EPA Superfund Explanation of Significant Differences ... · Contingency Plan (NCP), ......

EPA Superfund Explanation of Significant Differences

Savage Municipal Water Supply Well Superfund Site EPA ID: NHD980671002

Milford, NH

September 2017

DECLARATION FOR EXPLANATION OF SIGNIFICANT DIFFERENCES SAVAGE MUNICIPAL WATER SUPPLY WELL SUPERFUND SITE

OPERABLE UNIT 2 MILFORD, NEW HAMPSHIRE

SEPTEMBER 2017

SITE NAME AND LOCATION

Savage Municipal Water Supply Well Superfund Site, Town of Milford, Hillsborough County, New Hampshire

STATEMENT OF PURPOSE

This decision document sets forth the basis for the determination to issue the attached Explanation of Significant Differences (ESD) for the Savage Municipal Water Supply Well Superfund Site (the Site), in Milford, New Hampshire.

STATUTORY BASIS FOR ISSUANCE OF THE ESD

Section 117(c) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C. Section 9617(c), requires that, if the remedial action being undertaken at a site differs significantly from the Record of Decision (ROD) for that site, EPA shall publish an ESD and the reasons such changes were made. The National Contingency Plan (NCP), 40 C.F.R. § 300.435(c)(2)(i), and Office of Solid Waste and Emergency Response (OSWER) Directive 9355.3-02, indicate that an ESD, rather than a ROD amendment, is appropriate where the adjustments being made to the ROD are significant but do not fundamentally alter the remedy with respect to scope, performance, or cost. EPA has determined that the adjustments to the September 27, 1991, Record of Decision (1991 ROD) provided in this ESD are significant but do not fundamentally alter the overall remedy for Operable Unit 2 (OU2) at the Site, with respect to scope, performance, or cost. Therefore, this ESD is being properly issued.

In accordance with Section 300.825(a) (2) of the NCP, this ESD will become part of the Administrative Record for the Site and will be available for public review at both the EPA Region 1 Records Center in Boston, Massachusetts, the Wadleigh Memorial Library in Milford, New Hampshire, and on-line at http://www.epa.gov/superfund/savage.

OVERVIEW OF THE ESD

This ESD documents the following additions and changes to the CERCLA remedy, as presented in the 1991 ROD:

1. The ESD modifies the Remedial Action Objectives (RAO) presented in the 1991 ROD to be consistent with current EPA guidance standards for groundwater remedies.

http://www.epa.gov/superfund/savage

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2. Makes a determination that the ongoing monitoring of the natural attenuation component of the remedy in OU2 and the observed reduction in groundwater contamination levels is consistent with the remedy meeting the standards to be designated a Monitored Natural Attenuation remedy.

3. Provides a change to terminology regarding groundwater cleanup levels. Specifically, interim cleanup levels (ICLs) identified in the 1991 ROD are now considered cleanup levels (CLs).

4. Clarifies the approach that will be utilized to determine that groundwater CLs have been attained; the groundwater restoration remedy is protective; and support for a determination that groundwater restoration is complete.

5. Updated CLs for a number of chemicals of concern for which the NH Ambient Groundwater Quality Standard (AGQS) values have been changed or for which new standards have been promulgated.

6. Updated applicable and relevant and appropriate standards (ARARs) identified in the 1991 ROD to add revised and newly promulgated State and Federal standards. The updated ARARs are included in Attachment 1.

7. Added EPA guidances addressing the implementation of groundwater remedies, specifically guidance establishing procedures for the designation and implementation of monitored natural attenuation (MNA) remedies.

This ESD will serve as the CERCLA decision document to record the changes to the remedy for OU2 detailed herein that does not fundamentally deviate in terms of scope, performance or cost, from the remedy described in the 1991 ROD and modified by the 1996 ESD which split OU2 from OU1 within the Site.

The State of New Hampshire has reviewed and commented on this ESD and concurs with its issuance. None of these revisions significantly changes the scope of the remedy.

DECLARATION

For the foregoing reasons, by my signature below, I approve the issuance of an Explanation of Significant Differences for OU2 at the Savage Municipal Water Supply Well Superfund Site in Milford, New Hampshire, and the changes stated therein.

Date Bryan Olson, Director Office of Site Remediation and Restoration

U.S. EPA Region 1 Explanation of Significant Differences Savage Municipal Water Supply Well

September 2017 Operable Unit 2

Contents I. INTRODUCTION ........................................................................................................ 1

A. Site Name and Location................................................................................................... 1 B. Lead and Support Agencies ............................................................................................. 1 C. Legal Authority................................................................................................................ 1 D. Summary of Circumstances Necessitating this Explanation of Significant Differences. 2 E. Availability of Documents............................................................................................... 3

II. SUMMARY OF SITE HISTORY, CONTAMINATION PROBLEMS AND SELECTED REMEDY................................................................................................. 3

A. Site History and Contamination Problems....................................................................... 3 B. Summary of the Selected Remedy................................................................................... 4

III. DESCRIPTION OF SIGNIFICANT DIFFERENCES................................................. 7 A. Modification of the Remedial Action Objectives ............................................................ 7 B. Change in Terminology for Groundwater Cleanup Level ............................................... 7 C. Modification of Cleanup Levels for Groundwater .......................................................... 8 D. Updating the ARARs and TBCs.................................................................................... 10

IV. SUPPORT AGENCY COMMENTS.......................................................................... 11 V. STATUTORY DETERMINATION........................................................................... 11 VI. PUBLIC INFORMATION ......................................................................................... 11

FIGURES:

Figure 1 – Site Plan

TABLES:

Table 1 – Updated Cleanup Levels

ATTACHMENTS:

Attachment 1 - Tables of Revised Applicable and Relevant and Appropriate Standards (ARARs)

EXPLANATION OF SIGNIFICANT DIFFERENCES SAVAGE MUNICIPAL WATER SUPPLY WELL SUPERFUND SITE

OPERABLE UNIT 2 MILFORD, NEW HAMPSHIRE

I. INTRODUCTION

A. Site Name and Location

Site Name: Savage Municipal Water Supply Well Superfund Site (the Site) NHD980671002

Site Location: Town of Milford, Hillsborough County, New Hampshire

B. Lead and Support Agencies

Lead Agency: United States Environmental Protection Agency (EPA)

Support Agency: New Hampshire Department of Environmental Services (NHDES)

C. Legal Authority

Under Section 117(c) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C. § 9617(c), 40 C.F.R. § 300.435(c) of the National Contingency Plan (NCP), and Office of Solid Waste and Emergency Response (OSWER) Directive 9355.3-02, if EPA determines that differences in the remedial action significantly change but do not fundamentally alter the remedy selected in the Record of Decision dated September 27, 1991 (1991 ROD), for the Site with respect to scope, performance, or cost, EPA shall publish an Explanation of Significant Differences (ESD). This ESD shall explain the differences between the remedial action set forth in the 1991 ROD for a section of the Site designated as Operable Unit 2 (OU2) by a 1996 ESD1, and the modified remedial action to be undertaken under this ESD.

