Revised On: Jan. 4, 2024 - 2:30 p.m.

1941 - 1948

Williams Air Force Base (WAFB) was constructed in 1941 and served as a training facility, primarily pilot training. At the time the base was constructed, the site was surrounded by irrigated farmland and desert. Industrial activities at WAFB included heavy maintenance of aircraft and ground equipment in support of pilot training.

WAFB played a strategic role in America's aviation history. Over a span of 52 years, more than 26,500 men and women earned their wings at Williams. Gearing up for the combat pilot demands of World War II, the Army Air Corps broke ground in southeast Mesa for its Advanced Flying School on July 16, 1941. In February 1942, the growing military base's name was changed to Williams Field to honor Charles Linton Williams, an Arizona-born pilot. The facility was re-designated as WAFB in January 1948. WAFB was the U.S. Army Air Corp’s foremost pilot training facility, graduating more student pilots and instructors than any other base in the country and supplying 25 percent of the U.S. Air Force (USAF) pilots annually. Contaminants from base activities included organic solvents and paint strippers, petroleum spills and leaks, metal plating wastes, hydraulic fluids, pesticides, and radiological wastes. Discharges and disposals at WAFB have resulted in soil and groundwater contamination.

1983

Site investigations initiated in 1983 under the auspices of the Department of Defense installation restoration program identified thirteen potentially contaminated areas including: two fire training areas, a fuel storage area, two surface storm drainage areas, a hazardous material storage area, a landfill, a pesticide burial pit, a radiological disposal area, and four underground storage tanks.

1989

WAFB was placed on the U.S. Environmental Protection Agency's (EPA's) National Priority List (NPL) on November 21. Remedial Investigations (RIs) initiated under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) discovered several new areas of contamination that were added to the existing list of sites.

1991 - 1993

WAFB was closed in 1993. After the announcement of closure in 1991, the community immediately began work to redevelop the base. Upon closing, WAFB was transferred to the Air Force Base Conversion Agency (AFBCA). AFBCA assumed responsibilities for the restoration and reuse of the base and worked with the Restoration Advisory Board (RAB) and Williams Redevelopment Partnership to maximize reuse of the land.

For cleanup purposes, the former base was divided into six operable units, OU-1 through OU-6. Each OU consists of many sites of potential concern; the following lists only the sites of primary interest for each OU:

OU-1 contains the main base landfill (LF004) for which a Record of Decision (ROD) was signed in 1994. The remedy specified a permeable cap (soil) and monitor wells. At the time of the ROD, only low levels of contaminants were present in the wells. In 1997, higher levels of contamination were discovered in the landfill monitor wells and a follow-on RI was conducted in 2000. Concentrations of contaminants in some of the monitor wells installed during the follow-on RI are the highest ever seen at the site and indicate that contamination is migrating off of the former base.

OU-2 addresses the groundwater and soil contamination at the ST-12. The results of the RI at ST-12 have confirmed that the primary contaminants are JP-4 (a jet fuel) and aviation gas (AVGAS). There is a groundwater plume at ST-12 which resulted from the leakage of an unknown quantity of JP-4 and AVGAS. It is estimated that the groundwater contains 640,000 to 1.4 million gallons of JP-4 and AVGAS. The EPA believes as much as 12 million gallons may be in the soil and groundwater. Rising groundwater in the area, 40 feet over the last ten years, has covered the fuel and smeared it across many feet of deep soil making access to the plume (for remediation) increasingly difficult. The ROD for OU-2 was signed in December 1992. The USAF has yet to implement a groundwater remedy at the site.

OU-3 formerly addressed the vadose zone beginning 25 feet below land surface down to the water table at ST012 which is now a part of OU-2. The primary site of concern at OU-3 now is the FT-02. The 25,000 cubic yards of contaminated deep soils at the site were treated in place by enhancing natural bacterial breakdown of contaminants with bioventing. The ROD for OU-3 was signed in late June 1996. The standards agreed to in the ROD have not been achieved. However, the USAF, in accordance with new state rules has conducted a risk assessment which determined that the cleanup levels attained do not pose a risk to human health or environment.

