^^"^ ^ ^ \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

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I S S Z ° ^ ^ ^ ^ ^ " ^ JACKSON BOULEVARD ^^ ^p^ ^.^ORDS CENTER REGION 5

%. ^ CHICAGO, IL 60604-3590

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406143

JW I 1 2011 REPLYTOTHE ATTENTION OF

Chairman Archie LaRose Leech Lake Band of Ojibwe 115 6'̂ Street NW, Suite E Cass Lake, MN 56633

Re: St. Regis Paper Co. Site U.S. EPA Responses to Band Concems Raised During Consultation and Notification of Decision Regarding Proposed Soils Remedial Altemative

Dear Chairman LaRose:

On Febmary 18, 2011, the United States Environmental Protection Agency (EPA or Agency) held a consultation session with the Leech Lake Band of Ojibwe (LLBO) so that the Agency could hear and understand the Band's concems and perspective regarding the proposed selection of a soil remedy altemative for the St. Regis Paper Co. Site in Cass Lake. This letter provides you with EPA's responses to concems raised by the Band during consultation session and notifies you of EPA's decision with respect to the Proposed Plan for Soil Cleanup.

Record of Consultation

The consultation took place by video conference. Participating on behalf of LLBO were Environmental Director Levi Brown, Superfund Coordinator John Persell, Executive Assistant to the Chahman Randy Firm, and Special Counsel Richard DuBey and Stephanie Weir. I participated on behalf of EPA, as well as Tim Drexler, Remedial Project Manager; Joan Tanaka, Remedial Section Chief; Jane Neumann, Superfund Tribal Coordinator; Willie Harris, Dhector of the Indian Environmental Office; and Barbara Wester, Thomas Tumer and Monesh Chabria of the Office Regional Counsel.

Attached is a summary of concems raised by the Band's representatives during the consultation session and a clarification of a concem conveyed to EPA in a letter dated March 3, 2011, from Mr. Brown to Mr. Drexler. We have provided an EPA response to each concem and to Mr. Brown's clarification.

National Remedy Review Board Recommendations

On April 6, 2011, Tim Drexler made a presentation to the National Remedy Review Board (NRRB) regarding the proposed remedy selection. The Band had submitted to the NRRB a written package of materials reflecting its perspective on the EPA-preferred altemative and also made a presentation to the NRRB on April 6. The Region received oral comments from the

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Board members on April 6 and a written summary of comments from the Board on May 20, 2011. The NRRB comments and Region 5's response are attached to this letter.

EPA's Decision and Steps Going Forward

I carefully weighed the input I received from the Band during consultation as well as all of the comments and opinions the Band staff have shared with EPA over the years leading to this decision, including comments on the draft Proposed Plan submitted by John Persell on June 3, 2011. Although I had hoped EPA and the Tribe would reach consensus on the soil remedy, both sides have identified clear differences. I have decided to propose for public comment Altemative 4A from the array of altematives in the Feasibility Study. The attached Proposed Plan describes the remedy in detail. The Proposed Plan will be published in the coming days and will extend for 30 days. A public hearing to receive community comments is scheduled for June 23, 2011, in Cass Lake. The Band is, of course, welcome to provide additional comments for the record during this period. This letter and its attachments will become part of the Site Administrative Record, which are documents that form the basis for EPA's decision.

After the public comment period, EPA will prepare a response to all comments received, and I will make a final remedy decision. We will contmue to collaborate with the Band's designated representatives as we move through the phases of site decision-making.

The role the Band has played with respect to this Site has been profoundly valuable. I would like to thank the Band for participating in the consultation process and in all Site activities. If you have any questions concerning our response to Band input or the remedy decision, please contact me at 312-353-9773 or your staff may contact Tim Drexler at (312) 353-4367. I look forward to a continued effective relationship between Superfund Division and the Band as we implement a final soil remedy for this Site and as we continue to implement the groundwater remedy.

Sincerely,

itr^ichard C. Karl, Director [/ Superfimd Division

Attachments: Concems of Band and EPA Responses NRRB Comments to Region 5, May 20, 2011 Region 5 Response to NRRB Comments, June 2011 Proposed Plan

cc: Levi Brown John Persell Richard DuBey

RESPONSE TO ISSUES RAISED BY LEECH LAKE BAND IN GOVERNMENT-TO-GOVERNMENT CONSULTATION REGARDING THE ST. REGIS PAPER CO. SITE FEBRUARY 18, 2011 MEETING AND MARCH 3, 2011 LETTER FROM LEVI BROWN

FEBRUARY 18, 2011, MEETING

Prior to explaining the Band's issues and concems. Band representative John Persell stated that Altemative 6 is the Band's first choice among the remedial altematives. Mr. Persell said Altemative 5 is the Band's second choice.

Band Concem #1: Altematives 1, 2, 3, 4, 7 and 8 do not provide soil cleanup measures that allow Tribal members the full scale of permanent homeland uses [should the Band come to own the property in the future]. EPA Response: EPA is empowered under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and the National Contingency Plan (NCP) to implement or require remedies that reflect the best balance of the nine criteria for remedy selection found at 300.430(e)(9)(iii). For sites with low level of contamination, such as the remaining soil contamination at the St. Regis site, the NCP notes at 300.430(a)(l)(iii)(B)that "EPA expects to use engineering controls, such as containment, for waste that poses a relatively low long-term threat or where treatment is impracticable." The proposed St. Regis remedy is consistent with the requirements and expectations of the NCP for remedy selection.

Our Superfund program guidance (Land Use m the CERCLA Remedy Selection Process, OSWER Directive No. 9355.7-04, May 25, 1995) notes that when selecting a remedy, the EPA should take into account reasonably anticipated future uses of the site. EPA does not consider all possible future uses when evaluating and selecting a remedial action. EPA initiated a community plarming process for the Site in 2005, which was abridged by mutual consent of the participants but nonetheless resulted in a draft vision for future use of the site. EPA considered the land uses described in that plan, as well as current uses, expressed intentions of current property owners, and existing zoning restrictions when weighing remedial altematives.

The Band does not currently own, nor have access to, the majority of the Site properties that are the subject of the proposed soil remedy. For the industrial/commercial properties at OUI, 0U2, and OU3 that are not owned by the Band, the one-foot soil cover in EPA-preferred altemative would provide a level of protection from surface soil contamination that allows all reasonably anticipated future uses. Once the remedy is in place, institutional controls (ICs) would protect the cover and still allow excavations while requiring that proper safeguards are in place and proper care is taken to restore the cover after any excavation. With those protections in place, EPA does not anticipate any restrictions on use of the property beyond those currently in place through zoning restrictions. Therefore, the altemative would be protective for commercial/industrial use.

With respect to residential properties, EPA guidance (Superfund Lead-Contaminated Residential Sites Handbook, OSWER Directive 9285.7-50, August 2003) recommends that a minimum of 1

ft. of clean soil be used to establish an adequate barrier from contaminated soil in a residential yard for the protection of human health. EPA considers a 2-ft. excavation appropriate for residential protection where surface contammation exceeds the calculated residential Preliminary Remediation Goals (PRGs). For properties that are below the PRGs but exceed the Band's Hazardous Substance Control Act (HSCA) cleanup standard, EPA considers that placmg a 1-ft. clean soil cover over the residual contamination, without excavation, will be protective of human health in addition to meetmg the HSCA. For most residential properties where surface contamination exceeds the PRGs, the 2-ft. depth should be sufficient to achieve backgroimd levels of site contaminants. ICs will be needed for any property that is still above PRGs at the 2-ft. excavation depth and for those properties where a cover is needed.

For the Division of Resource Management (DRM) property, which is owned by the Band, the 2-ft. excavation and clean fill (on the narrow area along the east fence line and the small area along the north property boundary that exceed the residential PRG) will protect against exposures for reasonably foreseeable future uses of this site. The area of this property expected to be remediated in this maimer is currently used for a mixture of equipment storage (in the open and m an existing building on a concrete slab) or for vehicle movement within the property (in graveled areas). EPA considered it reasonably foreseeable that these current uses would continue. The area of ecological risk adjacent to the DRM property in the southwest comer of OU2 (the existing contaminated soil vault) which exceeds the PRGs for pentachlorophenol (PCP) will be excavated (and backfilled with clean soil) to a considerably greater depth of up to 5 feet to remove contaminated soil affecting organisms at depth. This remedy will protect ecologic resources in this area of Fox Creek, ensuring those resources are available for use by the Band. In addition, a one-foot soil cover will be placed in any imexcavated area that exceeds the HSCA cleanup values for PCP.

Band Concem #2: Many of these lands [within the site] would likely not be taken into tmst status by the Department of Interior (DOI) for the Band in the future. EPA Response: Although the Band does not own the majority of lands that are subject to the current proposed soil remedy, EPA recognizes the Site is within the boundaries of the Reservation. Therefore, EPA consulted the DOI Office of Solicitor General regarding the issue of how the Department considers fee-to-tmst applications for properties on or adjacent to Superfund National Priorities List (NPL) sites. While DOI could not comment on hypothetical fee-to-tmst transfers, the Department did not mle out such a fee-to-tmst transfer of property after completion of an EPA-approved cleanup, mcluding property subject to ICs. Fee-to-tmst transfers of all property are subject to DOI regulations, and the Department retains the ultimate discretion to make such determinations. While we will continue to coordinate with DOI as the St. Regis Site remedial activities move forward, we also strongly encoiu-age the Band to work directly with DOI and the Bureau of Indian Affairs to follow up on specific concems regarding the fee-to-tmst process relating to properties included in this Site.

Band Concem #3: The provision for utilities to potential homes on many of these lands does not appear to be safely accommodated by the above altematives [1,2,3,4,7,8]. EPA Response: A component of the EPA-preferred altemative (4A) is placement of ICs in order to protect the soil cover and so that if any excavation is planned, like that needed for utility emplacement, that EPA is contacted so that the work is performed safely and that the soil cover

is restored properly. These measures will make it possible to provide utilities to any new development. Such redevelopment has safely occurred after remedy completion at other Superfimd shes.

Band Concem #4: The Band believes EPA has less than enough information to make an informed choice of remedy, specifically, the degree to which soil contaminant concentrations are estimated. This information gap allowed the PRPs to overestimate costs for Altemative 6 (the Band's preferred altemative), resulting in an unfair evaluation of the cost comparison of altematives. The Band reiterated its request that a complete site remedial investigation be completed. EPA Response: EPA believes it has sufficient information on which to base its decision and that a second remedial mvestigation is unnecessary. The Agency's position is that the expected costs for excavation remedies are reasonable in the Feasibility Study (FS). The following Site characteristics support the conclusion that the depth of soil contamination in the former operation area is properly estimated in the FS:

• The soil is very sandy, so the likelihood of percolation of site contaminants to lower soil is high.

• Based on groundwater sampling results, there is likely contaminant source material at and near the water table at depths ranging from 7 feet to more than 17 feet in the former pond areas on the IP and BNSF Railway Company properties. These anticipated areas of deep excavation in order to reach HSCA cleanup levels significantly increased the average excavation depth and the high costs in Altemative 6 in the FS.'

• Up to a foot of excavation was required in some areas to reach a soil dioxin level that was still 100 times the HSCA clean up level in city-owned portions of OUI during EPA-ordered removal actions; Dioxin levels in two of the three investigative samples collected in industrial/commercial areas of OUI at a depth of 2 feet were found to be over 15 times the HSCA clean up level for dioxin. These findings indicate the likelihood that broad and deep excavation would be required across OUI to meet die HSCA level under Altemative 6.

