Re: Notification of Phase IV Remedy Implementation Plan Submittal

August 26, 2015

File No. 01.0025623.10

The Honorable Sefatia Romeo Theken
Mayor of Gloucester
9 Dale Avenue
Gloucester, Massachusetts 01930 / Richard Sagall, Chairperson
Board of Health
3 Pond Road
Gloucester, Massachusetts 01930

Re: Notification of Phase IV Remedy Implementation Plan Submittal

Former Gloucester Manufactured Gas Plant (MGP)

Harbor Loop, Gloucester, Massachusetts

Release Tracking Number (RTN) 3-25126

Dear Mayor Theken and Mr. Sagall:

Per the requirements of the Massachusetts Contingency Plan (MCP), specifically 310 CMR 40.1403(3)(a) and (e), this letter is intended to notify you that a Phase IV Remedy Implementation Plan(RIP) for the above-referenced Site is being submitted to the Massachusetts Department of Environmental Protection (MassDEP), and that associated field activities will be initiated shortly thereafter. The Phase IV RIP describes Comprehensive Remedial Actions (CRAs) that will be conducted to achieve a condition of No Significant Risk (NSR) at the Site. Related field activities will be conducted over a period of two to three construction seasons beginning on or after September 8, 2015.

As required by the MCP, the following sections of the Phase IV RIP are attached: a description and conceptual plan of the activities; and a discussion of the measures that will be implemented to limit or mitigate impacts to environmental receptors and natural resource areas. A schedule for the proposed Phase IV Remedy Implementation is also attached. A copy of the Phase IV RIP submittal can be viewed after August 28, 2015 under RTN 3-35126at the MassDEP website: Copies of the report can also be obtained by contacting Mr. Kenneth Lento at (781) 907-3655 or the undersigned.

If you have any questions concerning this letter, please contact the undersigned at 7812783805.

Very truly yours,

GZA GEOENVIRONMENTAL, INC.

Matthew J. Barvenik, LSP

Senior Principal

cc:MassDEP – NERO

Kenneth E. Lento, National Grid

Attachments: Description of the Comprehensive Remedial Actions

J:\25,000-26,999\09.0025623.00\Phase IV - RIP\Phase IV Report\Appendices\Appendix Q - Public Notices\BOH & City Notice of Phase IV RIP Submittal.docx

DESCRIPTION OF REMEDIAL ACTIONS

1.00INTRODUCTION

On behalf of Massachusetts Electric Company d/b/a National Grid (National Grid), GZA GeoEnvironmental, Inc. (GZA) and Anchor QEA, LLC (Anchor QEA) have prepared this Phase IV Remedy Implementation Plan (RIP) for the Gloucester Gas Light Company (GGLC) Manufactured Gas Plant (MGP) facility (the Site). The Site is located off Harbor Loop and Rogers Street in Gloucester, Massachusetts and has been assigned Release Tracking Number (RTN) 3-25126 by the Massachusetts Department of Environmental Protection (MassDEP).

1.10PROJECT SUMMARY

Response actions are being conducted at the Site to meet the requirements of the Massachusetts Contingency Plan (MCP, 310 CMR 40.0000). A Locus Map is included as Figure 1, and an Aerial View of the Site showing properties within the disposal site boundary is presented as Figure 2. As shown on Figure 2, the Site extends across upland and in-water (marine) areas of multiple properties, which are owned by various commercial and governmental entities. To facilitate assessment and remedial activities, the Site has been divided into Marine and Upland Areas. The Upland Area has been further subdivided into the Southern Area and Northern Area based on historical and present-day ownership and land uses.

