Fourth Five-Year Review Report for Minot Landfill Minot Ward County

Five-Year Review Report

Fourth Five-Year Review Report for Minot Landfill EPA ID NDD980959548

Minot Ward County, North Dakota

September 2016

Prepared By: United States Environmental Protection Agency Region 8 Denver, Colorado

Approved by: Date: MtvvL~~ Martin Hestmark Assistant Regional Administrator Office of Ecosystems Protection and Remediation

Table of Contents

List of Acronyms ...... iv Executive Summary ...... v Five-Year Review Summary Form ...... vi 1.0 Introduction ...... 1 2.0 Site Chronology ...... 2 3.0 Background ...... 2 3.1 PHYSICAL CHARACTERISTICS ...... 2 3.2 LAND AND RESOURCE USE...... 3 3.3 HISTORY OF CONTAMINATION ...... 5 3.4 INITIAL RESPONSE ...... 5 3.5 BASIS FOR TAKING ACTION ...... 5 4.0 Remedial Actions ...... 6 4.1 REMEDY SELECTION ...... 6 4.2 REMEDY IMPLEMENTATION ...... 8 4.3 OPERATION AND MAINTENANCE (O&M) ...... 9 5.0 Progress Since the Last Five-Year Review ...... 10 6.0 Five-Year Review Process ...... 11 6.1 ADMINISTRATIVE COMPONENTS ...... 11 6.2 COMMUNITY INVOLVEMENT ...... 11 6.3 DOCUMENT REVIEW...... 11 6.4 DATA REVIEW ...... 15 6.5 SITE INSPECTION ...... 17 6.6 INTERVIEWS ...... 17 7.0 Technical Assessment ...... 18 7.1 QUESTION A: IS THE REMEDY FUNCTIONING AS INTENDED BY THE DECISION DOCUMENTS? ...... 18 7.2 QUESTION B: ARE THE EXPOSURE ASSUMPTIONS, TOXICITY DATA, CLEANUP LEVELS AND REMEDIAL ACTION OBJECTIVES (RAOS) USED AT THE TIME OF REMEDY SELECTION STILL VALID? ...... 19 7.3 QUESTION C: HAS ANY OTHER INFORMATION COME TO LIGHT THAT COULD CALL INTO QUESTION THE PROTECTIVENESS OF THE REMEDY? ...... 19 7.4 TECHNICAL ASSESSMENT SUMMARY ...... 19 8.0 Issues ...... 20 9.0 Recommendations and Follow-up Actions ...... 20 10.0 Protectiveness Statement ...... 20 11.0 Next Review ...... 21 Appendix A: List of Documents Reviewed ...... A-1 Appendix B: Interview Forms ...... B-1

Appendix C: Site Inspection Checklist ...... C-1 Appendix D: Photographs from Site Inspection Visit ...... D-1 Appendix E: Data Review ...... E-1 Appendix F: Institutional Control ...... F-1 Appendix G: Proposed Site Reuse Plan for Future Redevelopment ...... G-1

List of Tables Table 1: Chronology of Site Events ...... 2 Table 2: Summary of Performance Goals in Groundwater ...... 7 Table 3: Annual O&M Costs ...... 9 Table 4: Progress on Recommendations from the 2011 FYR ...... 10 Table 5: Previous and Current ARARs for Groundwater COCs ...... 12 Table 6: Institutional Control (IC) Summary Table ...... 13 Table E-1: Groundwater Monitoring Data for Inorganic COCs (2011 to 2016) ...... E-1 Table E-2: Groundwater Monitoring Data for Organic COCs (2011 to 2016) ...... E-2 Table E-3: Screening Level Vapor Intrusion Evaluation ...... E-3 Table E-4: Screening Risk Evaluation of Detected COCs in Groundwater or Leachate ...... E-4

List of Figures Figure 1: Site Location Map ...... 4 Figure 2: Location of Institutional Control ...... 14 Figure 3: Monitoring Well Location Map ...... 16

iii

List of Acronyms

ARAR Applicable or Relevant and Appropriate Requirement CERCLA Comprehensive Environmental Response, Compensation and Liability Act CFR Code of Federal Regulations COC Contaminant of Concern DCE 1,2-Dichloroethylene EPA United States Environmental Protection Agency ESD Explanation of Significant Differences FDHU First District Health Unit FS Feasibility Study FYR Five-Year Review HQ Hazard Quotient IC Institutional Control MCL Maximum Contaminant Level MCLG Maximum Contaminant Level Goal µg/L Micrograms per Liter MOCP Monitoring, Operations and Contingency Plan MVTL Minnesota Valley Testing Laboratories, Inc. NCP National Oil and Hazardous Substances Pollution Contingency Plan NDDH North Dakota Department of Health NPL National Priorities List O&M Operation and Maintenance OU Operable Unit PRP Potentially Responsible Party RAO Remedial Action Objective RI Remedial Investigation ROD Record of Decision RPM Remedial Project Manager RSL Regional Screening Level RSMCL Secondary Maximum Contaminant Level SVOC Semi-Volatile Organic Compound TBC To-Be-Considered VOC Volatile Organic Compound

Executive Summary

The 26-acre Minot Landfill Superfund site (the Site) is a closed waste disposal facility, located about 1 mile southwest of downtown Minot in Ward County, North Dakota. The City of Minot operated a landfill on site from 1961 to October 1971, placing municipal and industrial wastes at the base of a deep ravine. Wastes included drums of oil, spent battery casings, calcium carbide and lime sludge. The City of Minot closed the landfill in 1971. Clayey material from the valley walls served as the final cover, which was then seeded. Subsequent recreation activities and traffic on the original cap caused erosion across the Site. In mid-1985, the County Health Department investigated the area due to reports of foul odors and gas bubbles in standing water and runoff from the waste. Further investigation by the North Dakota Department of Health (NDDH) and the United States Environmental Protection Agency (EPA) found soil, groundwater, surface water (localized ponding), sediment and landfill gases were contaminated with benzene, toluene, chlorinated organic compounds, phenol and phenol-related compounds, polycyclic aromatic hydrocarbons, and metals.

EPA listed the Site on the Superfund program’s National Priorities List (NPL) in March 1989. The selected remedy included excavating contaminated source material and placing it on site in a capped landfill as well as construction of leachate control and passive gas venting systems. In addition, the remedy required long-term monitoring and institutional controls to protect the remedy and prevent exposure to contamination. After completing remedial actions, EPA officially deleted the Site from the NPL on April 1, 1997. The triggering action for this five-year review (FYR) was the signing of the previous FYR on May 3, 2011.

The remedy is protective of human health and the environment because contaminated source material has been excavated and contained on site beneath a landfill cap. The institutional control is in place to prevent future land uses that could damage the remedial components in place and to prohibit installation of groundwater supply wells on the Site or in the immediate vicinity of the Site (Section 6.3 and Appendix F). In addition, long-term monitoring results demonstrate that contaminants of concern (COCs) are consistently meeting performance standards in groundwater and leachate, and people are not using groundwater at the Site or in the area surrounding the Site.

Five-Year Review Summary Form

SITE IDENTIFICATION

Site Name: Minot Landfill Superfund Site

EPA ID: NDD980959548

Region: 8 State: ND City/County: Minot/Ward

SITE STATUS

NPL Status: Deleted

Multiple OUs? Has the site achieved construction completion? No Yes

REVIEW STATUS

Lead agency: EPA

Author name: Frances L. Costanzi and Claire Marcussen and Treat Suomi

Author affiliation: EPA Region 8 and Skeo

Review period: 11/01/2015 – 09/30/2016

Date of site inspection: 07/07/2016

Type of review: Statutory Review number: 4

Triggering action date: May 3, 2011

Due date (five years after triggering action date): May 3, 2016

OU(s) without Issues/Recommendations Identified in the Five-Year Review: OU1

Sitewide Protectiveness Statement (if applicable) Protectiveness Determination: Addendum Due Date (if applicable): Protective Click here to enter date. Protectiveness Statement: The remedy is protective of human health and the environment because contaminated source material has been excavated and contained on site beneath a landfill cap. The institutional control is in place to prevent future land uses that could damage the remedial components in place and to prohibit installation of groundwater supply wells on the Site or in the immediate vicinity of the Site. In addition, long-term monitoring results demonstrate that contaminants of concern (COCs) are consistently meeting performance objectives in groundwater and leachate, and people are not using groundwater at the Site or in the area surrounding the Site.

Fourth Five-Year Review Report for Minot Landfill Superfund Site

1.0 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 protective of human health and the environment. FYR reports document FYR methods, findings and conclusions. In addition, FYR reports identify issues found during the review, if any, and document recommendations to address them.

The United States Environmental Protection Agency (EPA) prepares FYRs pursuant to the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Section 121 and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). CERCLA Section 121 states:

If the President selects a remedial action that results in any hazardous substances, pollutants, or contaminants remaining at the site, the President shall review such remedial action no less often than each 5 years after the initiation of such remedial action to assure that human health and the environment are being protected by the remedial action being implemented. In addition, if upon such review it is the judgment of the President that action is appropriate at such site in accordance with section [104] or [106], the President shall take or require such action. The President shall report to the Congress a list of facilities for which such review is required, the results of all such reviews, and any actions taken as a result of such reviews.

EPA interpreted this requirement further in the NCP, 40 Code of Federal Regulations (CFR) Section 300.430(f)(4)(ii), which states:

If a remedial action is selected that results in hazardous substances, pollutants, or contaminants remaining at the site above levels that allow for unlimited use and unrestricted exposure, the lead agency shall review such action no less often than every five years after initiation of the selected remedial action.

Skeo, an EPA Region 8 contractor, conducted the FYR and prepared this report regarding the remedy implemented at the Minot Landfill Superfund site (the Site) in Minot, Ward County, North Dakota. EPA’s contractor conducted this FYR from November 2015 to September 2016. The City of Minot is the lead agency for developing and implementing the remedy for the potentially responsible party (PRP)-financed cleanup at the Site. The North Dakota Department of Health (NDDH), as the support agency representing the State of North Dakota, has reviewed all supporting documentation and provided input to EPA during the FYR process.