• Following soil excavation during the state-lead remedy, over 80% of the site was regraded. In addition, soil from 0U2 was relocated to OUI. Because of this heavy soil disturbance during the original remedy there is no expectation that contaminant concentrations would consistently decrease with increasing depth.

• Measured backgroimd concentration of dioxin in soil in this area is 7-8 ppt, which is extremely close to the LLBO HSCA cleanup standard of 10 ppt. It is reasonable to assume that a high volume of soil would need to be removed from the site to achieve the LLBO HSCA standard of 10 ppt dioxin.

Band Concem #5: Noise factors mentioned [in the FS altematives analysis] as negative impacts of tmck traffic have little merit in an area accustomed to many trains passing through town daily and nightly with train whistles at the Highway 371 crossing in town. EPA Response: EPA appreciates the Band's perspective. An evaluation of the short-term effectiveness of a remedy includes multiple factors, according to the NCP and agency guidance.

^ Contaminated groundwater impacted by these suspected source areas is being addressed separately from this soil remedy.

Those factors include impacts on the local community, the remedy's impact with respect to transportation, protection of workers, and timeframe for implementing the remedy. The noise factor alone would not change the conclusion of whether a particular altemative meets the short-term effectiveness criterion.

Band Concem #6: The Band opposes any permanent storage of contaminated soil on the Reservation. EPA Response: EPA prefers a soil altemative that includes shipment of excavated soil to an off-site landfill, which is consistent with the Band's preference. However, the existing on-site contaminated soil vault from the cleanup m the 1980s is expected to be permanent. EPA has no plans to remove the contents of that cell. The vault continues to be maintained in a manner that is consistent with federal and state regulations and is protective, and EPA will continue to monitor its effectiveness in the future. Our perspective about the protectiveness of the vault was further discussed in our letter dated November 19, 2010 to John Persell from Tim Drexler (EPA Response to Support Agency Partners' Comments on Draft Feasibility Study Report - Soils).

Band Concem #7: The Band would like EPA to consider potential savings in calculating the overall cost of those remedial altematives involving off-site transportation of contammated soils were the PRPs to use rail transport rather than tmcks. This could reduce the costs for Altematives 5 and 6. EPA Response: EPA requested in its May 26, 2011, letter conditionally approving the Feasibility Study Report that IP provide cost estimates for using rail to transport contammated soil from the site, and EP did provide those figures. The preliminary cost estimates of using rail transport would be an increase in the cost and duration of the remedy. A rail spur would be required at the the site and at the landfill location m addition to the cost of rail car rental and the cost to tmck the soil the short distance from the rail spur to the landfill.

Band Concem #8: Fencing property takes it out of use m the community. EPA Response: Properties within the site that are owned by IP are already fenced, although that was not required by EPA for implementation of the original remedy. Additionally, as a part of the removal actions, fences were placed on portions of the BNSF Railway property and Cass Forest Products property that exceeded 1 ppb for dioxin to prevent exposures to site contaminants. Once the final remedy is completed, those fences will not be needed. However, EPA cannot compel property owners to remove an existing fence. EPA is not proposmg to requhe any additional fencing as any part of the remedy in the preferred altemative. The EPA-preferred altemative would provide sufficient protection such that additional fencing is uimecessary from a protectiveness standpoint. If a property owner chooses to fence portions of its property, the Agency caimot prevent that.

Band Concem #9: The Band would like its people to live in the site area without institutional controls. EPA Response: EPA appreciates the Band's concem about mcludmg institutional controls as part of the remedy. EPA has weighed this concem along with the factors it is required to consider when selecting a remedy. The remedy that we believe is both protective and the most cost-effective (Altemative 4A) mcludes use of ICs. Altemative 6A, which does not limit soil excavation depth, would still requke ICs due to the continuing groimdwater contamination and

the presence of the contaminated soil containment vault. Additionally, the LLBO HSCA contemplates that ICs may be an appropriate component of remedial actions and addresses the Band's enforcement of those ICs.

Band Concem #10: The Band would like EPA to consider, when choosing a remedy, the long-term, negative impact on the local economy from this site. EPA Response: Past or future economic impact of the presence of a Superfund site is not among the nine factors EPA is directed by the NCP and CERCLA to consider when choosing a remedy. EPA's mandate under those authorities is to look forward and prevent future negative impacts to human health and the environment. However, one factor the NCP requires EPA to consider is Community Acceptance. EPA will listen to and weigh any concems expressed by the community that the EPA-preferred altemative may negatively impact the local economy in the future. EPA strongly supports re-use and redevelopment of Superfund NPL sites, and many sites have been successfully redeveloped. As mentioned in the response to Band Concem #1 above, EPA brought a site re-use contractor to Cass Lake for visioning sessions in 2005. In Febmary 2011 we renewed our offer of additional redevelopment support to the community. The preferred altemative would allow re-use of commercial areas of the site now vacant and would make residential areas safe, with limitations on excavation in either area.

MARCH 3, 2011, LETTER FROM LEVI BROWN TO TIM DREXLER

Band Concem: LLBO Environmental Director Levi Brown, in a letter to Tim Drexler dated March 3, 2011, clarified a concem of the Band that EPA, in choosing an altemative which leaves contaminated soil in place and applies a cover as a remedy, is not interpreting the HSCA as the Band intends. EPA Response: EPA reviewed the language of the HSCA before concluding that a preferred remedy for the Site could include a cover. As written, HSCA does not direct the manner in which cleanup levels are achieved. HSCA does provide for distinguishing different types of land use and also provides for the use of monitoring and deed restrictions and other ICs in the context of remedial actions.

? £% ' \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

I 2 ! S ^ WASHINGTON. D.C. 20460

OFFICE OF SOLID WASTE ANO EMERGENCY

RESPONSE

May 20, 2011

MEMORANDUM

SUBJECT: National Remedy Review Board Recommendations for the St. Regis Paper Company Site

FROM: Amy R. Legare, Chair w _ - = « ^ ^ ^ ; ^ ^ ^ i ^ National Remedy Review Board ' /

TO: Douglas Ballotti, Acting Director Superfund Division U.S. EPA Region 5

Purpose

The National Remedy Review Board (the Board) has completed its review of the proposed cleanup action for the St. Regis Paper Company Superfund site, in Cass County, MN. This memorandum documents the Board's advisory recommendations.

Context for Board Review

The Administrator established the Board as one of the October 1995 Superfund Administrative Reforms to help control response costs and promote consistent and cost-effective remedy decisions. The Board furthers these goals by providing a cross-regional, management-level, "real time" review of high cost proposed response actions prior to their being issued for public comment. The Board reviews all proposed cleanup actions that exceed its cost-based review criteria.

The Board review is intended to help control remedy costs and to promote both consistent and cost-effective decisions. The National Oil and Hazardous Substances Pollution Contingency Plan (NCP)mandates that, in addition to being protective, all remedies must be cost-effective. The Board considers the nature of the site; risks posed by the site; regional, state, tribal and potentially responsible party (PRP) opinions on proposed actions; the quality and reasonableness of the cost estimates; and any other relevant factors or program guidance in making our advisory recommendations. The overall goal of the review is to ensure sound decision making consistent with current law, regulations, and guidance.

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Generally, the Board makes the advisory recommendations to the appropriate regional division director. Then, the region will include these recommendations in the administrative record for the site, typically before it issues the proposed cleanup plan for public comment. While the region is expected to give the Board's recommendations substantial weight, other important factors, such as subsequent public comment or technical analyses of response options, may influence the region's final remedy decision. The Board expects the regional division director to respond in writing to its recommendations within a reasonable period of time, noting in particular how the recommendations influenced the proposed cleanup decision, including any effect on the estimated cost of the action. Although the Board's recommendations are to be given substantial weight, the Board does not change the Agency's current delegations or alter the public's role in site decisions; the region has the final decision-making authority.

Overview of the Proposed Action

The St. Regis Paper Company Superfund site is located within the exterior boundaries of the Leech Lake Band of Ojibwe (LLBO) Indian Reservation and in the City of Cass Lake in Cass County, Minnesota. The site is composed of a former wood-treating facility (demolished in 1986) operable unit (OU) 1, a hazardous waste containment vault area (OU2), a former bum pit area near the fonner city dump (0U3), vacant city-owned property (OUI), residential properties (OU7) and commercial properties (OUI). Chemicals used in the wood-treating processes changed over the operational history of the facility. Creosote was used in wood treatment from the beginning of operations. Pentachlorophenol (PCP), which contained dioxin as an impurity, was added to the process in around 1960. Ammoniacal copper arsenate (ACA) was also used from 1969 until the closure of the plant.

The site was listed on the Superfund National Priorities List in 1984. The Minnesota Pollution Control Agency (MPCA) was originally the lead agency for the site. The MPCA oversaw the implementation of a remedial investigation/feasibility study (FS) by the potentially responsible parties (PRPs), which led to PRP-implemented remedial actions from 1985 to 1988. Those actions included: (1) excavation and on-site disposal of all site sludges and contaminated soil to a visual standard in a Resource Conservation and Recovery Act Subtitle C land disposal unit, called the "containment vault;" (2) extension of the Cass Lake Community Water System to residents potentially affected by site contaminated groundwater; and (3) implementation of a groundwater extraction and treatment system.

In 1995, the U.S. Environmental Protection Agency (EPA) took over as lead Agency for the site at the request of the LLBO. The PRPs have been conducting continued groundwater treatment under the EPA oversight since that time. The EPA, during the course of conducting five-year reviews, identified and conducted additional work, including: (1) soil and other media sampling; (2) removal measures; (3) interim remedial measures; (4) a human health and ecological risk assessment (HHERA); and (5) an FS for the residual site soil contamination. In 2006, the PRPs conducted an interim residential remedial action. This action included initial and ongoing indoor residential cleaning and placement of three inches of clean fill in residential yards. The FS for the residual soil contamination is almost final.

The action the Board reviewed addresses only soil-related contamination that remains after state-lead remedial and EPA-lead removal actions were conducted. Groundwater contamination continues to be

addressed through operation and maintenance of the implemented groundwater remedy. The primary human health contaminants of concern (COCs) identified in the site risk assessment are dioxin/furans and polycyclic aromatic hydrocarbons (PAHs). Ecological COCs identified in the HHERA include PCP and PAHs. The objectives of the recommended actions are: (1) to eliminate exposure to soil contaminants in residential properties (OUT); (2) to prevent worker exposures to soil contaminants in commercial/industrial areas (OUI, 0U2, and 0U3); (3) to prevent worker exposures to contaminated groundwater during any future soil excavations in OUI and OU3; and (4) to eUminate ecological exposures in the soil in the southwest area of the hazardous waste containment vault (0U2).

Based on a site-specific risk assessment, and after consultation with EPA headquarters, Region 5 selected dioxin clean up values of 63 parts per trillion (ppt) for residential properties and 380 ppt for industrial/commercial areas. Also in consultation with EPA headquarters, Region 5 recognizes the Leech Lake Band of Ojibwe Hazardous Substance Control Act (HSCA) as an applicable or relevant and appropriate requirement (ARAR) for the site. The HSCA calls for clean up levels of 10 ppt for dioxin in soil and 2 ppb for PCP, regardless of property use.

