergency responses) at or related to the Midvale Slag Superfund Site
requiring your office to respond? If so, please give details of the events and results of the response.
Ludwig and Smathers said there haven’t been any incidents or emergencies relative to the cleanup
remedy.

6. Do you feel well informed about the Site’s activities and progress over the last five years? Do you
know how to contact the Environmental Protection Agency if you have questions or concerns
about the Midvale Slag Superfund Site? Smathers has regular oversight communication with UDEQ
on Site progress reports on a neighboring (Sharon Steel/Jordan Bluffs Development) former
Superfund Site. Other than groundwater inspection reports there is not much for Ludwig’s division to
be informed about with the former Midvale Slag Site. Smathers is the City’s regular point of contact
for institutional controls with the EPA and UDEQ and said he works well with project managers.

7. Over the past five years, have there been any changes in your department’s policies or regulations
that impact the Midvale Slag Superfund Site and/or your role? Ludwig and Smathers said there have
not been any changes to policy or regulations.

8. Over the past five years, have there been any changes in land use surrounding the Midvale Slag
Superfund Site? Are you aware of potential future changes in land use? If so, please describe.
Ludwig and Smathers said the commercial/residential zoning designations are the same and they
aren't aware of any re-zoning changes. However, there were a few sizable construction projects
within the last five years at Bingham Junction. Ludwig said the Salt Lake County Parks added a boat
ramp for canoes and kayaks to put-in and take-out on the Jordan River. Located at the 7800 South
Trailhead a concrete ramp was installed, away from any cleanup areas. The ramp project involved the
City throughout. Smathers also said CHG Healthcare completed a terraced parking garage and IHC is
expanding their warehouse, pouring footings, arranging utilities as well as moving soil. Both projects
required oversight from Midvale City and Smathers said both companies were great to work with and
were aware of the institutional controls.

9. Do you have any comments, suggestions, or recommendations regarding the Site’s management or
operation (institutional controls)? If so, what types of future problems do you think (1) could occur;
or (2) would concern you and/or your department? Ludwig and Smathers said the institutional
controls are working well at the Site with very few parcels left for future development. Property
owners are knowledgeable and have communicated construction projects well with the Midvale
Cities Engineers office.

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Midvale Slag Superfund Site
Five-Year Review
Interview of Local Agencies

Site Name: Midvale Slag Superfund Site
EPA ID: UTD081834277
January 22, 2024
Type of Contact: Telephone Contact Made By: Dave Allison, UDEQ-DERR
Person Contacted
Name: Angelo Calacino, AICP
Park Development Project Manager
Planning & Development Section
Organization: Salt Lake County – City Parks and
Recreation
Address:
2001 South State Street, Ste S4-700
Salt Lake City, Utah 84190
Phone Number [phone]

1. Is your organization/department aware of the Midvale Slag Superfund Site and the actions taken to
address environmental contamination? Angelo Calacino is a Park Development Project Manager for
Salt Lake County and was involved with the construction of a non-motorized boat ramp located at the
7800 South Trailhead associated with the Jordan River in October 2023. The 120-foot long, 6-foot
wide boat ramp is part of Phase 1 of the Jordan River Water Trail to provide recreation access to
canoes or kayaks along the Jordan River.

The ramp project was located near previously remediated property and riparian zone areas but did
not encroach upon institutional controls at the Site. Calacino said he was familiar with Site history
and didn’t expect this project to be a concern. The boat ramp project was coordinated well with
Midvale City, as well as other required permitting agencies for the Jordan River. The County City
Parks and Recreation Department operates and maintains parks, trails, open space, golf courses,
recreation centers, swimming pools and ice centers.

2. Does your office conduct routine communications and/or activities (Site visits, inspections,
reporting activities, participation in meetings, etc.) for the Midvale Slag Superfund Site? If so,
please briefly summarize the purpose and results of these communications and/or activities.
Calacino said the Boat Ramp projects provide an access amenity for recreation river use and are
being placed at various trail locations along the Jordan River. Outside of the required permits to do
work on a river, Calacino was not in an area associated with Superfund land use controls. Calacino
said the County takes every opportunity to communicate and coordinate trail projects with the public
and met with Midvale City in every phase of the project.
3. Are you aware of any community concerns regarding the Midvale Slag Superfund Site or its
operation and administration? If so, please give details. Calacino was not aware of any community
health related issues or concerns related to the Site history.

4. Over the past five years, have there been any complaints, violations, or other incidents (e.g.,
vandalism, trespassing, or emergency responses) at or related to the Midvale Slag Superfund Site
requiring your office to respond? If so, please give details of the events and results of the response.
No, Calacino said the permitting process is rigorous and involves many parties, County Flood Control,
State Water Rights, State Forestry, Fire and State Lands, any time you do work on a river. Oversight at
this level enables good coordination and awareness to make sure these projects are transparent and

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done right. In case there is an environmental issue, the permits require immediate notification to the
County Health Department and associated agencies.

5. Do you feel well informed about the Site’s activities and progress over the last five years? Do you
know how to contact the Environmental Protection Agency if you have questions or concerns
about the Midvale Slag Superfund Site? Calacino has worked well with Midvale City and although he
has not had to work with EPA or UDEQ on this project, is confident the right people are notified
through the permitting process.