This is the fourth FYR for the Site. The triggering action for this statutory review is the May 3, 2011 FYR. The FYR is required due to the fact that hazardous substances, pollutants or

contaminants remain at the Site above levels that allow for unlimited use and unrestricted exposure. The Site consists of one operable unit (OU) which is addressed in this FYR. 2.0 Site Chronology

Table 1 lists the dates of important events for the Site. Table 1: Chronology of Site Events

Event Date Ward County discovered contamination at the Site June 17, 1985 EPA completed a site investigation October 10, 1986 EPA proposed the Site for listing on the Superfund program’s June 24, 1988 National Priorities List (NPL) EPA listed the Site on the NPL March 31, 1989 The City of Minot (City) initiated a removal action to place a fence December 4, 1989 around burial site A, construct drainage controls and complete cap repairs The City completed the removal action July 18, 1990 EPA issued an Administrative Order on Consent to the City to August 13, 1990 complete a remedial investigation/feasibility study (RI/FS) EPA issued a Unilateral Administrative Order to the City to September 28, 1990 complete an RI/FS; the City initiated the RI/FS EPA completed a baseline risk assessment April 15, 1992 The City completed the RI/FS and the EPA issued the Site’s Record June 21, 1993 of Decision (ROD) A Consent Decree was entered into Federal District Court between February 7, 1996 the United States, the State of North Dakota and the City of Minot, in which the City agreed to complete the remedial design, remedial action and operations and maintenance (O&M) activities; the City started the remedial design EPA issued an Explanation of Significant Differences (ESD) to April 10, 1996 modify the landfill remedy components The City completed the remedial design April 26, 1996 The City started remedial action construction June 3, 1996 EPA issued the Preliminary Close-Out Report demonstrating September 4, 1996 completion of remedial construction The City started O&M activities October 1996 The Remedial Action Completion Report was signed by EPA November 29, 1996 EPA issued the Site’s Final Close-Out Report documenting remedy December 2, 1996 action completion EPA deleted the Site from the NPL April 1, 1997 EPA signed the Site’s first FYR September 12, 2001 EPA signed the Site’s second FYR September 19, 2006 EPA signed the Site’s third FYR May 3, 2011

3.0 Background

3.1 Physical Characteristics

The 26-acre Site is located in a deep ravine in a rural residential and commercial area about one mile southwest of downtown Minot in Ward County, North Dakota (Figure 1). The Site is known

locally as the closed "Old Minot Landfill" to differentiate it from the local active landfill. The Site is situated 2,000 feet south of the Souris River and east of the intersection of the Burdick Expressway and the combined U.S. Highway 2 and 52 Bypass. A housing development is located next to the northeastern fence line of the Site (Figure 1). Commercial businesses, including the Maysa Arena (an ice rink), border the west side of the landfill. Another ravine located immediately northwest of the Site, and between the Site and the Maysa Arena, contains a closed landfill of construction and demolition debris. The Minot Fire Department has constructed a fire training facility at the southwest entrance of the Site immediately outside of the landfill footprint. Agricultural areas are located southwest of the Site. The entire Site is covered in grass. There are a few trees around the perimeter of the cap; however, there are no trees or structures on the cap.

The closed landfill slopes from the south down to the north where the leachate discharges to the sanitary sewer and is treated by the City of Minot water treatment facility. The primary aquifer zones include the poorly consolidated clay bedrock followed by glacial clay till with discontinuous sand seams, followed by the saturated waste-filled valley. Site groundwater is present at shallow depths within the glacial till deposits and flows from the south of the landfill towards the Souris River to the north. The saturated till is not used as a source of potable water due to very low yields and its poor natural water quality. However, the groundwater within the till may provide limited recharge to other aquifer systems.

3.2 Land and Resource Use

Grass covering the Site is harvested twice a year as hay. Since late 1989, most of the Site has been enclosed with a chain-link fence to restrict public access. A mobile home community and a housing development border the Site to the northeast with the closest mobile home located about 500 feet northeast of the landfill. Agricultural areas are located southwest of the Site. Surrounding land uses include rural residential and commercial uses. Several businesses are located immediately north of the Site. They include a restaurant, the Maysa Arena with parking lot and an industrial facility. The mobile home community, nearby residences and businesses obtain water from the City of Minot's municipal water system.

In 2006, the City of Minot proposed an extension of the road that accesses a new housing development along the eastern edge of the landfill adjacent to the cap. NDDH rejected the proposal. In 2013, EPA completed a site reuse evaluation. It demonstrated that areas adjacent to the Site are ready for future residential, commercial, light industrial, recreational and agricultural use. In 2014, the City redeveloped the southwest entrance of the Site as a training facility for the Minot Fire Department. The training facility is located immediately outside of the landfill footprint along Highway 2 and 52 Bypass. In the winter, the City uses a portion of the Site to store snow during snow removal events. The Minot Park District is in the process of expanding the Maysa Arena and associated parking areas. Minot is also developing plans to convert the Site into the Maysa Recreational Area and will be submitting these plans to EPA and NDDH for approval. Planned amenities include disc golf, mountain biking trails and a cross country course. Redevelopment is planned for the late spring of 2017, pending approval.

Figure 1: Site Location Map

Disclaimer: This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational purposes only regarding EPA’s response actions at the Site.

3.3 History of Contamination

Although the Site property has had several owners since 1961, the past owners were not involved in operating the on-site facility. The City operated a landfill at the Site from 1961 to October 1971. Although the exact composition of wastes disposed of at the Site is not known, refuse included drums of oil, spent battery casings, calcium carbide and lime sludge. Discussions with past landfill operators indicated that refuse was received from the City of Minot, other neighboring towns, farms, industries and military sites and was covered daily with about 6 inches of clay-rich soil.

The City closed the landfill in the fall of 1971. Closure included covering the refuse with about 3 feet of clay material from the valley walls, which was then seeded. In mid-1985, Ward County’s First District Health Unit (FDHU) received a complaint of gas bubbles escaping from the surface of the Site. After inspecting the Site, FDHU contacted NDDH’s Environmental Health Section regarding observations of foul odors, gas bubbles in standing water and water drainage from waste. NDDH conducted a site inspection in June 1985. NDDH arranged a meeting at the Site in late summer with the City and the landowners and requested that the previous landowners control surface water drainage, repair eroded channels and install a gas venting system. NDDH contacted EPA's Region 8 office to discuss the investigative approach for the Site.

3.4 Initial Response

Preliminary investigations by EPA in 1986 found that soil, groundwater, surface water, sediment and landfill gases at the Site were contaminated. EPA proposed the Site for listing on the Superfund program’s National Priorities List (NPL) on June 24, 1988. EPA finalized the listing on March 31, 1989. In December 1989, the City of Minot initiated a removal action that included installing a perimeter fence around the landfill, construction of surface runoff/erosion controls (including swales and storm sewer piping), and seeding of areas disturbed by construction and exposed slopes on the hills along the southern edge of the Site. In 1990, the City performed additional work to repair drainage ditches and swales to complete the removal action.

EPA issued a Unilateral Administrative Order and Statement of Work to the City of Minot in September 1990 to complete a remedial investigation and feasibility study (RI/FS) for the Site. The City retained a contractor to complete the RI/FS in 1992.

3.5 Basis for Taking Action

Both the physical and chemical data indicate that significant groundwater contamination has not migrated from the Site. However, uncontrolled releases of contaminants at low levels does occur from leachate seeps and landfill gas releases. EPA completed a baseline risk assessment (BRA) in 1992. The BRA found no current human exposure pathways to soil or groundwater at the Site, since restrictions were already in place to prevent exposure. However, the BRA also found that, without restrictions, future exposures to landfill gas and groundwater in contact with landfill waste would create potential unacceptable risks. The BRA identified volatile organic compounds (VOCs) as the primary contaminants of concern (COCs) in groundwater and landfill gas with contributions from semi-volatile organic compounds (SVOCs), pesticides and metals in groundwater. The human health risks associated with future exposure to soil, sediment and

surface water were within EPA’s acceptable risk range or below EPA’s noncancer hazard quotient (HQ) of 1. In addition, the BRA identified that surface run-off was expected to flow from the landfill toward the Souris River and groundwater discharge into surface waters and sediments was potentially a migration pathway of concern for ecological receptors.

4.0 Remedial Actions

In accordance with CERCLA and the NCP, remedial actions are required to protect human health and the environment and to comply with applicable or relevant and appropriate requirements (ARARs). Several remedial alternatives were considered for the Site. Final selection was made based on an evaluation of each alternative against nine evaluation criteria that are specified in Section 300.430(e)(9)(iii) of the NCP. The nine criteria are:

1. Overall Protection of Human Health and the Environment 2. Compliance with ARARs 3. Long-Term Effectiveness and Permanence 4. Reduction of Toxicity, Mobility or Volume through Treatment 5. Short-Term Effectiveness 6. Implementability 7. Cost 8. State Acceptance 9. Community Acceptance

4.1 Remedy Selection

The EPA signed the Site’s Record of Decision (ROD) on June 21, 1993. The ROD did not formally identify remedial action objectives (RAOs). However, it did identify specific elements that the response action would address to eliminate or mitigate potential threats:

 Prevent direct contact with landfill contents including the solid waste, leachate and gas.  Manage leachate levels in the landfill to prevent leachate seeps through the cap and to reduce the potential for leachate migration from the landfill to the groundwater.  Reduce pressures in the landfill that can damage the landfill cap and can increase the potential for leachate migration.  Prohibit any human activity on the landfill that would expose receptors to refuse or leachate, or that would damage the containment system.  Evaluate remedy effectiveness through regular groundwater monitoring.

The remedy selected in the 1993 ROD and modified by the 1996 Explanation of Significant Differences (ESD) included:

 Institutional controls to prohibit construction on the landfill, or the use of water beneath the landfill or in the immediate vicinity of the landfill for drinking water purposes.

 Passive leachate collection system and treatment in the City of Minot’s wastewater treatment facility.  Consolidation of landfill waste in the vicinity of leachate seeps under the cap.  Construction of a cap, consisting of 18 inches of clay, 12 inches of root zone material and 6 inches of topsoil to cover the limits of buried waste.  Long-term groundwater and leachate monitoring to detect future releases of contaminants.  Landfill gas collection using passive gas vents.

The 1993 ROD and 1996 ESD identified drinking water quality standards in accordance with the Safe Drinking Water Act [40 CFR parts 141 and 143] as the performance standards for groundwater. In addition, the 1993 ROD stated that groundwater adjacent to the landfill shall not contain contaminants at levels that cause the groundwater to exceed the 1 x 10-4 to 1 x 10-6 risk range for carcinogens, or the noncancer HI to exceed 1 for potential receptors next to the landfill. The ROD and ESD did not provide a summary of chemical-specific numeric cleanup goals for groundwater or leachate. They stated that protocols for determining compliance with remediation goals and performance standards would be developed during the remedial design.

