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ISE. UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

% pqo t '' REGION VII 726 MINNESOTA AVENUE

KANSAS CIPi', KANSAS 66101

[DEC 5 0 ; : ;3

Mr. Gary Schuster Vice President of Finance & Administration Dico, Inc. 200 S.W. 16th Street Des Moines, Iowa 50309

Re: Des Moines TCE Site

Dear Mr. Schuster:

This letter provides the U.S. Environmental Protection Agency's (EPA) initial comments on the two work plans entitled "Removal Action, Operable Unit No.4, Dico, Inc." and "Surface Remediation, Dico, Inc.," dated December 10 and 14, 1993 respectively, and submitted during our meeting on December 17, 1993. These and any other questions and comments which arise during further review of the plans will be discussed in our conference call on January 6, 1994. Find attached specific comments to the two work plans for building cleanup and surface remediation. This letter also reviews the general requirements for the conduct of a removal action at the site.

EPA agrees that certain removal actions are necessary at the site and in general will support additional action at the Dico facility as is proposed in the subject work plans. However, these actions must be selected and conducted in accordance with the National Contingency Plan, which includes a requirement that, to the extent practicable, removal actions contribute to the efficient performance of any anticipated long-term remedial action. EPA anticipates completion of the 0U2 remedial investigation/feasibility study (RI/FS) according to the current schedule and future completion of an RI/FS for 0U4 to resolve the necessary final action for both operable units. EPA's comments on the subject work plans, attached to this letter, consider these issues and requirements to promote consistency between the proposed and anticipated future response actions at the site.

Also, as we discussed in the December 17, 1993, meeting, the removal actions must be conducted pursuant to an administrative order issued by EPA. In anticipation of negotiating a consent agreement with Dico to conduct these activities, EPA is drafting an Administrative Order on Consent (AOC), which we hope to send you shortly subsequent to our conference call on January 6.

RECYCLE-.*

We have scheduled the conference call on January 6, 1994 at 10:30 a.m. to 12:00 p.m. Eastern time (EST), 9:30 to 11:00 a.m. Central time (CST). To enter the conference call dial (202) 260 4242, Should you have any questions regarding this letter or the attached information, contact me at (913) 551-7726.

Sincerely Yours

Glenn Curtis Remedial Section Superfund Branch Waste Management Division

cc Jerry Shanholtzer, Titan Wheel (w/ enclosure) Bob Drustrup, IDNR (w/ enclosure)

Comments to the Removal Action Work Plan

December 10, 1993

General comments:

1. The work plan must include a confirmation sampling program. It is recommended that the work plan include, at a minimum, the following component:

Aggressive air monitoring activities that will be conducted at the conclusion of the removal action activities and potentially periodically thereafter. The discussion should indicate the methods that will be used and how the results of the aggressive air monitoring will be used to assess the acceptability of the condition obtained and/or maintained by the removal action activities. In addition, all sampling activities must be conducted in accordance with an approved Quality Assurance Project Plan.

2. The work plan should include a detailed Operation and Maintenance (O&M) plan for the final (building) surface coverages proposed. The O&M plan should include, at a minimum, the following components:

A description of and schedule for periodic inspections of the final surface coverages and insulation materials to identify any conditions (e.g., cracking, spoiling, or deterioration due to wear, penetration of surfaces without repair, damaged/deteriorated insulation) that may unacceptably diminish the integrity of the surface coverage materials or insulation materials.

Repair and replacement methods that will be used to maintain the integrity of the surface coverage materials in the event of cracking, spoiling, deterioration due to wear, and intended/accidental surface penetration.

Specific Comments: 1

1. Section 1.0. First Paragraph. Last Sentence. The work plan should include a statement of qualifications regarding City Environmental Contracting, Inc. (CEC) or the consultant to be used in the completion of the response action presented in the work plan. At a minimum, the statiement should discuss representative experience with these types of removal action activities and indicate that CEC's personnel implementing the removal action will be trained and

medically monitored in accordance with OSHA regulations for hazardous waste site activities (29 CFR 1910.120).