The MCP Phase IV Comprehensive Remedial Alternatives (CRAs) described in this reporthave been designed to address the Southern and Marine Areas[1] of the Site, collectively designated as the Project Area. Property owners within the Project Area include the United States Coast Guard (USCG), the City of Gloucester (City), National Grid, Maritime Gloucester; and Kristensen Realty, LLC (KRLLC); additional information about each of the properties is provided in Section 2.00. Selected CRAs at these properties and in Gloucester Inner Harbor will include excavation and capping of MGP-impacted soils, removal of coal tar in the form of dense non-aqueous phase liquid (DNAPL), removal of MGP-impacted sediment, off-Site treatment and/or disposal of remediation waste, and post-dredging placement of backfill and a sub-aqueous porewater cap. This will involve removal and replacement of waterfront pile-supported structures, construction of interim docking structures, construction and/or replacement of seawalls, excavation and construction of an engineered barrier, dredging across approximately 7 acres of Gloucester Inner Harbor, and placement of sub-aqueous fill material in the harbor for seawall stability and porewater control purposes.

Permits for the project have been sought from multiple local, State, and Federal agencies. The timing of the project will be affected by Division of Marine Fisheries (DMF) Time of Year (TOY) restrictions (for in-water work) and the requirements of property owners. The project is anticipated to begin in September 2015, and given its technical, regulatory, and logistical complexity, will extend over a period of up to three years. Work will be sequenced so as to limit impact to operations at each of the properties.

7.00DESCRIPTION AND CONCEPTUAL PLAN OF REMEDIAL ACTIVITIES, including relevant design parameters (310 CMR 40.0874(3)(b)(5) and (6))

The following sections provide a conceptual plan and description of how the CRAs outlined in Section 4.00 will be implemented during the Phase IV. Additional information regarding the proposed sediment dredging, backfilling, and capping, soil excavation, seawall construction, and marine structure removal and replacement activities is provided in the Specifications included in Appendix D. A listing of the key elements of the work, cross-referenced to the relevant Specification sections, is provided in Specification Section 01 10 00 – Summary of Work.

7.10MARINE AREA SITE PREPARATION

To provide access for in-water remediation equipment, piers and floating docks at the USCG, City of Gloucester, National Grid, and Maritime Gloucester properties will have to be removed. As a consequence, interim structures will be constructed to allow some in-water operations at the USCG and Maritime Gloucester properties to continue during the remedial efforts. In addition, measures to augment structure stability will be implemented at the USCG and Maritime Gloucester seawalls prior to dredging. The in-water structure removal and construction activities that will be implemented at the various properties are described below.

7.10.1USCG Floating Docks

During each remediation work season, USCG vessels will be temporarily re-located from their existing floating docks. The existing gangway, steel braces, and timber float at the Northern Floating Dock will be removed to provide access for dredge equipment, and will be replaced prior to the end of each work season. The existing gangway and timber float at the Southern Floating Dock will be used in the construction of the interim floating dock system described below, and will similarly be replaced prior to the end of each work season.

To limit disruption to USCG operations during the remediation, an interim floating dock system for up to three vessels will be constructed adjacent to Pier 2 at 17 Harbor Loop (see Drawing S-14). To accommodate the interim system, the Pier 2 substructure will be repaired by replacing timber fender piles and cross-bracing elements that are in poor condition, and reinforcing additional timber piles with fiber reinforced polymer (FRP) jackets to enhance their strength and longevity. The interim system will consist of a timber pile-supported landing, two timber floating docks, and an aluminum gangway. Temporary fuel, lighting, water, and electrical services for the USCG vessels will be provided at this location.

This interim location, while suitable for USCG access, is not sheltered from wind and wave surges. Therefore, a temporary bottom-anchored floating breakwater will be installed as shown on Drawing S-14. The breakwater will consist of two bottom-anchored concrete floats, each approximately 13 feet by 41 feet in dimension. These floats will extend over the 2004 Harbor Commissioner’s line into a Federal anchorage area, under permit approval from the United States Army Corps of Engineers (USACE) and a 10A Permit issued by the Gloucester Harbormaster.

Following the completion of the remediation project, the interim floating dock system and breakwater will be removed from Pier 2, and the Northern and Southern floating docks will be re-located to their existing locations at the USCG property.

