DSHW-2023-207758

Module IX 1 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
MODULE IX – SWMU 58 CORRECTIVE MEASURES PROGRAM
IX.A. REQUIRED PROGRAM
IX.A.1. The Permittee shall maintain a Corrective Measures Program (CMP) for Solid
Waste Management Unit (SWMU) 58 in accordance with Utah Admin. Code
R315-264-101 and this Permit. The elements comprising SWMU 58 are outlined
in Condition X.C. In accordance with the purpose of the CMP, the Permittee
shall treat groundwater contaminants in the SWMU 58 plume and treat residual
soil contamination within the vadose zone beneath source areas located in
SWMUs that have previously undergone corrective measures and are in
post-closure care, as outlined in Condition X.D.3. The CMP shall comply with
the requirements of R315-264-101, and this Permit.
IX.A.2. The overall management strategies for the SWMU 58 CMP are specified in the
Corrective Measures Implementation Plan (CMIP) for Soils (2010), Addendum 1
to the CMIP for Soils (2012), and the CMIP for Groundwater (2014), hereafter
referred to as the CMIPs (2010, 2012, 2014). The Permittee shall conduct
corrective measures in accordance with the CMIPs (2010, 2012, 2014) and the
following four primary elements to ensure the protection of human health and the
environment:
IX.A.2.a. Implementation of the Updated Groundwater Management Area (GWMA)
Plan (2022) and Institutional Controls to prevent current and future human
and ecological exposure to contaminated groundwater.
IX.A.2.b. Source area corrective measures that will reduce the potential for
downgradient migration of contaminants and prevent further degradation of
groundwater. These corrective measures include soil vapor extraction and air
sparging to remove high concentrations of volatile contaminants from
groundwater and the vadose zone.
IX.A.2.c. Monitored natural attenuation (MNA) of low contaminant concentrations in
the diffuse portion of the plume, through both physical and biological
processes; and
IX.A.2.d. Implementation of the contingency plans presented in the Updated GWMA
Plan (2022), the Corrective Measures Study (CMS) Report (2012), and the
CMIP for Groundwater (2014).
IX.A.2.e. As necessary, the Permittee shall prepare and implement additional plans, or
updates to the existing plans, per the requirements of Condition VII.C.2, to
address unforeseen changes, such as contamination migrating faster than
expected to potential receptor wells.

Module IX 2 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
IX.B. SELECTED CORRECTIVE MEASURES FOR SWMU 58
IX.B.1. The Permittee shall conduct the corrective measures for the SWMU 58
groundwater plume as specified in the approved CMIPs (2010, 2012, 2014),
which are divided into two parts: Corrective measures for the source area portion
of the plume, and corrective measures for the diffuse portion of the plume.
IX.B.1.a. All decision documents will follow the public participation process in
accordance with Utah Admin. Code R315-124.
IX.C. CORRECTIVE MEASURES
IX.C.1. The Permittee shall maintain institutional controls that prohibit further
development of contaminated groundwater within the TEAD-N GWMA,
including the on-Depot portions of the plume, the BRAC Property, and off-Depot
portions of the plume, as outlined in the Updated GWMA Plan (2022) and in
accordance with the requirements of Condition VIII.C.5
IX.C.2. The Permittee shall implement soil vapor extraction at each of the source areas in
accordance with the requirements of the CMIP for Soils (2010) and Addendum 1
to the CMIP for Soils (2012) to reduce contaminant concentrations in the vadose
zone until there is no longer any Trichloroethene (TCE), Perchloroethylene
(PCE), or Carbon tetrachloride (CTC) migration to groundwater.
IX.C.2.a. Additionally, the Permittee shall continue to operate soil vapor extraction at
the C-Avenue Outfall in accordance with the requirements of the CMIP for
Soils (2010) and Addendum 1 to the CMIP for Soils (2012) until the risks to
future industrial indoor workers associated with vapor intrusion from soil gas
meet Utah Admin. Code R315-101 standards and approval for discontinuing
treatment is approved by the Director of the Division of Waste Management
and Radiation Control (Director).
IX.C.3. The Permittee shall implement air sparging at each of the source areas in
conjunction with the soil vapor extraction systems, to reduce contaminant
concentrations in groundwater, in accordance with the requirements of the CMIP
for Groundwater (2014). Reducing the mass of VOCs in the groundwater source
areas will reduce the migration of VOCs from the source areas to the diffuse
portion of the groundwater plume.
IX.C.4. Requirements for system installation work plans, construction reports, and
operation and maintenance (O&M) plans for the soil vapor extraction and air
sparging systems are outlined in the CMIPs (2010, 2012, 2014).
IX.C.5. Soil vapor extraction and air sparging system installation work plans, construction
reports, and O&M plans shall be maintained in the Operating Record per the
requirements of Condition VII.C.5.