OU-4 includes South Desert Village (SDV) which is currently serving as student housing for Arizona State University (ASU) East. Beneath SDV is a former six-station skeet range which was demolished and graded in 1950, prior to construction of SDV. Contamination in the form of lead pellets in soil associated with the former skeet range underlies 85 housing units in SDV.  Since complete removal of contaminated soils would have required demolition of this valuable housing, a compromise solution involved removal of the top six inches of contaminated soil and installation of six inches of clean soil. The replacement soil is considered a protective cap over the remaining contamination, and will be subject to repair and maintenance, as well as land use restrictions in the form of a voluntary environmental mitigation and use restriction (VEMUR). The VEMUR defines the affected area as non-residential, and places deed restrictions to bind occupants to maintain the protective cap.

OU-5 was set up to address nine soil sites which were closed out through expedited removal fill actions. No groundwater contamination is known to exist at any of the OU-5 sites. The OU-5 ROD was signed in February

1998

OU-6 was established to address three sites requiring additional investigation. The site of primary concern (site SS-17 Old Pesticide/Paint Shop) at OU-6 revealed soil contamination (dieldrin and volatile organic compounds [VOCs]). A removal action of dieldrin contaminated soil was completed and backfilled with clean soil following verification of clean up goals. The dieldrin contaminated soil was transported to a temporary treatment facility constructed near the former base landfill to undergo bioremediation.

1998 - 2004

OU-3 primary concern was the FT-02. Bioventing utilized at the site did not attain residential cleanup levels. The USAF disagreed with the regulatory agencies’ (ADEQ and EPA) determination that a Declaration of Environmental Use Restrictions (DEUR) was required for the site. Changes (November 2004) in the USAFs policy regarding acceptable risk and reliance on a 1998 USAF “receptor evaluation” (risk assessment) led to a USAF decision that the site was suitable for unrestricted use.

2004 - 2005

OU-2 addressed groundwater and soil contamination at site ST-12. The USAF and subcontractors completed design of the groundwater and vadose zone remedies. The vadose zone remedy consisted of a full-scale soil vapor extraction (SVE) system. The SVE system began operation in April 2005. The groundwater remedy consisted of a process called Thermal Enhanced Extraction (TEE). As of December 2004 the construction was 90% complete. However, the USAF decided to withdraw the funding for completion of construction and operation of the TEE system. The USAF notified the regulators of the funding withdrawal in February 2005. At that time the USAF had already spent approximately $3,000,000 in the design and construction of the TEE system. EPA and ADEQ issued a formal letter of dispute regarding USAF's failure to implement the remedial action at site ST-12.

2006

OU-1 contains LF-04. Over the past two years numerous monitor wells had shown a marked increase in trichloroethylene (TCE) and tetrachloroethylene (PCE). Contaminants appeared to be moving off-site.

2007

The first phase (soil vapor investigation) of the RI to find the source and extent of VOC's in the groundwater at LF004 was begun. Additionally, three off-site borings were drilled and groundwater samples collected to determine where off-site groundwater monitor wells may be needed.

In November, the dieldrin-contaminated soil from the Old Pesticide/Paint Shop (SS-17) was removed northeast of the  LF004 following an unsuccessful attempt at bioremediation. A total of approximately 6,000 cubic yards of contaminated soil and amendments were removed from the site and disposed of under an approved work plan. Following removal of the contaminated soil and amendments, confirmation sampling of the underlying soil indicated five “hot spots” where additional soil removal is required.

SVE continued to remove JP-4 from the vadose zone at ST012. Construction continued on the TEE pilot project, which was designed to remove the fuel from the groundwater.

The Building 760 site, the site of gasoline releases from the former base service station, was being redeveloped by ASU East. Five groundwater monitor wells were abandoned to make way for building construction. The USAF proposed replacement of the monitor wells, as well as installation of SVE wells and construction of a soil vapor treatment system. [Note: ADEQ’s Underground Storage Tank Program (UST) assumed oversight of this project.] DEURs were completed for site SS021, Facility 1013 (a leaking UST [LUST] site).

2008

The schedule for the RI to find the source and extent of VOCs in the groundwater at LF004 was extended. The USAF completed the soil vapor investigation fieldwork. TCE found in soil gas samples and increasing concentrations of TCE in one groundwater monitor well caused the USAF to expand the investigation in the area northeast of the landfill and delay submittal of the RI report. Additional borings to sample deep soil and groundwater were planned. A peer review committee was assembled by the USAF to review the work to date and plans for additional investigation of the site, and to advise the USAF and its contractor regarding data gaps, locations for additional groundwater monitor wells, and potential remedial technologies. Four new monitor wells were installed at the site.