Region 5 proposed Altemative 3 A to the Board, which includes excavation of contaminated soil on residential properties exceeding 63 ppt for dioxin and 1.6 milligram per kilogram (mg/kg) benzo(a)pyrene-equivalent (B(a)PE) to a maximum of two feet; and covering soil with one foot of clean fill in industrial/commercial areas of the site that exceeds 63 ppt dioxin and 1.6 mg/kg B(a) PE. In addition, contaminated soil in an identified area of ecological risk in 0U2 above an ecological preliminary remediation goal (PRG) of 31 mg/kg for PCP and 18 mg/kg for high molecular weight PAHs would be excavated to a maximum depth of five feet. Unexcavated surface soil in this area that exceeds the LLBO HSCA clean up level for PCP will be covered. This, altemative achieves the identified ARARs, including the LLBO HSCA, through a site-wide average of remaining contaminant concentrations. The institutional controls include maintaining the integrity of the cover in the residential areas (0U7) and commercial/industrial areas (OUI, 0U2, and 0U3).

National Remedy Review Board Advisory Recommendations

The Board reviewed the information package describing this proposal and discussed related issues with Region 5 staff and management (in person: Timothy Drexler, Joan Tanaka, and Monesh Chabria; on video conference: Barbara Wester, Thomas Tumer, and Jane Neumann) on April 6, 2011. The Leech Lake Band of Ojibwe was represented by Richard DuBey (in person); and John Percell and Levi Brown via video conference. The MPCA was represented via video conference by Susan Johnson, Doug Beckwith, Jeff Lewis, Steve Lee, Steve Hennes, and Mark Elliott. The Minnesota Department of Health was represented via video conference by Emily Hansen and Rita Messing. Beverly Conerton represented (via video conference) the Office of the Minnesota Attomey General.

This review is premised upon the decision by the Assistant Administrator of the Office of Solid Waste and Emergency Response (OSWER) that the HSCA is an ARAR for this remedial action. Based on its review and discussion, the Board offers the following comments:

St. Regis Final - 5/20/11

Site Characterization

Based on the information presented there has been: 1) no post-remedial action confirmation sampling conducted for the portions of the site that were subject to previous state-lead response actions (e.g., pond areas); 2) insufficient subsurface sampling to collect data on the horizontal and vertical extent of contamination; and 3) no evaluation of the potential for COC migration to groundwater. Given these shortcomings, the Board recommends that the Region include vsfithin the decision documents sufficient explanation regarding how site characterization is being accomplished consistent with the NCP (e.g., 40 CFR 300.430(b) and (d)), OSWER Directive No. 9355.3-01, October 1988, Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA, Interim Final (e.g.. Chapter 3.4), EPA guidance 540/1-89/002, December 1989, Risk Assessment Guidance for Superfund, Volume I, Human Heahh Evaluation Manual (Part A), Interim Final (e.g., Chapter 4); OSWER Directive No. 9355.4-23, July 1996, Soil Screening Guidance User's Guide (e.g.. Chapter 2).

The Board also recommends that the Region ensure decision documents address how future Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) response actions may address subsurface soils (since the HSCA 10 ppt standard for dioxin in soil appears to cover all soils, not just surface soil contamination) and/or groundwater contamination. In addition, the Board recommends that the Region require confirmation sampling for the previous state-lead response actions for the ponds to ascertain that the response action goals were met.

Institutional Controls

The package presented to the Board describes institutional controls (ICs) that are common components of all remedial altematives but did not discuss differentiation between the types of controls necessary in order for each of the altematives to be protective. The Board recommends that the decision documents more clearly identify the media; activity to be restricted; and party responsible for implementing, monitoring and enforcing each IC. The Board also recommends that the Region keep in mind that ICs often can be more effective if they are layered or implemented in series. In addition, the cost of implementing the ICs should be included in the cost breakdown for each altemative. The Board recommends that the decision documents also include descriptions of any requirements for cover/cap maintenance in those areas where ICs are required.

Human Health Risk

The information presented to the Board indicates that the Region will meet the HSCA soil cleanup goal of 10 ppt dioxin by averaging the surface soil concentration site wade. The Board recommends that, to help ensure protectiveness, the Region consider meeting the 10 ppt dioxin soil cleanup goal by exposure units (i.e., individual residential properties), consistent with OSWER Directive No. 9285.6-10, December 2002, Calculating Upper Confidence Limits for Exposure Point Concentrations at Hazardous Waste Sites. For large commercial/industrial areas, the Board recommends that the Region consider breaking the site or the individual OUs into small sub areas and meeting the cleanup criteria for each individual sub area.

St. Regis Final-5/20/11

Principal Threat Waste

The package presented to the Board did not address the presence of principal threat waste (PTW) in surface soils at the site (as opposed to potential non-aqueous phase liquids [NAPLs] in groundwater plumes). However, the Region did mention PTW in the nine-criteria evaluation portion of the package where it indicated the PTW materials were not present for the surface soil remedy. The Board notes that OSWER Directive No. 9380.3-06FS, A Guide to Principal Threat and Low Level Threat Waste, states that source material "includes or contains hazardous substances, pollutants or contaminants that act as a reservoir for migration of contamination to groundwater, to surface water, to air, or acts as a source for direct exposure." Furthermore, the guidance states that PTW includes highly toxic waste (see Highlight 3). The Board recommends that in its decision documents, the Region include a more robust explanation as to how its reading of this directive and its approach to treatment are consistent with the statute and the NCP. In particular, this explanation should address CERCLA's preference for treatment "to the maximum extent practicable" as an independent parameter, which is separate and independent of CERCLA § 121 requirements regarding protectiveness and ARARs.

Remedy Performance

The information package frequently suggests that the Region is deferring discussion on the existing groundwater remedy to a future decision document. The Board recommends that progress made on the implementation of the existing groundwater remedy be included in this decision document, because, at the very least, the progress achieved to date may be relevant to the soil remedy approach and the inclusion of ICs. In addition, the Board recommends that the decision document contain a clear explanation that the ongoing groundwater cleanup is not being addressed as part of this remedial action at this time.

Applicable or Relevant and Appropriate Requirements

The Board notes that the ARAR list provided in Attachment 4 (Potential State and Tribal ARARs and TBCs) of the review package included items that should not be identified as ARARs (i.e., Executive Orders, Occupational Safety and Health Act, municipal ordinances). The Board recommends that the Region carefully review the ARAR list and, if needed, consult with Headquarters to ensure that all appropriate standards are included. In addition, the Region should make certain that statutory and regulatory references are precise enough to identify the specific substantive provisions related to particular components of all the altematives the Region considered, including the preferred altemative. The inclusion of this type of precise infonnation in the proposed plan is necessary if the interested public is going to have a meaningful opportunity to comment.

Cost

The preferred altemative (3 A) presented to the Board incorporated off-site disposal of excavated material from 0U7 and the ecological exceedance area in 0U2. The cost estimates for the preferred altemative is $29.8 million in comparison to altemative 3B, on-site disposal, which is $27.7 million. The site area includes a containment vault (0U2) as well as part of a former city dump (0U3). It appears that these areas will continue to manage site waste in perpetuity. Therefore, the Board recommends that the

5 St. Regis Final-5/20/11

Region reconsider the on-site disposal option for the excavated material in light of the potential cost-savings that may be realized.

In the package presented to the Board, all off-site disposal options only considered the use of tmcks to transport excavated material. With the close proximity of the BNSF Railway (one of the performing PRPs) tracks to the site, the use of rail to transport the excavated material could significantly reduce the costs and short-term impacts during remedy implementation. The Board notes that the LLBO discussed this point in their comments, and recommends that the Region evaluate this transportation option as part of the proposed altematives.

Administrative Record

The Board notes that the Region has information relevant to the remedy selection that exists in a number of site documents. Given the complexity of the issues surrounding the remedy decision, the Board recommends that the Region consolidate the existing record into an organized format that more clearly and easily summarizes and presents the data and data interpretations which have led to the Region's selection of the preferred altemative. The goal of this effort would be to effectively communicate the Region's basis and rationale for its selection of the preferred altemative in a fashion consistent with the statute, NCP, and relevant guidance; such communication would help facilitate meaningful public participation during the public comment period for the proposed plan.

Conclusion We commend the Region's colliaborative efforts in working with the Board and stakeholder groups at this site. We request that a draft response to these recommendations be included with the draft proposed plan when it is forwarded to the Office of Superfiind Remediation and Technology Innovation's Site Assessment and Remedy Decisions (SARD) branch for review. The SARD branch will work with both your staff and the Board to resolve any remaining issues prior to your release of the record of decision. This memo will be posted to the Board's website (http://www.epa.gov/superfund/programs/nrrb) within 30 calendar days of my signamre. Once your response is final and made part of the site's administrative record your response will also be posted on the Board's website.

Thank you for your support and the support of your managers and staff in preparing for this review. Please call me at (703) 347-0124 should you have any questions.

cc: J. Woolford (OSRTI) E. Southeriand (OSRTI) E. Gilberg (OSRE) R. Cheatham (FFRRO) D. Ammon (OSRTI) D. Cooper (OSRTI) NRRB Members

St. Regis Final - 5/20/11

June 17,2011 MEMORANDUM

SUBJECT: U.S. EPA Region 5 Superfiind Division Response to May 20, 2011 National Remedy Review Board Recommendations for the St. Regis Paper Company Site; Cass County, Mirmesota iss County. Mirmesota

FROM: j^ icQ^rd C. Kkl, Director Superfund Division

TO: Amy R. Legare, Chair National Remedy Review Board

On May 20, 2011, the National Remedy Review Board provided Recommendations to Region 5 on the Region's preferred remedial altemative for the St. Regis Paper Company site in Cass Lake, Minnesota. The following are Region 5's responses to the Board's Recommendations.

Site Characterization

NRRB Recommendation: Based on the information presented there has been: 1) no post-remedial action confirmation sampling conducted for the portions of the site that were subject to previous state-lead response actions (e.g., pond areas); 2) insufficient subsurface sampling to collect data on the horizontal and vertical extent of contamination; and 3) no evaluation of the potential for COC migration to groundwater. Given these shortcomings, the Board recommends that the Region include within the decision documents sufficient explanation regarding how site characterization is being accomplished consistent with the NCP (e.g., 40 CFR 300.430(b) and (d)), OSWER Directive No. 9355.3-01, October 1988, Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA, Interim Final (e.g.. Chapter 3.4), EPA guidance 540/1-89/002, December 1989, Risk Assessment Guidance for Superfund, Volume 1, Human Health Evaluation Manual (Part A), Interim Final (e.g.. Chapter 4); OSWER Directive No. 9355.4-23, July 1996, Soil Screening Guidance User's Guide (e.g.. Chapter 2).

The Board also recommends that the Region ensure decision documents address how future Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) response actions may address subsurface soils (since the HSCA 10 ppt standard for dioxin in soil appears to cover all soils, not just surface soil contamination) and/or groundwater contamination. In addition, the Board recommends that the Region require confirmation sampling for the previous state-lead response actions for the ponds to ascertain that the response action goals were met.

Region 5 Response: Region 5 will ensure that sufficient documentation exists in the Administrative Record to support its remedial altemative decision. Documentation will include the state-lead RI/FS and Remedial actions that were conducted by the Responsible Party and the subsequent work that was conducted to identify and address contamination that remained after the original Remedial actions.

Because the original Remedial actions conducted by the PRPs with MPCA oversight were performed to a visual standard, analytical data were not used to demonstrate that work had been conducted properly. In response to concems about contamination remaining on-site after implementation of the original remedial actions, EPA conducted a 2001 multi-media sample collection effort and then oversaw the 2003 soil Removal Program sampling effort by the PRPs. Information from these sampling events led to the excavation and offsite disposal of approximately 2,500 cubic yards of contaminated soil on property owned by the City of Cass Lake in 2004. Confirmation sampling was conducted for these actions, and no dioxin soil contamination above 1 ppb was left in the excavated areas. In addition, in 2006, the BNSF Railway Company performed a Removal Action on BNSF railway property by excavating approximately 500 cubic yards of contaminated soil above 5 ppb for dioxin and replacing it with clean soil, and by placing fencing and a vegetative cover in two areas with dioxin concentrations between 1 and 1.9 ppb. Removal actions were also conducted on property owned by Cass Forest Products in 2006 by placing fabric and gravel or fencing at two work areas with soil dioxin concentrations of 1.6 ppb and 1.2 ppb. In 2004 a Human Health and Ecological Risk Assessment was initiated (completed in 2011) to evaluate the risks that remained from residual site contamination. The soil risks identified in that risk assessment are being addressed by the final soil Remedial action.