The Site's 1996 Final Remedial Design Report listed groundwater COCs and performance standards (Table 2) only for those COCs with established federal maximum contaminant levels (MCLs), maximum contaminant level goals (MCLGs) and secondary MCLs (SMCLs) established under the Safe Drinking Water Act. According to the 1996 Monitoring, Operations, and Contingency Plan (MOCP), groundwater COCs included for long-term monitoring were a subset of the COCs identified in the 1993 ROD. Several COCs were eliminated – COCs not detected in groundwater or leachate during the RI, COCs that were detected but did not have an established drinking water standard, and, in the case of the polychlorinated biphenyl Aroclor 1254, COCs detected in a leachate sample but not in monitoring wells surrounding the landfill.

Table 2: Summary of Performance Goals in Groundwater

Performance Goala Contaminants of Concern (micrograms per liter – µg/L) Benzene 5b Toluene 1,000b Tetrachloroethylene 5b Trans-1,2-dichloroethylene 100b (trans-1,2-DCE) Vinyl chloride 2b Barium 2,000b Chromium 100b Copper 1,300c Zinc 5,000d Notes: a. Presented in the 1996 Remedial Design Report. b. Primary MCL. c. Federal MCLG. d. Federal SMCL.

The ROD identified air quality standards pertinent to the requirements as performance standards for landfill gas. 1 However, EPA determined that performance goals for landfill gas were not warranted because EPA determined the emissions without treatment are less than 1 pound per day of total VOCs, precluding the need for landfill gas monitoring.

The ROD identified surface water regulations that leachate management actions should achieve; specific COCs and numeric criteria were not provided. According to the 1996 MOCP, the City of Minot’s wastewater treatment plant has indicated that leachate quality or flow monitoring was not required for treatment purposes. The MOCP further recommended comparison of leachate samples to groundwater performance standards since the leachate collection line collects groundwater/leachate from beneath the landfill. The monitoring data is further summarized in Section 6.4.

Although the BRA demonstrated that unrestricted exposure to soil was within EPA’s acceptable cancer risk and noncancer hazard limits, EPA identified a performance standard for soil in order to comply with the Applicable or Relevant and Appropriate Requirements (ARARs) for the state landfill design requirements. Leachate seeps are not acceptable under the North Dakota landfill design requirement regulations (the North Dakota Solid Waste Management Act and pertinent federal solid waste land disposal requirements [40 CFR parts 241 and 257]). Therefore, EPA established the soil performance objective to remove contaminated soils in the vicinity of the leachate seeps to a depth of about 3 feet and to consolidate the material under the landfill cap.

4.2 Remedy Implementation

In the 1996 Consent Decree, the City of Minot agreed to perform the Site’s remedial design and remedial action and operation and maintenance (O&M) activities at the Site. The City completed the remedial design between February 1996 and April 1996. The City completed the remedial action between June 1996 and November 1996 and included the following activities:

 Completion of several test pit excavations to verify the presence of waste and determine its configuration.  Installation of a passive leachate collection system within the landfill and associated drainage system that discharges to the City of Minot's wastewater treatment facility.  Installation of riser pipes extending upward from the leachate drain to serve as passive gas vents and clean-outs.  Installation of removable wind turbines at the top of each riser pipe to help remove the gas from the landfill by inducing a vacuum.  Excavation of identified waste and placement of the material under a new cap that was improved so that a uniform, minimum thickness of capping material was in place across the landfill.  Site seeding and fertilizing.  Replacement of the existing silt fence around catch basins with riprap.

1 40 CFR Part 6, Subpart C, Parts 50, 52, 61 and 241, the North Dakota Solid Waste Management Act, and North Dakota air pollution control regulations as performance standards for landfill gas.

 Installation of erosion matting in the swales between catch basins, in perimeter ditches and in the cap improvement area.  Installation of a permanent fence that surrounds this containment area.  Installation of seven groundwater monitoring wells and four piezometers around the perimeter of the landfill.  Disposal of leachate in the wells during abandonment in the City's municipal sanitary sewer system.  Implementation of institutional controls through local land use ordinances restricting activities that could damage the landfill cap and prohibit installation of groundwater supply wells within or in the immediate vicinity of the landfill. (See Section 6.3 for more details on institutional controls implemented at the Site.)

EPA and NDDH concluded that the remedial action had been successfully implemented. EPA issued the Site's Final Close Out Report in December 1996. EPA deleted the Site from the NPL in April 1997.

4.3 Operation and Maintenance (O&M)

The O&M period for the Site, as detailed in the Site's MOCP, began in October 1996. The City of Minot performs all O&M work, which includes groundwater monitoring for seven wells and one leachate location, inspection of the landfill passive gas vents, leachate management, and all maintenance work. The City also mows the area regularly, reseeds and corrects any areas of erosion, and maintains the 6-foot security fence that surrounds the landfill.

The City samples seven groundwater monitoring wells and four piezometers around the perimeter of the landfill on an annual basis, in accordance with the 1993 ROD. A leachate sample is also collected concurrent with the monitoring well samples. The City continues to operate the leachate and passive gas vent systems.

The projected annual cost presented in the 1993 ROD was $39,700. The 1996 ESD modified the remedy by replacing active gas and leachate collection systems with passive systems. This modification reduced the projected annual O&M cost to $8,500 per year. O&M annual costs during this review period all fell below this estimate (Table 3). These costs are for groundwater monitoring and all maintenance work (which includes mowing the area regularly and actively reseeding or correcting any areas of erosion). All O&M activities are being accomplished in a timely fashion. Expenditures for the past five years have been consistent.

Table 3: Annual O&M Costs

Year Total Cost (rounded to the nearest $1,000) 2011 $5,000 2012 $5,000 2013 $5,000 2014 $5,000 2015 $5,000

5.0 Progress Since the Last Five-Year Review

The protectiveness statement from the 2011 FYR for the Site stated:

The remedy at OU l of the Minot Landfill currently protects human health and the environment because it is functioning as intended by the Site's decision documents, the exposure assumptions, toxicity data, cleanup levels and remedial action objectives (RAOs) used at the time of remedy selection are still valid, and no other information has come to light that could call into question the protectiveness of the remedy. Contaminated source material has been excavated and is being contained on the Site beneath a landfill cap. Institutional controls are in place to prevent future land uses that could damage the remedial components in place and to prohibit installation of groundwater supply wells on the Site or in the immediate vicinity of the Site. No groundwater at the Site or in the area surrounding the Site is currently being used. However, in order for the Site's remedy to be protective in the long-term the following actions need to be taken:

• Areas of erosion on the landfill cap need to be addressed. • Trees bordering the cap need to be removed. • Drainage swales need to be cleaned out and inspected on a regular basis.

The 2011 FYR included three issues and recommendations. This report summarizes each recommendation and its current status below.

Table 4: Progress on Recommendations from the 2011 FYR

Party Milestone Action Taken and Date of Recommendations Responsible Date Outcome Action Fill eroded areas with Completed. Eroded clean material and re- City 02/01/2012 areas filled with black 09/19/2011 vegetate. dirt and area reseeded. Remove the two Completed. Trees cut Russian Olive trees City 02/01/2012 09/19/2011 down and removed. bordering the cap. Drainage swales are Completed. Drainage choked with excess City 02/01/2012 swales were cleaned 09/19/2011 vegetation and debris. out.

6.0 Five-Year Review Process

6.1 Administrative Components

EPA Region 8 initiated the FYR in November 2015 and scheduled its completion for September 2016. EPA remedial project manager (RPM) Frances Costanzi led the EPA site review team, which also included Kirk Johnson and Kathleen Kangas from NDDH and contractor support provided to EPA by Skeo. In November 2015, EPA held a scoping call with the review team to discuss the Site and items of interest as they related to the protectiveness of the remedy currently in place. The review schedule established consisted of the following activities:

 Community notification.  Document review.  Data collection and review.  Site inspection.  Local interviews.  FYR Report development and review.

6.2 Community Involvement

EPA will make the final FYR Report available to the public. EPA will place copies of the document in the designated site repository: Minot Public Library, located at 516 2nd Avenue SW, Minot, North Dakota 58701. Upon completion of the FYR, EPA will place a public notice in the Minot Daily News newspaper to announce the availability of the final FYR Report in the Site’s document repository.

6.3 Document Review

This FYR included a review of relevant, site-related documents, including the ROD, ESD, remedial action reports and recent monitoring data. A complete list of the documents reviewed can be found in Appendix A.

ARARs Review

Section 121 (d)(2)(A) of CERCLA specifies that Superfund remedial actions must meet any federal standards, requirements, criteria or limitations that are determined to be ARARs. ARARs are those standards, criteria or limitations promulgated under federal or state law that specifically address a hazardous substance, pollutant, contaminant, remedial action, location or other circumstance at a CERCLA site. To-Be-Considered (TBC) criteria are non-promulgated advisories and guidance that are not legally binding, but should be considered in determining the necessary level of cleanup for protection of human health or the environment. While TBCs do not have the status of ARARs, EPA's approach to determining if a remedial action is protective of human health and the environment involves consideration of TBC criteria along with ARARs.

Chemical-specific ARARs are specific numerical quantity restrictions on individually listed contaminants in specific media. Examples of chemical-specific ARARs include the MCLs

specified under the Safe Drinking Water Act as well as the ambient water quality criteria enumerated under the Clean Water Act. The remedy selected for this Site was designed to meet or exceed all chemical-specific ARARs and meet location- and action-specific ARARs.

Groundwater ARARs According to the Site's 1996 Final Remedial Design Report, cleanup goals for nine groundwater COCs in the 1993 ROD were based on federal MCLs, MCLGs and SMCLs. Chemical-specific ARARs from the 1993 ROD were compared to current national primary and secondary drinking water regulations (40 CFR 141-143) (Table 5). Chemical-specific ARARs for the Site remain unchanged. Table 5: Previous and Current ARARs for Groundwater COCs Performance Currentb ARARs ARARs Change COC Goal (µg/L)a (µg/L) Organics Benzene 5 5c none Toluene 1,000 1,000c none Tetrachloroethene 5 5c none Trans-1,2-DCE 100 100c none Vinyl chloride 2 2c none Inorganics Barium 2,000 2,000c none Chromium 100 100c none Copper 1,300 1,300d none Zinc 5,000 5,000e none Notes: a. Values listed in Section III, Table 4 of the 1996 Remedial Design Report. b. National Primary and Secondary Drinking Water MCLs are available at: http://water.epa.gov/drink/contaminants/index.cfm (accessed 09/14/2015). c. Federal MCL. d. Based on the action level for copper, which is regulated by a treatment technique. e. Federal secondary MCL.

