(413) 784-1100 (617) 565-3420 J. Western Regional Office ...

Conunonwealth of Massachusetts Department of Environmental Protection Western Regional Office 436 Dwight Street Springfield, Massachusetts 01103 (413) 784-1100

United States Environmental Protection Agency New England Region J. F. Kennedy Federal Building Boston, Massachusetts 02203 (617) 565-3420

August 13, 1997

Jane Magee General Electric Company Area Environmental and Facility Operations 100 Woodlawn Avenue Pittsfield, Massachusetts 01201

Re: DEP: 1-0147 Pittsfield; EPA: Area 6; GE/Housatonic River; Proposal for Human Health Risk Assessment; Final 'Comments

Dear Ms. Magee:

The Massachusetts Department of Environmental Protection (DEP) and the United States Environmental Protection Agency (EPA) (the Agencies) have reviewed the following document:

Proposal for Human Health Risk Assessment of the Housatonic River (Proposal), February 14, 1996, prepared by ChemRisk for the General Electric Company (GE).

The Proposal is required by EPA's RCRA Corrective Action Permit's Special Permit Condition A.7 and is intended to fulfill the requirements of DEP's and GE's Administrative Consent Order and the Massachusetts Contingency Plan (MCP).

In accordance with the Public Involvement Plan, notifications' of the Proposal being placed in the public infonnation repositories were sent, by GE, to the parties on the notification mailing list at the time of the submittal, along with notifications of how and to whom to submit comments during the public comment period.

The Agencies are hereby issuing their final comments on, and conditional approval of, the Proposal. The Agencies previously issued draft comments on November 19, 1996. On December 19, 1996, GE submitted its response to the draft comments. The Agencies met on March 6, 1997 with GE to discuss GE's comments. In preparing the attached final comments, the Agencies have considered GE's comments as well as comments submitted by the Connecticut Department of Public Health and the Housatonic River Initiative

*124631*

SDMS DocID 124631

Ms. Jane Magee August 13, 1997 Page 2

(Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Environmental Engineering).

As discussed with GE, the Agencies support focusing the initial risk assessment work on generating a risk-based concentration (i.e., cleanup goal) for each exposure scenario. GE should derive a residential cleanup goal (and submit it to the Agencies for review and approval) before cleanup goals are developed for other exposure scenarios. The Agencies anticipate needing a final residential cleanup goal before cleanup goals are needed for other exposure scenarios such as recreational or farming.

The Agencies note that, since the initial risk assessment work will be focused on generating risk-based concentrations, it is not necessary to identify all foreseeable future uses of the Housatonic River floodplain at the time that this initial work is conducted and the results submitted. A separate document containing maps which identify future uses of the floodplain could be submitted to the Agencies by GE after the initial risk assessment report has been completed. In any case, the Agencies expect and require GE to proceed expeditiously to conduct the human health risk assessment in' accordance with the proposed Scope of Work, as modifled by the enclosed comments. The Agencies also require that GE submit to the Agencies for review and approval, within 30 days from the date of this letter, a proposed schedule for completing specific deliverables required for completion of the risk assessment.

If you have any questions regarding these matters, please contact J. Lyn Cutler at (413) 784-1100 extension 316 or Bryan Olson at (617) 573-5747.

Sincerely,

( l_~;r{:~{h.-

.J Lyn Cutler Section Chief Special Projects Bureau of Waste Site Cleanup Massachusetts Department of Environmental Protection

Bryan Olson Environmental Engineer

Corrective Action Section

Office of Site Remediation and

Restoration

U.S. EPA, New England Region

Attachment AWl hhrafin.1tr

Ms. Jane Magee

August 13, 1997

Page 3

cc: Andrew Thomas, Jr., Esq., GE Andrew Silfer, GE

Richard Gates, GE

Jane Gardner, GE

James R. Bieke, Esq., Shea & Gardner Robert Goldman, Blasland, Bouck & Lee Harley Laing, EPA New England Region Matt Hoagland, EPA New England Region Douglas Luckerman, Esq., EPA New England, ORC Mary Ballew, EPA New England Jan Reitsma, Undersecretary, EOEA Mary Holland, Regional Director, DEP WERO Alan Weinberg, Regional Engineer, DEP WERO Robert Bell, Esq., DEP OGC Ralph Child, DEP OGC, Boston Margaret Harvey, DEP ORS Susan Steenstrup, DEP WERO Mayor Edward Reilly, City of Pittsfield Conunissioner of Health, Pittsfield Pittsfield Conservation Commission Housatonic River Initiative State Senator Andrea Nuciforo State Representative Daniel E. Bosley State Representative Christopher J. Hodgkins State Representative Shaun P. Kelley State Representative Peter J. Larkin Public Information Repositories Charles Fredette, Connecticut DEP Gary Ginsberg, Connecticut DPH Robert Smith, Connecticut DEP John Looney, Esq., Conn. AG's Office Richard Webb, ?Esq., Conn. AG's Office Betsy Harper, Esq., Mass. AG's Office Matthew Brock, Esg., Mass. AG's Office Ken Finkelstein, Ph.D., NOAA Anton P. Giedt, Esq., NOAA OGC Mark Barash, Esq., U.S. DOl Steve Gold, Esq., U.S. DOJ Addie Fiske, Esq., U.S. DOJ Kelmeth Carr, Ph.D., U.S. F&WS Carol Rowan West, DEP, ORS Nancy Bettinger, DEP, ORS