The purpose of a Remedial Investigation, as noted in the NCP 300.403(d) is to "collect data necessary to adequately characterize the site for the purpose of developing and evaluating effective remedial altematives. To ch£u:acterize the site, the lead agency shall, as appropriate, conduct field investigations, including treatability studies, and conduct a baseline risk assessment." The guidance documents mentioned in the above Recommendation specify approaches for data collection in order to appropriately characterize a site. The necessary data to conduct a baseline risk assessment, and develop and evaluate remedial altematives for the remaining soil contamination at the St. Regis site exists collectively in the 1985 Remedial Investigation Report, the 1988 Response Action Report for the Treating Facility and the 1988 Response Action Report for the City Dump, the August 23, 2002 Data Evaluation Report, the January 2, 2004, Final Report for the 2003 St. Regis Site Soil Sampling and the January 19, 2011 Human Health and Ecological Risk Assessment. The post-Removal reports from the removal actions include the September 15, 2005 Final Report for UAO Soil Removal Action for City-owned Property, the September 2006 Soil Removal Action Implementation Report for BNSF Industrial Property; and the November 10, 2006 Completion of Voluntary Response Action at Cass Forest Products .

In a letter dated November 19, 2010, EPA addressed concems from the MPCA and the Leech Lake Band of Ojibwe (LLBO) about insufficient data to make a remedy selection decision for the remaining soil contamination. Specifically, lack of soil sampling at depth and possibility of contaminant hotspots in soil were identified as alleged data gaps.

Concem has been expressed by MPCA that there may be "hot spots" of highly contaminated soil on the site. Available information indicates that there are no remaining areas of highly contaminated soil left on site. Waste source and highly contaminated soil removal was a part of the original Remedial actions conducted by the Responsible Party under MPCA oversight, and

subsequent Removal actions based on additional soil sampling. Post-Removal confirmation sampling indicates that most of the soil left in the fonner operations area is less than the current residential dioxin preliminary remediation goal of I ppb. Two areas on the BNSF property with dioxin soil concentrations between 1.0 and 1.9 ppb have been vegetated and fenced pending the permanent soil remedy.

Since the original remedial actions, over 20 years of monitoring data have shown a measurable reduction in the contaminant concentration of the groundwater plume. Nine of the thirteen remedy extraction wells have seen significant reductions in the concentration of PCP over time. Currently, the average concentration of pentachlorophenol (PCP) pumped from the extraction wells into the treatment system from the site is 1,670 micrograms per liter (ug/L). The pump-and-ireat system has also been effectively reducing the mass of coniaminants in the groundwater. As of the end of the 2009 calendar year, over 12,000 kilograms (kg) of PCP and over 6,000 kg of PAHs had been removed from groundwater by the treatment system. Annual reports indicate that the annual PCP mass removal rates were approximately steady from 1991 to 2006 and have shown a decreasing rate from 2006 through 2009. Nonetheless, six extraction wells continue to pump elevated (>1000 ug/L) PCP concentrations. These facts indicate the continued efficacy of the groundwater pump-and-treat system and a gradually diminishing area releasing contaminants to groundwater.

The near-surface geologic regime of the site is sandy, which promotes the downward transport of any contamination in the soil colunrn to the water table. It would be inconsistent with observed reductions in site groundwater contamination if highly concentrated soil contamination remains above the water table and significantly contributes to the groundwater plume. There likely remains some contamination residues at or below the water table that serves as a source to the groundwater plumes associated with the former site ponds in Operable Unit 1 (OUI) and the city dump pit in OU3; however, this contamination is being addressed through the existing groundwater treatment system. Concentration histories from monitoring wells around the site generally indicate decreasing or stable concentrations. Stable concentrations occur near source areas or in distal portions of the plumes, while decreasing concentrations have mostly been recorded in intermediate wells. For example, at W212 located down-gradient of the OUI pump-and-treat wells, there has been a 1000-fold decrease in PCP and napthalene concentrations since 1986, while near-OU3-source W2106 shows essentially unchanged PCP concentrations during this period. The groundwater contaminant plumes will continue to be treated until groundwater remedial action objectives are met; therefore, the contamination residues at or below the water table are being addressed by the groundwater remedial action. EPA believes that this existing groundwater remedial action is an effective approach for addressing the groundwater source material.

There has been interest expressed by the LLBO for greater characterization of the residual soil contamination to determine a better estimate of the volume of soil contaminated above 10 ppt dioxin identified in the Feasibility Study. A lower estimate of soil contaminated above 10 ppt would indicate lower costs for the remedial altematives evaluated in the Feasibility Study that call for excavation of soil above 10 ppt dioxin.

After excavation of visibly contaminated soil from the site and placement in the on-site vault during the original Remedial actions, over 80% of the former operations area was re-graded. Additionally, soil from the 0U2 area was moved to portions of OUI. Therefore the residual contamination in the vertical soil profile can be expected to be heterogeneous over a large portion of the site. Because of the heterogeneity, it would be costly and time consuming to perform a new site characterization to reach a high degree of confidence. The site dioxin soil remediation goal is 10 ppt, and measured dioxin background in this area is 7-8 ppt. It would be extremely difficult to distinguish a reasonably manageable area or volume of soil contamination on the 160 acre site above 10 ppt dioxin. Existing data indicates, and it is a reasonable conclusion, that very large volumes of soil above 10 ppt dioxin remain at the site. The proposed remedial measure for residual soil contamination is cover with Institutional Controls. This approach provides.long-tenTi protection that is cost-effective and implementable. -,£PA believes that additional residual soil data is not necessary to support the proposed remedial action for residual soil contamination. An appropriate array of effective remedial measures for addressing this residual soil contamination is presented in the Feasibility Study.

Since (1) an initial remedy was implemented at the site to remove hotspots and visually contaminated soil after the performance of an RI/FS, (2) residually contaminated site soils have been redistributed over most of the former operations area, and; (3) Removal actions for contaminated soils have been conducted by the Responsible Parties under EPA oversight; Region 5 believes that a cover altemative for the former operations area, coupled with effective Institutional Controls, is adequate to address risks at the industrial/commercial portions of the site. Five-Year Reviews will be required to assure that the implemented remedy remains protective of human health and the environment.

The MPCA's remedial action objectives for removing the site ponds in the original Remedial action were to adequately protect the public and the environment from exposures to site contaminants from groundwater and surface water. As noted above, there is no reason to believe that significant contaminant source material remains in the soil column in the former pond area. EPA's continuing oversight of the site groundwater treatment system will ensure that the MPCA objectives are met. Confirmation sampling for the pond excavations, conducted over 20 years ago, after other significant sampling and Removal actions have taken place, is neither practical nor necessary.

Institutional Controls

NRRB Recommendation: The package presented to die Board describes institutional controls (ICs) that are common components of all remedial altematives but did not discuss differentiation between the types of controls necessary in order for each of the altematives to be protective. The Board recommends that the decision documents more clearly identify the media; activity to be restricted; and party responsible for implementing, monitoring and enforcing each IC. The Board also recommends that the Region keep in mind that ICs often can be more effective if they are layered or implemented in series. In addition, the cost of implementing the ICs should be included in the cost breakdown for each altemative. The Board recommends that the decision documents also

include descriptions of any requirements for cover/cap maintenance in those areas where ICs are required.

Region 5 Response: Appendix G to the FS Report, which will be a part of the Administrative Record for the site, contains tables that summarize the anticipated institutional controls for each altemative and for each Operable Unit of the site. ICs on deeds or property as well as ordinances are listed in order to obtain the necessary layering of controls.

Most of the required ICs will be on properties whose future use EPA views to be industrial/ commercial. These areas, which include 0U1,'0U2, and 0U3, are owned by the responsible parties. OUI is zoned industrial/commercial by the City of Cass Lake. 0U2 and 0U3 are not currently zoned but 0U2 is wholly owned by IP and contains the contaminated soil vault. 0U3 is owned by the City of Cass Lake and is the location of the city dump. EPA anticipates that ICs will be implemented by the owners on the OUI, OU2, and 0U3 properties to restrict land use and protect the soil cover. Additionally, ICs are needed to protect workers from potential exposures from digging over the contaminated groundwater plume areas. It is anticipated that Environmental Covenants/Easements will be implemented between the four owner/responsible parties and EPA. The City of Cass Lake also has an existing ordinance to prevent drilling water wells in the OUI area. Engineering controls to prevent worker exposures to the groundwater plumes are also planned and will be implemented by the property owners.

It is anticipated that most residential properties that will require excavation will reach background for the COCs within the first foot. No ICs will be needed for these properties. However, if a residential excavation does not reach background within the top 2-feet, a residential IC will be sought, such as a city registry and deed notices. With respect to private properties that do not require excavation but have residual soil contamination that is above the HSCA clean up levels and will require a clean soil cover, ICs, in the form of deed notices and a city registry, will be sought. The purpose of residential area ICs will be for the protection of the soil cover and notification of contamination at depth. Residential ICs, although difficult to procure, would be implemented under EPA oversight.

Estimates of the overall costs to implement ICs, based on professional judgment, are a part of the costs listed under each Altemative in the FS Report

Human Health Risk

NRRB Recommendation: The information presented to the Board indicates that the Region will meet the HSCA soil cleanup goal of 10 ppt dioxin by averaging the surface soil concentration site wide. The Board recommends that, to help ensure protectiveness, the Region consider meeting the 10 ppt dioxin soil cleanup goal by exposure units (i.e., individual residential properties), consistent with OSWER Directive No. 9285.6-10, December 2002, Calculating Upper Confidence Limits for Exposure Point Concentrations at Hazardous Waste Sites. For large commercial/industrial areas.

the Board recommends that the Region consider breaking the site or the individual OUs into small sub areas and meeting the cleanup criteria for each individual sub area.

Region 5 Response: In response to the Board's request. Region 5 evaluated the use of exposure units for site remediation as opposed to a site-wide surface average. After a review of both residential and industrial/commercial site properties. Region 5 decided use individual property boundaries for residential properties as exposure units, as recommended, and to utilize the grid stmcture developed for soil sampling of the industrial/commercial areas as exposure units for those properties. The existing sampling grid was developed for 5-point conipositc sampling for the 2001 and 2003 sampling events and was expanded for the 2004 sampling'program. Grid cell size in the industrial/commercial areas ranges from about 0.4 acres to about 3.5 acres. Region 5 considers these cells the appropriate exposure units for the industrial/commercial areas. They are about the recommended size and they represent reasonable units of exposure. Altemative 4 of the FS Report utilizes these grids, along with individual residential properties, as exposure units to determine which grid cells meets PRGs. Selecting Altemative 4 as the remedial altemative will result in a clean up based on the exposure units recommended by the Board. For that reason. Region 5 has decided to propose selection of Altemative 4 as the preferred altemative for soil remediation at the St. Regis site.