Landfill Gas ARARs

The 1993 ROD identified federal and state air quality standards as performance standards to be achieved by the passive landfill gas management system. These standards include federal regulations established under 40 CFR Part 6, Subpart C, Parts 50, 52, 61 and 241, the North Dakota Solid Waste Management Act, and North Dakota air pollution control regulations. The numeric standards were not provided in the ROD. However, performance goals for landfill gas were not warranted because EPA determined the emissions without treatment are less than 1 pound per day of total VOCs, precluding the need for landfill gas controls.

Soil ARARs Chemical-specific ARARs are not available for soil contaminants. The soil/waste were remediated based on the results of geophysical investigations and presence of leachate seeps.

Institutional Control Review

Table 6 lists the institutional control associated with the Site. According to the ordinance (Appendix F), except as approved by the director of public works, no person may enter upon, by vehicle or by foot, the property defined as "no-entry premises." The no-entry premises boundary is shown in Figure 2 and generally follows the Superfund site boundary. The ordinance indicates that the director of public works shall limit his/her approval to enter the "no-entry premises" to those persons who are performing clean-up or remedial action work, including inspection and monitoring activities, required under the Consent Decree. In addition, the director of public works had granted permission for the relocation of the Minot Fire Department Training Grounds to the area. The ordinance authorizes subsequent access to the training facility for the future conducting of firefighting training exercises under the direct supervision and authority of the City of Minot Fire Department. The ordinance limits the firefighting to be conducted with the equipment and structures placed on the Site with the specific requirement that all firefighting activities will occur within this portion of the parcel, which is designated as undisturbed grounds or grounds/areas where no waste has been previously disposed of or deposited. The ordinance also prohibits the installation of groundwater supply wells or any subsurface boring on any property defined as the no-entry premises or within one 150 feet of the no-entry premises.

Table 6: Institutional Control (IC) Summary Table

ICs Called for in ICs IC Media the Decision Instrument in Place Needed Objective Documents City Ordinance No. Restrict installation of Groundwater Yes Yes 3406, § 1 Section 16- groundwater wells. 51s

Restrict subsurface City Ordinance No. boring on premises or Soil Yes Yes 3406, § 1 Section 16- within 150 feet of the 51a no-entry premises. Notes: a. City ordinance information obtained from: https://www2.municode.com/library/nd/minot/codes/code_of_ordinances?nodeId=COOR_C H16HESA_ARTIIISUINCO_S16-50LEPU (accessed 05/20/16).

The City of Minot is currently working on a proposal to reuse other portions of the Site as a community park which may include a cross country running course, mountain bike trails and a disc golf course. However, City Ordinance No. 3406, § 1 Section 16-51 currently prohibits such uses.

Figure 2: Location of Institutional Control

6.4 Data Review

Groundwater sampling data collected by the City of Minot from June 2011 through May 2016 were reviewed for this FYR by comparing the results to the ROD performance standards which also are the chemical-specific ARARs for the Site. The data includes results for one background well (OW-MW1) and six monitoring wells downgradient of the landfill (OW-101A, -102A, - 103A, -104A, -105A and -107A) as well as a leachate sample from a manhole from the sanitary sewer adjacent to Burdock Expressway (Figure 3). The City's contractor, Minnesota Valley Testing Laboratories, Inc. (MVTL), provided the sampling results. The inorganic COCs barium, chromium and copper were below detection in all seven monitoring wells; however, the detection limit of 250 µg/L for chromium in wells OW-101A, OW-103A and OW-105A has consistently been above the cleanup goal (100 µg/L). This does not present a concern because the most downgradient leachate collection point has consistently shown that chromium has been below detection for the last five years with a detection limit of 50 µg/L. Zinc was detected sporadically in four monitoring wells and detected five times in the leachate sample. However, none of the detections were above the cleanup goal (Appendix E, Table E-1).

The organic COCs were below detection in all seven monitoring wells. Benzene and vinyl chloride were detected in the leachate sample above cleanup goals in 2012 and 2014. The benzene concentration of 5.3 micrograms per liter (µg/L) detected in 2012 and 2014 was only slightly above the cleanup goal of 5.0 µg/L. The vinyl chloride concentrations in 2012 and 2014 of 51.7 µg/L and 49 µg/L, respectively, are more than 10 times higher than the cleanup goal (2 µg/L). The concentrations of all organic COCs were below detection in 2015 and toluene was the only organic COC detected in 2016, at a concentration well below the cleanup goal. The groundwater data are presented in Appendix E (Table E-2).

In 2014, 2015 and 2016, MVTL included the results for the full VOC scan. Three contaminants, acetone, dichlorodifluoromethane and ethyl ether, which were not selected as groundwater COCs were detected in several monitor wells. Acetone was detected in OW-101A, 102A and 105A, ethyl ether and dichlorodifluoromethane were detected in OW-104A. Several organic contaminants not identified as COCs were also detected in the leachate samples collected in 2014, 2015 and 2016. These data are discussed further in Section 7.2.

Figure 3: Monitoring Well Location Map

6.5 Site Inspection

The site inspection took place on July 7, 2016. Participants included EPA RPM Frances Costanzi, Kirk Johnson and Kathleen Kangas from NDDH, Treat Suomi from EPA contractor Skeo, Dan Jonasson and Jason Sorenson from the City of Minot’s Public Works Department, and Jarrod Olson, Elly DesLauriers, and Ron Merritt from the Minot Park District. The group toured the Site. Wells, fencing and general conditions were noted and photographed (Appendix E). All wells were secure and labeled but labels did not always match wells illustrated on site maps. Complete results are available in the completed site inspection checklist in Appendix C.

The site inspection was led by EPA RPM Frances Costanzi. The Site is construction complete, has been deleted from the NPL, and is currently monitored and maintained according to the Site's O&M Plan. The City of Minot is currently working on a proposal to reuse other portions of the Site as a community park that may include a cross country running course, mountain bike trails and a disc golf course.

A copy of the proposed reuse plan is included in Appendix G. Since the 2011 FYR, an area at the southwest entrance of the Site along the U.S. Highway 2 and 52 Bypass South immediately outside of the landfill footprint has been redeveloped; the area now includes a training facility for the Minot Fire Department. The facility is located within the fenced area of the Site, immediately outside the western-most landfill footprint. In addition, the Minot Park District is in the process of expanding the Maysa Arena and associated parking areas located north of the landfill.

6.6 Interviews

The FYR process included interviews with parties affected by the Site, including the City of Minot and regulatory agencies involved in site activities or aware of the Site. The purpose was to document the perceived status of the Site and any perceived problems or successes with the phases of the remedy implemented to date. All of the interviews took place by email. The interviews are summarized below. Appendix B provides the complete interviews.

Fran Costanzi: Fran Costanzi represents EPA and is the RPM for the Site. Overall, she believes the remedy is functioning as designed. The landfill cover vegetation is well-established and the City appears to be maintaining the remedy appropriately. She commented that the recent addition of the fire training facility is an example of successful reuse at the Site. She is not currently aware of any effects of the Site on the surrounding community. She is comfortable with the status of institutional controls at the Site, which may be unnecessarily restrictive as future site uses are considered. Ms. Costanzi commented that the preliminary reuse proposal sounds interesting and is well-suited for the Site, but certain site-related documents may need to be updated when the reuse is implemented. Lastly, she mentioned the landfill gas vents are unusually short and the landfill appears to still be producing some gas. This would become an issue in the future that would need to be addressed in O&M planning before recreational reuse activities could occur.

Kirk Johnson: Kirk Johnson represents NDDH for the Site. Overall, he believes the Site is well- maintained, except for a few bare spots and weedy areas atop the final cover that will need more

topsoil and adapted grass seeding. He also believes the remedy is functioning as intended. Mr. Johnson has not heard any complaints from nearby residents in the past five years. The State has not conducted any site-related activities over the five-year period; however, prior to the site inspection, the City of Minot unveiled a proposed park and trail plans for part of the Site. Mr. Johnson believes the park and trail proposal will be workable with a few controls. These include fencing off passive vents and inspecting the grass cover on the final cap frequently. These controls should be included in a facility O&M plan.

John Reynolds: John Reynolds represents the City of Minot as the O&M contractors and PRPs for the Site. Overall, he believes site activities are going well and the remedy is working as intended. He commented that City of Minot staff visit the Site several times a year and take care of any issues that arise during these visits. The City of Minot spends about $5,000 a year on O&M activities, which include groundwater monitoring, fence repairs and truck track repair from winter snow storage. There have been no significant changes in O&M requirements or opportunities to optimize O&M activities. Mr. Reynolds believes the proposed reuse of the Site is a step in the right direction.

Ron Merritt: Ron Merritt represents the Minot Park District for the Site. He believes the City maintains the Site well and he has not noticed any major issues. The community is excited about the recreation possibilities at the Site, with no negative effects on the surrounding community. He believes the remedy has performed very well to this point. Mr. Merritt feels well-informed regarding site activities.

7.0 Technical Assessment

7.1 Question A: Is the remedy functioning as intended by the decision documents?

Yes. The remedy is functioning as intended because the City of Minot excavated, consolidated, stabilized/solidified and isolated contaminated soils under the landfill cap in the vicinity of leachate seeps. The City improved the original landfill cap to limit precipitation infiltration and control stormwater runoff. In addition, the cap over the source area and adjacent slope areas has a well-established vegetative cover. During the site inspection, there was a small bare area observed near manhole LW3 that was about 2 feet wide by 4 feet long. City staff indicated that they would reseed the area. The condition of the drainage swales, riprap and other water control structures on the Site are intact and functioning as designed.

Access to the Site is restricted by a locked security fence, signs are present around the perimeter of the Site, and the Site is regularly inspected and maintained in accordance with the O&M Plan.

