DSHW-2024-004042

January 11, 2024
Erin Trinchitella, Director
Base Operations Directorate
Tooele Army Depot
JMTE-BON, Bldg. 501
1 Tooele Army Depot
Tooele, Utah 84074-5003
RE:Comments for the Draft Final Corrective Measures Implementation Plan
Solid Waste Management Units 1 and 25Tooele Army Depot – South Area
EPA ID UT5210090002
Dear Ms. Trinchitella:
The Division of Waste Management and Radiation Control has completed its review of theDraft Final Corrective Measures Implementation Plan for Solid Waste Management Units 1 and 25 that
was receivedSeptember 26, 202.
Based on our review the following questions and comments must be addressed:
A table should be added to the CMIP indicating which IDFs are included for each type of closure for Phase 1. Or, if available, add a reference to the location in the QAPP or attachments
where this is located.
In areas where runoff from IDFs drain into area with other IDFs (e.g. downgradient from the side of Mustard Mtn in SWMU 1), how will this runoff water be managed to avoid runoff and
ponding.
Is there a plan to define SWMUs 1 and 25 as areas of contamination (AOC)? This would enable movement and management of contaminated material within the IDFs? Specifically for Section
1.5.2 and 1.5.3.
Section 1.5.4. MNA – This section should also reference monitoring IAW the GMP.
Section 1.5.5. Please note that a Post Closure Plan for inclusion in Module VI of the RCRA part B permit modification will be required. What is the schedule for TEAD submitting this
plan (Class III permit modification)? Section 3.3.5 states Permittee will provide, but a schedule is necessary to insure inspections for IDFs upon completion of Phase 1.
p. 3-5, section 3.1.6, bullet 2. Subgrade and Protective Soil Layers.
Is a 2” maximum particle size too large to protect the GLC layers from puncture? Is there a need to review and restrict the angularity of the material, particularly if the maximum size
of particles is 2 inches? Typically, this material would be non-angular.
What is the minimum depth of subgrade/grading layer? In the supplied drawings there is no minimum specified? Since the Operations Layer can contain material up to 6” that has no restrictions
on angularity it seems that there should be a minimum subgrade/grading layer to prevent large angular material from the operations layer from coming into contact with the GCL liner system.
The Division will inspect the soils for use in these layers prior to their initial use and periodically throughout the project.
p. 3-6, section 3.1.8.1.
In areas where the slope of the cover is greater than 3% and up to 8% will a drainage geocomposite be implemented above the GCL liner to aid in draining the protective layer to prevent
slumping/sliding and erosion of the protective layer? Also, in the non-GCL covered IDFs, what will be the determining factors for inclusion of the rip-rap layer.
Section 3.2.5 – the monitoring well at 1-152 should be installed immediately downgradient of the IDF and, if possible, outside of SWMU 1. Also, in Figure 17-1, revise the figure to include
groundwater flow direction and potentiometric contours showing that the proposed location for the well at 1-152 is located in a downgradient location.
Section 3.3.1 – The final grading of the borrow area must ensure there will be no ponding water at the site.
Section 3.3.2 – the 100x100 grid system – will this grid use the grid system established during the surface stabilization work or will this be a new grid? If a new grid, a roadmap that
ties the surface stabilization grid to the RFI IDF numbers and to this new grid will be required.
p. 3-22, section 3.3.5. The “General Description of the facility” bullet is repeated.
QAPP WS#12. Table 12-1 – The overall precision for water for field duplicates is ≤30%. The DWMRC QAPP (A.7) specifies a limit of <20%. Discuss projects-specific requirements that
justify a higher level of non-precision. Table 12-2 - The overall precision for soil for field duplicates is ≤50%. The DWMRC QAPP (A.7) specifies a limit of <40%. Discuss projects-specific
requirements that justify a higher level of non-precision.
Section 17.1. The new well (at 1-152) is to be sampled for hexavalent chromium. Is total chromium also to be analyzed to assess if speciation is reflective of background or will 100%
of hexavalent chrome be attributed to the IDF?
QAPP WS#17. Confirmation data will be compared to the industrial RSLs. How will this be conducted? Using each point or will a representative EPC be calculated?
QAPP WS#17. How were the numbers of confirmation samples for the three IDFs determined? Justify the representativeness of the samples.
QAPP WS#18. Table 18.2 - The sampling depth for the confirmation samples for 1-172, 25-005, and 25-023 is listed as 0-1 ft bgs. The samples should reflect the surface of the removal
area, and be collected from the top 2 cm.
QAPP WS#19. Table 19-1 lists the holding time for hexavalent chrome as 28 days. The text in the footnote appears inconsistent with the text in WS#17, which indicates samples will be
collected in the afternoon and shipped overnight to the lab to minimize prep and extraction time. Clarify.
The State of Utah Lab certification for EMAX is expired. Please provide a current certification.
Appendix C. IDF 25-005, It is unclear what the final grading/elevations will be for this IDF. Please submit a drawing that shows this in detail.
Appendix D. 31 00 00 Earthwork, Sections 2.1.1, 2.1.2, 2.1.3 See the abovecomments (p. 3-5, section 3.1.6) relating to these sections of the of this specification. Modifications to section
3 may be required if changes are made to these specifications.
Appendix D. 31 05 19 Geosynthetic Clay Liner section 1.3, Definitions. E. “NSTALLER” please fix.
Appendix F. Is there a schedule for this appendix to be submitted?
If you have any questions, please call Brad Lauchnor at [phone].
Sincerely,
Paige Walton,Corrective Action Section Manager
Division of Waste Management and Radiation Control
PW/BML/

c:Jeff Coombs, Health Officer, Tooele County Health Department
Bryan Slade, Environmental Health Director, Tooele County Health DepartmentTyson Erickson, Environmental Protection Specialist, TEAD(email)
Keller Davis, Senior Project Manager, APTIM (email) [e-mail]
List email addresses next to the names of persons who are to receive a copy via email.