Module IX 3 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
IX.D. DIFFUSE AREA CORRECTIVE MEASURES
IX.D.1. Institutional Controls that prohibit further development (i.e., withdrawal) of
impacted groundwater within the GWMA, including the on-Depot portions of the
plume, the BRAC Property, and off-Depot portions of the plume, are outlined in
the Updated GWMA Plan (2022), and shall be maintained in accordance with the
requirements of Module VIII.
IX.D.2. Every five years, the Permittee shall evaluate and reassess the effectiveness of
natural attenuation of TCE as a corrective measure for the diffuse plume. The
Permittee shall incorporate key findings of the effectiveness of monitored natural
attenuation evaluations into the groundwater model.
IX.D.3. In the event that monitored natural attenuation or source area remediation is
ineffective at maintaining plume stability, and the diffuse plume migrates further
downgradient, approaching or moving beyond the GWMA boundary, the
Permittee shall evaluate the impacts to human health and the environment and
implement the contingency actions requirements in Condition IX.E.
IX.D.3.a. These contingencies, if needed, may be implemented either individually or in
combination, depending on the current corrective measures program.
IX.E. CONTINGENCY ACTIONS
IX.E.1. The Permittee shall perform contingency actions if TCE is reported and
confirmed at concentrations equal to or exceeding 1 µg/L and 5 µg/L in
groundwater collected from a sentinel well, per Condition X., or if a receptor well
is impacted.
IX.E.1.a. The first time the concentration of TCE in a sentinel well equals or exceeds
1 µg/L, the Permittee shall notify the Director in writing within 7 days and the
Permittee shall continue to monitor the impacted well.
IX.E.1.b. Should the concentration of TCE in a sentinel well exceed 5 µg/L, the
following steps will be taken:
IX.E.1.b.i. The Permittee shall notify the Director in writing within 7 days that each
specified well exceeded 5 µg/L TCE. Within 14 days of receiving the
original analytical results, the Permittee shall collect a confirmation
sample from each well;
IX.E.1.b.ii. Within 30 days of receiving the original analytical results documenting an
exceedance, the Permittee shall perform a receptor survey; and
IX.E.1.b.iii. In accordance with the Condition X.E., the Permittee shall install new
downgradient sentinel well(s).

Module IX 4 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
IX.E.2. Contingency A – Based on the results of the receptor survey, the Permittee may
be required to immediately supply water to at-risk receptors. If a downgradient
receptor is impacted, the Permittee shall implement the appropriate water supply
option as specified in Sections 4.6 and 4.7 of the GWMA Plan (2022).
IX.E.3. Contingency B – The Permittee shall implement air sparging at each groundwater
monitoring well where the TCE exceedance occurred, and the Permittee shall
develop a groundwater sampling plan as specified in Section 4.3.2 of the CMIP
for Groundwater (2014). An evaluation shall also be completed to determine if
additional steps need to be taken to protect downgradient receptors.
IX.E.4. Contingency C – Should TCE concentrations exceed 5 µg/L in one or more of the
sentinel wells, and Contingency B is deemed ineffective at addressing the risk, the
Permittee shall evaluate active remediation technologies and shall choose the
technology or a combination of technologies, based on what is most feasible and
effective for the location where remediation of the TCE exceedance is needed.
Upon approval of a remedial technology by the Director, the Permittee shall
conduct the approved remediation method over a broad area of the plume
boundary where downgradient receptor(s) are at risk.
IX.E.4.a. The Permittee shall prepare and submit for written Director approval a
workplan to address the risk to downgradient receptors from the TCE
exceedance, in accordance with the requirements in Section 4.3.3 of the CMIP
for Groundwater (2014). In preparing the workplan, the Permittee shall
coordinate with stakeholders.
IX.E.5. Contingency D – Should natural attenuation and/or source remediation prove
ineffective at controlling the TCE plume, even if downgradient receptors are not
at risk, the Permittee shall directly remediate TCE “hot spots” within the plume
(i.e., non-source areas with TCE concentrations greater than 50 µg/L).
IX.F. CORRECTIVE MEASURES COMPLETION CRITERIA
IX.F.1. The Permittee shall prepare a Corrective Measures Completion Report when the
Permittee believes that the approved corrective measures completion criteria or
the groundwater protection standards or approved alternate concentration limits in
accordance with Condition IX.J. have been achieved. The purpose of the
Corrective Measures Completion Report is to fully document how the Corrective
Measures completion criteria have been met and to justify why the Corrective
Measures or groundwater monitoring may cease, or both.