Water quality data from the last five years for the Site's seven monitoring wells and leachate reports indicate that only benzene and vinyl chloride were detected above cleanup goals which also are the chemical-specific ARARs for these two COCs in the leachate samples collected in 2012 and 2014. However, the concentrations of all organic COCs were either below detection or below cleanup goals/ARARs in 2015 and 2016.

A city ordinance prohibits land uses that could damage the cap as well as installation of groundwater supply wells on the landfill or in the immediate vicinity of the landfill. Combined with landfill capping and passive gas vents, this ordinance minimizes the potential exposures to humans from waste materials and/or landfill off-gas. A land use institutional control is in place to limit specific activities, such as installation of groundwater wells or subsurface boring on the premises or within 150 feet of the no-entry premises. The passive gravity drain system manages leachate levels in the landfill to reduce the potential for leachate migration into the groundwater. Groundwater monitoring data suggest that this system is effective in meeting this goal.

7.2 Question B: Are the exposure assumptions, toxicity data, cleanup levels and remedial action objectives (RAOs) used at the time of remedy selection still valid?

Yes. There have been no changes to ARARs for the COCs. There have been no other changes in toxicity data that would call into question the protectiveness of the remedy. There has been one significant change to the EPA’s standardized risk assessment methodology. A vapor intrusion pathway evaluation using multiple lines of evidence is now a part of the methodology. While VOCs are COCs for groundwater at the Site, the concentrations are either below detection or close to detection limits. Based on an evaluation using EPA’s vapor intrusion calculator (Appendix E, Table E-3), the concentrations in groundwater demonstrate that this is an incomplete future exposure pathway.

In 2014, 2015 and 2016, MVTL included the results for the full VOC scan. Sampling detected four contaminants: acetone, cis-1,2-DCE, dichlorodifluoromethane and ethyl ether, which were not selected as COCs. Acetone was detected in OW-101A, 102A and 105A, ethyl ether and dichlorodifluoromethane were detected in OW-104A. In addition, several contaminants not identified as COCs were also detected in the leachate samples collected in 2014, 2015 and 2016.The detections of four contaminants detected in groundwater and leachate samples were compared to EPA’s tap water regional screening levels (RSLs) to determine if any new COCs should be identified (Appendix E, Table E-4). No COCs were identified because all detections were within EPA’s risk management range of 1 x 10-6 to 1 x 10-4 or below the noncancer HQ of 1.

7.3 Question C: Has any other information come to light that could call into question the protectiveness of the remedy?

No. However, if proposed reuse plans move forward, EPA, NDDH and the City of Minot may need to evaluate and update site documents, as necessary, to accommodate the planned reuse. The institutional control currently required would likely need to be re-considered. Other considerations may include relocating fencing and modifying landfill vents.

7.4 Technical Assessment Summary

The remedy is functioning as intended. The City of Minot has remediated contaminated soils and placed them under the landfill cap, and improved the original landfill cap to limit precipitation infiltration and control stormwater runoff. A locked security fence restricts access to the Site, signs are present around the perimeter of the Site, and the Site is regularly inspected and maintained in accordance with the O&M Plan.

Water quality data from the last five years for the Site's seven monitoring wells indicate that groundwater COCs are below detection or are below cleanup goals, which are also the chemical- specific ARARs for Site groundwater. Benzene and vinyl chloride were detected in the leachate sample above cleanup goals in 2012 and 2014. However, they were below detection or below cleanup goals in 2015 and 2016. Other contaminants were detected that were not originally identified as COCs. A screening-level risk evaluation indicates that there are no new COCs present in site groundwater or leachate.

The institutional control is in place that prohibits land uses that could damage the cap and prohibits installation of groundwater supply wells on the landfill or in the immediate vicinity of the landfill. The City has had preliminary discussions on possibly redeveloping the landfill area as a recreational park with trails and disc golf. If the plans become more definitive, additional considerations may be needed for the site documents.

8.0 Issues

No current site issues were identified as part of this FYR that affect the protectiveness of the remedy.

9.0 Recommendations and Follow-up Actions

No issues and recommendations were identified that affect the protectiveness of the remedy. The following additional items, though not expected to affect protectiveness, warrant additional follow up:

 Evaluate if the detection limit for chromium sampled from wells OW-101A, OW-103A and OW-105A can be lowered to 50 µg/L to improve O&M activities at the Site.  Update the O&M plan with GIS locations of wells and leachate sampling locations as not all monitoring locations were able to be located during the site inspection.  The current institutional control may be overly restrictive since the ordinance limits site access to persons who are performing clean-up or remedial action work with one exception: a small portion of the Site, where the Minot Fire Department Training Grounds was relocated, outside of the landfill footprint and an area that the City uses to store excess snow.  Site documents, including the MOCP, may require revision prior to any future recreational use of the Site to ensure such use is protective, does not negatively impact the remedy and is in compliance with the remedy decision and other site documents.

10.0 Protectiveness Statement

installation of groundwater supply wells on the Site or in the immediate vicinity of the Site. In addition, long-term monitoring results demonstrate that contaminants of concern are consistently meeting performance objectives in groundwater and leachate, and people are not using groundwater at the Site or in the area surrounding the Site.

11.0 Next Review

The next FYR will be due within five years of the signature/approval date of this FYR.

Appendix A: List of Documents Reviewed

Consent Decree, United States of America and City of Minot, 1996 (including the Statement of Work which is an Appendix to the Consent Decree), February 7, 1996.

Explanation of Significant Differences to the Record of Decision, Old Minot Landfill, April 1996, United States Environmental Protection Agency Region 8, 1996.

Final Site Close-Out Report, Minot Landfill Superfund Site, December 1996.

Final Remedial Action Completion Report, Minot Landfill Superfund Site, November 1996, Wenck, 1996.

First Five-Year Review Report for Minot Landfill Site. United States Environmental Protection Agency Region 8, September 2001.

Groundwater Monitoring-2011. Minot Old Landfill Spring Event, MVTL, June 2011.

Groundwater Monitoring-2012. Minot Old Landfill Spring Event, MVTL, April 2012.

Groundwater Monitoring-2013. Minot Old Landfill Spring Event, MVTL, May 2013.

Groundwater Monitoring-2014. Minot Old Landfill Spring Event, MVTL, April 2014.

Groundwater Monitoring-2015. Minot Old Landfill Spring Event, MVTL, April 2015.

Groundwater Monitoring-2016. Minot Old Landfill Spring Event, MVTL, May 2016.

Monitoring, Operations and Contingency Plan, Wenck. 1996.

Record of Decision (ROD), Old Minot Landfill, United States Environmental Protection Agency Region 8, June 1993.

Second Five-Year Review Report for Minot Landfill Site. United States Environmental Protection Agency Region 8. September 2006.

Superfund Site Progress Profile, Minot Landfill. Available online at: http://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0602957&msspp=medL. Last updated May 23, 2016.

Third Five-Year Review Report for Minot Landfill Site. United States Environmental Protection Agency Region 8. May 2011.

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Appendix B: Interview Forms

Minot Landfill Superfund Site Five-Year Review Interview Form Site Name: Minot Landfill EPA ID No.: NDD980959548 Subject Name: __Fran Costanzi______Affiliation: __USEPA RPM______Subject Contact Information: ______Time: ____2:30pm______Date: _____7/29/16______

Interview Format (circle one): In Person Phone Mail Other: email

Interview Category: EPA RPM 1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as appropriate)? I recently became the Remedial Project Manager (RPM) for the site and my first visit to the site was for the five-year review site inspection. Overall, it seems that the remedy is operating as designed. The landfill cover vegetation is well-established and the City appears to be maintaining the remedy appropriately. The recent addition of the fire training facility appears to be an example of successful and useful reuse.

2. What have been the effects of this Site on the surrounding community, if any? It is my understanding that the cleanup (appropriately closing the landfill) addressed earlier community concerns. I am not aware of any current effects on the community.

3. Are you aware of any complaints or inquiries regarding site-related environmental issues or remedial activities since the implementation of the cleanup? No, I am not.

4. What is your assessment of the current performance of the remedy in place at the Site? The remedy is operating as designed.

5. Are you comfortable with the status of the institutional controls at the Site? If not, what are the associated outstanding issues? The institutional controls are in place and appear to be functioning as designed. They may be unnecessarily restrictive as we consider future use and we may decide to modify them.

6. Are you aware of any community concerns regarding the Site or the operation and management of its remedy? If so, please provide details. No, I am not.

7. Do you have any comments regarding the proposed reuse at the Site? The preliminary proposal sounds interesting and well-suited for the site with some possible minor modifications. Additionally, the decision documents, consent decree, institutional controls, and operation and maintenance manual may need to be updated to reflect the proposed reuse.

8. Do you have any comments, suggestions or recommendations regarding the management or operation of the Site’s remedy? The landfill gas vents are unusually short and the landfill appears to still be producing some gas. This issue may need to be addressed, particularly if the proposed reuse goes forward and there are more people, and especially children, having access to the site.

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Minot Landfill Superfund Site Five-Year Review Interview Form Site Name: Minot Landfill EPA ID No.: NDD980959548 Subject Name: Kirk Johnson Affiliation: N.D. Dept. of Health__ Subject Contact Information: Work ph: 701-328-4918; email: [email protected]__ Time: 8:39 am__ Date: 8:30 am

Interview Format (circle one): In Person Phone Mail Other: email

Interview Category: State Agency 1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as appropriate)? Overall, the Site appeared well maintained. However, there were some bare spot and weedy areas on the final cover that appear to need more topsoil and adapted grass seeding.

2. What is your assessment of the current performance of the remedy in place at the Site? It appears that the remedy put in place during the Superfund status is functioning well.

3. Are you aware of any complaints or inquiries regarding site-related environmental issues or remedial activities from residents in the past five years? No, I have not heard of any complaints or inquiries.

4. Has your office conducted any site-related activities or communications in the past five years? If so, please describe the purpose and results of these activities. I am not aware of any site-related activities, or communications for re-use within the past five years. However, just prior to this year’s inspection, the City of Minot unveiled a proposed park and trail plain for portions of the former Superfund site and adjacent non-landfilled city properties.

5. Are you aware of any changes to state laws that might affect the protectiveness of the Site’s remedy? I am not aware of any changes to state law that would affect the protectiveness of the final landfill cap.