1 Operable Unit 2 (OU2) was delineated as the area of the extended plume encompassing “all contaminated groundwater at the Site outside of the area defined as the OK Tool Source Area.” Operable Unit 1 (OU1) was delineated as the OK Tool Source Area, encompassing the portion of the plume where levels of groundwater contamination were the highest. See Figure 1 and a more detailed description of the OU boundaries in Section IIB, below.

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D. Summary of Circumstances Necessitating this Explanation of Significant Differences

This ESD modifies the Remedial Action Objectives (RAOs) for the OU2 remedy from those identified in the 1991 ROD to further define the remedy’s requirements to protect human health and the environment. This ESD provides a change to terminology regarding groundwater cleanup levels. Specifically, interim cleanup levels (ICLs) identified in the 1991 ROD are now considered cleanup levels (CLs). This ESD also clarifies the approach that will be utilized to determine that groundwater CLs have been attained; the groundwater restoration remedy is protective; and support for a determination that groundwater restoration is complete.

This ESD describes how the natural attenuation component of the 1991 ROD remedy for groundwater includes monitoring requirements and the observed reduction in groundwater contamination levels that is consistent with meeting EPA guidance standards to be designated as a Monitored Natural Attenuation (MNA) remedy within OU2.2 Groundwater within OU2 subject to operation of the groundwater treatment system and MNA is expected to achieve the remedy’s groundwater cleanup standards within the 60-year period identified in the 1991 ROD3.

Since issuance of the 1991 ROD, a number of the applicable and relevant and appropriate standards (ARARs) identified in the 1991 ROD have changed or been modified. Additional environmental or facility siting statutes or regulations have been promulgated since the 1991 ROD and need to be added as ARARs for the OU2 CERCLA remedy. This ESD also identifies additional federal documents that do not constitute ARARs that should be considered to ensure protectiveness or are otherwise appropriate for use in implementing the OU2 remedy. Such documents are commonly referred to as TBCs (To Be Considered). The updated ARARs and TBCs are identified in Attachment 1, and include in part:

1. Updated ICLs included in the 1991 ROD for a number of chemicals of concern for which the NH Ambient Groundwater Quality Standard (AGQS) values have been changed or for which new standards have been promulgated.

2. Updated ARARs identified in the 1991 ROD to add revised and newly promulgated State and Federal standards.

3. Added EPA guidances addressing the implementation of groundwater remedies, specifically guidance establishing procedures for the designation and implementation of MNA remedies.

This ESD will serve as the CERCLA decision document to record the changes to the remedy for OU2 detailed herein that do not fundamentally deviate in terms of scope,

2 This modification of the natural attenuation component of the 1991 ROD to meet MNA standards was also made for an area of OU1 defined as the “Groundwater Cleanup Area,” through a 2016 Amended ROD.

3 Section X of the 1991 ROD estimates that it will take 15 to 60 years to attain the Interim Groundwater Cleanup Levels following implementation of the selected remedy.

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performance or cost, from the remedy described in the 1991 ROD and modified by the 1996 ESD that split OU2 from OU1 within the Site.

E. Availability of Documents

This ESD and supporting documentation shall become part of the Administrative Record for the Site. The ESD, and the Administrative Record are available to the public for review on-line at http://www.epa.gov/superfund/savage.

The ESD and its Administrative Record are also available for review at the locations and times listed below:

U.S. Environmental Protection Agency Records Center 5 Post Office Square, Suite 100 (OSRR02-3) Boston, MA 02109-3912 Telephone: (617) 918-1440 Fax: (617) 918-1223 E-mail ([email protected])

Open Monday through Thursday from 9:30 AM – 3:30 PM, excluding federal holidays.

And at:

Wadleigh Memorial Library 49 Nashua Street Milford, NH 03055 Telephone: (603) 249-0645

Open Monday through Thursday from 9:30 AM – 8:30 PM, Friday from 9:30 AM – 5:00 PM, Saturday from 9:00 AM – 1:00 PM and Sunday (September – May) from 1:00 PM – 5:00 PM.

II. SUMMARY OF SITE HISTORY, CONTAMINATION PROBLEMS AND SELECTED REMEDY

A. Site History and Contamination Problems

The Site is located in the Town of Milford, New Hampshire, about 2 miles west of the center of town. The Site includes a groundwater plume that generally extends from the intersection of Route 101 and Elm Street eastward approximately 6,000 feet (ft). It is roughly bounded on the north and east by the Souhegan River and on the south by Elm Street and Tucker Brook. The Site lies within the 500-year floodplain of the Souhegan River.

In February, 1983, as part of the first routine sampling of water supplies for organic compounds, the New Hampshire Water Supply and Pollution Control Commission found

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http://www.epa.gov/superfund/savage

mailto:[email protected]

mailto:[email protected]

several volatile organic compounds (VOCs) above drinking water standards in water from the Savage Municipal Water Supply well. The VOCs found included 1,1,1-trichloroethane (TCA), trichloroethylene (TCE), trans-1,2 dichloroethylene (trans-1,2-DCE) tetrachloroethylene (PCE), and 1,1 dichloroethane. Similar VOCs (i.e., PCE and trans-1,2-DCE) were also found at that time in the water drawn from the well supplying the nearby Milford Mobile Home Park. The State of New Hampshire immediately ordered the Town to cease use of the Savage Municipal Water Supply well.

Four major industrial plants were situated to the west of the previously operational Savage Municipal Water Supply well: Hendrix Wire and Cable Corporation, Hitchiner Manufacturing Company, Inc., OK Tool Company, and New England Steel Fabricators, Inc. From the 1940s until the 1980s, process waters and wastes from these four industrial facilities were released untreated to the ground or to the surface waters flowing through the Site.

In March, 1983, at the request of the State, EPA conducted an emergency removal action to supply bottled water to residences of the mobile home park. This action was completed in May 1983 when the mobile home park's water distribution system was connected to the existing municipal water supply system.

The Site was proposed for inclusion on the National Priorities List (NPL) on September 1, 1983, and was included on the final NPL on September 1, 1984.

B. Summary of the Selected Remedy

The 1991 ROD for the entire Site was signed on September 27, 1991. The 1991 ROD established the following RAOs for the Site-wide groundwater remedy:

• Prevent ingestion of contaminated groundwater that would pose an unacceptable risk to human health; and

• Restore groundwater quality to meet federal and state ARARs.

The specific elements of the selected remedy identified in the 1991 ROD included:

• Extraction and treatment of contaminated groundwater,

• Natural attenuation of contaminated groundwater,

• Utilization of institutional controls such as deed restrictions and zoning ordinances to restrict the use of contaminated groundwater, and

• Implementation of an environmental monitoring program, including monitoring of groundwater, surface water, sediments, and existing household wells obtaining drinking water from the aquifer.

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The 1991 ROD also established ICLs in groundwater for contaminants of concern identified in the baseline risk assessment and found to pose an unacceptable risk to either public health or the environment. ICLs have been set based on either reference dose based on unacceptable risk, the pertinent ARARs (e.g. federal maximum contaminant levels or state groundwater quality standards) or other suitable criteria. The 1991 ROD anticipated that EPA would make periodic assessments of the protection afforded by the remedial action as the remedy was being implemented and at the completion of the remedial action and that the ICLs may be adjusted based on ARARs, risk, or other federal and state standards that may have been promulgated or implemented since issuance of the 1991 ROD. The 1991 ROD estimated that meeting ICLs site-wide would take 15 to 60 years, and that achieving ICLs in the portions of the plume that would undergo natural attenuation would take 10 to 35 years.

