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Explanation of Significant Differences NllfRIC Site 7 - Tank Farm 1, Decision Units 1-1, 1-2, and 1-3 (OU 13)

Naval Station Newport, Rhode Island Expansion of the Decision Unit 1-1 Soil Excavation Area Footprint

INTRODUCTION AND STATEMENT OF PURPOSE

An Explanation of Significant Differences (ESD) is required for Site 7 - Tank Farm 1, Decision Unit (DU) 1-1, 1-2, and 1-3, within Naval Station (NAVSTA) Newport, Portsmouth, Rhode Island. Site 7 is designated as Operable Unit (OU) 13. This ESD modifies the 2016 Record of Decision (ROD) by expanding the footprint for the DU 1-1 surface soil excavation. The modification is significant because it increases the volume of soil requiring removal and disposal required under the ROD and increases the cost of implementing the remedy, but does not fundamentally alter the overall cleanup approach documented in the ROD.

The Navy is the lead agency, with oversight from the United States Environmental Protection Agency (EPA) and Rhode Island Department of Environmental Management (RIDEM), for cleanup of sites at NAVSTA Newport in the Installation Restoration Program (IRP) under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) as modified by the Superfund Amendments and Reauthorization Act of 1986 (SARA).

The ROD for DU 1-1, 1-2, and 1-3 at Site 7 -Tank Farm 1 was signed by the Navy on August 10, 2016 and signed by EPA on September 21, 2016. The Navy is issuing this ESD as part of the public participation requirements under Section 117(c) of CERCLA, Section 300.435(c)(2)(i) of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), and the Navy IRP. In accordance with Section 300.825(a)(2) of the NCP, this ESD will become part of the Administrative Record for the facility. The Administrative Record also contains background information that was used in determining the selected remedy, as documented in the ROD, and in preparing this ESD. The Administrative Record for NAVSTA Newport is included as part of the Information Repository, which is available for review at the following web site: http://go.usa.gov/DyNw.

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SITE HISTORY, CoNTAMINATION, AND SELECTED REMEDY

Site History Site 7 - Tank Farm 1 (OU13), is a SO-acre former fuel storage and distribution area in the northern portion of the NAVSTA Newport facility, located in Portsmouth, Rhode Island. Within Site 7 -Tank Farm 1 are DU 1-1, 1-2, and 1-3, which are the three Decision Units addressed by the 2016 ROD. DU 1-1 is located in the southeast portion of Tank Farm 1 and DU 1-2 and DU 1-3 are located in the central portion of Tank Farm 1. The site was used by the Navy as a fuel storage area and distribution facility from 1940 until it was leased to the Defense Logistics Agency (DLA) Energy in 1974. DLA Energy continued to use the site as a fuel storage area and distribution facility until operations were terminated in 1998. The site has been inactive since 1998, aside from the occasional environmental-related activity (i.e., soil sampling, vegetation clearing, etc.) performed by Navy and DLA Energy contractors. Tank Farm 1 is also used by Department of Defense (DoD) personnel for deer hunting during portions of the year.

DU 1-1 is defined as soil associated with the Ethyl Blending Plant (EBP) (includes the EBP and associated previously designated AOCs TFl -004, TFl -005, and TFl-018). DU 1-2 is defined as soil associated with Transformer Vault 2 (TV2) and DU 1-3 is defined as soil associated with Transformer Vault 3 (TV3).

Contaminants in soil were identified during past environmental assessments at DUs 1-1, 1-2, and 1-3 and were attributed to previous activities within each area. Contaminants in soil at DU 1-1 are likely attributable to former operations at the EBP, such as engine idling, operation of the heating system at the plant, use of lubricants, etc. Contaminants in soil at DU 1-2 and DU 1-3 are attributed to historical releases of PCB-containing oils adjacent to TV2 and TV3.

Contaminants of Concern Contaminants of concern (COCs) listed in the 2016 ROD include selected metals and polycyclic aromatic hydrocarbons (PAHs) in surface soil at DU 1-1 and polychlorinated biphenyls (PCBs) in surface soil at DU 1-2 and 1-3.

Selected Remedy The Selected Remedy for soil at DU 1-1, 1-2, and 1-3, as described in the ROD, includes the following components:

,.. Limited soil excavation and off-site disposal will remove surface soils exceeding Industrial Remedial Goals (RGs) (including RIDEM GA Leachability Criteria) for DU 1-1 and allow for industrial and restricted recreational use.

,.. Limited soil excavation and off-site disposal will remove surface soils exceeding the Industrial and Ecological RGs (including RIDEM Leachability Criteria) for DU 1-2 and 1-3 and allow for i ndustria I and restricted recreational use.

> Land Use Controls (LUCs) will be established to prevent residential and other unrestricted use to address soil that will remain above Residential RGs at DU 1-1, 1-2, and 1-3.