Principal Threat Waste

NRRB Recommendation: The package presented to the Board did not address the presence of principal threat waste (PTW) in surface soils at the site (as opposed to potential non-aqueous phase liquids [NAPLs] in groundwater plumes). However, the Region did mention PTW in the nine-criteria evaluation portion of the package where it indicated the PTW materials were not present for the surface soil remedy. The Board notes that OSWER Directive No. 9380.3-06FS, A Guide to Principal Threat and Low Level Threat Waste, states that source material "includes or contains hazardous substances, pollutants or contaminants that act as a reservoir for migration of contamination to groundwater, to surface water, to air, or acts as a source for direct exposure." Furthermore, the guidance states that PTW includes highly toxic waste (see Highlight 3). The Board recommends that in its decision documents, the Region include a more robust explanation as to how its reading of this directive and its approach to treatment are consistent with the statute and the NCP. In particular, this explanation should address CERCLA's preference for treatment "to the maximum extent practicable" as an independent parameter, which is separate and independent of CERCLA § 121 requirements regarding protectiveness and ARARs.

Region 5 Response: Region 5 will include a discussion of principal threat wastes in the decision document. The proposed remedy addresses residual soil contamination. The contaminated soil is not a source material, and is not highly toxic or highly mobile; therefore not a principal threat waste. There is no known treatment for soil contaminated at these low concentrations; therefore the proposed remedial actions provide for treatment to the maximum extent practicable.

Remedy Performance

NRRB Recommendation: The information package frequently suggests that the Region is deferring discussion on the existing groundwater remedy to a future decision document. The Board recommends that progress made on the implementation of the existing groundwater remedy be included in this decision document, because, at the very least, the progress achieved to date may be relevant to the soil remedy approach and the inclusion of ICs. In addition, the Board recommends that the decision document contain a clear explanation that the ongoing groundwater cleanup is not being addressed as part of this remedial action at this time.

Region5 Response: ..<..-, Region 5 will ensure that documentation on the history and progress of the gi'oundwater remedy'^ is included in the Record of Decision for the site. A short discussion of the success of the implemented groundwater Remedial action is found in the response to the Site Characterization Recommendation.

ARARs

NRRB Recommendation: The Board notes that the ARAR list provided in Attachment 4 (Potential State and Tribal ARARs and TBCs) of the review package included items that should not be identified as ARARs (i.e.. Executive Orders, Occupational Safety and Health Act, municipal ordinances). The Board recommends that the Region carefully review the ARAR list and, if needed, consult with Headquarters to ensure that all appropriate standards are included. In addition, the Region should make certain that statutory and regulatory references are precise enough to identify the specific substantive provisions related to particular components of all the altematives the Region considered, including the preferted altemative. The inclusion of this type of precise information in the proposed plan is necessary if the interested public is going to have a meaningful opportunity to comment.

Region 5 Response: Region 5 has reviewed the ARAR list contained in the FS Report and is confident that document accurately represents potential ARARs for the site. The Record of Decision will list requirements that are considered ARARs for the site. Region 5 will consult with HQ on the ARAR list during ROD development.

Cost

NRRB Recommendation: The preferred altemative (3 A) presented to the Board incorporated off-site disposal of excavated material from 0U7 and the ecological exceedance area in 0U2. The cost estimates for the preferred altemative is $29.8 million in comparison to altemative 3B, on-site disposal, which is $27.7 million. The site area includes a containment vault (0U2) as well as part of a former city dump (OU3). It appears that these areas will continue to manage site waste in perpetuity.

Therefore, the Board recommends that the Region reconsider the on-site disposal option for the excavated material in light of the potential cost-savings that may be realized.

In the package presented to the Board, all off-site disposal options only considered the use of tmcks to transport excavated material. With the close proximity of the BNSF Railway (one of the performing PRPs) tracks to the site, the use of rail to transport the excavated material could significantly reduce the costs and short-term impacts during remedy implementation. The Board notes that the LLBO discussed this point in their comments, and recommends that the Region evaluate this transportation option as part of the proposed altematives.

Region 5 Response: Region 5 considers that the discussion of costs associated with on-site disposal options within the FS Report to contain sufficient detail for the purposes of evaluation of those altematives. Region 5 will ensure that the Proposed Plan and Record of Decision for the site contain sufficient justification for the choice of off-site soil disposal. Within that discussion. Region 5 will weigh the added cost of off-site disposal, estimated to be less than 4% of the total cost or $1.8 M, against tribal and community concems associated with leaving contaminated soil on site.

The responsible parties have generated a preliminary cost estimate for transporting soil by rail in Altemative 6A as an addendum to the FS Report. The cost for rail transport was determined to be more expensive than the cost of tmcking. The duration of contaminated soil load out was also anticipated to be several years longer for rail compared to tmcking. In addition to the cost issues, the responsible parties detailed implementation issues, including potential difficulties securing approvals to constmct a rail spur for soil unloading.

Administrative Record

NRRB Recommendation: The Board notes that the Region has information relevant to the remedy selection that exists in a number of site documents. Given the complexity of the issues surrounding the remedy decision, the Board recommends that the Region consolidate the existing record into an organized format that more clearly and easily summarizes and presents the data and data interpretations which have led to the Region's selection of the preferred altemative. The goal of this effort would be to effectively communicate the Region's basis and rationale for its selection of the preferred altemative in a fashion consistent with the statute, NCP, and relevant guidance; such communication would help facilitate meaningful public participation during the public comment period for the proposed plan.

Region 5 Response: Region 5 will ensure that the Administrative Record contains all the data and documents considered to propose and select the site remedial action. Reviewers evaluating the Agency's record process will have the information considered by the Agency in reaching the decision to propose and select the remedial action. The record will be clearly indexed and organized.

Thank you for the national perspective the NRRB has provided on the St. Regis Paper Company site remedy selection process. Please contact me at 312-886-4752, or the Remedial Project Manager, Tim Drexler, at 312-353-4367, if you have any questions about this response.

cc: J. Woolford (OSRTI) E. Southeriand (OSRTI) E. Gilberg (OSRE) J. Reeder (FFRRO) D. Ammon (OSRTI) D. Cooper (OSRTI) NRRB Members

EPA Proposes Soil Cleanup Plan for St. Regis Paper Company Site

St. Regis Paper Company Site Leech Lake Reservation Cass County, Minnesota

Date: June 17, 2011

The purpose of this Proposed Plan is to give background information about the St. Regis Paper Company site, describe the various cleanup altematives considered, and identify EPA's preferred cleanup alternative. The public is encouraged to comment on this Proposed Plan. EPA will be accepting comments for 30 days from the issuance of this Proposed Plan. Members of the public are also encouraged to attend and participate in a public meeting at the Cass Lake-Bena Elementary School at 15 4 6:30 pm.

th Street NW, Cass Lake, Minnesota, on Thursday, June 23, 2011, at

The St. Regis Paper Company Site Location

To clean up soil contamination at the St. Regis Paper Company site, the U.S. Environmental Protection Agency Region 5 (EPA) is proposing the following remedial measures: 1) excavate or cover contaminated soil on impacted residential properties and backfill excavated soil with clean soil; 2) cover contaminated soil on industrial/commercial properties owned by the site responsible parties with one foot of clean soil and maintain the cover; 3) pave commercial/industrial work areas that use heavy equipment and pave residential/commercial unpaved roads; 4) excavate contaminated soil in a former site work area due to ecological risks;

5) transport the excavated contaminated soil to an off-site facility for disposal, 6) monitor surface water in the nearby forested wetland; and 7) place institutional controls on property where hazardous substances above cleanup levels remain below the cover or soil backfill area.

These measures to remediate the site will be protective of human health and the environment, meet applicable and/or relevant and appropriate regulations, be cost effective, and will be effective in the long term.

After review and consideration of information provided by the public during a comment period and at a public meeting, and consultation with its Tribal partner the Leech Lake Band of Ojibwe (LLBO) and its State partner the Minnesota Pollution Control Agency (MPCA), EPA will select a final cleanup plan for contaminated soil at the site. The final cleanup plan, which will be announced in local newspaper notices and presented in an EPA document called the Record of Decision (ROD), could differ from this Proposed Plan depending on information or comments EPA receives during the public comment period.

The public is also encouraged to review the supporting documents for the St. Regis Paper Company site at any of the following locations: the Cass Lake Library, the Bemidji State University Library, the LLBO Division of Resource Management, and the Cass Lake City Clerk's Office. The supporting documents include, but are not limited to, the 1985 Remedial Investigation Report, the 1988 Response Action Reports for the Treating Facility and the City Dump, and the soil sampling results from investigations by EPA and responsible parties for the site, including the 2002 Data Evaluation Report, the 2004 Final Report for the 2003 St Regis Site Soil Sampling, the 2006 Soil Removal Action Implementation Report for BNSF Industrial Property, the 2006 Completion of Voluntary Response Action at Cass Forest Products, and the 2011 Human Heahh and Ecological Risk Assessment (HHERA) and the 2011 Site Feasibility Study (FS) Report. The HHERA studied the potential for health effects to residents and workers from the remaining site soil contamination; and effects on the environment from contamination at the site. The FS identified, evaluated, and compared different cleanup alternatives.

About the St. Regis Paper Company Site

The St. Regis Paper Company site (site) is located in the City of Cass Lake, Cass County, Minnesota and is fully within the exterior boundaries of the LLBO Reservation. The former operations area of the site is primarily on 125 acres of property south of the BNSF Railway tracks, and east of Highway 371, and was used as a wood treatment facility from about 1958 until 1985. The site includes any areas where contamination from the wood treatment facility has migrated. The site includes residential properties near the former operations area and areas of site-related contamination adjacent to the City of Cass Lake's former municipal dump which is located south of a portion of the Chippewa National Forest, east of County Road 147, and north of Fox Creek.

The wood treating process at the site consisted primarily of pressure treating wood with creosote and other chemicals. Wastewater from wood treating was placed in ponds on the site between 1957 and 1980. This wastewater was also used occasionally to spray grass near the ponds and other areas of the site. After 1980, site wastewater was reused, evaporated in tanks, or disposed

in a sewage drain located in Chippewa National Forest that led to the City of Cass Lake sewage treatment tank near the City Dump. Sludge from wood treatment was disposed of on the eastern edge of the site and in a waste pit near the Cass Lake City Dump. Sludges and waste oil from the site were occasionally burned in that waste pit.

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In 1984, the St. Regis Paper Company site was listed on the EPA National Priorities List (NPL). In 1985, the MPCA and the former owner/operator of the wood treating facility, Champion International Corporation (Champion), reached an agreement on clean up for the site. MPCA and Champion signed two clean up orders, one for the wood treatment area and one for the waste pit near the City Dump. Wood preserving operations ceased in the fall of 1985.

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St. Regis Paper Company Site Operable Units

Site Characteristics

A Remedial Investigation and Feasibility Study (RI/FS), completed in 1984 under MPCA oversight, identified contaminants of concern (COCs) that pose potential risks to human health and/or the environment including; pentachlorophenol, dioxin, and polycyclic aromatic hydrocarbons. Pentachlorophenol (PCP) was used as a part of the wood treatment process at the site. PCP is a manufactured chemical that is used for wood preservation and as an insecticide.

PCP can cause liver effects, damage to the immune system, reproductive effects, and developmental effects. Dioxin was an impurity in the PCP that was used at the St. Regis site. Dioxin has been shown to be very toxic in animal studies and, in humans, causes effects on the skin and probably causes cancer. Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals formed during the incomplete burning of coal, oil, gasoline, wood, garbage, or any plant or animal material. It is found in cigarette smoke, soot, and creosote. Animal studies show some PAHs caused birth defects and decreased body weight. In humans, breathing or long periods of skin contact to mixtures that contain PAHs can cause cancer. EPA's evaluations further identified high molecular weight PAHs (HPAHs) and benzo(a)pyrene equivalent B(a)PE, which are groups of PAHs. HPAHs are a useful combination of PAHs for determining ecological risk. B(a)PE is a group of PAHs used to determine human health risk.