6. Do you have any comments, suggestions, or recommendations regarding the Site’s management or
operation (institutional controls)? If so, what types of future problems do you think (1) could occur;
or (2) would concern you and/or your department? Calacino said the Boat Ramp projects have
worked well and he doesn’t expect future construction work at the Site.

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Midvale Slag Superfund Site
Five-Year Review
Interview of Community Members

Site Name: Midvale Slag
EPA ID: UTD081834277
January 31,2024
Type of Contact: Teleconference Call Contact Made By: Dave Allison and Tony Howes,
UDEQ-DERR
Person Contacted
Name: Shayleena Gaitan, Park Manager
Cheri Goss, IPG Regional Property Manager
Chris Bowden, IPG Director Construction &
Maintenance
Organization: Winchester Estates, Mobile Home
Park Investment Property Group

Address:
6403 South 710 West
Murray, UT 84123

Investment Property Group Corporate Office
136 Heber Avenue Suite 308
Park City, UT 84060
Phone Number: [phone]
1. Are you aware of the Midvale Slag Superfund Site and the response work that was taken or is
underway to address environmental contamination? Shayleena Gaitan, Park Manager, Cheri Goss,
Investment Property Group (IPG) Regional Property Manager, and Chris Bowden, IPG Director
Construction & Maintenance said what was known of the Site history. Although local management of
the Winchester Mobile Home Park located in Murray, Utah, was not familiar with the property
cleanup history of Midvale Slag. There was knowledge with the property owner, IPG of Site records
as the company purchased Winchester Estates in 2017. Winchester Estates is part of OU1 and
involved 14 residential yards with lead and arsenic contamination cleanup requiring an 18-inch clean
soil cap located in the southwestern area of the mobile home park. Soil was not cleaned up
underneath where mobile homes were situated. There was also an undeveloped portion of the
property excavated down 2-feet and replaced with clean fill.

2. What’s your overall impression (your general sentiment) of the response work taken/underway
that was completed at the Midvale Slag Superfund Site? IPG Management said there have not been
any issues with the property and want to identify exact cleanup property locations to best manage
cleanup parcels if land use were to change in the future.
3. What would you say are the effects that past and current mining operations had on the community
surrounding the Midvale Slag Superfund Site? IPG Management said they could not think of
anything affecting current property use.

4. Are you aware of any community concerns regarding the Midvale Slag Superfund Site, as it pertains
to actions taken or underway to address environmental contamination? IPG Management said they
were not aware of any current community concerns and had conversations over the years of cleanup
activities on nearby properties.

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5. Over the past five years, have there been any events, incidents, or activities at the Midvale Slag
Superfund Site that concern you? If so, please provide details. IPG Management said the area where
mobile homes were cleaned up have remained undisturbed and without any construction activity
since IPG has owned Winchester Estates.

6. Do you feel well informed about the activities and progress over the last five years at the Midvale
Slag Superfund Site? Do you know how to contact the Environmental Protection Agency and/or
UDEQ-DERR if you have questions or concerns about the Midvale Slag Superfund Site? Also, do you
feel the Agencies communicate with the public or respond effectively to their comments? IPG said
although the Five-Year Review was the initial interaction with UDEQ or EPA since buying the
property, there hasn’t been a need to contact anyone regarding the cleanup properties. IPG said they
would expect any permitting process would bring the proper notification of Murray City and possibly
to EPA or UDEQ. IPG said they have the contact information of Project Managers at UDEQ and EPA
and would call with any questions.

7. Do you have any additional comments, suggestions, or recommendations regarding the Midvale
Slag Superfund Site management (for example, questions pertaining to institutional controls)? IPG
Management requested an overlay map from UDEQ or EPA to know where the cleanup occurred to
address any issues in the future. A map would also be helpful if any property damage occurred on
cleanup properties such as a water line break or utility work. Murray City Engineering did confirm
their office is familiar with the Site history and would be able to provide information if permits were
initiated. IPG Management said the Winchester Mobile Home park is successful and they’re not
aware of any plans to sell the property in the future.

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Midvale Slag Superfund Site
Five-Year Review
Interview of Local Agencies

Site Name: Midvale Slag Superfund Site
EPA ID: UTD081834277
February 2, 2024
Type of Contact: Teleconference Call

Contact Made By: Dave Allison and Tony Howes,
UDEQ-DERR
Person Contacted
Name: Jim Blankenau, Environmental Program
Manager, Dan Olson, Facilities Manager Nick Rice,
Industrial Hygiene Director and Chris Shurtleff,
Safety and Process Improvement Manager
Organization: Intermountain Health Care (IHC)-
Supply Chain Fulfillment Center
Address:
Kem C. Gardner Supply Chain Center
7302 S. Bingham Junction Blvd.
Midvale, UT 84047
Phone Number: [phone]

1. Is your organization/department aware of the Midvale Slag Superfund Site and the actions
underway to address environmental contamination? Jim Blankenau, Environmental Program
Manager, Dan Olson, Facilities Manager, Nick Rice, Industrial Hygiene Director, and Chris Shurtleff,
Safety and Process Improvement Manager, oversee Site operations at the IHC building, a 327,000
square foot, fulfillment center. This includes any facility construction and landscaping where
institutional controls would be implemented. The IHC Staff said they are familiar with the former
Midvale Slag Superfund cleanup history and the facility underwent a warehouse expansion project
within the last Five-Year timeframe. The facility operates 24-hours a day, and 365 days a year with
four areas of operations: Category Management, Purchasing, Logistics and Materials Management,
Support Services and Business Programs and Services.