SVE to remove JP-4 from the vadose zone continued at the ST012. The TEE pilot project, designed to remove the fuel and fuel components from the groundwater, began operation. Steam injection into the lower saturated zone (the deeper of two water bearing units that are to undergo treatment) began on October 28th, (with steam injection into the upper water bearing zone scheduled to occur approximately two weeks later). The project is scheduled to last approximately one year. Six new groundwater monitor wells were installed at the site.

The DEURs were completed for sites FT002, ST012, and SS020 to facilitate dispersal of the property to the Gateway Airport.

2009

Base-wide activities included publishing an update to the Base-wide Sampling and Analysis Plan and a Base-wide Waste Management Plan, and recording a DEUR on site SS016 (Bldg 1085) to complete the ROD requirements. The transfer of SS016 to the Phoenix-Mesa Gateway Airport was completed.

The USAF performed the following activities:

Conducted and reported semi-annual groundwater monitoring in accordance with the RODConducted significant landfill maintenanceConducted a final field effort to supplement the RI, where one area was found to have a surface soil to groundwater contamination connectionInstalled 31 new groundwater monitor wells at Site LF004Produced a site LF004 Groundwater Monitoring Work PlanConducted a bench scale ozone sparging testConducted operations at site ST012 performing Steps 2 through 5 of the TEE Work PlanCollected post TEE application samples following test operationsConducted and reported four quarters of groundwater monitoringProduced a site ST012 Groundwater Monitoring Work PlanConducted and reported annual groundwater monitoring at site SS017Produced a site SS017 Groundwater Monitoring Work PlanFinalized a work plan to conduct step-out excavations at the temporary treatment facility and awarded a contract to conduct the step-out excavationsPublished the Parcel N Debris Area preliminary assessment/site inspection (PA/SI) work plan and initiated work on itCompleted installation of a fence around Parcel NPublished a final Interim Parcel N PA reportAwarded a contract to complete the Parcel N Debris Area PA/SIConducted and reported four quarters of groundwater monitoring at site ST035Produced a site ST035 Groundwater Monitoring Work PlanInstalled five new groundwater monitor wellsCompleted installation of an SVE systemDiscarded military munitions

2010

Efforts at the former WAFB progressed on many fronts:

The completion of a Supplemental RI report for LF004 that included a draft Focused Feasibility Study.Parcel N underwent an investigation searching for munitions constituents as well as sampling and testing at selected locations for CERCLA contaminants. A more detailed investigation is planned for a section of Parcel N that has been identified as one of great concern and is scheduled for 2011.A report evaluating the pilot test of the TEE system at ST012 was submitted for review. The SVE system continues to remove contaminants from soils below the former fuel storage area;A pilot SVE system was constructed at the site of the former automobile gas station. The system was designed and constructed to blend into the surrounding ASU campus and its operation to be non obtrusive.The USAF completed a program to replace groundwater monitor wells that have become submerged by rising groundwater. Additional wells to monitor the different groundwater formations at the site were also set in the various hydrographic layers. New wells were also installed to delineate groundwater contamination.Groundwater monitoring at the site continues to be conducted to evaluate the remedial effort.

2011

The USAF performed the following activities:

Hired AMEC Corporation as their performance-based remediation (PBR) contractor.Performed routine groundwater monitoring, inspections, and operation and maintenance of remedial systemsCompleted work plans, groundwater monitoring reports, operation and maintenance (performance) reports, and inspection reports, as requiredCompleted installation of groundwater monitor wells at sites ST035 and LF004, and abandonment of wells at site FT002Finalized the OU-6 removal action completion reportFinalized the site ST012 containment study work planHeld a public meeting and completed the OU-6 amended proposed plan

2012

The USAF performed the following activities:

Performed routine groundwater monitoring, inspections, and operation and maintenance of remedial systemsCompleted Work Plans, groundwater monitoring reports, operation and maintenance (performance) reports, and inspection reports, as requiredInstalled five off-base groundwater monitor wells south of the landfill site (LF004) to monitor for possible off-site migration of contaminationCompleted a Five Year Review (FYR)Began operation of the site ST012 groundwater containment system, an interim remedial action designed to operate until the full scale Steam Enhanced Extraction system is designed and constructedCompleted a new base-wide Quality Assurance Project Plan and standard operating proceduresPerformed and reported on the final site inspection and munitions and explosives of concern clearance (Phase 3) munitions response at the site XU403aCompleted a Finding of Suitability to Transfer (FOST) for the Air Force Research Laboratory (AFRL), Mesa Research SiteCompleted the final in-well air stripping and monitor well installation work plan for site ST035 and installed one remediation well and two groundwater monitor wells