6. Are you comfortable with the status of the institutional controls at the Site? If not, what are the associated outstanding issues? I think the city’s use of portions of the final cap for snow storage may have contributed to certain bare spots on the edge of the final cover, when a loader or bulldozer might have scraped the topsoil off to some degree.

7. Do you have any comments regarding the proposed reuse at the Site? I think the City’s Park System proposal for light reuse of the site ‘disc park’ and walking/running trails on parts of the final cover and adjacent properties is workable with some controls. Blocking off the many passive vents with metal cages, etc., is mandatory for any public access reuse controls. Also, frequent checking of the grass cover on the final cap is essential to any plan.

8. Do you have any comments, suggestions or recommendations regarding the management or operation of the Site’s remedy? I think that a well-thought out ‘light’ reuse plan is workable as long as institutional controls over the sensitive aspects (i.e., passive vents and protection of final vegetative cover), with regular inspections (at a minimum, each month), are included in a facility (park) Plan of Operation/Maintenance.

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Minot Landfill Superfund Site Five-Year Review Interview Form Site Name: Minot Landfill EPA ID No.: NDD980959548 Subject Name: John Reynolds Affiliation: Sanitation Sup Subject Contact Information: [email protected] Time: 3:30 p.m. Date: 7/28/2016

Interview Format (circle one): In Person Phone Mail Other: e-mail

Interview Category: O&M Personnel

1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as appropriate)? Site looks good.

2. What is your assessment of the current performance of the remedy in place at the Site? The remedy in place is working well.

3. What are the findings from the monitoring data? What are the key trends in contaminant levels that are being documented over time at the Site? This data has been e-mailed separately.

4. Is there a continuous on-site O&M presence? If so, please describe staff responsibilities and activities. Alternatively, please describe staff responsibilities and the frequency of site inspections and activities if there is not a continuous on-site O&M presence. The staff visit’s the site several times a year taking care of any issues that may come up.

5. Have there been any significant changes in site O&M requirements, maintenance schedules or sampling routines since start-up or in the last five years? If so, do they affect the protectiveness or effectiveness of the remedy? Please describe changes and impacts. No.

6. Have there been unexpected O&M difficulties or costs at the Site since start-up or in the last five years? If so, please provide details. The City of Minot spends about $3,000 a year. This activity includes fence repairs and repair of truck tracks from winter snow removal.

7. Have there been opportunities to optimize O&M activities or sampling efforts? Please describe changes and any resulting or desired cost savings or improved efficiencies. No.

8. Do you have any comments regarding the proposed reuse at the Site? No.

9. Do you have any comments, suggestions or recommendations regarding O&M activities and schedules at the Site? No.

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Minot Landfill Superfund Site Five-Year Review Interview Form Site Name: Minot Landfill EPA ID No.: NDD980959548 Subject Name: John Reynolds Affiliation: Subject Contact Information: [email protected]______Time: 3:30 p.m. Date: 7/28/2016 Interview Location: Office

Interview Format (circle one): In Person Phone Mail Other: e-mail

Interview Category: Potentially Responsible Parties (PRPs)

1. What is your overall impression of the remedial activities at the Site? Site looks good.

2. What have been the effects of this Site on the surrounding community, if any? No effects.

3. What is your assessment of the current performance of the remedy in place at the Site? The remedy at the site is working well. 4. 5. Are you aware of any complaints or inquiries regarding environmental issues or the remedial action from residents since implementation of the cleanup? I am not aware of any issues with residents in the area.

6. Have there been any problems with unusual or unexpected activities at the Site, such as emergency response, vandalism or trespassing? No.

7. Are you aware of any changes to state laws or local regulations that might affect the protectiveness of the Site’s remedy? No.

8. Do you feel well-informed regarding the Site’s activities and remedial progress? If not, how might EPA convey site-related information in the future? Yes.

9. Do you have any comments regarding the proposed reuse at the Site? I think the proposed reuse of the site is a step in the right direction.

10. Do you have any comments, suggestions or recommendations regarding the management or operation of the Site’s remedy? No.

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Minot Landfill Superfund Site Five-Year Review Interview Form Site Name: Minot Landfill EPA ID No.: NDD980959548 Interviewer Name: Ron Merritt Affiliation: Minot Park District Subject Name: Claire Marcussen Affiliation: Skeo Solutions Subject Contact [email protected] Information: Time: Date: 07/29/16 Interview Location:

Interview Format (circle one): In Person Phone Mail Other: Email

Interview Category: Potentially Responsible Parties (PRPs)

1. What is your overall impression of the remedial activities at the Site? Not sure what they would normally look like, but it looks well cared for, no major issues.

2. What have been the effects of this Site on the surrounding community, if any? Excitement from community at a possible recreation site, no negative effects.

3. What is your assessment of the current performance of the remedy in place at the Site? I think it looks like it has performed very well.

4. Are you aware of any complaints or inquiries regarding environmental issues or the remedial action from residents since implementation of the cleanup? Not aware of any.

5. Have there been any problems with unusual or unexpected activities at the Site, such as emergency response, vandalism or trespassing? No.

6. Are you aware of any changes to state laws or local regulations that might affect the protectiveness of the Site’s remedy? No.

7. Do you feel well-informed regarding the Site’s activities and remedial progress? If not, how might EPA convey site-related information in the future? Yes, but I have been involved in planning for a potential new use.

8. Do you have any comments regarding the proposed reuse at the Site? Great use of the Site, and citizens are excited.

9. Do you have any comments, suggestions or recommendations regarding the management or operation of the Site’s remedy? The City is doing a very good job.

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Appendix C: Site Inspection Checklist FIVE-YEAR REVIEW SITE INSPECTION CHECKLIST

I. SITE INFORMATION

Site Name: Minot Landfill Date of Inspection: 07/07/2016 Location and Region: North Dakota, Region 8 EPA ID: NDD980959548 Agency, Office or Company Leading the Five-Year Weather/Temperature: Cloudy, 60° Fahrenheit Review: EPA Region 8 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 John Reynolds 7/28/16 Name Title Date Interviewed at site at office by phone Phone: Problems, suggestions Report attached: 2. O&M Staff Name Title Date Interviewed at site at office by phone Phone: Problems/suggestions Report attached: See Appendix B 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). Fill in all that apply.

Agency EPA Contact Francis Costanzi RPM 7/29/16 Name Title Date Phone No. Problems/suggestions Report attached: See Appendix B

Agency State Department of Health Contact Kirk Johnson 7/18/16 Name Title Date Phone No. Problems/suggestions Report attached: See Appendix B

Agency Contact Name Title Date Phone No. Problems/suggestions Report attached:

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Agency Contact Name Title Date Phone No. Problems/suggestions Report attached:

4. Other Interviews (optional) Report attached: Ron Merritt, Minot Park District

III. ON-SITE DOCUMENTS AND 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 Readily available Up to date N/A plan Remarks:

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:

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

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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

2. O&M Cost Records Readily available Up to date Funding mechanism/agreement in place Unavailable Original O&M cost estimate: $39,000 per year Breakdown attached Total annual cost by year for review period if available From: 01/01/2011 To: 12/31/2011 $5,000 Breakdown attached Date Date Total cost

From: 01/01/2012 To: 12/31/2012 $5,000 Breakdown attached Date Date Total cost

From: 01/01/2013 To: 12/31/2013 $5,000 Breakdown attached Date Date Total cost

From: 01/01/2014 To: 12/31/2014 $5,000 Breakdown attached Date Date Total cost

From: 01/01/2015 To: 12/31/2015 $5,000 Breakdown attached Date Date Total cost

3. Unanticipated or Unusually High O&M Costs during Review Period Describe costs and reasons: None V. ACCESS AND INSTITUTIONAL CONTROLS Applicable N/A A. Fencing 1. Fencing Damaged Location shown on site map Gates secured N/A Remarks: The fence is well maintained and the Site is secure. EPA, NDDH and the City of Minot are discussing and evaluating fencing needs for the remedy in light of the projected reuse of the Site as a public park. B. Other Access Restrictions 1. Signs and Other Security Measures Location shown on site map N/A Remarks: There was adequate signage on the access gates indicating access was restriced. C. Institutional Controls (ICs)

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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): The City of Minot owns the property and has a regular presence through monthly inspections and the use of a portion of the Site by the Minot Fire Department for training activities. Frequency: Monthly Responsible party/agency: City of Minot Contact John Reynolds Sanitation 07/27/2016 701-857- Superintendent 4144 Name Title Date 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: The City of Minot is working with EPA and the Minot Department of Health to determine if the site documents and existing city ordinance will need to be changed to accommodate reuse of the Site as a park. D. General 1. Vandalism/Trespassing Location shown on site map No vandalism evident Remarks: 2. Land Use Changes On Site N/A Remarks: Following coordination with EPA, the City of Minot built a fire department training center on part of the Site in 2014. In addition, the City is developing a plan to use the remainder of the Site as a park with a cross country running trail, a disc golf course and mountain bike trails. 3. Land Use Changes Off Site N/A Remarks: The Minot Park District is in the process of expanding the Maysa Arena and associated parking areas located north of the landfill. VI. GENERAL SITE CONDITIONS A. Roads Applicable N/A 1. Roads Damaged Location shown on site map Roads adequate N/A Remarks: B. Other Site Conditions Remarks: VII. LANDFILL COVERS Applicable N/A A. Landfill Surface

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1. Settlement (low spots) Location shown on site map Settlement not evident Arial extent: Depth: Remarks: Due to the uneven nature of the capped area, it is difficult to determine if any settlement has occurred over time. There was no apparent evidence of short-term settlement.

2. Cracks Location shown on site map Cracking not evident Lengths: Widths: Depths: Remarks:

3. Erosion Location shown on site map Erosion not evident Arial extent: Depth: Remarks:

4. Holes Location shown on site map Holes not evident Arial extent: Depth: Remarks:

5. Vegetative Cover Grass Cover properly established No signs of stress Trees/shrubs (indicate size and locations on a diagram) Remarks: There was a small bare area observed near LW3 that was approximately 2 feet wide by 4 feet long. City staff indicated they would reseed this area. A few small areas had been affected by trucks depositing snow on the Site during the winter. The City had seeded these areas and new vegetation is becoming established.

6. Alternative Cover (e.g., armored rock, concrete) N/A Remarks:

7. Bulges Location shown on site map Bulges not evident Arial extent: Height: Remarks:

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:

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.)