Module IX 5 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
IX.F.1.a. When TCE concentrations and other contaminants pose a minimal threat to
human health and the environment, the Permittee may petition the Director to
cease corrective measures and approve clean closure status of SWMU 58.
Upon written approval from the Director, the Permittee shall update the
Permit in accordance with Condition VII.I.2.a.
IX.F.1.b. The Permittee may petition the Director to cease source area corrective
measures when the Permittee can demonstrate corrective measure
ineffectiveness. If remaining TCE concentrations or other contaminants in the
source area pose a threat to human health or the environment, the Permittee
shall submit a Site Management Plan and implement monitored natural
attenuation in the source areas and continue monitoring per the requirements
of the SWMU 58 groundwater monitoring plan, in accordance with the
requirements of Condition X.C.
IX.G. OPERATION OF SOIL VAPOR EXTRACTION AND AIR SPARGING
REMEDIATION SYSTEMS
IX.G.1. The Permittee shall maintain and operate the source area soil vapor extraction and
air sparging remediation systems as specified in CMIPs (2010, 2012, 2014),
Operations, Maintenance and Monitoring (OM&M) Work Plans for each system
(2014), and this Permit.
IX.G.2. The Permittee shall maintain a remote alarm system, or equivalent, for each of the
remediation systems. This alarm system shall be capable of remediation system
shutdown in the event of a malfunction that could impair the performance of the
remediation system or threaten human health or the environment.
IX.G.3. The Permittee shall operate the source area remediation systems in a manner that
will prevent spills, releases, or other adverse effects to human health and the
environment.
IX.G.4. The Permittee shall train all personnel operating the remediation systems as
outlined in Condition II.U.
IX.G.5. The Permittee shall operate the source area soil vapor extraction and air sparging
remediation systems eight months per year (April through November), weather
permitting, as specified in the CMIPs (2010, 2012, 2014), followed by a period of
rebound monitoring as described below.

Module IX 6 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
IX.G.5.a. The Permittee shall monitor the rebound in contaminant concentrations in soil
vapor and groundwater in accordance with Condition IX.H during
nonoperational months (December through March).
IX.G.5.b. The Permittee shall notify the Director in writing 10 days in advance of soil
vapor extraction/air sparging remediation system startup and shall provide a
schedule of upcoming soil vapor extraction/air sparging operations.
IX.G.6. The Permittee shall maintain a current Operation, Maintenance and Monitoring
(OM&M) Manual for each remediation system, which specifies routine and
non-routine system checks and maintenance, field work, management, and
recordkeeping activities to maximize system runtime.
IX.G.6.a. Soil vapor extraction OM&M activities shall include optimization of the soil
vapor extraction systems to support air sparging operations and to maximize
mass removal and/or zone of influence (ZOI), per the CMIPs (2010, 2012,
2014).
IX.H. PERFORMANCE EVALUATION OF CORRECTIVE MEASURES
IX.H.1. The Permittee shall conduct source area sampling to support the assessment of
corrective measures performance, including:
IX.H.1.a. Soil gas samples from soil vapor extraction wells, vapor monitoring wells, and
vertical soil gas wells as specified in Table 4.1 (Building 679) and Table 4.2
(C Avenue Outfall) of the CMIP for Soils (2010), and Table 5.1 (Building
615, Building 620, and Landfill) of Addendum 1 to the CMIP for Soils
(2012).
IX.H.1.b. Soil vapor extraction effluent sampling to confirm compliance with
Department of Air Quality (DAQ) de minimus exemption per Utah Admin.
Code R307-410-15 and R307-410-16.
IX.H.1.c. Groundwater samples from source area monitoring wells associated with each
air sparging system, as specified in Table 3.2 of the BRAC Property Soil
Vapor Extraction and Air Sparging OM&M Work Plan (2014) and Table 4.4
of the Former Sanitary Landfill Air Sparge Work Plan (2014).
IX.H.2. The Permittee shall submit to the Director annually, on or before September 15th
of each year, Performance Evaluation Reports for each of the source area soil
vapor extraction and air sparging remediation systems. Each report shall include,
at a minimum:
IX.H.2.a. Soil vapor extraction and air sparging system operating data and laboratory
analytical results of soil gas, system effluent, and groundwater samples