EPA issued the 1996 ESD detailing changes to the selected remedy in a portion of the contaminated plume. The 1996 ESD divided the remedy into two operable units. OU1, the OK Tool Source Area, is the portion of the plume where levels of groundwater contamination are the highest. The OK Tool Source Area is defined in greater detail in the consent decree4 (CD) for the Site. Operable Unit 2 (OU2) is the extended plume as that term is defined in the CD as “all contaminated groundwater at the Site outside of the area defined as the OK Tool Source Area.” The 1996 ESD only included changes to the selected remedy for OU1.

The 1996 ESD added the following elements to the remedy for OU1:

• Construction of a subsurface slurry wall to isolate the areas that exhibited the highest concentrations of contaminants of concern (COCs),

• Soil vapor extraction (SVE) with air sparging (AS) to remove near-surface sources within the slurry wall, and

• Reinjection of treated groundwater via two injection wells and a recharge pit.

1. OU1 Remedy

An amended Record of Decision was issued on August 24, 2016 (2016 AROD) that significantly changed the remedy for OU1. The 2016 AROD details the remedy that has been implemented at OU1, as well as the changes to the remedy specified in the AROD to address contamination in deep bedrock within OU1. OU1, the OK Tool Source Area, is defined in detail in the CD; and in general includes all of the OK Tool property and additional property to the east, north, and west of the OK Tool Property. The cleanup at OU1, the OK Tool Source Area, is being performed by EPA and the NHDES.

4 United States of America and State of New Hampshire v. Conductron Corporation d/b/a Hendrix Wire & Cable, et al., Civil Action No. 94-174L, D.N.H. June 27, 1994.

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2. OU2 Remedy

The 1991 ROD remedy for the area of the Site designated as OU2 by the 1996 ESD included three wells installed into the deep overburden to extract contaminated groundwater from the overburden and shallow bedrock zones, groundwater monitoring and natural attenuation of groundwater outside of the capture zone of the extraction system. The remedy, as designed, involved treatment of extracted groundwater by air stripping and discharge of the treated water to the unconsolidated aquifer via three reinjection wells and a surface water discharge to the Souhegan River. The extended plume within OU2 spreads eastward from OU1, is approximately 1 mile in length and about 2,500 ft in width.

The cleanup at OU2 is being performed by Hendrix Wire and Cable Corporation, and Hitchiner Manufacturing Company, Inc., the Settling Defendants (SDs), pursuant to the CD.

The extraction and treatment system was constructed in early to mid-2004 and began operation in October 2004. The system operated until December 2015. In September 2015, a temporary suspension of groundwater extraction and treatment activities at OU2 was initiated to assess potential rebound after influent concentrations had stabilized at low concentrations and to evaluate opportunities for optimizing the system. The system at OU2 will be put back into operation following the temporary suspension.

To date, 25 rounds of groundwater elevation and quality monitoring have been conducted by the SDs to assess remedy progress in OU2. Overall, the OU2 treatment and extraction system has operated effectively, but has now reached a point of substantially diminished contaminant mass removal. Although substantial progress has been made in improving overburden groundwater quality in OU2, some “recalcitrant” areas of higher PCE concentrations (greater than 100 μg/L) continue to persist in the deep overburden within areas of OU2. The ongoing temporary suspension test is being performed by the SDs to gather additional information and data regarding the mechanisms causing the elevated PCE concentrations observed in the deep overburden, and to develop recommendations for optimizing the OU2 extraction and treatment system.

Portions of the extended plume outside of the capture zone of the extraction and treatment system rely on natural physical, chemical, and biological processes to attenuate contaminant concentrations in groundwater. The 1991 ROD specified that the groundwater monitoring component of the remedy would include the monitoring of the natural attenuation of contamination in groundwater outside the capture zone of the groundwater extraction wells. Attenuation of the contaminant plume in OU2 due to advection and dispersion is monitored and evaluated as an element of the SDs environmental monitoring program (EMP). In addition, the ongoing temporary suspension includes periodic monitoring for geochemical tracers and other parameters to assess natural attenuation.

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III. DESCRIPTION OF SIGNIFICANT DIFFERENCES

A. Modification of the Remedial Action Objectives

The 1991 ROD established the following RAOs for the Site-wide groundwater remedy:

• Prevent ingestion of contaminated groundwater that would pose an unacceptable risk to human health; and

• Restore groundwater quality to meet federal and state ARARs.

The ESD modifies the OU2 RAOs to be consistent with EPA guidance standards for groundwater remedies and are now identified as:

• Restore groundwater quality to beneficial use5; and • Prevent ingestion of groundwater until groundwater cleanup standards are achieved for OU26.

B. Change in Terminology and Clarification of Process for Evaluating the Attainment of Groundwater Cleanup Levels

The ICLs included in the 1991 ROD were selected based on Maximum Contaminant Levels (MCLs) and non-zero MCLGs established under the Safe Drinking Water Act, or more stringent New Hampshire AGQS. For contaminants without federal/state drinking water standards (ARARs), site-specific, risk based ICLs were calculated. If a groundwater cleanup value established by any of the methods described above was not capable of being detected with good precision and accuracy, or was below what was deemed to be the background value, then the practical quantification limit or background value was selected as the ICL. This ESD changes the terminology such that the ICLs for groundwater are now the CLs for groundwater.

The 1991 ROD described a process for evaluating when groundwater cleanup levels have been achieved. Through this ESD, the evaluation of attainment of groundwater Cleanup Levels is being clarified and updated, as follows:

The determination that groundwater CLs have been met will now be based on site-specific considerations. In particular, EPA will consider historical and current monitoring data, contaminant distribution, trend analysis, and the appropriateness of the compliance monitoring program (i.e., locations, frequency of monitoring, sampling parameters, etc.). At the time this determination is made, EPA will provide a complete description of this technical evaluation documenting attainment of groundwater CLs.

After all groundwater CLs have been met, as determined by EPA consistent with Agency guidance available at the time, EPA will perform a risk evaluation which considers additive

5 Within OU2 the beneficial reuse of the groundwater is as a drinking water aquifer. 6 Note that even after OU2 groundwater cleanup standards are achieved and OU2 groundwater institutional controls (ICs) can be terminated, there may be an area within OU2 that lies within a well restriction zone established for OU1 as an IC to prevent the drawing of contaminated groundwater from OU1 into OU2.

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risk from remaining COCs considering all potential routes of exposure to document the residual risk based on exposure to groundwater at the site. The residual risk evaluation will document the potential risk associated with the concentrations of COCs remaining in groundwater at the site (if detected).