2013

The USAF completed several items during this period:

LF004 (OU1)

A draft ROD Amendment for Operable Unit 1.Well installation as part of Pre-Design Investigation field activitiesAnnual and period specific groundwater monitoring reportsA Technical Memorandum for the April 2013 Cap MaintenanceAn Annual Landfill Inspection Report dated October 10 2012An Amended Proposed Plan for Operable Unit 1, Landfill 004A Focused Feasibility Study for Site LF004.An LF004 Off-site Well Inspection and Sampling Report

ST012 (OUs=2)

A Focused Feasibility Study for OU-2 remedial alternativesA draft Remedial Design and Remedial Action Work PlanA ROD Amendment 2 for OU-2 groundwaterDocuments discussing select groundwater well installations/modificationsA report detailing amendments added to the ST012 groundwater treatment systemAnnual and period specific groundwater monitoring reportsAnnual and period specific groundwater containment system reportsAnnual and period specific SVE system operation and result reportsA memorandum documenting research on potential contamination encountered during previous construction work in Avoca Street near Site ST012

FT02 (OU3)

One annual Site FT02 DEUR report was submittedThe USAF initiated a program to systematically sample its active and closed bases for perfluorinated compounds (PFC's) at fire training areas as the unregulated chemicals gained increasing regulatory attention for their potential risks to human health and the environment.

SDV (OU4)

Two semi-annual Protective Cap Inspection Reports were released (dated Sept. 19, 2012 and Jan. 3, 2013).

OU6

A Revised OU-6 Removal Action Completion Report (RACR).

SS017 (OU6)

Continued groundwater monitoringA Groundwater Monitoring Report for the 2012 Annual EventA draft Supplemental Risk Assessment for soil removal action

ST035

One groundwater monitoring well (MW-21) installation notificationSelect well modification notificationsAnnual and period specific groundwater monitoring reportsAnnual and period specific SVE system operation and result reports

Facility 1013

One annual Facility 1013 DEUR report was submitted.

Site Wide and Miscellaneous Areas

A Site Characterization and Corrective Action Completion report was submitted for UST closure actions completed at the Base’s navigation beacon facilityA site-wide Groundwater Monitoring Report for August 2012

2014

The USAF completed several items during this period:

LF004 (OU1)

Initiated a site remedy consisting of SVE, in-well air stripping (IWAS) and chemical oxidationLandfill cover inspections and maintenanceLandfill cover drainage pattern maintenance and cover erosion control maintenanceAnnual and period specific groundwater monitoring reportsFinal Annual 2013 Groundwater Monitoring ReportRemedial Design and Remedial Action Work Plan for Operable Unit 1 Groundwater and Soil Gas RemediesAnnual Landfill Cap Inspection and Maintenance Report, September and November 2013 EventsPre-Design Oxidant Test Work Plan (Addendum 1 to the Final Pre-Design Investigation Work Plan, Site LF004)Final ROD Amendment, Operable Unit 1Technical Memorandum on LF004 Groundwater Monitoring Program OptimizationGroundwater Monitoring Report, May 2013 EventAmended Proposed Plan for Operable Unit 1, Landfill 004An off-site well inspection and sampling reportSelect well modification notifications

Parcel N Debris Area (XU403a) (OU1)

Excavation, investigation and removal of:

Unexploded ordnance (UXO)Discarded military munitions (DMM)Munitions constituents (MC)Empty chemical weapons (mustard gas oil) training sample vials

(ST012 OU2)

Installed and initiated a Steam Enhanced Extraction SystemRemedial Design and Remedial Action Work Plan for Operable Unit 2 Revised Groundwater RemedySVE System Operation and Maintenance Report, July through September 2013SVE System Operation and Maintenance Report, April through June 2013SVE System Operation and Maintenance Report, January through March 2013Containment System Status and Shutdown Report, July through October 2013Containment System Status Report, April through June 20132012 Annual Containment System Status Report,Containment System Status Report, January through March 2013Declaration of Environmental Use Restriction (DEUR) for Site ST012 for 2013Annual 2012 Groundwater Monitoring ReportSVE System Operation and Maintenance 2012 Annual Performance ReportSVE System Operations and Maintenance, July through September 2012ROD Amendment 2, Groundwater, Operable Unit 2Select well modification notifications

FT02 (OU3)

Installed and re-initiated an SVE system.