TECHNICAL AND REVIEW COMMENTS

of

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

and

MASSACHUSETTS DEPARTMENT of ENVIRONMENTAL PROTECTION

GENERAL ELECTRIC COMPANY

Pittsfield, Massachusetts

EPA l.D. MAD002084093, Area 6

MCP Site Number: 1-0147

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT

OF THE HOUSATONIC RIVER

Prepared by ChemRisk on behalf of General Electric Company

Submitted: February 14, 1996

INTRODUCTION

The U.S. Environmental Protection Agency, New England Region (EPA) and the Massachusetts Department of Environmental Protection (DEP) (the Agencies) have compiled the. following list of general and specific comments relating to completeness and technical accuracy and adequacy of the Proposal For Human Health Risk Assessment Of The Housatonic River, prepared by ChemRisk on behalf of the General Electric Company (GE) and submitted to the Agencies on February 14, 1996 ("GE's Risk Assessment Proposal). The Agencies have reviewed the Proposal for Human Health Risk Assessment for completeness and consistency with appropriate EPA and DEP regulation, policy, and guidance.

In preparing these comments, the Agencies have considered comments submitted by the Connecticut Department of Public Health and the Housatonic River Initiative (Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Enviromnental Engineering). TIle Agencies issued Draft Technical And Review Comments dated November 19, 1996 for comment. The Agencies received comments on the Draft from GE on December 19, 1996. On March 6, 1997 the Agencies met with GE to discuss GE's comments. The Agencies have considered GE's comments and discussions with GE in preparing these revised draft comments.

There are two general themes that are common to many of the Agencies' comments. First, many of the Agencies' comments address areas of GE's Risk Assessment Proposal that are not consistent with appropriate EPA and DEP regulation, policY, and guidance. Second, the Agencies have commented on exposure assumptions proposed by GE that do not adequately characterize: (l) the receptor subpopulation whose activities (described by the frequency and duration of their actions) represent a full and unrestricted use of the site; and (2) the "Reasonable Maximum Exposure" (RME).

The Agencies' comments are divided into two major sections; General Comments and Specific Comments. Specific comments are organized into sections corresponding to the sections in GE's Risk Assessment Proposal. The Agencies note that several comments appear in more than one section of this attachment. The Agencies have repeated a comment each time the issue appeared in

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GE's Proposal document. Each comment that is repeated refers to the section in which the

comment first appeared.

Attachment A to these comments contains a list of relevant EPA and DEP policy and guidance.

The Agencies will evaluate, and approve or disapprove, GE's Human Health Risk Assessment

Report in accordance with and based on EPA and DEP policy and guidance listed in Attachment A.

The Agencies recognize that many of the documents listed in Attachment A have already been

consulted by Chern Risk in preparing the Risk Assessment Proposal.

Attachment B to these comments contains the general EPA format and content recommendations for

Human Health Risk Assessment Reports. GE should review these recommendations and ensure that

its Human Health Risk Assessment Report contains the appropriate information specified therein, to

the extent consistent with the comments set forth below and the revised Human Health Risk

Assessment Proposal as approved by the Agencies.

A. GENERAL COMMENTS

I. In Section 1.3, GE proposes to evaluate potential risks to human health iteratively, for each exposure scenario, in order to focus the assessment on areas where risks to human health are most likely to be present. GE proposes to first evaluate the river and floodplain reach with the highest concentrations of Chemicals of Potential Concern (COPC) (i.e., GE facility to Woods Pond Dam). As proposed by GE, if this evaluation shows no significant risks for a given scenario or if it shows a clear pattern of decline to acceptable risks by the downstream boundary of the reach, then additional iterations of that scenario for further reaches downstream of Woods Pond will not be performed.

TIle Agencies support the objective of streamlining the risk assessment by eliminating calculations that will not provide useful information. Toward that end, the Agencies have agreed to focus the risk assessment on calculating risk-based concentrations (i.e., cleanup goals) for each exposure scenario and pathway. Below such risk-based concentrations, exposure would not pose a significant risk. TIlUS, in lieu of numerous separate risk calculations, the risk assessment report should tabulate exposure point concentration (EPC) estimates for each area to which an exposure scenario applies (for the areas where sampling data are available). At a minimum, for each exposure point, the upper 95 percent confidence limit of the mean should be calculated as the EPC (see comment 34). The average concentration detected should also be presented. To determine whether a significant risk of harm exists at any location, the EPe should simply be compared with the risk-based concentration for the relevant exposure scenario(s). For each exposure area, the risk assessment report should indicate whether the EPe exceeds the relevant risk-based concentration.

This approach would have a number of advantages:

Calculating risk-based concentrations for each scenario eliminates the need for repetitive calculations. Only the EPe for each location would be reported; location-specific risk estimates would not be needed. Further, separate risk calculations for all exposure scenarios that are foreseeable at each location would be ullllecessary.