This updated approach to evaluating attainment of groundwater CLs, protectiveness of the groundwater remedy, and completion of groundwater restoration efforts reflects: 1) acknowledgement that MCLs established under the Safe Drinking Water Act are deemed protective by EPA; 2) consideration of all potential routes of exposure for groundwater; 3) improved methods for assessing data variability and other dynamic aquifer conditions that impact monitoring data; and 4) reliance on up-to-date technical guidance and tools. This updated approach will support determinations when groundwater at the Site has been restored for its permissible, beneficial use, and that the groundwater no longer presents an unacceptable risk to human health due to the presence of site-related contaminants.

C. Modification of Cleanup Levels for Groundwater

This ESD includes a modification of CLs for select contaminants of concern for which the applicable regulatory standards have been changed or for which new regulatory standards have been promulgated and brings the OU2 Remedy into accord with the recently amended OU1 Remedy as detailed in the AROD.

Since issuance of the 1991 ROD the applicable NHDES groundwater standards have changed for a number of the contaminants of concern identified in the 1991 ROD, including 1,1-dichloroethane, cis-1,2-Dichloroethene and arsenic. In addition, NHDES has promulgated regulatory standards for 1,4 dioxane. Although the change in the standards for some of the CLs may result in less time needed to meet the cleanup levels for those constituents, no modeling effort has been undertaken to predict what the change in time may be, if any. Some of the ROD CLs remain unchanged.

In 2009, the SDs analyzed groundwater samples for 1,4-doxane, for which New Hampshire had established an AGQS of 3 ug/l. The SDs analyzed samples from three extraction wells and 17 groundwater monitoring wells within OU2. 1,4-dioxane was not detected at all in any of the extraction wells, but was detected at below the AGQS of 3 ug/l at five monitoring wells, and above the AGQS at six monitoring wells. Prior to the 2009 sampling, analysis for 1,4-dioxane had previously been conducted for groundwater in the extended plume in 2003, but the analysis was to a detection limit of 10 ug/l. 1,4-dioxane was not identified in the 1991 ROD as a COC but is added as a COC by this ESD.

Table 1 below specifies the CLs for groundwater included in the 1991 ROD and their basis, and the updated cleanup levels established through this ESD to be applied to groundwater within OU2.

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Table 1 - Updated Cleanup Levels Operable Unit 2, Savage Municipal Water Supply Well Superfund Site

Milford, New Hampshire

Compound 1991 ROD ICLs

ug/L (ppb)

Basis 2017 ESD Updated

AGQS/MCL ug/L (ppb)

1,1-Dichloroethane 3,500 RfD 81(1)

trans-1,2-Dichloroethene (2)

100 MCL 100

cis-1,2-Dichloroethene Not established

- 70

1,1-Dichloroethylene 7 MCL 7 Benzene 5 MCL 5 1,1,1-Trichloroethane 200 MCL 200 Methylene Chloride (3) 5 MCL 5 Tetrachloroethene (PCE)

5 MCL 5

Trichloroethene (TCE) 5 MCL 5 Antimony 3 MCL 6 Arsenic(4) 50 MCL 10 Beryllium 1 MCL 4 Chromium 100 MCL 100 Lead 15 Action

Level 15

Nickel 100 MCL 100 1,4 dioxane (5) - - 3

Notes: (1) At the time of the 1991 ROD, a Maximum Contaminant Level (MCL) had not been established for 1,1-dichloroethane. The concentration listed is the State Ambient Groundwater Quality Standard (AGQS) based on cancer potency factor of 9.1x10-2

(milligrams per kilograms per day)-1 derived by State. (2) Using the more restrictive MCL for cis-1,2-dichloroethene (Cis = 70, Trans = 100). (3) Methylene Chloride is listed under the AGQS as dichloromethane and has a limit of 5 μg/L. (4) The arsenic standard was changed from 50 parts per billion (ppb) to 10 ppb by the United States Environmental Protection Agency in 2001. The New Hampshire Department of Environmental Services has also changed the AGQS to 10 ppb per RSA 485 C:6 (MCL) and Env-Ws 316.01. (5) 1,4 dioxane is detected in OU2 and therefore added to the contaminants of concern.

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Bold = effective cleanup goal Italic = cleanup goal added in this ESD ROD = Record of Decision AGQS = New Hampshire Ambient Groundwater Quality Standards μg/L = micrograms per liter ICL = interim cleanup levels MCL = maximum contaminant level RfD = reference dose

D. Updating the ARARs and TBCs

The ESD also updates the ARARs cited in the 1991 ROD both to include the revised State and Federal standards and to identify additional standards that were not specifically identified in the 1991 ROD. The updated ARARs tables are included in Attachment 1.

In April 1999, subsequent to the issuance of the 1991 ROD, EPA issued a guidance for utilizing monitored natural attenuation at Superfund sites7. The guidance specifies procedures for monitoring and evaluating natural attenuation performance and provides standards for: 1) developing a monitoring program to demonstrate that attenuation is occurring; 2) verifying that the plume is not expanding; and 3) determining whether remediation objectives will be attained within a reasonable time period, among other things. This ESD adds the procedures in the MNA guidance, which were not cited in the 1991 ROD, as components of the OU2 natural attenuation remedy as it is applied to the portions of the extended plume in OU2 that are outside of the capture zone of the groundwater extraction wells. It also makes the determination that the 1991 ROD’s estimate for achieving groundwater cleanup standards through natural attenuation within 35years is still valid based on MNA guidance procedures and data collected from historic and ongoing groundwater monitoring within OU2 (see Gradient Corp.’s 2015 Annual Groundwater Quality Monitoring Report).

Since the 1991 ROD, the State of New Hampshire has revised and renumbered its environmental regulations. The State of New Hampshire has also promulgated new surface water and groundwater quality standards. This ESD updates ARARs cited in the ROD both to include the revised State environmental regulations and the new State standards.

It also includes the addition of some federal statutes and/or regulations as ARARs in order to: 1) ensure that planning and decision-making incorporate fish and wildlife protection considerations in consultation with the resource agencies (U.S Fish and Wildlife and NH Fish and Game Department); 2) add wetlands and flood regulations to replace others that no longer exist; 3) add storm-water standards to be met to prevent surface waters from being impacted by operation and maintenance practices; and 4) clarify that groundwater cleanup standards identified in the 1991 ROD will also be used as monitoring standards to assess groundwater until CLs are achieved.

7 Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites, USEPA, April 1999, Directive 9200.4-17P

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IV. SUPPORT AGENCY COMMENTS

EPA has worked cooperatively with NHDES to develop this ESD and NHDES concurs with the changes to the remedy specified in this ESD.

V. STATUTORY DETERMINATION

In accordance with Section 121 of CERCLA, EPA, in consultation with NHDES, has determined that the modified remedy remains protective of human health and the environment, complies with all Federal and State requirements that are applicable or relevant and appropriate to this remedial action, meets the remedial action objectives specified in the 1991 ROD, and is cost-effective.

VI. PUBLIC INFORMATION

In accordance with Section 117(d) of CERCLA and Section 300.825(a) of the NCP, this ESD and the Administrative Record are available for public review at the locations and times listed in Section 1 above as well as on the internet at www.epa.gov/superfund/savage. Adobe Reader is required to review the documents. Notice of the release of the ESD will be published in the Milford Cabinet Press.