SDV (OU4)

Released Semi-annual Protective Cap Inspection Report conducted July 15, 2014Released Semi-annual Protective Cap Inspection Report conducted January 21, 2014Released Semi-annual Protective Cap Inspection Report conducted August 9, 2013

SS17 (and OU6)

Continued groundwater monitoringGroundwater Monitoring Report, 2013 Annual EventGroundwater Monitoring Report, 2012 Annual EventA final supplemental risk assessment relating to the Old Pesticide/Paint Shop soil removal action

ST035

Annual and period specific groundwater monitoring reports.Annual and period specific SVE system operation and result reports.Groundwater Monitoring Report August 2013 EventAnnual 2013 Groundwater Monitoring ReportGroundwater Monitoring Report August 2013 EventGroundwater Monitoring Report, May 2013 EventGroundwater Monitoring Report, February 2013 EventAnnual 2012 Groundwater Monitoring ReportField Variance Memorandum regarding Monitor Well InstallationSVE System Operation and Maintenance Report, July through September 2013SVE System Operation and Maintenance Report, April through June 2013SVE System Operation and Maintenance January through March 2013SVE System Operation and Maintenance 2012 Annual Performance ReportSVE System Operation and Maintenance, July through September 2012SVE System Operation and Maintenance, April through June 2012

Site-Wide and Miscellaneous Areas

A site-wide Groundwater Monitoring Report for August 2013

2015

The USAF completed several items during this period:

LF004 (OU1)

Continued a site remedy consisting of SVE, IWAS and chemical oxidationContinued landfill cover inspections and maintenanceContinued landfill cover drainage pattern maintenance and cover erosion control maintenanceContinued annual and period specific groundwater monitoring reportsConstruction Completion/Start up Report for Operable Unit 1, Groundwater and Soil Gas RemediesAnnual Landfill Inspection and Maintenance Report, September and October 2014Groundwater Monitoring Report, May 2014 Event

Parcel N Debris Area (XU403a) (OU1)

Continued evaluating prior findings

ST012 (OU2)

Continued steam enhanced extraction systemSVE System Operation and Maintenance Report, July through September 2014SVE System Operation and Maintenance Report, April through June 2014SVE System Operation and Maintenance Report, January through March 2014Annual 2013 Groundwater Monitoring ReportSVE System Operation and Maintenance 2013 Annual Performance ReportConstruction Completion/Start up Report for Operable Unit 2, Revised Groundwater RemedyRevision No. 2 to SVE Operations Maintenance and Monitoring Manual, Post Steam Enhanced Extraction Installation

FT02 (OU3)

Remediation Construction Complete and Start Up ReportContinued SVE system

SDV (OU4)

Semi-annual Protective Cap Inspection Reports, conducted July and January

SS017 (and OU6)

Submission of Responses to Comments and Revised Draft Final Amended Proposed Plan for Operable Unit 6 Continued groundwater monitoringGroundwater Monitoring Report, 2014 Annual Event

ST035

Continued groundwater monitoring reports.Groundwater Monitoring Report August 2014 Event, Bldg. 760, UST 0-005338, LUST 0293.09 AND .10Final Groundwater Monitoring Report, May 2014 Event

Facility 1013

Closure Report for Building 1013; UST 0-005338, LUST 293.18

Site-wide and Miscellaneous areas

A site wide Groundwater Monitoring ReportPerfluorinated Compounds Preliminary Assessment, former AFRL, Mesa, AZ

2016

The USAF completed several items during this period:

LF004 (OU1)

Continued site remedy monitoringContinued landfill cover inspections and maintenanceContinued annual and period specific groundwater monitoring reportsRemedial Action Quarterly Status Report, July Thru September 2015, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, April Thru June 2015, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, Jan. Thru Mar. 2015, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, Startup Thru Dec. 2014, for Operable Unit 1, Groundwater and Soil Gas RemediesAnnual Landfill Cap Inspection and Maintenance Report, September, October, and December 2015 Events