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The comparison of risk-based concentrations to measured exposure point concentrations facilitates incorporation of additional data as it becomes available.

Using EPC estimates as indicators of risk would enable the investigators to document risk at a large number of exposure points in a concise manner. It will not be necessary to selectively focus on the locations likely to pose the highest risk. All locations that could pose a significant risk would be identified.

This approach gives project managers the flexibility of accounting for cumulative exposures as appropriate for each location in risk management decisions. It is not necessary to establish a priori which combination of exposures apply at each location.

Adoption of the risk-based concentration approach would eliminate the need to pare down the assessment document by focusing only on a small subset of locations. EPC estimates would be presented for all locations of potential concern.

In addition to calculating risk-based concentrations, GE should also include a "forward" calculation (risk estimate) for each exposure scenario. TIle purpose of presenting risk estimates in addition to risk-based concentrations is for illustrative purposes only and to make the risk assessment more clear and complete. For the risk estimates, GE should select an EPC that is likely to be in the range of what a cleanup value would be for a given scenario. Using a selected EPC (rather than calculating it using site data) is preferable because? it avoids the need for discussions between GE and the Agencies about which properties should be used as the basis for the EPC.

2. Based on the discussion in Section 7 of the Risk Assessment Proposal, it appears that GE intends to calculate cumulative risks separately for each exposure scenario (i.e., GE intends to assume that exposure scenarios are mutually exclusive). The Agencies believe this is an acceptable approach for the risk assessment, particularly if the focus is on risk-based concentrations. However, the Agencies note that risk management decisions may be made based on plausible combinations of exposure scenarios (for example, canoeing and picnicking; residential exposures and consumption of fish).

3. As part of the uncertainty section of the risk assessment, GE must address the potential for PCBs to act as endocrine disruptors. GE should consider the discussion provided in Attachment C, which reflects Agency views on potential endocrine disrupting effects.

4. GE states that it has proposed "reasonable and realistic values" for exposure parameters to be used in the risk assessment. For each exposure scenario, the Agencies favor the development of one risk estimate (or risk-based concentration) that is consistent with both the EPA-defined Reasonable Maximum Exposure (RME) or High End Exposure (HEE) and the "full use" assumptions specified in the Massachusetts Contingency Plan (MCP). TIle Agencies also recommend the development of a central tendency risk estimate for each exposure scenario to meet EPA requirements and to provide a point of reference indicative of the uncertainty and variability inherent in exposure and risk estimates.

RME is defined as the highest exposure that could reasonably be expected to occur for a given exposure pathway at a site. HEE is defined as a plausible estimate of the individual exposure for those persons at the upper end of an exposure distribution. Some of the exposure assumptions proposed by GE will not adequately characterize the RME or HEE. In the

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detailed comments which follow, the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures. GE should note that guidance on RME and HEE assumptions is contained in EPA's rusk Assessment Guidance for Superfund, Volume I, Parts A and B, listed in Attachment A, EPA Region One rusk Update (EPA, 1994) and EPA's 1992 Guidelines for Exposure Assessment, also listed in Attachment

A.

The MCP states: "The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use". Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates.

5. For purposes of tile MCP, reasonably foreseeable uses includes "any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses... " (310 CMR 40.0923(3?.

B. SPECIFIC COMMENTS

Section 2.0 Site Characterization Current Uses ofFloodplain

1. There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified. Such land uses/activities are identified below and should be addressed by GE in the Risk Assessment.

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watching/wildlife watching. TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal. For example, retired persons may visit Canoe Meadows several times per week. Young children also may visit the area frequently as palt of school field trips and camp groups.

On page 2-9, GE should describe what is meant by "other recreational activities in the

water,lI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road. The Proposal should describe current uses of the floodplain in this stretch of the river.

Reasonably Foreseeable Uses ofFloodplain

2. On page 2-12, the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level. This statement is not necessarily true for the following reasons.

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TIle Housatonic River is the largest watenvay in the area, is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource.

After remediation of the Housatonic River occurs, there will likely be increased interest in and use of the River for recreational purposes.

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River.

It is inappropriate to' base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population.

3. Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan.

4. On page 2-14, the Risk Assessment Proposal states that because of the local, state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements, new construction (if any) will likely be limited to additions or renovations, despite widespread designation of floodplain areas as residential. It is not necessarily true that new construction will be restricted in the floodplain. Construction may still take place in the floodplain if compensatory flood storage can be found. In addition, in the town zoning laws described in the Proposal, new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure. Also, zoning reqnirements may be amended. The Agencies do not agree that local, state and federal restrictions will necessarily preclude future residential development in the floodplain. Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses.

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable. GE should conduct this mapping exercise in cooperation with Agency Project Managers, who will consider, on a case-by-case basis, tlle extent to which factors may preclude specific activities and uses.

Section 4.0 Hazard Identification

4.1 Selection of Media of Concern

5. GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond.

Based on groundwater categorization, GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road. For the record, the Agencies note that groundwater downstream of New Lenox

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