Section 1.0. Second Paragraph. Last Sentence. References to "future activities" throughout this work plan must recognize that the proposed removal action achieves conditions that are acceptable for the ongoing (current) industrial use of the facility. It is understood that anticipated ongoing industrial use of the facility will involve only DICO product storage and distribution activities consistent with the site specific industrial exposure scenario.

The proposed removal action activities, once refined by the following comments and presented in an approved work plan, will be recognized as removal action measures that may be consistent with final remedial actions associated the buildings portion of 0U4. Although it is understood that the removal action will provide sufficient abatement of current exposure threats associated with known site contamination and relative to ongoing current industrial use conditions at the facility; more extensive, additional, or complementary remedial actions may be necessary to achieve a final condition acceptable for future use of the facility. It is anticipated that details of any remedial actions will be the product of the yet to be conducted RI/FS activities related to 0U4.

Section 1.0. Third Paragraph. This paragraph is redundant with the previous paragraph and could be deleted.

Section 1.1. Fourth Paragraph. First Sentence. The sentence should also indicate that dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin or 2,3,7,8-TCDD) and PCBs (polychlorinated biphenyls) have also been identified within a portion of the original 6U2 area based on the results of various dust, wipe, insulation, and product surface sampling activities.

Section 1.1. Fourth Paragraph. In a manner similar to the other detected contaminants of concern, the discussion should jaddress the source(s) (or suspected source(s)) of the dioxin and PCBs detected at the site.

Section 1.1. Fifth Paragraph. | This paragraph should be revised to include parallel discussions about production operations and the fate of finished products that were wipe sampled (after the flooding) in October 1993 in anticipation of removing them from the site.

7. Section 1.1. Fifth Paragraph. Fourth Sentence. Replace "ISOPIA" with "USEPA" or define the acronym.

8. Section 1.1. Fifth Paragraph. Last Sentence. Revise the sentence to specify the "former aldrin tank" to prevent confusion with other OU4 tanks.

9. Section 1.1. Sixth Paragraph. The paragraph should be revised to be delineate all elements of problems at the site (i.e.; pesticides, herbicides and inorganics within 0U2; pesticides, herbicides, dioxin, and PCBs within the 0U4 buildings; the foi-mer aldrin mixing tank and surrounding soil contamination; partially characterized and totally uncharacterized areas of 0U4 that are generally located south and east of Building No. 5).

10. Section 1.1. Seventh Paragraph. The discussion regarding the soil disking area is correct, but conflicts with the companion Surface Remediation Work Plan dated December 14, 1993. Further evaluation and confirmation sampling of the soil disking area is necessary to confirm that the previously established action levels have been satisfied.

11. Section 1.1. Seventh Paragraph. Last Sentence. Replace "extend" with "extent".

12. Section 1.1. Last Paragraph. First Sentence. Replace "Adrin" with "Aldrin" and replace "ISOPIA" with "USEPA" or define the acronym.

13. Section 2.0. First Paragraph. First Sentence. Complete "elimination" of the contamination is presumed to be difficult. It is more likely that the building cleanup activities will "reduce the contamination to safe and acceptable levels" and that correspond to an established USEPA action level. Confirmation sampling (e.g., wipe sampling, aggressive air sampling) must be conducted to confirm that the contamination has been reduced below the established action level.

14. Section 2.0. First Paragraph. Third Sentence. The work plan should be revised tb include discussion regarding how interior building surfaces will be prepared prior to the application of paints or sealer materials. !

15. Section 2.0. Third Paragraph. Replace "site" with "0U4 buildings" and refer to Specific Comment No. 2 regarding "future use".

16. Section 3.0. First Paragraph. Second Sentence. The sentence should be revised to indicate that personal protective equipment requirements will also be included within the health and safety plan.

17. Section 3.0. The work plan should be revised to include additional detailed information about the (building) surface preparation methods and materials and the surface coverage materials that will be used for various interior surfaces. Attachment 1 is offered as a recommendation of both the type of additional information desired and potentially suitable coverage materials for the anticipated interior surfaces.

18. Section 3.0. Buildings No.'s 4 and 5 Subsection. It is recoinmended that ceiling and wall insulation materials be repaired or replaced as necessary, prior to vacuuming activities. Therefore, Steps 3 and 4 should be conducted and renumbered as Steps 1 and 2 and former Steps 1 and 2 should become Steps 3 and 4.