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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 (Channel lined with erosion control mats, riprap, grout bags or gabions that descend down the steep side slope of the cover and will allow the runoff water collected by the benches to move off of the landfill cover without creating erosion gullies.) 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

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Remarks: Some of the vents were low to the ground. During consideration of reuse, evaluation of the vents will be needed to ensure they do not pose a risk to people using the Site. Some of the shorter vent pipes may need to be replaced or extended to ensure the height is appropriate to protect human health. In addition, the City, NDDH and EPA are evaluating the need to fence off the vents to ensure the protectiveness of the remedy durng reuse.

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 Properly secured/locked Functioning Routinely sampled Good condition Evidence of leakage at penetration Needs maintenance N/A Remarks: All wells that were found were locked and secured. An updated survey of wells on the Site may be warranted. LW3 was found during the site inspection but it is unclear if this well is routinely sampled.

4. Extraction Wells Leachate Properly secured/locked Functioning Routinely sampled Good condition Evidence of leakage at penetration Needs maintenance N/A Remarks: Leachate samples are taken at a manhole cover; during the site inspection, the sampling location was unclear. Adding this location to an updated map with GIS locations of wells and sampling locations would be helpful as part of an updated O&M Plan.

5. Settlement Monuments Located Routinely surveyed N/A Remarks: There are no settlement monuments.

E. Gas Collection and Treatment Applicable N/A F. Cover Drainage Layer Applicable N/A G. Detention/Sedimentation Ponds Applicable N/A H. Retaining Walls Applicable N/A I. Perimeter Ditches/Off-Site Discharge Applicable N/A VIII. VERTICAL BARRIER WALLS Applicable N/A IX. GROUNDWATER/SURFACE WATER REMEDIES Applicable N/A A. Groundwater Extraction Wells, Pumps and Pipelines Applicable N/A B. Surface Water Collection Structures, Pumps and Pipelines Applicable N/A C. Treatment System Applicable N/A D. Monitoring Data 1. Monitoring Data Is routinely submitted on time Is of acceptable quality

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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:

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 Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief statement of what the remedy is designed to accomplish (e.g., to contain contaminant plume, minimize infiltration and gas emissions). The selected remedy, as outlined in the decision documents, has been implemented and is performing as designed. EPA, NDDH and the City of Minot are evaluating the remedy to determine if any adustments need to be made based on plans to reuse the Site as a community park. Overall, the Site is well maintained and the City has a regular presence at the Site. B. Adequacy of O&M Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their relationship to the current and long-term protectiveness of the remedy. The O&M Plan should be revisited and updated as plans for reusing the Site move forward. In addition, an updated map illustrating the location of all wells and sampling locations will be helpful for reuse planning efforts, future five-year reviews and other inspections. C. Early Indicators of Potential Remedy Problems Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future. None. D. Opportunities for Optimization Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy. Planning for recreational reuse at the Site offers an opportunity to evaluate fence needs and also to update the Site's O&M Plan.

Site visit participants: Fran Costanzi (EPA) Kirk Johnson (NDDH) Kathleen Kangas (NDDH) Treat Suomi (Skeo) Dan Jonasson (Minot Public Works Department) Jason Sorenson (Minot Public Works Department) Jarrod Olson (Minot Park District) Elly DesLauriers (Minot Park District) Ron Merritt (Minot Park District)

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Appendix D: Photographs from Site Inspection Visit

Minot Fire Department training facility

Gas vent on landfill

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Southeastern edge of Site with fence line visible

Landfill surface drainage culvert

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Vegetation on landfill

Bare area on site needing revegetation

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Site vegetation

View of landfill from eastern edge

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Northern fence line near well OW-107A

’ Manhole where leachate sampling may occur

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Locked well LW1 Well LW3

Locked and labeled well set 103 Locked and labeled well pair 105. All wells (outside fence line) were secure and labeled but labels did not always match wells illustrated on site maps.

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Appendix E: Data Review Table E-1: Groundwater Monitoring Data for Inorganic COCs (2011 to 2016) Barium Chromium Copper Zinc Sample Date Cleanup Goals (µg/L) 2,000 100 1,300 5,000 OW-MW-1 2011 <100 <50 <50 <50 2012 <100 <50 <50 110 2013 <100 <50 <50 <50 2014 <100 <50 <50 <50 2015 <100 <50 <50 <50 2016 <500 <250 <250 <250 OW-101A 2011 <500 <250 <250 <250 2012 <500 <250 <250 <250 2013 <500 <250 <250 <250 2014 <500 <250 <250 <250 2015 <500 <250 <250 <250 2016 <500 <250 <250 <250 OW-102A 2011 <100 <50 <50 <50 2012 <100 <50 <50 200 2013 <100 <50 <50 <50 2014 <100 <50 <50 <50 2015 <100 <50 <50 <50 2015 <100 <50 <50 <50 2016 <100 <50 <50 <50 OW-103A 2011 <500 <250 <250 <250 2012 <500 <250 <250 <250 2013 <500 <250 <250 <250 2014 <500 <250 <250 <250 2015 <500 <250 <250 <250 2016 <500 <250 <250 <250 OW-104A 2011 <100 <50 <50 <50 2012 <100 <50 <50 160 2013 <100 <50 <50 <50 2014 obstructed or frozen 2015 <100 <50 <50 <50 2016 <100 <50 <50 <50 OW-105A 2011 <500 <250 <250 <250 2012 <500 <250 <250 <250 2013 <500 <250 <250 <250 2014 <500 <250 <250 <250 2015 <500 <250 <250 <250 2016 <500 <250 <250 <250 OW-107A 2011 <100 <50 <50 <50 2012 <100 <50 <50 170 2013 <100 <50 <50 <50 2014 obstructed or frozen 2015 <100 <50 <50 <50 2016 <100 <50 <50 <50 Leachate 2011 350 <50 <50 90 2012 250 <50 <50 250 2013 <100 <50 <50 70 2014 280 <50 <50 <50

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Barium Chromium Copper Zinc Sample Date Cleanup Goals (µg/L) 2,000 100 1,300 5,000 2015 <100 <50 <50 90 2016 <100 <50 <50 100 Notes: Bold italic = value detected but below the cleanup goal.

Table E-2: Groundwater Monitoring Data for Organic COCs (2011 to 2016) Trans-1,2- Vinyl Benzene PCE Toluene DCE Chloride Sample Date Cleanup Goals (µg/L) 5 100 5 1,000 2 OW-MW-1 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 <0.4 <0.5 <0.4 <0.5 <0.6 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 <0.4 <0.5 <0.4 <0.5 <0.6 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 <0.5 <0.6 OW-101A 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 <0.4 <0.5 <0.4 <0.5 <0.6 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 <0.4 <0.5 <0.4 <0.5 <0.6 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 <0.5 <0.6 OW-102A 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 <0.4 <0.5 <0.4 <0.5 <0.6 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 <0.4 <0.5 <0.4 <0.5 <0.6 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 <0.5 <0.6 OW-103A 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 <0.4 <0.5 <0.4 <0.5 <0.6 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 <0.4 <0.5 <0.4 <0.5 <0.6 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 <0.5 <0.6 OW-104A 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 <0.4 <0.5 <0.4 <0.5 <0.6 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 obstructed or frozen 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 <0.5 <0.6 OW-105A 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 <0.4 <0.5 <0.4 <0.5 <0.6 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 <0.4 <0.5 <0.4 <0.5 <0.6 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 <0.5 <0.6 OW-107A 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 <0.4 <0.5 <0.4 <0.5 <0.6 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 obstructed or frozen

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Trans-1,2- Vinyl Benzene PCE Toluene DCE Chloride Sample Date Cleanup Goals (µg/L) 5 100 5 1,000 2 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 <0.5 <0.6 Leachate 2011 <0.4 <0.5 <0.4 <0.5 <0.6 2012 5.3 1.1 <0.4 1.1 51.7 2013 <0.4 <0.5 <0.4 <0.5 <0.6 2014 5.3 0.7 <0.4 1.2 49.0 2015 <0.4 <0.5 <0.4 <0.5 <0.6 2016 <0.4 <0.5 <0.4 23 <0.6 Notes: Bold = value detected but below the cleanup goal. Bold = value detected above the cleanup goal.

Table E-3: Screening Level Vapor Intrusion Evaluation Vapor Intrusion Maximum Residential Contaminant Residential Detection (µg/L) Noncancer Riskb HQc Acetone 147.6 (L-2016) -- 0.000007 Bromodichloromethane 1.4 (L-2016) 1.6 x 10-6 -- Bromoform 7.5 (L-2015) 6.4 x 10-8 -- Carbon disulfide 3.4 (L-2016) -- 0.003 Chlorobenzene 1.4 (L-2014) -- 0.003 Chlorodibromomethane 3.5 (L-2015) -- -- Chloroform 11.2 (L-2016) 1.4 x 10-5 0.02 Cumene 0.8 (L-2014) -- 0.0009 Dibromomethane 0.8 (L-2015) -- 0.006 1,2-Dichlorobenzene 1.4 (L-2014) -- 0.0005 1,4-Dichlorobenzene 10.8 (L-2014) 4.2 x 10-6 0.001 Dichlorodifluoromethane 7.0 (OW-104A 2016) -- 0.94 Ethylbenzene 8.0 (L-2014) 2.3 x 10-6 0.003 Ethyl ether 36.6 (L-2014) -- -- Tetrahydrofuran 12.7 (L-2014) -- 0.00002 Methyl ethyl ketone 7.1(L-2016) -- 0.000003 Methyl isobutyl ketone 2.7 (L-2015) -- 0.000005 Notes: a. Current EPA Vapor Intrusion Calculator available at https://www.epa.gov/sites/production/files/2016-07/visl-calculator_v_351.xlsm (accessed 07/28/2016). -- = inhalation toxicity values not established. OW = well location and year sampled. L = leachate sample.