2. What’s your overall impression (your general sentiment) of the actions performed at the Midvale
Slag Superfund Site? The IHC Staff said the cap remedy is working. IHC knows the conditions they are
dealing with and the institutional controls to follow. To have this oversight knowledge onsite helps
inform contractors to make sure projects are handled properly. There is good general knowledge on
the corporate level as well as onsite and prior to any construction steps taken working with Midvale
City. All work well together to make sure the proper permitting and handling procedures are in place.

3. Does your office conduct routine communications and/or activities (Site visits, inspections,
reporting activities, participation in meetings, etc.) for the Midvale Slag Superfund Site? IHC Facility
Managers do participate with annual inspections and with groundwater sampling of onsite wells and
said regulators are good to notify and schedule sampling activities. The IHC Staff said they do not
have any formal communication or reporting activities outside of a third-party requirement with
contractors and the permitting processes with Midvale City.

4. Are you aware of any community concerns regarding the Midvale Slag Superfund Site or its
operation and administration? If so, please give details. No one from the IHC Staff had heard
anything regarding health or environmental concerns from the community over the last five years.
The IHC staff said when the building was new, built in 2012, there was a lot of communication with
employees regarding the cleanup history. Arsenic getting into the drinking water and indoor air

32

quality were perceptions of concern onsite. However, there was a lot of outreach to employees to
communicate what the real risks were, what remediation steps were taken, and what controls are in
place. Today, those concerns are silent and have been over the last five years.

5. Over the past five years, have there been any complaints, violations, or other incidents (e.g.,
vandalism, trespassing, or emergency responses) at or related to the Midvale Slag Superfund Site
requiring your office to respond? IHC Staff said no emergency or complaints have been received and
only a minor equipment failure of a snow melt break required a repair. IHC Staff said there are a lot
of eyes onsite and water sensors in their landscaping system to detect any water leaks which would
be addressed quickly.

6. Do you feel well informed about the Site’s activities and progress over the last five years? Do you
know how to contact the Environmental Protection Agency if you have questions or concerns
about the Midvale Slag Superfund Site? IHC Staff said they have good contacts in place internally
with IHC management, Midvale City Engineering, and UDEQ. IHC said the Site has matured to the
extent it is on cruise control, being well informed, communication exchange, and managing Site
cleanup areas.

7. Over the past five years, have there been any changes in land use surrounding the Midvale Slag
Superfund Site? Are you aware of potential future changes in land use? IHC Staff said there hasn’t
been any changes as far as facility management or processes with any soil removal or landscaping on
Site. IHC Staff said they are nearing completion of a 50,000 square foot warehouse expansion which
included an IHC environmental contractor that conducted environmental oversight. There was also
an expansion of the Parcel B parking lot which included a retaining wall and gravel base placed for
drainage. The project added 1/3 more parking lanes to the Site and was completed prior 2020.

8. Do you have any comments, suggestions, or recommendations regarding the Site’s management or
operation (institutional controls)? If so, what types of future problems do you think (1) could occur;
or (2) would concern you and/or your department? IHC Staff said the facility property master plan
has expansion capability, a building street front and or a parking terrace were possibilities at one
time. No future plans are on the horizon to build anything more at the IHC Site.

33

Midvale Slag Superfund Site
Five-Year Review
Interview of Local Agencies

Site Name: Midvale Slag Superfund Site
EPA ID: UTD081834277
February 6, 2024
Type of Contact: Telephone Contact Made By: Dave Allison, UDEQ-DERR
Person Contacted
Name: Mark Murdock,
Project Coordinator
Organization: CHG Healthcare Office Buildings -
Gardner Company
Address:
Gardner Company
201 South Main St, Suite 2000
Salt Lake City, UT 84111

CHG Healthcare Corporate HQ.
7259 S. Bingham Junction Blvd.
Midvale, UT 84047
Phone: [phone]

1. Is your organization/department aware of the Midvale Slag Superfund Site and the actions
underway to address environmental contamination? Mark Murdock is a Partner and Project
Coordinator with the Gardner Company, the property owner leasing the CHG Healthcare
Headquarters building located at approximately 7200 South Bingham Junction Boulevard, Midvale,
Utah. Murdock said the CHG Office Buildings underwent a Site expansion parking project covering 4-
acres within the last five years. As contaminants are left in place within the project Site any
excavation activities at the Site are subject to the Midvale City Institutional Controls Ordinance. The
Gardner Company has developed the majority of the Midvale Slag Superfund Site beginning in 2007
known as Bingham Junction located between 7200 South and 7800 South Street. This includes the
View 72 Corporate Center office park where the CHG Healthcare Headquarters was opened in 2017.

2. What’s your overall impression (your general sentiment) of the actions performed at the Midvale
Slag Superfund Site? Looking back (since 2007) at the progress of Bingham Junction, Murdock said
the Site development has been an awesome experience. Everyone has been really good to work with,
Midvale City, EPA and UDEQ, it has been a great partnership and continues to be so.

3. Does your office conduct routine communications and/or activities (Site visits, inspections,
reporting activities, participation in meetings, etc.) for the Midvale Slag Superfund Site? If so,
please briefly summarize the purpose and results of these communications and/or activities over
the past several years. With the parking structure, Murdock said there were the usual permit
applications and planning meetings with Midvale City prior and throughout the construction.
Murdock said the Gardner team also had weekly Site and monthly coordination meetings with all
development team members’ contractors and the Midvale City Site Coordinator.