19. Section 3.0. Buildings No.'s 4 and 5 Subsection.Step 2. This step should indicate that HEPA (High Efficiency Particulate Air) filters will be used in conjunction with dry vacuum equipment on all exposed interior building surfaces (i.e., roof/building beams, trusses, ceiling and wall insulation material, piping and electrical conduits, equipment and storage surfaces, all other appurtenant surfaces, and floors).

20. Section 3.0. Buildings No.'s 4 and 5 Subsection. Steps 3 and 4. The work plan should be revised to include additional information regarding ceiling and wall insulation repair and replacement methods. The additional discussions, at a minimum, should' include the following information:

Will existing insulation be removed or will new insulation materials be applied over existing insulation? Will new foil, plastic or other materials be used to cover damaged portions of insulation? How and with what materials will the insulation joints be covered? ' 1

21. Section 3.0. Buildings No.'s 4 and 5 Subsection,Step 5, The work plan should be revised tb include additional information and discussion regarding the "industrial unit (tenant floor washer/sweeper)" that is proposed for the dry vacuuming and washing of floor surface areas.

22. Section 3.0. Buildings No.'s 4 and 5 Subsection.Step 6. The work plan should be more specific (similar to the level of detail represented within Attachment 1) and indicate the interior building surfaces (e.g., walls, floors, piping and electrical conduits, insulation, doors?, windows?) that will be painted.

23. Section 3.0. Buildings No.'s 4 and 5 Subsection.Step 7. In an effort to prevent potential future damage to wall insulation materials, the work plan should be revised to indicate how wall surfaces will be protected up to a minimum height of 8 to 10 feet above the floor or the highest level (the tops of) skids, stored products, or industrial equipment are located and which could impact the wall insulation material.

2 4. Section 3.0. Buildings No.'s 4 and 5 Subsection,Step 8. The work plan should specify and delineate the types of waste materials (e.g., personal protective equipment, floor sweepings, vacuumed dust, wash and rinse waters, removed insulation) anticipated during the removal action activities.

25. Section 3.0, Aldrin Tank Area Subsection. The work plan should indicate hoW; the removal action activities to remove the aldrin tank and associated contaminated soils will be coordinated with the removal action activities within the Maintenance Building. In particular, how and when will the temporary closure of the doorway between the Maintenance Building and the Aldrin Tank Annex be modified or replaced with a permanent closure of the Maintenance Building?

26. Section 3.0. Aldrin Tank Area Subsection. Step 1. The work plan should include a description of debris removal, handling, decontamination, and disposal activities associated with the aldrin tank annex.

27. Section 3.0. Aldrin Tank Area Subsection. Step 3. The work plan should include a description of the anticipated extent of soil contamination that will be removed from the aldrin tank area: It is anticipated that contaminated soil above the USEPA action level will be removed. The work plan sliould also discuss confirmation sampling activities associated with the removal of contaminated soils.

28. Section 3.0. Aldrin Tank Area Subsection. Step 4. The work plan should include a discussion regarding the decontamination methods that will be used for the former aldrin tank as well as the anticipated disposal method.

2 9. Section 3.0. Aldrin Tank Area Subsection. Step 5. Although the proposed incineration of contaminated soils is likely acceptable, this step of the work plan could indicate that the contaminated soils removed from the aldrin tank area will be disposed at regulated facilities based on analytical results received from representative samples.

30. Section 3.0. Aldrin Tank Area Subsection. Step 6. The source of clean soil should be indicated within the work plan.

31. Section 3.0. Building 1. 2 and 3 Subsection. Step 6. The removal of the referenced fuel oil tank (presumed to be an underground storage tank) may not be appropriate within the context of the proposed removal action activities. The exact tank location and any associated data should be provided to USEPA. Note also that a state closure plan may be required for the tank removal activities.

32. Appendix A. Figures 1-1 and 1-2. The shading pattern used to delineate 0U4 should not include the two buildings located north of the DICO office building. If it is DICO's intent to include these two buildings within 0U4, DICO should provide supporting information to USEPA.