The MPCA developed three Operable Units as a part of the RI/FS for the site. Operable Unit 1 (OUI), located approximately between South 3'̂ '̂ Street and the BNSF Railway tracks, consists of the north former operations area, of which portions are currently owned by the site responsible parties: Intemational Paper Company (IP) who acquired Champion, BNSF Railway Company (BNSF), the City of Cass Lake, and Cass Forest Products. Operable Unit 2 (0U2) is a former operations area to the southwest of OUI. IP is the sole owner of 0U2. 0U3 is that portion-of the former City of Cass Lake dump on which site-related wood preservation contaminants were located. 0U3 is owned by the City of Cass Lake. EPA also identified Operable Unit 7 (0U7) which is composed of the predominantly residential area surrounding the site. Operable Units 4, 5, and 6 are for administrative purposes only.

The 1984 RI/FS identified large areas of soil contamination in OUI and 0U2 and a smaller area of soil contamination in 0U3. Former ponds, used for the disposal of contaminated sludges, were also evaluated. In addition, two areas of groundwater contamination were identified in OUI and 0U3 with high concentrations of PCP and PAH.

Work performed by Champion under state oversight to address site contamination included clean up of the soil and containment and treatment of the contaminated groundwater as well as monitoring the remaining contamination. Specifically, the clean up involved: (1) excavating over 40,000 cubic yards of visibly contaminated soil and the sludge from excavated ponds and the city dump pit and placing the material in a newly constructed on-site RCRA-standard hazardous waste cell, commonly referred to as the "containment vault"; (2) installing contaminated groundwater extraction wells at OUI and 0U3 and a groundwater treatment system; (3) long-term operation and maintenance of the groundwater extraction and treatment system; (4) long-term operation and maintenance of the containment vault; and (5) long-term monitoring of the groundwater.

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Pipelines

MPCA Site Remedial Actions

In 1995, EPA became the lead agency for the St. Regis site. Because the standard at the time of the first site remedy was to clean up contaminated soil to visual standards (if visible staining was removed, the area was considered clean), no confirmatory sampling was conducted after completion of the cleanup. Concerns were later raised during the Remedy Reviews, conducted every 5 years, about possible remaining contamination. As a result, in 2001, EPA conducted additional sampling, including soil sampling. EPA concluded that OUI and 0U2 needed to be further evaluated for possible additional soil removal. EPA also determined that a risk assessment was needed to evaluate how protective the remedy was to residents, workers, and the environment. During 2003 and 2004, samples of soil, sediment, surface water, house dust, groundwater, plants, and animals were collected and evaluated by EPA, LLBO, and IP. Soil sampling was predominantly surficial with some additional samples at the one-foot and two-foot depths. EPA collected mostly shallow samples because human health risk assessments are based on the shallow soils to which residents and workers are mostly exposed.

Sampling on GUI showed soil dioxin values as high as 7,100 parts per trillion (ppt) on city property and 6,200 ppt on BNSF property. 0U2 had dioxin soil values as high as 3,300 ppt. 0U3 showed dioxin values in the soil as high as 385 ppt. B(a)PE values in OUI ranged from below the average background concentration of 1.6 milligrams per kilogram (mg/kg) to 11.6

mg/kg. At 0U2, two values of 33 mg/kg and 12 mg/kg were present. No other values for B(a)PE in 0U2 exceeded 3.9 mg/kg.

Soil sampling conducted on the residential properties of 0U7 in 2001, 2003, and 2004 showed contaminant concentrations for dioxin ranging from below the average background level of about 7.5 ppt to 480 ppt. B(a) PE values on residential properties were all below 1.47 mg/kg. Indoor settled dust samples were also collected in ten of the neighborhood homes that were selected based on the yard dioxin soil concentrations. The screening value of 2 nanograms per square meter for dioxin, based on the New York World Trade Center response, was exceeded at five of the sampled residences. For that reason, in 2005 as an interim measure, EPA issued an interim Record of Decision (ROD) and ordered IP to clean the inside of nearby residences, apply a three-inch layer of clean soil and grass on yards, and apply dust suppressant to unpaved roads.

Based on soil sampling results that exceeded EPA policy standards, EPA ordered IP to excavate shallow soil on the City-owned property above 1,000 ppt for dioxin. Also, through a 2005 Consent Order with EPA, BNSF excavated shallow soil on its property that was above 5,000 ppt and the remaining soil in the excavation, with a concentration of 1,100 ppt, was covered with clean soil. Two other contaminated soil areas on the BNSF property that were between 1,000 and 1,900 ppt for dioxin were vegetated and fenced. Two contaminated soil areas were also identified on Cass Forest Products property with values that were 1,600 ppt and 1,200 ppt for dioxin. These areas were either capped with fabric and gravel or fenced by IP to prevent exposures to workers. In all, these EPA-lead cleanups resulted in excavation of more than 3,900 tons of contaminated soil from former operations areas. The soil was disposed offsite.

Although this proposed remedy concerns site soils only, EPA also continues to evaluate the site groundwater. Groundwater contamination at the site remains at OUI and 0U2 and continues to be treated by the extraction system put in place by the responsible parties in the late 1980s. Since the original remedial actions, over 20 years of monitoring data have shown a measurable reduction in the contaminant concentration of the groundwater plume. Nine of the thirteen remedy extraction wells have seen significant reductions in the concentration of PCP over time. Currently, the average concentration of PCP pumped from the extraction wells into the treatment system from the site is 1,670 parts per billion (ppb), indicating the system continues to pump elevated PCP concentrations. The pump-and-treat system has also been effectively reducing the mass of contaminants in the groundwater. As of the end of the 2009 calendar year over 12,000 kg of PCP and over 6,000 kg of PAHs had been removed from groundwater by the treatment system. Annual reports indicate that the annual PCP mass removal rates were approximately steady from 1991 to 2006 and have shown a decreasing rate from 2006 through 2009. These facts indicate that the groundwater pump-and-treat system continues to be effective and that there is a gradually diminishing area releasing contaminants to groundwater.

SCOPE AND ROLE OF THE ACTION

EPA expects that this action will be the final action for contaminated soil at the site. IP, under the oversight of EPA with assistance from LLBO and MPCA, will continue to evaluate the site groundwater remedy and monitor the remainder of the site to make sure that it is protective of human health and the environment. IP will also continue to operate the groundwater treatment

system and monitor the groundwater until drinking water standards are reached. The Remedial Action Objectives for the St. Regis Soil Remedy are to prevent current and future exposure to contaminated soil through a combination of excavation, clean soil cover, and paving at the site.

SUMMARY OF SITE RISKS

IP conducted an HHERA under the oversight of EPA, in consultation with LLBO and MPCA, to determine the current and future effects of site contaminants on human health and the environment. 0U7 is zoned residential by the City of Cass Lake. This is the current and reasonably anticipated future land use for this portion of the site. Therefore, the HHERA focused on health effects for both children and adults, in a residential setting in 0U7, that could result from current and future direct contact with contaminated soil. OUI is zoned industrial/commercial by the City of Cass Lake. 0U2 is commercial property owned by IP and 0U3 is the location of site-related contaminants adjacent to the city dump. The HHERA evaluated worker exposures in OUI, 0U2, and 0U3. Ecological risk was evaluated in all areas in and adjacent to the site. It is EPA's current judgment that the measures identified in the Preferred Alternative in this Proposed Plan, or other active measures considered in the Proposed Plan, are necessary to protect public health and the environment from actual or threatened releases of hazardous substances into the environment.

This proposed plan addresses only the risks from contaminants in soils.

Human Health Risks

The HHERA evaluated risks to human health resulting from site wood treating operations. In August 2008, the HHERA concluded that there were still risks to residents and workers at the site above EPA's acceptable levels. Based on these resuhs, IP and BNSF Railway Company agreed in September 2008, to perform an FS to evaluate remedial alternatives for addressing the remaining site risks. EPA approved the FS Report in June 2011.

The HHERA showed that the following exposures to the contaminated soil and groundwater at the site present unacceptable risks to human health:

• Future exposure of residents to dioxin and B(a)PE contaminated soil in yards; • Current and future exposure of industrial workers to dioxin and B(a)PE contaminated

soil in industrial/commercial areas of the site; and • Future exposure of utility workers to PCP and PAH contaminated groundwater by

digging in either a portion of the former operations area or in the pit area near the former city dump.

Ecological Risks

The HHERA also evaluated ecological risks associated with the site former wood treating operations at the site and in adjacent areas that included Fox Creek, Cass Lake, and Pike Bay. The HHERA showed that the following exposures to contaminated soil at the site present unacceptable risks to invertebrates:

• Current exposure to PCP and HPAHs in a portion of the former operations area near the southwestem comer of the containment vault ("ecological risk area").

REMEDIAL ACTION OBJECTIVES

The Remedial Action Objectives for the site include:

• Prevent unacceptable potential risk to human health from future exposure to site-related COCs by eating soil or garden vegetables, breathing soil and indoor dust, and skin contact at residential properties in and adjacent to 0U7.

• Prevent unacceptable potential risk to human health from future exposure to site-related COCs in OUI, 0U2, and 0U3 through eating or breathing of soil, skin contact, and indoor dust routes, from worker exposures.

• Prevent unacceptable potential risk to human health from future exposure to site-related COCs in OUI and 0U2 surface soil through transfer by runoff and/or windblown dust to nearby residential property and roads.

• Prevent unacceptable potential risk from future exposures to site-related COCs in OUI and 0U3 through eating, breathing, and skin contact during below-ground construction by workers in the areas of contaminated groundwater.

• Prevent unacceptable risks to organisms from exposure to site-related COCs in 0U2 soil.

This proposed action will reduce the excess cancer risk associated with exposure to contaminated soil to about one in 1,000,000. This will be achieved by reducing the concentrations of the soil contaminants and covering soil to proposed target levels. EPA has also identified target contaminant levels for organisms in the 0U2 area. The proposed action will reduce environmental exposures for these target organisms to acceptable levels.

PRELIMINARY CLEAN UP LEVELS

Contaminants of Concern

The Contaminants of Concern identified in the HHERA for human health include dioxin and B(a)PE. Contaminants of Concern identified for ecological risk include HPAHs and PCP. These contaminants are described in the Site Characteristics section of this Proposed Plan.

Preliminary Remediation Goals

Preliminary Remediation Goals (PRGs) are used in developing and evaluating alternative clean up actions for a site. Final clean up levels will be established in the ROD. EPA developed the proposed cleanup levels for the soil contaminants identified in the HHERA based on both protective risk-based calculations in the HHERA and a review of tribal and state clean up

regulations which are referred to as Applicable or Relevant and Appropriate Requirements (ARARs).

Based on the results of the HHERA, EPA considers 63 parts per trillion (ppt) for dioxin and the background level of 1.6 parts per million (ppm) for B(a)PE in soil to be protective of human health in 0U7. For OUI, 0U2, and 0U3, the calculated clean up concentrations of 380 ppt for dioxin and 4.1 ppm for B(a)PE are protective of worker exposures. These values represent the middle of EPA's acceptable range of protectiveness from one in 10,000 to one in 1,000,000 excess cancer risk. EPA selected this level of protection, one in 100,000, based on a consideration of LLBO tribal lifeways and uncertainties identified in the HHERA, including dioxin cancer risks.