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Attachments

OU2 Management of Migration – Groundwater Extraction/Treatment, Monitored Natural Attenuation, Institutional Controls Savage Municipal Water Supply Well Superfund Site

Action-Specific ARARs

Requirement Status Requirement Synopsis Action to be Taken to Attain ARAR Changes from 1991 ROD & 1996 ESD

Federal Requirements

Resource Conservation and Recovery Act (RCRA), 42 U.S.C. §§ 6901, et seq., 40 C.F.R. Parts 261, 262 and 264

Applicable for remedial actions where hazardous waste will be moved and Relevant and Appropriate for remedial actions where hazardous waste left in place.

New Hampshire has been delegated the authority to administer these RCRA standards through its state hazardous waste management regulations (Env-Hw 100-1100). These provisions have been adopted by the State.

Any wastes generated by remedial activity will be analyzed by appropriate test methods. If found to be hazardous wastes, then they will be managed in accordance with the substantive requirements of the State hazardous waste regulations. Wastes that may be generated include: investigation derived waste from monitoring activities and contaminated media produced during the O&M of the groundwater treatment system, monitoring wells and other components of the remedy.

The ROD only cites 40 C.F.R. Part 262 as an applicable federal standard.

Clean Water Act; National Pollutant Discharge Elimination System (NPDES); Section 402, 33 U.S.C. § 1342, 40 C.F.R.122,125, 131, 136, 450

Applicable Establishes the specifications for discharging pollutants from any point source into the waters of the U.S. Also, includes stormwater standards for activities disturbing more than one acre.

Effluent from the treatment system will meet the substantive requirements of the NPDES program if discharged to surface waters. If O&M or any other remedial activities alter more than one acre of land, then stormwater standards will apply.

As cited in the ROD except the ROD only cited section 122 and did not include stormwater standards at 40 C.F.R. Part 450.

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Clean Water Act, National Recommend Water Quality Criteria (NRWQC)(33 U.S.C. § 1314, 40 CFR Part 131)

Relevant and Appropriate

NRWQC are health-based criteria developed for chemical constituents in surface water. They have been developed to protect aquatic life and human health from harmful effects due to exposure to chemically impacted surface water. NRWQC can be more stringent than MCLs if it is necessary to protect aquatic organisms. The more stringent NRWQC for aquatic life will be relevant and appropriate under certain circumstances.

The more stringent NRWQC for aquatic life will be relevant and appropriate for monitoring surface water quality from discharges of the treatment system under certain circumstances.

Cited in the ROD as a chemical-specific standard, however, these are action-specific standards addressing surface water monitoring. Cited in the ROD as Ambient Water Quality Criteria at 33 U.S.C. 304(a)(1).

Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites, OSWER Directive 9200.4-17P (April 21, 1999)

To Be Considered

EPA guidance regarding the use of monitored natural attenuation for the cleanup of contaminated soil and groundwater. In particular, a reasonable time frame for achieving cleanup standard though monitored attenuation would be comparable to that which could be achieved through active restoration.

Based on the operation of the groundwater treatment system and monitoring data to date EPA has estimated, based on this MNA guidance, that groundwater cleanup standards will be achieved within the ROD’s estimate of 60 years.

The ROD does not cite this guidance.

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Summary of Key Existing EPA CERCLA Policies for Groundwater Restoration June 26, 2009 OSWER Directive 9283.1-33

To Be Considered

Guidance on developing groundwater remedies at CERCLA sites.

Within OU2, groundwater is estimated to achieve federal drinking water and risk-based standards or more stringent State groundwater standards within the ROD’s estimate of 60 years. Groundwater use restrictions will be in place for as long as the groundwater exceeds cleanup standards. Groundwater monitoring using these standards will be used to determine where ICs are required and to document if cleanup standards are achieved.

The ROD does not cite this guidance.

Regulation of Applicable U.S. Army Corps of Engineers Any remedial activities such as the These regulations are Activities Affecting permit program identifying federal installation of discharge or collection moved to the Location-Waters of the United statutes, policies and procedures. pipes conducted along the Souhegan specific ARARs table States, 33 C.F.R. River with comply with these under Clean Water Act, Parts 320-329 regulations. Section 404 (33 U.S.C. §

1344); Section 404(b)(1) Guidelines for Specification of Disposal Sites for Dredged or Fill Material

Clean Air Act – Relevant and Define levels of air quality The on-site air stripper will have its off- Cited in the ROD as a National Ambient Air Appropriate necessary to protect public health gas treated to ensure that any chemical-specific Quality Standards with an adequate margin of discharge to the ambient air meets standard, however, these (40 C.F.R. Part 50 safety. Secondary standards pertinent regulations. are action-specific

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define levels of air quality necessary to protect public welfare from any known or anticipated adverse effects of a pollutant.

standards addressing air discharge standards for the air stripper.

State Requirements

Contaminated Site Applicable Env-Or Part 607 requires ICs will be established to protect ROD contains general Management, NH monitoring of the groundwater against use of contaminated citation to Env-Ws 410. Admin. Code Env-Or quality, requires implementation groundwater until groundwater cleanup Section Env-Ws 410.26 600: Part 607, of measures to restore the standards are achieved. Groundwater changed to Env-Or 607.05 Groundwater groundwater quality, and requires monitoring will be required until by the State. Management an evaluation of the effectiveness cleanup standards are achieved and Permits; Part 608, of the measures. Part 608 therefore monitoring wells will be The ROD does not cite the Activity and Use establishes standards for setting installed, operated, and other regulatory Restrictions; Part institutional controls to protect decommissioned under these requirements of Env-Or 610, Monitoring human health and components of

the remedy. Part 610 establishes standards for monitoring groundwater, including requirements and criteria for constructing, developing, and decommissioning monitoring wells.

standards. Contaminated media generated from installation of wells, and any other remedial activity will be managed in compliance with these standards. Activity and use restrictions will be established to prevent disturbance to the components of the remedy (including the treatment system and monitoring wells). There will be at least yearly compliance monitoring to ensure groundwater use and activity restrictions remain in place and are enforced.

600, including standards for activity and use restrictions.

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Hazardous Waste Management Act and Hazardous Waste Regulations, RSA Ch. 147-A, Env- Hw 100-1100

Applicable for remedial actions where hazardous waste will be moved and Relevant and Appropriate for remedial actions where hazardous waste left in place.

Establishes standards for the treatment, storage, transport and disposal of hazardous waste and the closure of hazardous waste facilities. New Hampshire has been delegated the authority to administer the federal RCRA standards through these state hazardous waste management regulations.

Management of hazardous wastes as part of the remedial action must comply with the substantive requirements of these regulations. Some of the specific sections of the regulations that pertain to the remedial action are cited below.

The ROD only includes a citation to part of the hazardous waste management regulations at Env-Wm 500. Env-Wm 100-1100 was changed to Env-Hw 100-1100 by the State.