4. Are you aware of any community concerns regarding the Midvale Slag Superfund Site or its
operation and administration? If so, please give details. Murdock said he is not aware of any
community concerns with the parking structure project or any of the Gardner Bingham Junction
developments. Murdock said as the Site was delisted in 2015 and as the remediation work ended, so
did much of the cleanup concerns.

34

5. Over the past five years, have there been any complaints, violations, or other incidents (e.g.,
vandalism, trespassing, or emergency responses) at or related to the Midvale Slag Superfund Site
requiring your office to respond? If so, please give details of the events and results of the response.
Murdock said Site management plans are in place with a knowledgeable construction team and
agency partners. Murdock said no incidents have occurred requiring a response to existing
infrastructure and landscapes. Gardner had a delay finishing the parking structure during COVID
(2020) in a time of uncertainty and finished the structure a couple years later. Murdock said the
interruption wasn’t unusual and not a problem.

6. Do you feel well informed about the Site’s activities and progress over the last five years? Do you
know how to contact the Environmental Protection Agency if you have questions or concerns
about the Midvale Slag Superfund Site? Murdock said the Midvale City Engineering office has been
great to work with and had good interactions with the UDEQ and EPA Project Managers during
groundwater sampling activities. Everyone knows each other, is responsive, and works well together.

7. Over the past five years, have there been any changes in land use surrounding the Midvale Slag
Superfund Site? Are you aware of potential future changes in land use? If so, please describe.
Murdock said there haven’t been any changes to zoning nor to the master plan for Bingham Junction.

8. Do you have any comments, suggestions, or recommendations regarding the Site’s management or
operation (institutional controls)? If so, what types of future problems do you think (1) could occur;
or (2) would concern you and/or your department? Murdock said everything has worked well with
all partnerships from planning, construction, and coordinating Site requirements. The parking
structure project was a big effort and straightforward regarding institutional control requirements.
Murdock said there are different expansion options at the CHG Healthcare Site which could change
depending upon economic conditions.

35

APPENDIX E – COC CONCENTRATIONS IN GROUNDWATER AND SURFACE WATER
MW-501s
Analyte and Units
Sample Date
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 1 U 5.7

MW-501i
Analyte and Units
Sample Date
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 0.41 J 3.6 J
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.
Note: MW-501s and MW-501i were not sampled in 2020 and the wells were abandoned in September 2020 as recommended in the previous 2019 FYR Report

36

MW-503s
Analyte and Units
Sample Date
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 2 U 1 U 10 U
June-20 NS NS NS NS
May-21 2 U 3 1 U 5 U
June-22 NS NS NS NS
May-23 2 UJ 3.6 J 1 U 5 U

MW-503i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 1 U 2.8 J
June-20 NS NS NS NS
May-21 2 U 0.57 J 1 U 2.6 J
May-22 NS NS NS NS
May-23 2 UJ 1 U 1 U 4.1 J
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the approximate concentration of the analyte in the sample.

37

MW-504s
Analyte and Units
Sample Date
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 0.12 J 4.8 J
June-20 NS NS NS NS
May-21 0.18 J 0.8 J 0.12 J 5.7
June-22 NS NS NS NS
May-23 2 UJ 1 U 1 U 6

MW-504i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 1 U 5.3
June-20 NS NS NS NS
May-21 0.15 J 0.42 J 0.13 J 6.3
May-22 NS NS NS NS
May-23 2 UJ 1 U 1 U 6.2
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

38

MW-505s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2.1 12.3 4.7 0.4 J
June-20 0.7 J 5.6 J 0.16 J 0.37 J
May-21 4.7 32 5.7 5 U
June-22 3.8 53 1.3 2.2 J
May-23 4.5 J+ 28 J 8 5 U

MW-505i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 1 U 1.9 J
June-20 2 U 0.45 J 1 U 2.2 J
May-21 0.18 J 0.92 J 1 U 2.6 J
May-22 0.14 J 0.57 J 1 U 3 J
May-23 2 UJ 1 U 1 U 3.6 J
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

39

MW-506s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 7.3 1 U 5 U
June-20 NS NS NS NS
May-21 0.13 J 20 1 U 5 U
June-22 NS NS NS NS
May-23 2 UJ 14 J 1 U 5 U

MW-506i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 1 U 4.3 J
June-20 NS NS NS NS
May-21 0.19 J 0.48 J 0.42 J 4.6 J
May-22 NS NS NS NS
May-23 2 UJ 1 U 1 U 4 J
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

40

MW-507s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 8.1 1 U 10 U
June-20 2 U 13 J 1 U 5 U
May-21 2 U 4.2 1 U 5 U
June-22 0.14 J 14 1 U 5 U
May-23 2 UJ 14 J 1 U 5 U

MW-507i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1 U 0.33 J 1.9 J
June-20 2 U 0.83 J 0.29 J 2.9 J
May-21 0.2 J 1.1 0.35 J 2.5 J
May-22 0.19 J 0.94 J 0.27 J 3.3 J
May-23 2 UJ 1 U 0.33 J 3.7 J
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