Parcel N Debris Area (XU403a) (OU1)

Site Inspection Report, Chemical Warfare Materiel, and Munitions and Explosives of Concern, Munitions Response Sites XU403A and XU403B

ST012 (OU2)

Continued Steam Enhanced Extraction systemSVE Systems/Steam Enhanced Extraction System, Operation and Maintenance, 2015 Third Quarter Performance ReportSVE Systems/Steam Enhanced Extraction System, Operation and Maintenance, 2015 Second Quarter Performance ReportSVE Systems/Steam Enhanced Extraction System, Operation and Maintenance, 2015 First Quarter Performance ReportSVE System/Steam Enhanced Extraction System, Operation and Maintenance, 2014 Annual Performance ReportAnnual 2014 Groundwater Monitoring ReportSubmission of Final Field Variance Memorandum #4 – Extraction and Treatment System ConstructionSubmission of Final Field Variance Memorandum #5 – Extraction and Treatment System Construction

FT02 (OU3)

Continued SVE systemSVE System, Operation and Maintenance Report, November 2014 Thru June 2015, Fire Protection Training AreaSVE System, Operation and Maintenance Report, Aug. Thru Oct. 2014, Fire Protection Training Area

SDV (OU4)

Semi-annual Protective Cap Inspection Reports, conducted July and January

SS017 (and OU6)

Continued groundwater monitoringGroundwater Monitoring Report, 2015 Annual Event

ST035

Continued groundwater monitoring reports.Groundwater Monitoring Report, February 2015 Event, Bldg. 760, ADEQ LUST File No. 0293-09 AND 0293-10, ADEQ Facility ID # 0-005338,Annual 2014 Groundwater Monitoring Report, UST 0-005338 LUST 0293.09 AND .10 – Bldg. 760

Site wide and Miscellaneous areas

A site wide groundwater monitoring reportPerfluorinated Compounds Preliminary Assessment, Former WAFB, Mesa, AZ

2017

The USAF completed several items during this period:

LF004 (OU1)

Continued site remedy monitoringContinued landfill cover inspections and maintenanceContinued annual and period specific groundwater monitoring reportsOperating Properly and Successfully Demonstration, for Operable Unit 1, Groundwater and Soil Gas Remedial ActionRemedial Action Quarterly Status Report, April Thru June 2016, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, January Thru March 2016, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, Oct. Thru Dec. 2015, And 2015 Annual Summary Report, for Operable Unit 1, Groundwater and Soil Gas RemediesAnnual Landfill Cap Inspection and Maintenance Report, September and October 2016 Events

Parcel N Debris Area (XU403a) (OU1)

Continue evaluation for steps forward

ST012 (OU2)

Continued extraction, containment, and monitoringAnnual 2015 Groundwater Monitoring ReportSubmission of Final Field Variance Memorandum #5A – Extraction and Treatment System Construction

FT02 (OU3)

Remedial Action Completion Report, Fire Protection Training

SDV (OU4)

Semi-annual Protective Cap Inspection Reports, conducted July and January

SS017 (and OU6)

Continued groundwater monitoring, Groundwater Monitoring Report, 2016 Annual Event

ST035

Continued groundwater monitoringCorrective Action Completion Report Under AAC R18-12- 26, ADEQ LUST File No. 0293-09 and 0293-10, ADEQ Facility ID # 0-005338, (Bldg. 760)Annual 2015 Groundwater Monitoring Report, ADEQ LUST File No. 0293-09 and 0293-10, ADEQ Facility ID # 0-005338, (Bldg. 760)

Site wide and Miscellaneous areas

A site wide groundwater monitoring reportQuality Program Plan For Site Inspection of Potential Perfluorinated Compound Release Areas At Multiple Base Realignment and Closure (BRAC) InstallationsFourth Five Year Review Report

2018

The USAF completed several items during this period:

LF004 (OU1)

Continued site remedy monitoringContinued landfill cover inspections and maintenanceContinued annual and period specific groundwater monitoring reportsRemedial Action Quarterly Status Report, January Thru March 2017, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, July Through September 2016, for Operable Unit 1, Groundwater and Soil Gas RemediesAnnual Landfill Cap Inspection and Maintenance Report, September and October 2017 Events

Parcel N Debris Area (XU403a) (OU1)