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Identification and Applicable These standards list particular Any wastes generated by remedial The specific State Listing of Hazardous hazardous wastes and identify activity will be analyzed under these identification and listing of Wastes, N.H. Admin. the maximum concentration of standards to determine whether they hazardous waste Code Env-Hw 400 contaminants for which the waste

would be a RCRA characteristic waste. The analytical test set out in Appendix II of 40 C.F.R. Part 261 is referred to as the Toxicity Characteristic Leaching Procedure (TCLP). The federal requirements 40 C.F.R. Part 261 are incorporated by reference.

are listed or characteristic hazardous waste. Wastes that may be generated include: investigation derived waste from monitoring activities and contaminated media produced during the operation and maintenance of the monitoring well system and other components of the remedy. Materials that are listed waste or exceed TCLP hazardous waste thresholds will be disposed off-site in a RCRA Subtitle C facility. Non-hazardous materials will be disposed appropriately.

regulations were not identified in the ROD.

Requirements for Hazardous Waste Generators, N.H. Admin. Code Env-Hw 500, including Part 507 Storage Requirements; Part 513 Emergency/ Remedial Actions

Applicable Requires a determination as to whether waste materials are hazardous and, if so, requirements for managing such materials on site prior to shipment off site. The federal requirements 40 C.F.R. Part 262 are incorporated by reference.

If any remedial activity generates hazardous wastes, then it will be managed in accordance with the substantive requirements of these regulations.

The ROD cited the general generator standards at Env-Wm 500, as well as specific provisions of these regulations pertaining to manifesting, recordkeeping, packaging and labelling. Env-Wm 500 has since been changed to Env-Hw 500 by the State. Only the substantive, environmental

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provisions of these regulations are ARARs.

Protection of Groundwater: R.S.A. 485-A: 13, NH Admin. Code Env-Wq 402

Applicable These regulations establish substantive requirements for discharges to groundwater, including prohibited discharges (Env-q 402.07), water quality sampling (Env-Wq 402.8). and compliance criteria (Env-Wq 402.22),

Discharges to groundwater from any component of the alternative will meet discharge standards.

ROD included the statutory citation and the regulatory citation at Env-Ws 410. The statutory citation has not changed, but Env-Ws 410 has been changed to Env-Wq 402 by the State.

Best Available Technology and Treatment Techniques, NH Admin. Code Env-Dw-722

Applicable Requires use of best available technology when treating organic and inorganic contaminants in wastewaters.

Remedial activities aimed at achieving MCLs for organic and inorganic contaminants will use the best available technology.

ROD contains citations to Env-Ws 346 and 347 changed to Env-Dw-722 by the State.

Standards of Design and Construction of Sewerage and Wastewater Treatment Facilities, Env-Wq 700

Applicable Requires use of best available technology when treating organic and inorganic contaminants in wastewaters.

Remedial activities aimed at achieving MCLs for organic and inorganic contaminants will use the best available technology.

ROD contains citation to Env-Ws 700 changed to Env-Wq-700 by the State.

Criteria for Groundwater Discharges (Env-Wq 402.04)

Applicable Establishes groundwater discharge criteria which include MCLs and MCLGs adopted by the Water Supply and Pollution Control Division.

Require remedial action to eliminate discharge of contaminants including VOCs and inorganic contaminants resulting in groundwater contamination above State MCL and MCLG levels.

Cited in the ROD as a chemical-specific standard, however, these are action-specific standards addressing

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discharges to groundwater. ROD citation (Env-Ws 410.09) changed to Env-Wq 402.04 by the State.

Surface Water Applicable Establish water quality criteria for Surface water monitoring standards for Cited in the ROD as a Quality Standards toxic substances. The criteria are assessing treatment system chemical-specific (Env-Wq 1700) essentially the same as the

federal NRWQC. Criteria are established for fresh and marine waters.

discharges to surface waters. standard, however, these are action-specific standards addressing surface water monitoring. ROD citation (Env-Ws 432) changed to Env-Wq 1700 by the State.

Enforcement of Classification, R.S.A. 485-A:12

Applicable Any discharge to groundwater or surface water that lowers the quality of the water below its classification is prohibited.

Remedial alternatives involving the discharge to groundwater or surface water must comply with these standards.

As cited in the ROD.

Standards for Applicable for This provision requires that wells Wells used for the remedy will be The ROD only cited well Construction, drinking be constructed, maintained, created, operated, and closed in abandonment section We Maintenance and water wells; relocated, and/or abandoned compliance with these standards. Well 604. Abandonment of Relevant and according to these regulations. restriction standards shall be Wells, NH Admin. Appropriate We 602.05 address restrictions incorporated into institutional controls Code We 600 for monitoring

wells on location wells in contaminated areas.

to prevent groundwater use within OU2 until groundwater cleanup standards are achieved.

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Air Pollution Control: Applicable Air pollution control statutory If operation and maintenance of As identified in the ROD. RSA Ch. 125-C; requirements. groundwater treatment system, Specific regulations monitoring wells or other remedial at Env-A cited below. actions cause a release of

contaminants into the air, emissions controls will be included in the remedial design to control emissions.

Ambient Air Quality Standards, NH Admin. Code Env-A 300

Applicable These regulations set primary and secondary ambient air quality standards (equivalent to federal standards). The standards do not allow significant deterioration of existing air quality in any portion of the state for: particulate matter, sulfur dioxide, carbon monoxide, nitrogen dioxide, ozone hydrocarbons and lead.

If there are remedial processes, including the groundwater treatment system and monitoring well system, that result in releases of contaminants into the air, air quality standards will be complied with during remedial activities.

Cited in the ROD (specifically Parts 303 and 304) as a chemical-specific standard, however, these are action-specific standards addressing the control of air emissions.

Air Pollution Control, Relevant and Establishes standards for the Discharges of contaminants to the air As cited in the ROD. Env-A 604-606 Appropriate release of air emissions including

VOC's and hazardous air pollutants. Applicable standards include the most stringent of the following requirements: 1) New source performance standards (40 CFR Part 60); 2) National Emission Standards for Hazardous Air Pollutants (40 CFR Part 61); 3) New Hampshire State Implementation Plan limits.

from treatment operations shall be restricted and treated to ensure that no regulatory air discharge limits are exceeded.

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Testing and Monitoring Procedures, NH Admin. Code Env-A 800

Applicable Require emission testing and ambient air quality monitoring. Establish procedures for VOC testing and Continuous Emission Monitoring.

Remedial measures generating air emissions will be tested to ensure the attainment of pertinent standards.


Fugitive Dust, N.H. Admin. Code Env-A Part 1002

Applicable Requires precautions to prevent, abate and control fugitive dust during specified activities, including excavation, maintenance, and construction.

Precautions to control fugitive dust emissions will be required during site remediation activities that could generate dust, such as O&M of the treatment system or installation and maintenance of the monitoring well system.


Regulated Toxic Air Pollutants, NH Admin. Code Env-A Part 1400

Applicable This regulation identifies toxic air pollutants to be regulated. These pollutants are also listed by EPA in 40 CFR 261. High, moderate and low Toxicity Classifications are established. Air toxics in these classifications are regulated when they occur in concentrations that cause adverse health effects including increased cancer risk.

If there are remedial processes that result in releases of contaminants into the air, air quality standards will be complied with during remedial activities.