Attachment 1

Comments to the Surface Remediation Work Plan

December 17, 1993

General Comments:

1. It is highly recommended that the soils in the portions of 0U4 proposed for capping, be sampled prior to any capping activities. Otherwise, the future necessary sampling activities conducted as part of the 0U4 RI/FS will require penetration of the cap and possible compromise to the caps integrity. It is anticipated that required sampling activities would involve a single round of soil sampling, similar to the post flood sampling for 0U2 conducted in October 1993. The sampling activities must be conducted in accordance with an approved Quality Assurance Project Plan and include analysis for pesticides, herbicides and dioxin.

2. The work plan must include a detailed Operation and Maintenance (O&M) plan for the asphaltic concrete cap proposed. The O&M plan should include, at a minimum, the following components:

A description of and schedule for periodic inspections for surface cracks and spoiling of the asphaltic concrete cap's integrity.

Repair and replacement methods that will be used to maintain the integrity of the cap in the event of cracking, spoiling, or intended/accidental cap penetration.

Specific Comments:

1. Section 1.0, First Paragraph. Last Sentence. The work plan should be revised as follows:

Indicate that contractor selection will also be based on the availability of contractor's personnel who are trained and medicallyimonitored, in accordance with OSHA regulations found in 29 CFR 1910.120, for hazardous waste site activities.

Include a statement of qualifications for the selected contractor(s) who will be responsible for implementing the surface remediation activities.

2. Section 1.0. Second Paragraph. Last Sentence.

References to "future activities" throughout this work plan must recognize that the proposed removal action achieves conditions that are acceptable for the ongoing industrial use of the facility (e.g., vehicular and

pedestrian traffic, equipment and product storage, no excavation within known hot spots of 0U2 site contamination, no excavation within uncharacterized areas of 0U4).

The proposed surface remediation activities, once refined by the following comments and presented in an approved work plan, will be recognized as a removal action measure for designated portions of the site that may be consistent with final remedial action at the site. Although it is understood that the removal action will provide sufficient abatement of current exposure threats associated with known site contamination and relative to ongoing current industrial use conditions at the facility; more extensive, additional, or complementary remedial actions may be necessary to achieve a final condition acceptable for future use of the facility. It is anticipated that details of any remedial actions will be the product of the ongoing Remedial Investigation/ Feasibility Study (RI/FS) process within 0U2 and the product of the yet to be conducted RI/FS activities related to 0U4.

Section 1.1. Third Paragraph. First Sentence. The sentence should also indicate that dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin or 2,3,7,8-TCDD) and PCBs (polychlorinated biphenyls) have also been identified within a portion of the original 0U2 area based on the results of various dust, wipe, insulation, and product surface sampling activities.

Section 1.1. Third Paragraph. In a manner similar to the other detected contaminants of concern, the discussion should address the source(s) (or suspected source(s)) of the dioxin and PCBs detected at the site.

Section 1.1. In a manner similar to the companion Removal Action Work Plan dated December 10, 1993 (Section 1.1, Fifth Paragraph), this work plan should]be revised to include discussions regarding operations and products related to the detected site contamination.

Section 1.1. Fourth Paragraph. ^ The paragraph should be revised to delineate all elements of problems at the site (i.e.; aldrin, dieldrin, pesticides, and inorganics within 0U2; aldrin, dieldrin, pesticides, dioxin, and PCBs within the 0U4 buildings; the former aldrin mixing tank and surrounding soil contamination; partially characterized

and totally uncharacterized areas' of 0U4 that are generally located south and east of Building No. 5).

7. Section 1.1. Last Paragraph. Last Sentence. Refer to Specific Comment No. 2 regarding "future use".

8. Section 2.0. First Paragraph. First Sentence. The sentence should be more precise and refer to an Appendix A figure rather than indicate that the "entire" exposed ground surfaces of the facility will be capped when some areas of the property are proposed to be left for natural drainage and other areas are intended to be "green spaces".