41

MW-601s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 9.2 3850 517 25.4
June-20 6.4 7030 J 420 20.7
May-21 7.3 7400 460 29
June-22 7.5 7000 460 26
May-23 7.8 J 4000 460 22

MW-601i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2.1 1760 0.22 J 16.7
June-20 1.2 J 1000 J 1 U 18
May-21 1.3 J 1800 1 U 20
May-22 1.3 J 1700 1 U 22
May-23 2 UJ 2100 1 U 18
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

42

MW-602s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 17.5 421 1 U 39.9
June-20 14.6 398 J 1 U 37.1
May-21 16.0 460 0.11 J 43
June-22 16.0 440 1 U 42
May-23 16 J 430 J 1 U 34

MW-602i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 13.7 1 U 7
June-20 0.84 J 27.7 J 1 U 5.9
May-21 0.83 J 41 0.34 J 8.7
May-22 0.71 J 21 1 U 7.5
May-23 2 UJ 48 J 1 U 8.1
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

43

MW-701s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 7.8 0.29 J 7.6 J
June-20 0.73 J 8.3 J 0.42 J 8.1
May-21 1.3 J 11 0.43 J 7.4
June-22 0.68 J 9.7 0.41 J 7.6
May-23 0.72 J 9.4 0.37 J 4.4 J
ACL 380 7000 1560 900

MW-701i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 0.47 J 1 U 6 J
June-20 0.41 J 0.81 J 1 U 6.5
May-21 0.14 J 0.61 J 1 U 5.4
May-22 0.25 J 0.63 J 1 U 7
May-23 2 UJ 1 U 1 U 5.1
ACL 380 7000 1560 900
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the approximate concentration of the analyte in the sample.

44

MW-702s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2.1 844 1 U 21 J
June-20 NS NS NS NS
May-21 0.15 J 18 1 U 5 U
June-22 NS NS NS NS
May-23 2 UJ 12 J 1 U 5 U
ACL 380 7000 1560 900

MW-702i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 0.45 J 1 U 14.5 J
June-20 NS NS NS NS
May-21 0.14 J 0.77 J 1 U 12
May-22 NS NS NS NS
May-23 2 UJ 1 U 1 U 11
ACL 380 7000 1560 900
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

45

MW-703s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 497 0.34 J 8.7 J
June-20 NS NS NS NS
May-21 1.9 J 2100 1 U 27
June-22 NS NS NS NS
May-23 2.2 J 2800 1 U 25
ACL 380 7000 1560 900

MW-703i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 0.96 J 1 U 1.2 J
June-20 NS NS NS NS
May-21 0.24 J 1.4 1 U 5.2
May-22 NS NS NS NS
May-23 2 UJ 1.1 J 1 U 6.7
ACL 380 7000 1560 900
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

46

MW-704s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 3 538 0.66 J 9.7 J
June-20 NS NS NS NS
May-21 1.3 J 590 0.25 J 13
June-22 NS NS NS NS
May-23 2 U 590 0.36 J 8.3
ACL 380 7000 1560 900

MW-704i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 41.4 1 U 0.47 J
June-20 NS NS NS NS
May-21 0.13 J 0.65 J 1 U 5 U
May-22 NS NS NS NS
May-23 2 U 0.62 J 1 U 3.3 J
ACL 380 7000 1560 900
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

47

MW-705s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2.2 346 1 U 5 UJ
June-20 NS NS NS NS
May-21 2 430 1 U 5 U
June-22 NS NS NS NS
May-23 2 J+ 390 1 U 5 U
ACL 380 7000 1560 900

MW-705i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 70.2 1 U 0.88 J
June-20 NS NS NS NS
May-21 0.46 J 84 1 U 5 U
May-22 NS NS NS NS
May-23 2 U 74 0.11 J 5 U
ACL 380 7000 1560 900
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

48

MW-706s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 57.9 186 0.85 J 45.2 J
June-20 67.5 168 J 1.1 22.8
May-21 62 190 0.64 J 16
June-22 68.0 200 0.81 J 42
May-23 53 J 230 0.99 J 49
ACL 380 7000 1560 900

MW-706i
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 4.7 1 U 2.9 J
June-20 2 U 4.4 J 0.13 J 2.8 J
May-21 0.14 J 4.4 0.25 J 4.2 J
May-22 0.2 J 5.2 1 U 3.8 J
May-23 2 U 5 1 U 3.8 J
ACL 380 7000 1560 900
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

49

MW-707s
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 31.3 0.2 J 1 J
June-20 NS NS NS NS
May-21 0.32 J 86 0.68 J 5 U
June-22 NS NS NS NS
May-23 2 U 110 0.15 J 2.1 J
ACL 380 7000 1560 900

MW-707i
Analyte and Units
Sample Date
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 2 U 1.1 1 U 1.1 J
June-20 NS NS NS NS
May-21 0.3 J 1.1 0.56 J 5 U
May-22 NS NS NS NS
May-23 2 U 1.3 0.18 J 2.4 J
ACL 380 7000 1560 900
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

50

SW-201
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 0.14 7.2 0.016 1.7 J June-20 2 U 11.4 J 0.2 U 1.5 J May-21 0.57 J 11 0.2 U 2.8 J June-22 2 U 10 0.2 UJ 3.1 J
May-23 2 U 5.1 0.2 U 1.9 J
SW-202
Sample Date
Analyte and Units
Antimony µg/L Arsenic µg/L Cadmium µg/L Selenium µg/L
May-19 0.14 7 0.016 1.7 J
June-20 2 U 10.7 J 0.2 U 1.8 J
May-21 0.69 J 10 0.16 J 2.4 J
June-22 2 U 10 0.2 UJ 2.6 J
May-23 2 U 6.4 0.2 U 2.1 J
µg/L Micro grams per Liter
U The analyte was analyzed for, but was not detected above the level of the reported sample quantitation limit.
J The result is an estimated quantity. The associated numerical value is the
approximate concentration of the analyte in the sample.