Module IX 7 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
collected per Condition IX.H.1 and the Groundwater Management Area
(GWMA) Plan;
IX.H.2.b. A summary of system maintenance and optimization, including any new soil
vapor extraction and air sparging wells installed;
IX.H.2.c. The zone of influence (ZOI) of each of the systems, as well as contaminant
removal rates and concentration reduction rates; and
IX.H.2.d. An evaluation of the advancement of each source area towards the Corrective
Action Objectives (CAOs) outlined in Condition IX.I., using, at a minimum,
the following analyses:
IX.H.2.d.i. Trend analyses of contaminant concentrations in groundwater;
IX.H.2.d.ii. Analysis of rebound contaminant concentrations in soil gas and
groundwater; and
IX.H.2.d.iii. Analysis of projected mass removal rates or concentration reduction rates
with continued remediation system operation during the next annual
period.
IX.H.2.e. Recommendations for optimization of future system operations.
IX.I. PERFORMANCE EVALUATION OF SWMU 58 CORRECTIVE
MEASURES PROGRAM
IX.I.1. The Permittee shall conduct the following required field activities to support
performance evaluation of the SWMU 58 Corrective Measures Program (CMP):
IX.I.1.a. Groundwater level measurements per Condition X.C.2.b.;
IX.I.1.b. Collection of groundwater samples from monitoring wells located throughout
SWMU 58, per Condition X.C.3; and
IX.I.1.c. Collection of groundwater samples from sentinel wells located beyond the toe
of the plume, per Condition X.C.3.a.iii.
IX.I.2. The Permittee shall submit to the Director, on or before April 15th of each year, an
Annual Groundwater Monitoring Report which shall include, at a minimum:
IX.I.2.a. A summary of the results of groundwater level measurements and
groundwater sampling;
IX.I.2.b. An assessment of groundwater flow rate and direction in the impacted
aquifers based on groundwater surface level measurements. An updated

Module IX 8 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
potentiometric map shall be created for the shallow, bedrock, and deep
aquifers;
IX.I.2.c. Groundwater contaminant trend analyses;
IX.I.2.d. Groundwater contaminant plume maps;
IX.I.2.e. The results of the annual monitoring well inspections conducted per the
requirements of Condition X.E.1.
IX.I.3. The Permittee shall submit to the Director, on or before October 15th every five
years, an update to the TEAD-N Groundwater Flow and Contaminant Transport
Model which shall include, at a minimum, the results of the model recalibration
and a summary analysis of the results.
IX.J. DURATION OF SWMU 58 CORRECTIVE ACTION PROGRAM
IX.J.1. The Permittee shall continue the groundwater corrective measures program for
SWMU 58 until such time as the Groundwater Protection Standard (GWPS) or
Alternate Concentration Limits established in accordance with Utah Admin. Code
R315-264-94(b) are not exceeded, as specified in Condition X.B through X.C.
and Utah Admin. Code R315-264-100(f), and R315-264-92. If the Permittee
believes the GWPS, alternate limits or approved Corrective Measures Criteria, in
accordance with Condition IX.F., have been attained, the Permittee shall prepare a
Corrective Measures Completion Report and submit it to the Director for written
approval. An appropriate statistical corrective action test, centering on confidence
intervals, shall be applied to groundwater monitoring results in accordance with
the USEPA Unified Guidance (2009 or current), or the ITRC Groundwater
Statistics and Monitoring Compliance Technical Guidance (2013 or current),
minimizing the false positive error rates to the extent possible.
IX.K. INSTALLATION RESTORATION WASTE MANAGEMENT
IX.K.1. In areas within the groundwater contaminant plume, the Permittee may generate
groundwater or process water contaminated with hazardous constituents from the
following processes: 1) development of newly constructed monitoring wells and
piezometers; 2) sampling of monitoring wells; and 3) condensate generated from
soil vapor extraction systems.
IX.K.2. Groundwater and process water contaminated with the hazardous constituents
listed in Table X-1 shall be characterized and, if deemed hazardous, disposed of
off-site at an approved hazardous waste treatment facility.
IX.L. REPORTING AND RECORDKEEPING
IX.L.1. The Permittee shall submit to the Director an annual Performance Evaluation
Report for each of the source area soil vapor extraction and air sparging

Module IX 9 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North
remediation systems. These reports shall be submitted, per Condition I.DD., no
later than September 15th of each year.
IX.L.2. The Permittee shall submit to the Director the analytical results required by
Conditions IX.H and IX.I., and the groundwater elevation data required by
Condition X.C., in accordance with the schedule outlined in Table IX-1.
Groundwater model updates, annual monitoring reports, potentiometric surface
maps, and contaminant concentration maps shall be submitted by October 15th of
the reporting year as required by IX.I.3.
IX.M. ASSURANCE OF COMPLIANCE
IX.M.1. The Permittee shall assure that monitoring and corrective action measures
necessary to achieve compliance with the groundwater protection standards are
taken during the term of the Permit.

Module IX 10 October 4, 2023
Groundwater Corrective Measures Program UT313820894
Tooele Army Depot – North

TABLE IX-1
SWMU 58 CORRECTIVE ACTION PROGRAM
REPORTING REQUIREMENTS AND SCHEDULE

REPORTING REQUIREMENT FREQUENCY
Soil vapor extraction/Air sparging Performance Evaluation
Reports (each system) Annual
Contaminant concentration maps of the impacted aquifer. Annual
Potentiometric surface maps of the impacted aquifer Annual
Results of groundwater flow and transport model
recalibration and a summary analysis of model findings. Every Five Years