> For DU 1-1, because there is only a thin layer of soil overlying bedrock at DU 1-1, it is likely that little to no soil is present below the EBP foundation. However, as a conservative measure, LUCs will also be required for the EBP structure footprint to prevent access to soil, if it exists, below the building.

. >- For DU 1-2 and DU 1-3, LUCs will be required for the TY2 and TV3 structure footprints to prevent access to soil below the buildings, since it has not been assessed.

> If the EBP (DU 1-1), TY2 (DU 1-2), and/orTV3 (DU 1-3) foundations are demolished ln the future, the presence or absence of soil beneath the buildings will be assessed and if soil is present, it will be remediated, if necessary, to meet Industrial RGs for DU 1-1 and the Industrial and Ecological RGs for DU 1-2 and DU 1-3. If and when TY2 and/or TV3 are demolished in the future, the demolition will meet Toxic Substances Control Act (TSCA) (15 U.S. C §§ 2601 et seq.) protectiveness standards so as not to create a threat of release to the environment.

Under this Selected Remedy, potential unacceptable human and ecological exposures to contaminated surface soil at DU 1-1, DU 1-2, and DU 1-3 will be eliminated through the combination of limited soil excavation and off-site disposal and LUCs. These actions will be supported by site inspections and five­year reviews. Implementation of this remedy will allow for continued industrial and restricted recreational use, which is consistent with the anticipated future uses for the site.

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BASIS FOR THE DOCUMENT

Consistent with the ROD, a soil pre-design investigation (PDI) was conducted in 2016 to further refine the extent of surface soils exceeding RGs within DU 1-1, DU 1-2, and DU 1-3. Based on the PDI results, the area and volume of surface soil at DU 1-1 requiring excavation and off-site disposal to meet Industrial RGs has expanded significantly because the extent of PAH impacts above Industrial RGs was much larger than estimated in the ROD. The areas requiring excavation and off-site disposal to meet Industrial and Ecological RGs for DU 1-2 and DU 1-3 were also refined but did not change significantly from the ROD estimates. Additionally, the LUC boundaries for DU 1-1, 1-2, and 1-3 were refined and expanded from estimated al"eas identified in the ROD. The expanded LUC boundaries are considered a non-significant change, since they do not result in a substantial cost increase.

The increased area and volume of surface soil at DU 1-1 requiring surface soil excavation and the associated increased cost (along with the increased cost to delineate the area) is considered a significant change that requires an ESD. The volume of surface soil to be excavated from DU 1-1 increased from the ROD estimate of approximately 130 cubic yards to approximately 904 cubic yards and the subsequent cost of remediation increased by 160% (i.e., greater than 50%) to an updated total present value cost of $608,000. Note that the depth of surface soil excavation is unchanged from the ROD. The initial and expanded limits of DU 1-1 surface soil excavation area are shown on Figure 1.

DESCRIPTION OF SIGNIFICANT DIFFERENCES

The significant difference in site conditions is the expansion of DU 1-1 surface soil excavation area beyond what was depicted in the ROD and the associated increased cost of the remediation. Based on this expansion, an additional estimated 774 cubic yards of impacted surface soil requires excavation and off-site disposal from DU 1-1, above the approximately 130 cubic yard estimate provided in the ROD.

With this change, the Selected Remedy will be protective of human health and the environment as presented in the ROD, and as documented in this ESD.

SUPPORT AGENCY COMMENTS

EPA and RIDEM representatives, as part of the NAVSTA Newport IR Team, have had ongoing involvement in the decision-making process associated with this new finding and subsequent change in the selected remedy for DU 1-1, 1-2, and 1-3 at Site 7 -Tank Farm 1. The Navy has obtained concurrence

from RIDEM on the modification to the selected remedy for DU 1-1, 1-2, and 1-3 at Site 7 -Tank Farm 1 as described in this ESD.

STATUTORY DETERMINATIONS

The Navy acknowledges the additional contamination present in surface soil at DU 1-1 within Site 7 - Tank Farm 1. The remedy documented in the ROD, which includes a combination of surface soil excavation with off-site disposal and LUCs to restrict future use, is an appropriate response action for the expanded area of contamination identified at DU 1-1.

Apart from the additional volume of soil to be addressed at DU 1-1, there is no other significant change to any component of the remedy. The proposed change to the selected remedy will continue to satisfy the statutory requirements of CERCLA Section 121, and the modified remedy will remain protective of human health and the environment and will continue to comply with federal and state ARARs and to be cost effective.

PUBLIC PARTICIPATION

Public participation requirements as outlined in the NCP, Section 300.435 (c) (2) (i), have been met by including this ESD in the Administrative Record for Site 7 and by publishing in local newspapers a notice of availability of the ESD. I n addition, the Navy regularly meets to discuss the status and progress of the !RP with the Restoration Advisory Board (RAB), which includes representatives from the local community.