Groundwater contamination continues to be addressed by the groundwater pump and treatment system previously installed and currently operated by IP. EPA is evaluating the effectiveness of the groundwater system independent of the action proposed in this document. While there are no current industrial or residential uses of groundwater, potential exposure to that contaminated groundwater by utility workers digging in site soil will be addressed in this action.

For protection of the ecological risk area in 0U2, EPA considers a clean-up level of 31 ppm for PCP and 18 ppm for HPAHs in soil to be protective of the environment based on studies of invertebrate toxicity.

Site ARARs

In 2000, LLBO promulgated the Hazardous Substances Control Act (HSCA) which establishes contamination clean up levels within the Reservation. The HSCA establishes a 10 ppt clean up level for dioxin in soil, which represents approximately a one in 1,000,000 excess cancer risk and is at the high end (most protective) of EPA's acceptable risk range. EPA considers the HSCA an ARAR for this site. Therefore, in addition to considering alternatives that meet the clean up levels identified by the site HHERA, altematives with methods for lowering the residual surface soil contamination to less than or equal to 10 ppt for dioxin are also evaluated.

The HSCA requires a clean up level of 2 parts per billion (ppb) for PCP in soil. Therefore, EPA evaluated alternatives whh methods that lower residual surface soil contamination in the ecological risk area of 0U2 to less than or equal to 2 ppb PCP for soil.

HSCA does not have cleanup standards for either B(a)PE or HPAHs.

SUMMARY OF REMEDIAL ALTERNATIVES

Remedial alternatives for the St. Regis Paper Company site are presented below. The alternatives are numbered to correspond with the numbers in the 2011 FS Report.

Common Elements

All of the altematives, with the exception of the "No Action" alternative (Altemative 1), contain common components. All of the action altematives require excavation of soil in 0U7 and in the area of ecological risk in 0U2. Except for Alternative 1, all of the altematives include institutional controls (e.g. deed restrictions such as an easement or covenant) to limit the use of portions of the site property, preserve the soil cover, and to ensure that workers are not exposed to the contaminated groundwater. Institutional Controls, including deed restrictions and restrictive covenants and easements on OUI, 0U2, and 0U3 will be implemented under EPA oversight and with the necessary involvement of the appropriate Support Agency. Monitoring to ensure the effectiveness of the remedy, including effectiveness of deed restrictions, are a component of each altemative, except Altemative 1, and will be implemented by the property owners. Monitoring and control of air quality (dust) during construction will be required for all alternatives. All altematives except Alternative 6 also include paving the unpaved roads in the site area and paving the work areas using heavy equipment on the Cass Forest Products property.

Cleanup Alternatives

EPA considered eight alternatives for cleaning up the St. Regis Paper Company site, each of which was evaluated against seven criteria required by Superfund law. The alternatives will be further evaluated against two criteria of tribal/state acceptance and community acceptance. See the "Explanation of the Nine Evaluation Criteria" section below. These alternatives are further explained in the FS. Here are summaries of the alternatives. Note that the soil cover and excavation volumes listed for each altemative are in cubic yards.

Cleanup Alternative 1 - No action

EPA includes a "No-Action" Alternative as a basis for comparison to the other cleanup alternatives. Since no action would be taken, this option would not protect human health and the environment from either current or future risk. House cleaning Interim Actions would also stop.

Cost: $0 Estimated O&M Cost: $0

Cleanup Alternatives 2A and 2B

Alternative 2A includes excavating contaminated soil on 0U7 above 63 ppt dioxin and the site background concentration of 1.6 ppm for B(a)PE to a maximum depth of 2 feet. EPA anticipates that contamination on most residential properties will be reduced to background levels in the first foot of excavation. If soil remains contaminated above clean up levels at the two-foot depth, marker material would be placed in the excavation before clean soil is placed on the yard. Institutional Controls, such as deed notices, would be sought for residential properties that will have residual contamination below the two-foot excavation depth. Other Institutional Controls such as a city registry of soil contamination at depth, would also be considered.

At OUI, 0U2, and 0U3, marker material and a one-foot layer of clean fill and top soil, followed by vegetation, would be placed in all areas with surface contamination above 380 ppt for dioxin and 4.1 ppm for B(a)PE. Institutional controls, which consist of non-engineered requirements relating to property use, would then be implemented by the property owners, the responsible parties for these areas, to monitor, protect and maintain the cover. Additionally, the heavy machinery areas owned by Cass Forest Products and all unpaved commercial and residential streets in the site area would be paved. Contaminated soil would also be excavated in the ecological risk area of 0U2 to a PCP concentration of 31 ppm and a HPAH concentration of 18 ppm. Institutional controls and warning signs would be placed in the contaminated groundwater areas of OUI and 0U3 by the responsible parties to prevent potential worker exposure by digging. Finally, the forested wetland area east of the former operations area would be monitored for any surface water contamination above acceptable levels.

Alternative 2B is identical to Altemative 2A, except that excavated soil under this altemative will be placed in a new on-site cell and covered.

Altemative 2A Alternative 2B Estimated Cost: $ 22.5 million Estimated O&M Cost (30 Yrs): $313,252 Estimated Construction Time: 3 Years Estimated Soil Cover: 78,600 Estimated Soil Excavation: 31,300 Estimated Truck Trips: 9,400

Estimated Cost: $ $20.3 million Estimated O&M Cost(30 Yrs): $310,782 Estimated Construction Time: 3 Years Estimated Soil Cover: 83,800 Estimated Soil Excavation: 31,300 Estimated Truck Trips: 7,700

Cleanup Alternatives 3A and 3B

Alternative 3A includes all of the elements of Altemative 2 except that the marker and one-foot clean soil cover on OUI, 0U2, and 0U3 would be extended to include all areas with surface contamination of dioxin above 63 ppt and B(a)PE concentrations above 1.6 ppm. ICs and monitoring would be extended to include the additional areas of cover.

Alternative 3B is identical to Altemative 3 A, except that excavated soil under this altemative will be placed in a new on-site cell and covered.

Alternative 3A Alternative 3B Estimated Cost: $29.8 million Estimated O&M Cost(30 Yrs): $400,446 Estimated Construction Time: 3 Years Estimated Soil Cover: 154,000 Estimated Soil Excavation: 31,300 Estimated Truck Trips: 14,400

Estimated Cost: $ 27.7 million Estimated O&M Cost(30 Yrs): $400,446 Estimated Construction Time: 3 Years Estimated Soil Cover: 161,400 Estimated Soil Excavation: 31,300 Estimated Truck Trips: 12,800

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Cleanup Alternatives 4A (EPA's Preferred Cleanup Alternative) and 4B

Alternative 4A includes all of the elements of Alternative 2 except that the one-foot clean soil cover and marker material on OUI, 0U2, and 0U3 would be extended to include any areas in OUI, 0U2, and 0U3 with surface dioxin soil contamination above 10 ppt for dioxin and also all unexcavated areas of 0U7 that are above 10 ppt for dioxin. In addition, a one-foot soil cover and marker material would be placed over surface contamination above the HSCA clean up value of 2 ppb for PCP in the ecological risk area of 0U2 that is not already addressed by excavation. ICs and monitoring would be extended to include the additional areas of cover.

Alternative 4B is identical to Altemative 4A, except that excavated soil under this altemative will be placed in a new on-site cell and covered.

Alternative 4A Alternative 4B Estimated Cost: $45.8 million Estimated O&M Cost(30 Yrs): $598,925 Estimated Construction Time: 5 Years Estimated Soil Cover: 326,200 Estimated Soil Excavation: 31,300 Estimated Truck Trips: 25,900

Estimated Cost: $ 44 million Estimated O&M Cost(30 Yrs): $598,925 Estimated Construction Time: 5 Years Estimated Soil Cover: 333,600 Estimated Soil Excavation: 31,300 Estimated Truck Trips: 24,300

Cleanup Alternatives 5A and 5B

Alternative 5A includes all of the elements of Alternative 3, but instead of cover on OUI, 0U2, and 0U3, all site areas with soil contamination above 63 ppt for dioxin and background concentrations for B(a)PE would be excavated. The excavated soil would be transported to an off-site landfill and replaced with clean fill and topsoil.

Alternative 5B is identical to Altemative 5A, except that excavated soil under this altemative will be placed in a new on-site cell and covered.

Alternative 5A Alternative 5B Estimated Cost: $103 million Estimated O&M Cost (30 Yrs): $401,050 Estimated Construction Time: 3 Years Estimated Soil Cover: 12,400 Estimated Soil Excavation: 607,700 Estimated Truck Trips: 81,800

Estimated Cost: $ 45 million Estimated O&M Cost (30 Yrs): $399,488 Estimated Construction Time: 3 Years Estimated Soil Cover: 123,300 Estimated Soil Excavation: 363,400 Estimated Truck Trips: 32,400

Cleanup Alternatives 6A and 6B

Alternative 6A is similar to Alternative 5 except that the excavation of contaminated soil in all site areas would be performed on soil that is above 10 ppt for dioxin and excavation in the area of ecological risk would be to the HSCA value of 2 ppb for PCP. The 10 ppt value for dioxin corresponds to about a one in 1,000,000 excess cancer risk.

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Alternative 6B is identical to Altemative 6A, except that excavated soil under this altemative will be placed in a new on-site cell and covered.

Alternative 6A Alternative 6B Estimated Cost: $ 201 million Estimated O&M Cost (30 Yrs): $616,988 Estimated Construction Time: 5 Years Estimated Soil Cover: 0 Estimated Soil Excavation: 1,157,000 Estimated Truck Trips: 154,000

Cleanup Alternatives 7A and 7B

Estimated Cost: $ 82 million Estimated O&M Cost (30 Yrs): $612,612 Estimated Construction Time: 5 Years Estimated Soil Cover: 168,400 Estimated Soil Excavation: 562,000 Estimated Truck Trips: 48,700

Alternative 7A is similar to Alternative 2 except it would excavate soil in 0U7 that is above 190 ppt for dioxin in surface soil and 8.1 ppm for B(a)PE in surface soil. Cover would be applied in OUI, 0U2 and 0U3 to surface soil that exceeds 2,000 ppt for dioxin and 41 ppm for B(a)PE. These clean up levels correspond to a one in 10,000 excess cancer risk.

Alternative 7B is identical to Altemative 7A, except that excavated soil under this altemative will be placed in a new on-site cell and covered.

Altemative 7A Altemative 7B Estimated Cost: $12.4 million Estimated O&M Cost (30 Yrs): $229,303 Estimated Construction Time: 2 Years Estimated Soil Cover: 9,200 Estimated Soil Excavation: 27,600 Estimated Truck Trips: 4,300

Cleanup Alternatives 8A and 8B

Estimated Cost: $ 10.5 million Estimated O&M Cost (30 Yrs): $226,420 Estimated Construction Time: 2 Years Estimated Soil Cover: 16,600 Estimated Soil Excavation: 27,600 Estimated Truck Trips: 2,800

Alternative 8A is like Alternative 7A except that cover in OUI, 0U2, and 0U3 would be applied to all areas with surface contamination above 190 ppt for dioxin.

Alternative 8B is identical to Altemative 8A, except that excavated soil under this altemative will be placed in a new on-site cell and covered.

Alternative 8A Alternative 8B Estimated Cost: $ 22 million Estimated O&M Cost (30 Yrs): $338,428 Estimated Construction Time: 3 Years Estimated Soil Cover: 103,800 Estimated Soil Excavation: 27,600 Estimated Truck Trips: 10,600

Estimated Cost: $ 19.9 million Estimated O&M Cost (30 Yrs): $338,428 Estimated Construction Time: 3 Years Estimated Soil Cover: 111,200 Estimated Soil Excavation: 27,600 Estimated Truck Trips: 9,300

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Explanation of the Nine Evaluation Criteria

EPA uses the following nine criteria as required by Superfund law, to evaluate and compare cleanup altematives. Each criterion is defined below, and a discussion of EPA's comparison of how each alternative meets or does not meet each one follows. See the table on the final page showing the summary of this evaluation.