Continue evaluation for steps forwardSite Inspection Addendum Letter Report, Chemical Warfare Materiel, and Munitions and Explosives of Concern, Munitions Response Sites XU403A and XU403B

ST012 (OU2)

Continued extraction, containment, and monitoringPilot Study Implementation Work Plan For Operable Unit 2, Revised Groundwater RemedyAppendix F & Appendix H - Pilot Study Implementation Work Plan For Operable Unit 2, Revised Groundwater RemedySVE Systems/Steam Enhanced Extraction System, Operation and Maintenance, 2016 Third Quarter Performance ReportSVE Systems/Steam Enhanced Extraction System, Operation and Maintenance, 2016 Second Quarter Performance ReportSVE Systems/Steam Enhanced Extraction System, Operation and Maintenance, 2016 First Quarter Performance ReportSVE Systems/Steam Enhanced Extraction System, Operation and Maintenance, 2015 Fourth Quarter Performance Report

FT02 (OU3)

Remedial Action Completion Report, Fire Protection Training Area

SDV (OU4)

Semi-annual Protective Cap Inspection Reports, conducted July and January

SS017 (and OU6)

Continued groundwater monitoring ROD For Operable Unit 6 (OU6)Field Variance Memorandum #1 – Quarterly Groundwater Monitoring – Groundwater Sampling Work Plan for Quarterly MonitoringGroundwater Monitoring Data Summary Report, January 2018Groundwater Monitoring Data Summary Report, October 2017

ST035

Undergoing post-closure administration

Site wide and Miscellaneous areas

A site wide groundwater potentiometric surface mapInstallation Specific Uniform Federal Policy Quality Assurance Project Plan Addendum, Former WAFB, Site Inspection of Potential Perfluorinated Compound Release Areas At Multiple BRAC Installations

2019

The USAF completed several items during this period:

LF004 (OU1)

Continued site remedy monitoringContinued landfill cover inspections and maintenanceContinued annual and period specific groundwater monitoring reportsRemedial Action Quarterly Status Report, July Through September 2017, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, April Through June 2017, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, January Through March 2017, for Operable Unit 1, Groundwater and Soil Gas RemediesRemedial Action Quarterly Status Report, October Through December 2016, for Operable Unit 1, Groundwater and Soil Gas Remedies

Parcel N Debris Area (XU403a) (OU1)

Continue evaluation for steps forwardSite Inspection Addendum Letter Report, Chemical Warfare Materiel, and Munitions and Explosives of Concern, Munitions Response Sites XU403A and XU403B

ST012 (OU2)

Continued extraction, containment, and monitoringSVE System and Other Activities, 2017 First and Second Quarter Performance ReportSVE System, Operation and Maintenance, 2016 Annual Performance Report, Volume 1 of 2SVE System, Operation and Maintenance, 2016 Annual Performance Report, Volume 2 of 2Annual 2016 Groundwater Monitoring Report

FT02 (OU3)

Revised Final - Remedial Action Completion Report, Fire Protection Training Area

SDV (OU4)

Semi-annual Protective Cap Inspection Reports, conducted July and January

SS017 (and OU6)

Continued groundwater monitoringGroundwater Monitoring Data Summary Report, May 2018, Revision 1.0Revised Final - Groundwater Monitoring Data Summary Report, January 2018

ST035

Post-closure administration

Site wide and Miscellaneous areas

A site wide groundwater potentiometric surface map

2020

The USAF completed several items during this period:

LF004 (OU1)

Continued site remedy monitoringContinued landfill cover inspections and maintenanceContinued annual and period specific groundwater monitoring reportsAnnual Landfill Cap Inspection and Maintenance Report, September and October 2018 Events

Parcel N Debris Area (XU403a) (OU1)

Continue evaluation for steps forward

ST012 (OU2)

Continued extraction, containment, and monitoring

FT02 (OU3)

Pending Site Closure

SDV (OU4)

Semi-annual Protective Cap Inspection Reports, conducted July and January

SS017 (and OU6)

Continued groundwater monitoringSS017 - FINAL – Final Field Variance Memorandum #2 – Groundwater Monitoring

ST035

Technical Memorandum, Post-Closure Activities, ADEQ LUST File No. 0293-09 & 0293-10, ADEQ Facility ID #0-005338

Site wide and Miscellaneous areas

A site wide groundwater potentiometric surface map