9. Section 2.0. First Paragraph. Third Sentence. The work plan should include additional detailed information regarding the design, analysis, and construction of the proposed asphaltic concrete cap and how it satisfies the intended use purposes (e.g., capping to both support truck/automobile traffic and prevent contaminant contact/release, capping for prevention of contaminant contact/release only). At a minimum, the additional work plan information should be based on the following criteria and considerations:

Pavement design and analysis should be completed in accordance with the "AASHTO Guide for Design of Pavement Structures" published in 1986 by the American Association of State,Highway and Transportation Officials.

Pavement design of interior road and parking surfaces should be conducted in accordance with "A Policy on Geometric Design of Highways and Streets" published in 1990 by the American Association of State Highway and Transportation Officials to ensure that the site's pavement system optimally satisfies the practical needs 1 of truck and automobile traffic and promotes vehicular safety on the property.

Pavement design and analysis dissumptions (e.g.; anticipated traffic loadings and volumes; design life of pavement surface(s); subgrade strength; etc.) should be provided as supporting information to the work plan.

asphaltic concrete final remedial action

Recognizing that the proposed cap may be a component of the at the site and an incremental investment at this time would significantly reduce long-term maintenance and repair costs, consideration should

be given to rigid pavement design of high traffic portions of the proposed cap areas.

Because many pavement failures are caused, at least in part, by inadequate drainage, and the proposed cap area is significant, a grading and drainage plan should be incorporated into design and construction of the cap.

To maintain pavement structure for long term life and to maintain separation between the existing subgrade materials and imported subgrade/leveling materials, a geotextile should be placed over the existing subgrade materials.

10. Section 2.0. First Paragraph. Fourth Sentence. Due to the substantial area proposed for the cap, this work plan should reflect considerations regarding storm water management and how it has been integrated into the proposed surface remediation plan. As proposed, it is anticipated that the increased surface water runoff entering the South Pond Drainage Area will be significant.

11. Section 2.0. First Paragraph. Last Sentence. Design consideration should be given to avoiding any construction excavation or natural ground blading activities within 0U4 until sufficient characterization data is available to evaluate any potential construction related risk condition.

12. Section 2.0. Second Paragraph. First Sentence. The work plan should be revised to provide additional details regarding the location and construction of the proposed green spaces. These revisions should support the premise that the green spaces will not interfere with the integrity and function of the cap.

13. Section 2.0. Second Paragraph. Last Sentence. The work plan should include the source and type of soil or gravel intended for fill or subgrade material at the facility.

14. Section 2.0. Last Paragraph. Refer to Specific Comment No. 2 regarding "future use".

1

15. Section 3.0. First Paragraph. First Sentence. The work plan should indicate what dust control measures will be employed during subgrade preparation activities.

16. Section 3.0. Second Paragraph. First Sentence. In a manner similar to the companion Removal Action Work Plan dated December 10, 1993, this work plan should specify that a site specific Health and Safety Plan will be prepared for the surface remediation activities.

17. Section 3.0. An implementation schedule for the surface remediation activities should be provided within the work plan. The schedule and related discussion should indicate how the surface remediation efforts will interface and be coordinated with the building cleanup activities.

18. Appendix A Figure. The Appendix A figure should be revised or supplemented to clearly illustrate the following surface remediation components:

Typical cross section of "light" and "heavy" asphalt cap, base materials, and subgrade preparations based on pavement design and analysis activities.

Cap integration with existing features of the site (e.g.; ground water monitoring and recovery wells; air stripper; soil disking area; railroad tracks; flood control levee; and above ground tanks, transformers, and concrete pads).

Construction details of green spaces intended to not interfere with the integrity and function of the asphalt surface.

Attachment 1 Surface Coverage Recommendations

SCOPE /MI bare metal surfaces within the buildings should be primed prior to the application of paint as a finished coat surface. Regardless of the number of paint coals previously applied, all interior building surfaces should be tie coated for suitable surface coverage materials and painted.