NS No Standard
µg/L micro grams per liter
Analyte
Jordan River Surface Water Quality Criteria
Human
Health (µg/L) Aquatic Wildlife
1 hr (µg/L) Aquatic Wildlife
4 Day (µg/L) Agriculture
(µg/L)
Antimony 4,300 NS NS NS
Arsenic NS 340 150 100
Cadmium NS 2 0.25 10
Selenium NS 18.4 4.6 50

51

APPENDIX F – SITE INSPECTION PHOTOS

Jordan River at Midvale Slag

52

Commercial office buildings at Bingham Junction/Midvale Slag

53

Monitoring wells MW602s and MW-602i

54

Monitoring wells MW702s and MW702i

55

Intermountain Health Care Supply Chain Fulfillment Center Expansion

56

APPENDIX G – SITE INSPECTION CHECKLIST
FIVE-YEAR REVIEW SITE INSPECTION CHECKLIST
I. SITE INFORMATION
Site name: Midvale Slag Date of inspection: 11/9/2023 Location and Region: Midvale, Salt Lake County, UT Region 8 EPA ID: UTD081834277
Agency, office, or company leading the five-year review: Utah Department of Environmental Quality Division of Environmental Response and Remediation
Weather/temperature: Sunny/46ºF
Remedy Includes: (Check all that apply) Landfill cover/containment Monitored natural attenuation Access controls Groundwater containment Institutional controls Vertical barrier walls Groundwater pump and treatment Surface water collection and treatment
Other
Attachments: Inspection team roster attached Site map attached II. INTERVIEWS (Check all that apply)
1. O&M Site manager Name: Title: Date:
Interviewed at Site at office by phone Phone no. Problems, suggestions;
2. O&M staff Name: Title: Date Interviewed at Site at office by phone Phone no. Problems, suggestions;
3. Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county offices, etc.) Fill in all that apply. Agency ____________________________ Contact ____________________________ __________________ ________ ____________ Name Title Date Phone no. Problems; suggestions; □ Report attached _______________________________________________ __________________________________________________________________________________

4. Other interviews (optional) Report attached as Appendix D
Individuals that were interviewed included personnel with Salt Lake City and British Petroleum. III. ON-SITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1. O&M Documents
O&M manual Readily available Up to date N/A As-built drawings Readily available Up to date N/A Maintenance logs Readily available Up to date N/A Remarks:
2. Site-Specific Health and Safety Plan Readily available Up to date N/A
Contingency plan/emergency response plan Readily available Up to date N/A
Remarks:

57

3. O&M and OSHA Training Records Readily
available Up to
date N/A
Remarks:
4. Permits and Service Agreements Air discharge permit Readily available Up to date N/A
Effluent discharge Readily available Up to date N/A
Waste disposal, POTW Readily
available
Up to
date
N/A
Other permits Readily available Up to date N/A
Remarks:
5. Gas Generation Records Readily available Up to date N/A
Remarks:
6. Settlement Monument Records Readily available Up to date N/A
Remarks:
7. Groundwater Monitoring Records Readily available Up to date N/A
Remarks: UDEQ/DERR conducts routine annual groundwater monitoring and sampling at the Site under a cooperative agreement with EPA.
8. Leachate Extraction Records Readily available Up to date N/A
Remarks:
9. Discharge Compliance Records Air Readily available Up to date N/A
Water (effluent) Readily available Up to date N/A Remarks:
10. Daily Access/Security Logs Readily available Up to date N/A Remarks:
IV. O&M COSTS
1. O&M Organization State in-house Contractor for State PRP in-house Contractor for PRP Federal Facility in-house Contractor for Federal Facility

58

2. O&M Cost Records
Readily available Up to date Funding mechanism/agreement in place Unavailable Original O&M cost estimate Breakdown attached
Total annual cost by year for review period if available From mm/dd/yyyy Date To mm/dd/yyyy Date Total cost Breakdown attached
From mm/dd/yyyy Date To mm/dd/yyyy Date Total cost Breakdown attached
From mm/dd/yyyy Date To mm/dd/yyyy Date Total cost Breakdown attached
From mm/dd/yyyy Date To mm/dd/yyyy Date Total cost Breakdown attached
From mm/dd/yyyy Date To mm/dd/yyyy Date Total cost Breakdown attached
3. Unanticipated or Unusually High O&M Costs During Review Period