· Representatives from the Navy, EPA, and RIDEM attend these meetings. The expanded size of DU 1-1 surface soil excavation area at Site 7 - Tank Farm 1 was discussed at the RAB meeting on January 18, 2017.

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FOR MORE INFORMATION

If you have questions or would like further information about the ESD for DU 1-1, 1-2, and 1-3 at Site 7 -Tank Farm 1, NAVSTA Newport, please contact:

Ms. Lisa Rama Public Affairs Office

690 Peary Street Naval Station Newport

Newport, RI 02841-1512 401-841-3538

Ms. Jane Dolan Remedial Project Manager

U.S. Environmental Protection Agency, Region 1 5 Post Office Square, Suite 100

Mail Code: OSRR07-1 Boston, MA 02109-3912

Telephone: 617-918-1272 E-mail: Dolan.Jane@epa.gov

Ms. Pamela Crump RIDEM Project Manager

Rhode Island Department of Environmental Management

235 Promenade St. Providence, RI 02908-5767

Telephone: (401) 222-2797 ext. 7020 E-mail: pamela.crump@dem.ri.gov

Dl!a.ARAnON

The OU 1-1 surface soll excavation area has expanded beyond what was depicted In the ROD due to the det:edioni of PAHs above remedial goals outside of the original estimated area. The volume of surface soil to be excavated from DU 1-1 lnaeased from approximately 130 cubic yards to approximately 904 cubic yards. The subsequent mst of remediation has lnaeased by 160% (I.e., greater .than 50%) to an updated total present value cost of $608,000. Therefore, an ESD to the 2016 ROD Is needed to doo.ment the additional costs and volume of surface soil tD be removed from DU 1-1. For the foregoing reasons, by my signature below, I approve the issuance of this Explanation of Significant Difference for the Record of Decision for Site 7 -Tank Farm 1, OU 1-1, 1-2, and 1-3 at NAVSTA Newport.

United states Department of the Navy:

yer Date er, NAVSTA Newport

United States Environmental Protection Agency:

1/>1/17 Bryan I). Olson Date Direct.or Office of Site Remediation and Restoration U.S. EPA Region 1

183688.23

183897.89

~ L.....J Extent of land Use Control Area

II -- Current Anticipated Extent of Surface Soil Excavation

- - - - Estimated Extent of Surface So• Excavabon from ROD

Drawn: JB 11/2712016 -- Topographic Contour Line (NAVO 88)

Approved: NO 11/27/2016 ·-- ·- - - - - - · Petroleum Distribulion (Remaining)

Project #: 60266436 - • • • • Ring DrahVBSW Drainage (Remaining)

Path: P:\G01,1t\Projects\NavyCLEAN AECOM·EnSafe MNewpof\\Gf S\Projects\Tan~F arm_ 1\ESOVdXO\Fig_ 1 _Expanded_Exc:avatlon_Area.mXd

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Scale in Feet

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FIGURE 1

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EXPANDED EXCAVATION AREA DECISION UNIT 1-1

ETHYL BLENDING PLANT EXPLANATION OF SIGNIFICANT DIFFERENCES

TANK FARM 1 (SITE 7) NAVSTA NEWPORT, RHODE ISLAND

RHODE ISLAND -- DEPARTMENT OF ENVIRONMENTAL MANAGEMENT

a 235 Promenade Street, Providence, RI 02908,5767

March 22, 2017

Bryan 0. Olson,_Director U.S. EPA, Region 1 Office of Site Remediation and Restoration 5 Post Office Square Suite 100 (OSR 07-5) Boston, MA 02109-3912

RE: Site 7 -Tank Fa1m 1, Decision Units 1-1, 1-2, and 1-3 (OU 13) Naval Station Newport, Rhode Island

Dear Mr. Olson:

1DD 401-222-4462

The Office of Waste Management has conducted a review of the Explanation of Significant Differences (ESD), dated January 2016, for Site 1 -Tank Farm 1, Decision Units 1-1, 1-2, anci 1-3, Naval Station Newport, Rhode Island. The ESD documents the increased area of surface soil at DU · 1-1 requiring excavation. This expansion significantly increases the volume of soil requiring excavation and off-site disposal and will increase the cost of remediation by 160%.· As a result of this review, the Department concurs with'this ESD.

If you have any questions, please feel free to contact Matthew DeS tefano of my staff at ( 401) 222-2797, extension 7141. ·

Sincerely, . , ,.. ..... rr'' ; .--,-' ,,,.-·"(·--·

1__..-.,-·/2 / / /;?/'' -/;>t,:.~ --v~,c .. ,c _ _. ,., t,Leo Hellested, P.E., Chief '·,

Office of Waste Management Department of Environmental Management

cc: Matthew Destefano, RlD EM/Office of Waste Management Nicholas Noons, RIDEM/Office of Waste Management Anni Loughlin, USBPA Jane Dolan, USEP A Jim Gravette, NA VF AC MID LANT

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