MATERIALS Paint should be delivered in original unopened containers with labels intact. Paint should be stored indoors at room temperatures between 45°F and 90°F. No unauthorized thinner or material should be included in the paint formulation for any purpose. Contractor implementing removal action activities should be responsible for ensuring the compatibility of painting products which will be in contact with each other or which will be applied over both painted and unpainted surfaces. Contractor should also be responsible for providing surface coverage materials that conform to all applicable air quality regulations al the point of application. Recommended surface coverage material types and manufacturers (e.g.; Ameron "Amcrcoat 385 Epoxy", Cook "920-A-226 /\rmorcote 54", Kop-Coat "Glamorglaze 200 Epoxy", or Tnemec "Tneme-Tread Series 67" for nonskid epoxy enamel coverage of concrete floors; /Ameron "Amercoat 5401HS Gloss Alkyd Enamel", Cook "801 Series Gloss Enamel", Kop-Coai "Glamortex 501 Enamel", or Tnemec "Series 2 Tneme-Gloss" for gloss alkyd enamel surface coverage) can be provided in response to requests by USEPA or others.

SURFACE PREP/ORATION Appropriate dermal and inhalation personal protective equipment should be worn during any surface preparation activities (e.g., vacuuming, cleaning, sanding, wire brushing) described within the Removal Action Work Plan or recommended by paint manufacturers. All surfaces should be dry, clean of oil and grease, and meet the recommendations of the paint manufacturer for surface preparation. Concrete floors should be prepared by removing all dirt, dust, and oil or grease stains by wire or fiber brushing or scrubbing, scraping, or other appropriate methods. Concrete floors to be painted with epoxy enamel should be etched with acid or brush blasted prior to priming. Subsequent cleaning and painting operations should be performed in a manner which prevents dust or other contaminants from getting onto freshly painted surfaces.

PRIMER AND PAINT APPLICATION Each coat should be hard and dry through the entire film before the next coat is applied. Primer and paint coverage showing cracks or blisters will not be acceptable. Special attention should be given to filling all crevices with primer and paint. Latex paint should be applied by brushing or rolling; spraying is not acceptable. Minimum dry film thickness of latex paint should be 3 mils. Application of epoxy enamel, including temperature limitations and protection from sunlight until top-coated, should be in accordance with the manufacturer's recommendations. Minimum dry film thickness of epoxy enamel should be 4 mils. Minimum dry film thickness of alkyd enamel should be 4 mils. Primer and paint should nol be applied at temperatures below the minimum temperature recommended by the paint manufacturers or when airborne dust, debris, or insects can collect on freshly covered surfaces. Surfaces that have been cleaned or prepared for painting should be covered with suitable tic coating material or primer as soon as possible.

p Attachment 1 (continued)

Surface

Structural and Miscellaneous Steel

Steel Doors, Steel Door Frames, Equipment, and Handrails

Concrete Walls, Columns, Floors and Curbing

Plaster and Wallboard

Electrical Equipment Cabinets and Similar Appurtenant Equipment

Cast Iron and Steel Piping

Insulated Piping (except aluminum jacketed

- insulation)-

PVC Piping and Materials

Ductwork (carbon steel)

Electrical Conduit (except banks of conduits in multiple

layers hung from ceilings) and Appurtenant Accessories

Primer

Rust-lnhibilive

Rust-lnhibitive

Same as Finish Coat

Same as Finish Coat

Rusi-Inhibitive

Rust-lnhibilive

As recommended by manufacturer of finish coats

Catalyzed Epoxy

Rusl-Inhibilive (for enamel) Same as Finish Coat (for latex)

Rusl-Inhibitive (for enamel) Same as Finish Coat (for latex)

Paint

Semigloss Alkyd Enamel

Gloss Alkyd Enamel

Epoxy Enamel

Satin Gloss Latex Emulsion

Gloss Alkyd Enamel

Alkyd Enamel (Gloss for any color coded piping and either

gloss or semigloss for all other piping)

Gloss or Semigloss /\Jkyd Enamel

Gloss /Mkyd Enamel

Semigloss Alkyd Enamel or Latex

Semigloss Alkyd Enamel or Latex

NOTE: These recommended primer and paint materials could be used for various surfaces in place of primer and finish coats of an epoxy enamel material as was proposed in the work plan for all interior surfaces. Although epoxy enamel materials may provide superior surface coverage in some applications, epoxy enamel may be incompatible with some surfaces and some previously coated surfaces.