Cited in the ROD’s chemical-specific ARAR table as Env-A 1300. Current citation is Env-A 1400 as an action-specific ARAR.

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OU2 Management of Migration – Groundwater Extraction/Treatment, Monitored Natural Attenuation and Institutional Control Savage Municipal Water Supply Well Superfund Site

Chemical-Specific ARARs Requirement Status Requirement Synopsis Action to be Taken to Attain ARAR Changes from 1991

ROD & 1996 ESD Federal

Requirements EPA Risk Reference To Be Dose levels developed by EPA to Risk-based standards developed No change. Dose (RfDs) Considered protect sensitive individuals over the

course of a life-time. RfDs reflect a daily exposure level likely to be without appreciable risk of adverse health effects.

using this guidance will be achieved through extraction/treatment and Monitored Natural Attenuation based on achieving risk-based groundwater standards within approximately 60 years.

EPA Carcinogenicity To Be Slope factors are developed by EPA Risk-based standards developed No change. Slope Factor Considered from Health Effects Assessments and

present the most up-to-date information on cancer risk potency. Slope factors are developed by EPA from Health Effects Assessments by the Carcinogenic Assessment Group.

using this guidance will be achieved through extraction/treatment and Monitored Natural Attenuation based on achieving risk-based groundwater standards within approximately 60 years.

Guidelines for To Be Guidance for assessing cancer risk. Risk-based standards developed The ROD does not cite Carcinogen Risk Considered using this guidance will be achieved this risk guidance. Assessment through extraction/treatment and EPA/630/P-03/001F Monitored Natural Attenuation based (March 2005) on achieving risk-based groundwater

standards within approximately 60 years.

Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens EPA/630/R-03/003F (March 2005)

To Be Considered

Guidance of assessing cancer risks to children.

Risk-based standards developed using this guidance will be achieved through extraction/treatment and Monitored Natural Attenuation based on achieving risk-based groundwater standards within approximately 60 years.

The ROD does not cite this risk guidance.

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ROD & 1996 ESD Safe Drinking Water Relevant Establishes maximum contaminant MCLs will be achieved through The ROD cites 40 Act (42 U.S.C. §300f and levels (MCLs) for common organic and extraction/treatment and Monitored C.F.R 141.11-16, et seq.); National Appropriate inorganic contaminants applicable to Natural Attenuation within however 40 C.F.R. primary drinking public drinking water supplies. Used as approximately 60 years. Subpart B now only water regulations relevant and appropriate cleanup consists of 40 C.F.R. (40 C.F.R. 141, standards for aquifers and surface 141.11-13 and there is Subpart B and G) water bodies that are potential drinking

water sources. no 141.14-16. All of Subpart G is cited for this amended remedy alternative (40 C.F.R. 141.60-66).

Safe Drinking Water Act (42 U.S.C. §300f et seq.); National primary drinking water regulations (40 C.F.R. 141, Subpart F)

Relevant and Appropriate for non-zero MCLGs only; MCLGs set as zero are To Be Considered

Establishes maximum contaminant level goals (MCLGs) for public water supplies. MCLGs are health goals for drinking water sources. These unenforceable health goals are available for a number of organic and inorganic compounds.

MCLGs will be achieved through extraction/treatment and Monitored Natural Attenuation within approximately 60 years.

The ROD cites 40 C.F.R. 141.50-51 as the MCLG regulation citation but the MCLGs are now within Subpart F, which incorporates 40 C.F.R. 141.50-55.

Drinking Water To Be Health Advisories are estimates of risk Risk-based standards developed The ROD does not cite Health Advisory Considered due to consumption of contaminated using this guidance will be achieved this risk guidance. for Manganese, drinking water; they consider non- through extraction/treatment and EPA-822-R-04-003 carcinogenic effects only. To be Monitored Natural Attenuation based January, 2004 considered for contaminants in

groundwater that may be used for drinking water where the standard is more conservative than either federal or state statutory or regulatory standards. The Health Advisory standard for manganese is 0.3 mg/l.

on achieving risk-based groundwater standards within approximately 60 years.

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ROD & 1996 ESD Clean Water Act, Ambient Water Quality Criteria (AWQC)(33 U.S.C. 304(a)(1)


AWQC are health-based criteria developed for chemical constituents in surface water. They have been developed to protect aquatic life and human health from harmful effects due to exposure to chemically impacted surface water. AWQC can be more stringent than MCLs if it is necessary to protect aquatic organisms. The more stringent AWQC for aquatic life will be relevant and appropriate under certain circumstances.

The more stringent AWQC for aquatic life will be relevant and appropriate under certain circumstances.

Moved to the Action-specific Table and changed to National Recommended Water Quality Criteria (NRWQC), 33 U.S.C. § 1314, 40 CFR Part 131

Clean Air Act – Relevant Define levels of air quality necessary to The on-site air stripper will have its Moved to the Action-National Ambient Air and protect public health with an adequate off-gas treated to ensure that any specific Table. Quality Standards Appropriate margin of safety. Secondary standards discharge to the ambient air meets (40 C.F.R. Part 50 define levels of air quality necessary to

protect public welfare from any known or anticipated adverse effects of a pollutant.

pertinent regulations.

State Requirements

Drinking Water Relevant State MCLs and MCLGs establish State MCLs and MCLGs will be ROD citation (Env-Ws Quality Standards: and maximum contaminant levels permitted achieved through extraction/ 315 - 317) changed to NH Admin. Code Appropriate in public water supplies and are the treatment and Monitored Natural Env-Dw 700 by the Env-Dw 700 for MCLs

and non-zero MCLGs only; MCLGs set as zero are To Be Considered

basis of State Ambient Groundwater Quality Standards (AGQS) that are applicable to site groundwater. The regulations are generally equivalent to the Federal Safe Drinking Water Act (SDWA).

Attenuation within approximately 60 years.

State.

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ROD & 1996 ESD New Hampshire Ambient Groundwater Quality Standards (NH AGQS) (Env-Or 603.03, Table 600-1)


Establishes maximum concentration levels for regulated contaminants in groundwater which result from human operations or activities. NH AGQS are equivalent to MCLs for contaminants that have MCLs. NH AGQS have been established for site groundwater contaminants for which no MCLs are established, and are derived to be protective for drinking water uses. The NH AGQS will be used for site contaminants where MCLs are not currently established.

These State groundwater standards will be achieved through extraction/ treatment and Monitored Natural Attenuation within approximately 60 years.

ROD citation (Env-Ws 410.05) changed to Env-Or 603.03, Table 600-1 by the State.

Criteria for Groundwater Discharges (Env-Ws 410.09)

Applicable Establishes groundwater discharge criteria which include MCLs and MCLGs adopted by the Water Supply and Pollution Control Division.

Require remedial action to eliminate discharge of contaminants including VOCs and inorganic contaminants resulting in groundwater contamination above State MCL and MCLG levels.

Moved to Action-specific Table. ROD citation (Env-Ws 410.09) changed to Env-Wq 402.04 by the State.

Surface Water Applicable Establish water quality criteria for toxic Discharges to surface water in or Moved to Action-Quality Standards substances. The criteria are essentially adjacent to the site must meet these specific Table. ROD (Env-Ws 432) the same as the federal AWQC.