V. ACCESS AND INSTITUTIONAL CONTROLS Applicable N/A A. Fencing
1. Fencing damaged Location shown on Site map Gates secured N/A Remarks:
B. Other Access Restrictions
1. Signs and other security measures Location shown on Site map N/A Remarks:
C. Institutional Controls (ICs) 1. Implementation and enforcement Site conditions imply ICs not properly implemented Yes No N/A Site conditions imply ICs not being fully enforced Yes No N/A
Type of monitoring (e.g., self-reporting, drive by) Midvale City enforces ICs at the Midvale Slag Site. Frequency Responsible party/agency Midvale City
Contact Billie Smathers Site Coordinator 801-567-7217 Name Title Phone no.
Reporting is up-to-date Yes No N/A Reports are verified by the lead agency Yes No N/A Specific requirements in deed or decision documents have been met Yes No N/A Violations have been reported Yes No N/A Other problems or suggestions: Report attached
2. Adequacy ICs are adequate ICs are inadequate N/A Remarks: Midvale City Ordinance ensures protection, maintenance and improvement of soil covers at the Site. Use of groundwater at the Site is restricted under Midvale City Ordinance and the Utah Department of Natural Resources Division of Water Rights Salt Lake Valley Groundwater Management Plan.

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D. General
1. Vandalism/trespassing Location shown on Site map No vandalism evident Remarks:
2. Land use changes on Site N/A Remarks:
3. Land use changes off Site N/A Remarks: VI. GENERAL SITE CONDITIONS
A. Roads Applicable N/A
1. Roads damaged Location shown on Site map Roads adequate N/A Remarks: The Site is a developed mixed residential and commercial area with asphalt roads.
B. Other Site Conditions
Remarks:
VII. LANDFILL COVERS Applicable N/A
A. Landfill Surface
1. Settlement (Low spots) Location shown on Site map Settlement not evident
Arial extent Depth
Remarks: The OU2 remedy consists of a barrier between Site wastes and human contact, it is not a true landfill. There are no covers on OU1.
2. Cracks Location shown on Site map Cracking not evident Lengths Widths Depths Remarks: N/A - monitoring not required
3. Erosion Location shown on Site map Erosion not evident Arial extent Depth
Remarks: N/A - monitoring not required
4. Holes Location shown on Site map Holes not evident
Arial extent Depth Remarks: N/A - monitoring not required
5. Vegetative Cover Grass Cover properly established No signs of stress Trees/Shrubs (indicate size and locations on a diagram) Remarks: The Site is a developed mixed residential and commercial area that includes landscaping
of grass, trees, and shrubs, which appear to be well maintained.
6. Alternative Cover (armored rock, concrete, etc.) N/A
Remarks: Riverbank stabilization and rock armor along the Jordan River appeared to be in good condition, visible signs of erosion were not observed.
7. Bulges Location shown on Site map Bulges not evident Arial extent Height Remarks: None
8. Wet Areas/Water Damage Wet areas/water damage not evident
Wet areas Location shown on Site map Arial extent
Ponding Location shown on Site map Arial extent
Seeps Location shown on Site map Arial extent
Soft subgrade Location shown on Site map Arial extent
Remarks: None

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9. Slope Instability Slides Location shown on Site
map No evidence of slope instability Arial extent
Remarks:
B. Benches Applicable N/A
(Horizontally constructed mounds of earth placed across a steep landfill side slope to interrupt the slope in order to slow down the velocity of surface runoff and intercept and convey the runoff to a lined channel.)
1. Flows Bypass Bench Location shown on Site map N/A or okay Remarks:
2. Bench Breached Location shown on Site map N/A or okay Remarks:
3. Bench Overtopped Location shown on Site map N/A or okay Remarks: C. Letdown Channels Applicable N/A
1. Settlement (Low spots) Location shown on Site map No evidence of settlement
Arial extent Depth Remarks:
2. Material Degradation Location shown on Site map No evidence of degradation Material type Arial extent Remarks:
3. Erosion Location shown on Site map No evidence of erosion Arial extent Depth Remarks:
4. Undercutting Location shown on Site map No evidence of undercutting Arial extent Depth Remarks:
5. Obstructions Type No obstructions Location shown on Site map Arial extent
Size Remarks:
6. Excessive Vegetative Growth Type No evidence of excessive growth Vegetation in channels does not obstruct flow
Location shown on Site map Arial extent Remarks:
D. Cover Penetrations Applicable N/A
1. Gas Vents Active Passive
Properly secured/locked Functioning Routinely sampled Good condition
Evidence of leakage at penetration Needs
Maintenance
N/A
Remarks:

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2. Gas Monitoring Probes
Properly secured/locked Functioning Routinely sampled Good condition
Evidence of leakage at penetration Needs
maintenance
N/A
Remarks:
3. Monitoring Wells (within surface area of landfill) Properly secured/locked Functioning Routinely sampled Good condition
Evidence of leakage at penetration Needs Maintenance N/A
Remarks: Require proper identification labeling of all wells
4. Extraction Wells Leachate Properly secured/locked Functioning Routinely sampled Good condition
Evidence of leakage at penetration Needs Maintenance N/A
Remarks:
5. Settlement Monuments Located Routinely
surveyed
N/A
Remarks:
E. Gas Collection and Treatment Applicable N/A
1. Gas Treatment Facilities
Flaring Thermal destruction Collection for reuse Good condition Needs Maintenance
Remarks:
2. Gas Collection Wells, Manifolds and Piping
Good condition Needs Maintenance Remarks:
3. Gas Monitoring Facilities (e.g., gas monitoring of adjacent homes or buildings) Good condition Needs Maintenance N/A Remarks:
F. Cover Drainage Layer Applicable N/A
1. Outlet Pipes Inspected Functioning N/A Remarks:
2. Outlet Rock Inspected Functioning N/A Remarks:
G. Detention/Sedimentation Ponds Applicable N/A
1. Siltation Area extent Depth N/A Siltation not evident
Remarks:
2. Erosion Area extent Depth
Erosion not evident Remarks:
3. Outlet Works Functioning N/A Remarks:
4. Dam Functioning N/A Remarks:
H. Retaining Walls Applicable N/A