1. Overall protection of human health and the environment: Altematives are evaluated to determine whether they can protect human health and the environment from unacceptable risks posed by hazardous substances, pollutants, or contaminants at the site by eliminating, reducing, or controlling exposures.

2. Compliance with applicable or relevant and appropriate requirements (ARARs): Alternatives are evaluated to determine whether they attain requirements under federal, tribal, state, and local environmental laws and regulations, or provide grounds for invoking a waiver.

3. Long-term effectiveness and permanence: Alternatives are evaluated for the degree of long-term effectiveness and permanence they provide and for the degree of certainty that the alternative will prove to be successful.

4. Reduction of toxicity, mobility, or volume through treatment: Alternatives are evaluated to determine the degree to which they employ recycling or treatment to reduce toxicity, mobility, or volume, including how they use treatment to address hazardous substances posed by the site.

5. Short-term effectiveness: Short-term impacts on the community and workers during implementation of alternatives are evaluated. These impacts include transportation (including noise, dust, and traffic hazards), protection of workers, and the timeframe for implementing the remedy.

6. Implementability: The ease of implementing alternatives is evaluated, considering technical difficulties and reliability of a technology, coordination with other offices and agencies, and availability of services and materials.

7. Cost: Capital and ongoing costs are evaluated.

8. State/Tribal Acceptance: The State's and Tribe's positions and key concerns on the preferred altemative and other altematives are considered, as well as comments on ARARs or proposed use of waivers. This assessment is completed after comments on this Proposed Plan are received.

9. Community Acceptance: The community's support of, reservations about, or opposition to components of the alternatives are considered. This assessment is completed after comments on this Proposed Plan are received.

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COMPARISON OF ALTERNATIVES

1. Overall Protection of Human Health and the Environment

Altemative 1, the "No Action" alternative, does not provide adequate protection because it does not address the risks to human health and the environment identified in the HHERA. Alternatives 2, 3,4,5, 6, 7 and 8 would provide adequate protection of human health and the environment by eliminating, reducing, or controlling risk through excavation, cover, engineering controls and/or institutional controls. In the different altematives, COCs are removed or covered to different risk-based levels: one in 10,000 excess cancer risk in Altematives 7 and 8; one in 100,000 in Alternatives 2,3, and 5; and one in 1,000,000 excess cancer risk in Alternatives 4 and 6. Altematives 5 and 6 reach protectiveness by excavation of contaminated soil and disposal either off-site or in an on-site containment cell. Alternatives 2, 3, 4, 7, and 8 reach their protectiveness goal by a combination of excavation and clean soil cover. Long-term maintenance and monitoring of the soil cover would be required under Alternatives 2, 3, 4, 7, and 8 to ensure that the cover remained protective. Any potential future excavation in the cover areas would require work plans for proper sampling and disposal of excavated soil at depth in addition to repair and continued maintenance of the cover.

2. Compliance with ARARs

Altematives 1, 2A/B, 3A/B, 5A/B, 7 A/B, and 8 A/B do not meet all ARARs. Alternatives 4A/B and 6A/B comply with all ARARs. Altematives 4A/B achieve HSCA cleanup levels by means of a combination of excavation and a soil cover; Alternatives 6A/B achieve HSCA cleanup levels by excavation of contaminated soil to HSCA clean up levels.

3. Long-term Effectiveness and Permanence

Alternatives 2 through 8 provide long-term effectiveness and permanence at different health-based levels. Surface soil with contaminant concentrations at higher risk levels in residential areas is excavated and replaced with clean soil. Surface soil with lower residual contaminant concentrations but above the HSCA limits in residential areas is covered. In the industrial/commercial areas of the site, the alternatives (except 6A/B) include covering contaminated soil over areas, the size of which varies by the degree of risk-based protectiveness each alternative achieves. Alternative 6A requires no long-term maintenance because all contamination above the HSCA clean up level is taken off-site. Institutional Controls for the covers to mitigate exposures to contaminated soil at depth are needed for all other alternatives. Alternatives with smaller covers will require less long-term maintenance than those with larger covers. Off-site disposal alternatives require less long-term maintenance than the on-site disposal altematives. Institutional Controls will be needed for all altematives to mitigate exposures to contaminated groundwater at depth.

4. Reduction of Toxicity, Mobility, or Volume of Contaminants through Treatment

None of the proposed alternatives reduce the toxicity, mobility, or volume of the soil contaminants through treatment. The large volume of relatively low soil contamination that is

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being addressed in this remedy does not lend itself to any cost effective treatment.

5. Short-term Effectiveness

Short-term effectiveness of the altematives decreases as more site soil is excavated and as more soil cover must be brought to the site. Greater amounts of off-site soil disposal will result in greater amounts of community disturbance related to transporting contaminated soil off-site and greater potential for worker injury. Because of this, on-site disposal altematives are more effective in the short term than off-site disposal alternatives. Altematives with larger soil covers will present some more short-term effectiveness issues than altematives with smaller covers, associated with transporting the clean soil on-site and installing the covers.

6. Implementability

All of the alternatives can be readily implemented, although implementing alternatives with larger amounts of soil for off-site disposal are more difficult due to the limited amount of appropriate landfill space available in Minnesota.

7. Cost

Costs for site alternatives range from no cost to $201 million. Altemative 6A is the most costly at $201 million. The "No Action" alternative is the least expensive; and Alternative 7B, at $10.5 million, is the least expensive altemative among those requiring some clean up action. The cost for soil transportation by rail instead of trucks for the "A" Altematives was considered in the FS Report and was estimated to be more costly than truck transportation. Therefore the costs for rail transportation are not presented.

8. Tribal/State Acceptance

LLBO does not support the proposed Altemative 4A, and instead, prefers Altemative 6A. LLBO has noted in communications to EPA its position that more characterization of the site is needed before selecting a remedy and that Alternative 4A is not consistent with the intent of the HSCA. LLBO also noted concerns regarding their potential future acquisition and use of site properties that have residual contamination and require the placement of Institutional Controls. LLBO believes that selection and implementation of Alternative 4A directly compromises potential future options to make full use of Reservation lands and place them in Trust.

The State of Minnesota has not yet formed an official position on EPA's preferred alternative. However, the State has expressed concerns that Alternative 4A does not require excavation to an appropriate depth in residential areas. Also, MPCA has stated that the magnitude and extent of soil contamination have not been adequately delineated at the site.

9. Community Acceptance

Community Acceptance of the Preferred Alternative will be evaluated after the public comment period ends and will be described in the ROD for the site.

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EPA's Preferred Alternative: Alternative 4A

Under Superfund law, the selected remedy must meet the threshold criteria of Overall Protection of HumanHealth and the Environment, and Compliance with ARARs. Alternative 4A meets these threshold criteria by excavating soils in those portions of 0U7 over a one in 100,000 excess cancer risk, and by covering those portions of 0U7 with residual soil contamination above ARAR-based (HSCA) limits to provide additional protection to a one in 1,000,000 excess cancer risk. In addition, marker material and a cover would be placed in areas of OUI, 0U2, and 0U3 that exceed the HSCA-based cleanup levels. Soil above ecological risk limits in 0U2 would be excavated; and the residual soil contamination above LLBO HSCA cleanup levels in 0U2 that is not excavated would be covered. Institutional controls will monitor and maintain the soil cover and ensure that any future planned disturbance of these covered areas at depth requires adequate sampling and proper disposal of contaminated soil and that the cover is then restored. Institutional and Engineering Controls will also prevent future groundwater exposures to workers or others digging in the groundwater plume areas of OUI and 0U3. This remedy is protective and meets applicable ARARs.

In addition to meeting the two threshold criteria, the selected remedy must be evaluated by assessing: Long-term Effectiveness and Permanence; Reduction of Toxicity, Mobility or Volume Through Treatment; Short-Term Effectiveness; Implementability; and Cost. Altemative 4A provides long-term and permanent protection against exposure to site-related contaminants by the combination of soil excavation and cover, coupled with appropriate Institutional Controls. Off-site disposal of excavated soil allows for less long term maintenance than on-site disposal of excavated soil and better addresses concems expressed by LLBO and the City of Cass Lake that excavated contaminated soil not be stored on site. Alternative 4A does not reduce toxicity, mobility or volume of the contamination because effective alternative treatment technologies or resource recovery technologies are not practical for large quantities of soil containing low levels of contamination. Alternative 4A also provides short-term effectiveness when proper health and safety measures are taken. Altemative 4A is implementable. Finally, Altemative 4A meets the evaluation criteria at a much lower cost than Alternative 6 (the only other protective altemative that meets the ARAR), and is therefore cost-effective.

In summary. Alternative 4A meets the two threshold criteria of Overall Protection of Human Health and the Environment, and Compliance with ARARs. It is comparable to Altemative 6, which also meets these threshold criteria, in terms of Long-Term Effectiveness and Permanence, Short-Term Effectiveness and Implementability. The cost for Alternative 4A is considerably less than for Alternative 6 which requires significantly more off-site or on-site disposal of soil. EPA believes Alternative 4A presents a remedy that is the best balance of our evaluation criteria.

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EPA's Preferred Alternative 4 showing sampled locations in colors: Green denotes excavation, blue denotes cover, yellow denotes below PRGs

Next Steps

EPA, in consultation with both LLBO and MPCA , will evaluate public reaction to the preferred cleanup alternative during the public comment period before deciding on a final cleanup altemative. Based on new information or public comments, EPA may modify its preferred altemative or choose another. EPA encourages the public to review and comment on the cleanup altematives.

EPA will respond in writing to all significant comments in a Responsiveness Summary which is part of the final decision document called the Record of Decision. EPA will announce the selected cleanup alternative in local newspaper advertisements and will place a copy of the Record of Decision in the local information repositories.

Chart comparing cleanup options with the nine Superfund remedy selection criteria

Evaluation Criterion Overall Protection of Human Health and the Environment Compliance with ARARs Long-term Effectiveness and Permanence Reduction of Toxicity, Mobility, or Volume through Treatment*** Short-term Effectiveness Implementability Alternative A Cost ($ millions) Alternative B Cost ($ millions) Tribal and State Acceptance

Community Acceptance

Al t l

O

O

O

O

N/A*.*

N/A** $0

$0

Alt2A/B

•

O

•

o •

• $22.5

$20.3

Alt 3A/B

•

O

•

o •

• $29 8

$27.7

Alt 4A*/B

•

•

•

O

•

• $45.8

$44

Alt 5A/B

•

O

•

o •

• $103

$45

Alt 6A/B

•

•

•

O

•

• $201

$82

Alt 7A/B

•

O

•

o •

• S12.4

$10.5

Alt 8A/B

•

O

•

o •

• $22

$19.9

LLBO disagrees with Alternative 4A and favors Alternative 6A for reasons stated previously at p 16. The State has not communicated a final official position on Alternative 4A but has disagreed with some

aspects of the proposed remedy for reasons stated previously at p 16. Will be evaluated after the public comment period

# Fully meets criterion ® Partially meets criterion O Does not meet criterion

* EPA's preferred alternative ** N/A: not applicable, since no remedy is being implemented in the No-Action Altemative *** Alternatives do not result in a reduction of toxicity, mobility, or volume through treatment because it is impractical to treat large volumes of soil having low contamination levels

19