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Table E-4: Screening Risk Evaluation of NonCOCs in Groundwater or Leachate Residential Tap Residential Maximum Residential Contaminant Water RSL (µg/L)a Noncancer Detection (µg/L) Riskb 10-6 HQ-1 HQc Acetone 147.6 (L-2016) NA 14,000 -- 0.01 Bromodichloromethane 1.4 (L-2016) 0.13 380 1.1 x 10-5 0.004 Bromoform 7.5 (L-2015) 3.3 380 2.2 x 10-6 0.02 Carbon disulfide 3.4 (L-2016) NA 810 -- 0.004 Chlorobenzene 1.4 (L-2014) NA 78 -- 0.02 Chloroform 11.2 (L-2016) 0.22 97 5.1 x 10-5 0.12 Cis-1,2-DCE 8.2 (L-2012) NA 36 -- 0.22 Cumene 0.8 (L-2014) NA 450 -- 0.002 Dibromochloromethane 3.5 (L-2015) 0.87 380 4.0 x 10-6 0.009 Dibromomethane 0.8 (L-2015) NA 8.3 -- 0.1 1,2-Dichlorobenzene 1.4 (L-2014) NA 300 -- 0.005 1,4-Dichlorobenzene 10.8 (L-2014) 0.48 570 2.2 x 10-5 0.02 Dichlorodifluoromethane 7.0 (OW-104A 2016) NA 200 -- 0.04 Ethylbenzene 8.0 (L-2014) 1.5 810 5.3 x 10-6 0.01 Ethyl ether 36.6 (L-2014) NA 3,900 -- 0.009 Tetrahydrofuran 12.7 (L-2014) NA 3,400 -- 0.004 Methyl ethyl ketone 7.1(L-2016) NA 5,600 -- 0.001 Methyl isobutyl ketone 2.7 (L-2015) NA 6,300 -- 0.0004 Notes: a. Current EPA RSLs available at https://www.epa.gov/risk/regional-screening-levels-rsls-generic-tables-may- 2016 (accessed 07/19/2016). b. Cancer risks calculated using the following equation, based on the fact that RSLs are derived based on 1 x 10-6 risk: cancer risk = (Maximum detection ÷ cancer-based RSL) × 10-6 c. Noncancer HQ calculated using the following equation: HQ = Maximum detection ÷ noncancer-based RSL NA = not applicable. EPA has not classified this chemical as a carcinogen. -- = risk not estimated. OW = well location and year sampled. L = leachate sample and year sampled.

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Appendix F: Institutional Control

ARTICLE III. - SUPERFUND INSTITUTIONAL CONTROLS

Sec. 16-50. - Legislative purpose. The city is a party to an action brought by the United States of America acting on behalf of the Environmental Protection Agency (EPA), under the Comprehensive Environmental Response, Compensation and Liability Act, 42 U.S.C. Section 9601 et seq. (Superfund). By means of a consent decree, the city was ordered and agreed to perform certain cleanup and remedial work at the Old Minot Landfill Superfund Site (site), an old sanitary landfill which the city operated until the late 1960's or early 1970's. As part of its commitments in the consent decree, the city agreed to implement the cleanup measures selected in the EPA's record of decision (ROD), issued on June 21, 1993. The ROD was subsequently modified by an April 10, 1996, explanation of significant differences (ESD). The ROD and the ESD require the city to adopt local land use restrictions and controls designed to prevent the disturbance of the cleanup or recontamination of the site. These land use restrictions are called "institutional controls." The "institutional controls" for this site place restrictions upon activities that would damage the clay and soil cap which the city will place over the landfill and upon the installation of groundwater supply wells within or in the immediate vicinity of the site.

(Ord. No. 3406, § 1)

Sec. 16-51. - No-entry premises—Restrictions upon certain activities. (a) Except as approved by the director of public works, no person may enter upon, by vehicle or by foot, the property herein defined as "no-entry premises." The director of public works shall limit his/her approval to enter the "no-entry premises" to those persons who are performing clean-up or remedial action work, including inspection and monitoring activities, required under the consent decree referenced in section 16-50. Additionally, the director of public works shall grant permission for the relocation of the Minot Fire Department Training Grounds to the area identified as Block 8 (Edgeview Estates First Addition: Block 8) of the Old Minot Landfill Superfund Site for purposes of relocating the Minot Fire Department Training Grounds at said location and also authorizing subsequent access to this facility for the future conducting of firefighting training exercises under the direct supervision and authority of the City of Minot Fire Department. These firefighting exercises shall involve various training evolutions and shall be conducted with the equipment and structures placed upon Block 8 with the specific requirement that all firefighting activities will occur on those portions of Block 8 which are designated as undisturbed grounds or areas where no waste has been previously disposed of or deposited. (b) No person may install groundwater supply wells or undertake any subsurface boring, i.e., geotechnical boring, on any property herein defined as the no-entry premises or within one hundred fifty (150) feet of the no-entry premises. However, pursuant to the authorization granted in subsection (a) above, the City of Minot shall be authorized to place and install water lines, sewer lines, and/or storm sewer services or lines as necessary or required for the relocation, operation, and maintenance of the Minot Fire Department Training Grounds on Block 8 of the Old Minot Landfill Superfund Site. These water, sewer, or storm sewer lines shall also be located on undisturbed grounds or areas where no waste has been previously disposed of or deposited.

(Ord. No. 3406, § 1; Ord. No. 4749, §§ 1, 2)

Sec. 16-52. - Same—Description. The no-entry premises referred to in subsection (a) of section 16-51 are located in Ward County, North Dakota, and are described legally as: (1) Edgeview Estates First Addition.

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a. Block 5: Beginning at the northwest corner of Block 5, being the intersection of the east boundary of 18th Street southwest with Block 11 and Block 5; thence along a curve to the right, a distance of 279.64 feet, said curve having a radius of 740.00 feet and a chord of 277.97 feet which bears N 58° 46′ 14.2″ E; thence S 21° 11′ 14.4″ E, a distance of 97.18 feet; thence S 17° 24′ 24.9″ E, a distance of 98.16 feet; thence S 63° 34′ 14.2″ W, a distance of 213.15 feet; thence N 39° 30′ 00.0″ W, a distance of 175.00 feet to the point of beginning. Tract contains 47,475.68 square feet. b. Block 6: Beginning at the northwest corner of Block 6, being the intersection of the east boundary of 18th Street southwest with Block 7 and Block 6; thence along a curve to the left a distance of 276.69 feet, said curve having a radius of 1380.14 feet and a chord of 276.23 feet which bears N 49° 15′ 22.7″ E; thence N 43° 30′ 47.4″ E, a distance of 107.90 feet; thence S 46° 29′ 12.6″ E, a distance of 144.89 feet; thence S 44° 51′ 17.5″ W, a distance of 415.94 feet; thence N 35° 00′ 00.0″ W, a distance of 166.12 feet to the point of beginning. Tract contains 58,967.59 square feet. c. Block 7: Beginning at the northeast corner of Block 7, being the intersection of the east boundary of 18th Street southwest with Block 7 and Block 6; thence S 35° 00′ 00.0″ E, a distance of 166.12 feet; thence S 77° 12′ 09.1″ W, a distance of 473.70 feet; thence along a curve to the right, a distance of 68.28 feet, said curve having a radius of 1462.99 feet and a chord of 68.27 feet which bears N 55° 39′ 46.7″ E; thence N 57° 00′ 00.0″ E, a distance of 322.33 feet; thence along a curve to the left, a distance of 48.18 feet, said curve having a radius of 1380.14 feet and a chord of 48.18 feet which bears N 56° 00′ 04.1″ E to the point of beginning. Tract contains 36,570.35 square feet. d. Blocks 8, 10, and 11: All. (2) Edgeview Estates Second Addition. a. Block 3: Beginning at the southeast corner of Block 3, thence N 49° 15′ 00″ W along a chord of a curve to the left of a distance of 247.90 feet, said curve is the south right-of-way line of 22nd Street SW; thence N 59° 00′ 00″ W, a distance of 207.99 feet along the south right-of- way line of 22nd Street SW, to the north/south existing fence; thence S 01° 04′ 24″ E, a distance of 267.47 feet along the existing fence to the south property line of said Block 3; thence S 89° 45′ 30.5″ E, a distance of 361.08 feet along the south property line of said Block 3 to the point of beginning. Described tract contains 1.25 acres. b. Block 4: Beginning at the northeast corner of Block 4, thence N 89° 47′ 38.5″ W, a distance of 692.85 feet to the existing fence; thence S 01° 04′ 24″ E, a distance of 292.89 feet to the northerly right-of-way line of 22nd Street SW; thence S 59° 00′ 00″ E, a distance of 249.35 feet to the point of curvature of a curve to the right with a radius of 797.91 feet and a chord of 270.25 feet which bears S 49° 15′ 00″ E; thence S 39° 30′ 00″ E, a distance of 54.88 feet to the south line of said Block 4; thence S 89° 45′ 30.5″ E, a distance of 234.39 feet along the south line of said Block 4 to the southeast corner of said Block 4; thence N 00° 02′ 13.9″ W, a distance of 638.52 feet along the east line of said Block 4 to the point of beginning. Described tract contains 8.04 acres. (3) Ward County, North Dakota. a. From the southeast corner of Lot A of Outlot 15 of Section 27-155-83, go along the south property line of said Lot A west a distance of 95 feet; then go north a distance of 40 feet; then go east to the east property line of said Lot A; then go southeasterly along the east property line of said Lot A to the southeast property corner. b. From the southwest corner of Lot B of Outlot 15 of Section 27-155-83, go east along the south property line a distance of 130 feet; then go north a distance of 40 feet; then go west to the west property line of said Lot B; then go southeasterly along the west line of said Lot B to the southwest corner of said Lot B.

(Ord. No. 3406, § 1; Ord. No. 3457)

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Sec. 16-53. - Savings clause. The city is imposing the restrictions provided for in this article under the powers of its Home Rule Charter, and particularly the police power of the State of North Dakota as invoked by or through that Charter, and the constitutional and statutory provisions attendant to the Charter. In the opinion of the city, such power is adequate to authorize the city to impose these restrictions without accomplishing a "taking" under either the federal or state constitutions, and, for that reason, the city is not obligated to pay compensation to any private property owner who may be adversely affected by such restrictions. Nevertheless, in the event a court of competent jurisdiction holds otherwise, and is sustained upon appeal (if any), it is the intention of the city that, rather than these restrictions being invalidated, it instead be allowed to pay a fair and just compensation for whatever compensable damages as may be suffered by private property owners who are adversely affected by these restrictions. In other words, the city would prefer to settle an "inverse condemnation" claim, or to have such claim adjudicated by the courts, instead of allowing the restrictions to be invalidated because they accomplish an uncompensated taking forbidden by law. (Ord. No. 3406, § 1)

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Appendix G: Proposed Site Reuse Plan for Future Redevelopment

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