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1. Deformations Location shown on Site map Deformation not evident
Horizontal displacement Vertical displacement Rotational displacement Remarks:
2. Degradation Location shown on Site map Degradation not evident Remarks:
I. Perimeter Ditches/Off-Site Discharge Applicable N/A
1. Siltation Location shown on Site map Siltation not evident Area extent Depth Remarks: 2. Vegetative Growth Location shown on Site map N/A Vegetation does not impede flow Area extent Type Remarks:
3. Erosion Location shown on Site map Erosion not evident Area extent Depth Remarks: 4. Discharge Structure Functioning N/A Remarks:
VIII. VERTICAL BARRIER WALLS Applicable N/A
1. Settlement Location shown on Site map Settlement not evident
Area extent Depth Remarks:
2. Performance Monitoring Type of monitoring Groundwater monitoring Performance not monitored Frequency Every five years Evidence of breaching
Head differential Remarks:
IX. GROUNDWATER/SURFACE WATER REMEDIES Applicable N/A
A. Groundwater Extraction Wells, Pumps, and Pipelines Applicable N/A 1. Pumps, Wellhead Plumbing, and Electrical Good condition All required wells properly operating Needs Maintenance N/A
Remarks:
2. Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances Good condition Needs Maintenance Remarks:
3. Spare Parts and Equipment Readily available Good condition Requires upgrade Needs to be provided
Remarks:
B. Surface Water Collection Structures, Pumps, and Pipelines Applicable N/A
1. Collection Structures, Pumps, and Electrical Good condition Needs Maintenance Remarks:
2. Surface Water Collection System Pipelines, Valves, Valve Boxes, and Other Appurtenances Good condition Needs Maintenance Remarks:

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3. Spare Parts and Equipment
Readily available Good condition Requires upgrade Needs to be provided
Remarks:
C. Treatment System Applicable N/A
1. Treatment Train (Check components that apply) Metals removal Oil/water separation Bioremediation Air stripping Carbon adsorbers Filters Additive (e.g., chelation agent, flocculent) Others
Good condition Needs Maintenance Sampling ports properly marked and functional Sampling/maintenance log displayed and up to date Equipment properly identified Quantity of groundwater treated annually Quantity of surface water treated annually
Remarks:
2. Electrical Enclosures and Panels (properly rated and functional)
N/A Good condition Needs Maintenance
Remarks:
3. Tanks, Vaults, Storage Vessels N/A Good condition

Proper secondary
containment
Needs Maintenance
Remarks:
4. Discharge Structure and Appurtenances N/A Good condition Needs Maintenance
Remarks:
5. Treatment Building(s)
N/A Good condition (esp. roof and doorways) Needs repair
Chemicals and equipment properly stored
Remarks:
6. Monitoring Wells (pump and treatment remedy)
Properly secured/locked Functioning
Routinely sampled Good condition
All required wells located Needs Maintenance N/A Remarks:
D. Monitoring Data
1. Monitoring Data
Is routinely submitted on time Is of acceptable quality
2. Monitoring data suggests: Groundwater plume is effectively contained Contaminant concentrations are declining
E. Monitored Natural Attenuation 1. Monitoring Wells (natural attenuation remedy) Properly secured/locked Functioning Routinely sampled Good condition All required wells located Needs Maintenance N/A Remarks:

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X. OTHER REMEDIES
If there are remedies applied at the Site and not covered above, attach an inspection sheet describing the physical nature and condition of any facility associated with the remedy. An example would be soil
vapor extraction.
XI. OVERALL OBSERVATIONS
A. Implementation of the Remedy
The purpose of the remedy is to prevent exposure to contaminated wastes/soils and groundwater. The cover constructed over OU2 Category II, III, and IV wastes is in place and prevents exposure to these wastes. Data from routine groundwater and surface water monitoring and sampling shows that COCs are below their respective ACL value. The data also shows contaminated groundwater is not migrating to uncontaminated portions of the US&G aquifer or the deep principal aquifer and the Jordan River remains protective of the aquatic environment. Riverbank stabilization and revegetation of the OU1 and OU2 riparian zones remains intact and prevents the erosion and potential sloughing of contamination into the Jordan River. Midvale City enforces an IC Ordinance that provides for the maintenance and repair of the cover to ensure future protectiveness and prohibits the installation of groundwater wells. In addition to the IC Ordinance, groundwater use at the Site is restricted under the Salt Lake Valley Groundwater Management Plan.
B. Adequacy of O&M
UDEQ/DERR performs routing groundwater and surface water monitoring and sampling to ensure that (1) contaminated groundwater does not migrate to uncontaminated areas of the US&G aquifer or the deep principal aquifer; (2) COC concentrations remain below their established ACL value; and (3) groundwater discharges to the Jordan River remains protective of the aquatic environment. Institutional controls restrict groundwater use and ensure long-term protectiveness.
C. Early Indicators of Potential Remedy Problems
None
D. Opportunities for Optimization
Not applicable at this time.