Criteria are established for fresh and marine waters.

standards. citation (Env-Ws 432) changed to Env-Wq 1700 by the State.

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ROD & 1996 ESD Ambient Air Quality Standards (Env-A 300, Parts 303 and 304)


Set primary and secondary ambient air quality standards equivalent to federal standards. These standards do not allow significant deterioration of existing air quality in any portion of the state for particulate matter, sulphur dioxide, carbon monoxide, nitrogen dioxide, ozone, hydrocarbons, lead, and fluoride.

The on-site air stripper will have its off-gas treated to ensure that any discharge to the ambient air meets pertinent regulations.

Moved to the Action-specific Table.

Toxic Air Pollutants (Env-A 1300

Applicable Establishes ambient air limits for 74 chemicals. Ambient air limits (AALS) are levels at or below which ambient air concentrations of a respective air contaminant will not adversely affect human health.

Any discharge to the ambient air from the on-site air stripper will meet the pertinent regulations.

Moved to the Action-specific Table.

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Location-Specific ARARs

Requirements Status Requirement Synopsis Action to be Taken to Attain ARAR Changes from 1991 ROD & 1996 ESD

Federal Requirements Fish and Applicable Any modification of a body of water Contact with appropriate federal No change. Wildlife or wetland requires consultation agencies will be maintained during Coordination with the U.S. Fish and Wildlife construction and O&M of any monitoring Act (16 U.S.C. Service and the appropriate state wells or other remedial infrastructure §661 et seq.) wildlife agency to develop

measures to prevent, mitigate, or compensate for losses of fish and wildlife.

that may alter protected resource areas

Floodplain Management and Protection of Wetlands (44 C.F.R. § 9)


FEMA regulations that set forth the policy, procedure and responsibilities to implement and enforce Executive Order 11988 (Floodplain Management) and Executive Order 11990 (Protection of Wetlands). Prohibits activities that adversely affect a federally-regulated wetland unless there is no practicable alternative and the proposed action includes all practicable measures to minimize harm to wetlands that may result from such use. Requires the avoidance of impacts associated with the occupancy and modification of federally-designated 100-year and 500-year floodplain and to avoid development within floodplain wherever there is a practicable alternative. An assessment of impacts to 500-year floodplain is required for critical actions – which

To the extent any remedial activities need to occur within federal jurisdictional wetland then all practicable measures will be taken to minimize and mitigate any adverse impacts. Erosion and sedimentation control measures would be adopted during construction, O&M, and restoration activities within federal jurisdictional wetlands. Standards for construction or O&M of any monitoring wells or other remedial infrastructure in federal jurisdictional wetlands or the 500-year floodplain will be attained based on a determination that (a) there is no practical alternative method that will achieve cleanup objectives with less adverse impact; (b) all practical measures would be taken to minimize and mitigate any adverse impacts from the work; (c) there would be no likely impact on federal threatened or endangered (T&E) species; (d) actions would be taken to minimize impact of hydrologic changes

Former wetland and floodplain regulations cited in the ROD that incorporated Executive Orders 11988 and 11990 at 40 C.F.R. Part 6, Appendix A no longer exist so have been replaced by regulatory requirements to meet the Executive Order standards at 44 C.F.R. § 9.

Page 1 of 4




includes siting hazardous waste facilities in a floodplain. Requires public notice when proposing any action in or affecting floodplain or wetlands.

during the work; (e) after completion of the work, there would be no significant net loss of flood storage capacity, and no significant net increase in flood stage or velocities; and (f) river and riverbanks would be restored and habitat will be improved. Public comment received on this draft ESD concerning any proposed alteration to wetlands and floodplain will be addressed in the final version of the ESD.

Clean Water Applicable For discharge of dredged or fill Under this alternative construction and The ROD only cited part of Act, Section material into federal jurisdictional O&M of the monitoring wells and any the applicable regulations at 404 (33 U.S.C. water bodies or wetlands, there other remedial infrastructure that will 40 C.F.R. Part 230. § 1344); must be no practical alternative result in the dredging or filling of federal Section with less adverse impact on jurisdictional wetlands would be subject 404(b)(1) aquatic ecosystem; discharge to these requirements. Activities must Guidelines for cannot cause or contribute to be conducted in accordance with these Specification of violation of state water quality requirements including, but not limited Disposal Sites standard or toxic effluent standard to, mitigation and/or restoration. EPA for Dredged or or jeopardize federal T&E species; has determined in the ROD that the Fill Material (40 discharge cannot significantly remedy satisfies the standards under C.F.R. Part degrade waters of U.S.; must take these regulations, including the LEDPA 230, 231 and practicable steps to minimize and requirements. 33 C.F.R. Parts mitigate adverse impacts; must 320-323) evaluate impacts on flood level,

flood velocity, and flood storage capacity. Sets standards for restoration and mitigation required as a result of unavoidable impacts to aquatic resources. EPA must determine which alternative is the “Least Environmentally Damaging

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Practicable Alternative” (LEDPA) to protect wetland and aquatic resources.

State Requirements Criteria and Conditions for Fill and Dredge In Wetlands: RSA Ch. 482-A and NH Admin. Code Env-Wt Parts 100-900

Applicable These standards regulate filling and other activities in or adjacent to wetlands, and establish criteria for the protection of wetlands from adverse impacts on fish, wildlife, commerce, and public recreation.

All activities within on-site State jurisdictional wetlands and floodplain areas will comply with these wetland protection requirements.

ROD citation (Env-Wm 300-400 and 600) changed to Env-Wt 100-900 by the State.

Siting requirements for hazardous waste facilities and variances, Env-Hw 304.08 (Existing facilities) and 304.09 (New facilities).


Flood control measures must be identified for any facility within the 100-year floodplain. Similarly, new facilities located within 3,000 feet of faults displaced in Holocene times must show that no faults pass within 200 feet of the facility.

Siting and O&M of the treatment facility will be done in accordance with these regulations.

ROD citation (He-P 1905.09) changed to Env-Ws 304.08 and 304.09 by the State.

Native Plant Protection Act, R.S.A. 217-A

Applicable Prohibits damaging plant species listed as endangered in the State.

Any remedial action that may damage state-listed endangered plants will need to meet these standards.

Not cited in the ROD.

Endangered Applicable Prohibits the taking of State-listed Any remedial action that may take state- Not cited in the ROD. Species endangered species and regulates listed species will need to meet these Conservation such activities with regard to State- standards. Act, R.S.A. listed threatened species. 212-A

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Terrain Alteration, Env-Wq 1500 and RSA 485-A:17

Applicable The purpose of these rules is to protect drinking water, surface water and groundwater from degradation resulting from any activity which significantly alters terrain or occurs in or on the border of the surface waters of the state. Env-Wq 1505.04 specifically addresses Stormwater Management and Erosion and Sediment Control.

Any significant excavation in or around the Souhegan River or other surface water bodies on-site as part of the remedial action will be conducted in compliance with the substantive requirements of these standards.

ROD citation (Env-Ws 415) changed to Env-Wq 1500 by the State.

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