7.10.2National Grid Pier and City of Gloucester Floating Docks

As described in Section 2.20, a wooden pile-supported pier owned by National Grid extends over both the National Grid property at 19 Harbor Loop and City of Gloucester property at 19R Harbor Loop. The pier is in poor condition, and an approximately 1,300-square foot (sf) section of it was removed in July 2012 as a safety measure at the request of the Gloucester Harbormaster. To facilitate in-water equipment access to the seawalls and Nearshore Area, the pier will be removed in its entirety at the start of the remediation project as described in Specification Section 02 40 00 – Demolition and Structure Moving.

At the end of the first work season, in accordance with an agreement with the City of Gloucester, National Grid will install an array of steel guide piles to support a new City of Gloucester floating dock system that will also extend over both properties. The guide piles will consist of 18-inch-diameter concrete-filled coated steel pipe piles, which will be drilled into the bedrock beneath the harbor to withstand tidal and wave action. Between work seasons, i.e., during the summer of 2016, these piles will be used to support an interim City of Gloucester floating dock system. Following completion of the project, the piles will support a new City of Gloucester floating dock system, which is described under Site Restoration activities in Section 7.80 of this Phase IV RIP.

7.10.3Maritime Gloucester Piers, Floating Docks and Gangway

The anticipated sequence of remediation at Maritime Gloucester includes construction of a vertical barrier (Section 7.70.2, below) during the first work season and dredging in the Nearshore Area to remove impacted sediments during the second work season. This will require temporary re-location of some Maritime Gloucester operations during the first work season, and removal and replacement of the piers at the property during the second work season, as described below.

During the first work season, the gangway and floating docks currently attached to the southern edge of the Main Pier will be temporarily re-located to an alternate location on the Maritime Gloucester property, and will be restored to existing conditions when access to the slip is restored. An interim timber landing will be constructed at the Northern Hauling Pier to provide access for the gig rowers club, which currently accesses the water via the southern landing at the Main Pier.

During the second work season, the gangway and floating docks at the Main Pier and the two hauling piers will be removed from their supports and stored. It is anticipated that the Maritime Gloucester Main Pier decking, and all but the most landward set of piles, will be removed, unless the contractor’s approach allows for sediment remediation objectives to be achieved with some portions of the pier remaining in place. Similarly, all or a select portion of the hauling piers will be removed; where possible, select timber piles may be left in place, and sediment removed around the piles during dredging. Once dredging and backfilling has been completed, the Main Pier and hauling piers will be reconstructed in kind and the floating docks and gangway will be restored.

7.10.4Maritime Gloucester Boat House Seawall Stability Enhancement

The Maritime Gloucester Boat House Seawall (Drawing EC-1) was constructed in the late 19th century, and does not meet current design factors of safety. Therefore, when the Maritime Gloucester Main Pier is removed, the existing row of wooden piles closest to the seawall will be left in place, to improve seawall stability during dredging. These piles will be augmented with seven steel H-piles and plates driven along the toe of the wall in front of the boat house. Concrete will be tremie poured between the piles/plates and the seawall, to provide additional stability specific to the boat house area (Drawing S-21). As an additional stabilization measure during dredging in front of the boat house, the top courses of the granite block seawall section will be temporarily removed, and the soil behind it will be excavated to an elevation of +5 feet NGVD. This will reduce the effective surcharge load on the wall and thus increase the overturning factor of safety during dredging in front of the boat house.

Impacted sediment seaward of the steel plates will be removed by interval dredging, following which the mudline will be brought back to existing grade with material providing similar strength to that removed (See Section 5.80). Once in-water backfilling has been completed, the granite blocks will be replaced and the excavation behind the seawall in the upland area will be filled with concrete. Four of the H-piles will be cut to elevation -2 feet NGVD; the remaining three will be left in place to support an approximately 8-foot-wide wooden walkway (Drawing S-29) providing waterfront access. The soil removed from the upland excavation will be managed under a Release Abatement Measure (RAM) Plan to be developed for the Maritime Gloucester property prior to the initiation of this phase of work.

7.10.5Debris Removal and Pre-Dredge Bathymetric Survey

Following removal/re-location of structures as described above, and prior to the removal of sediments, a visual debris survey will be performed at each of the areas where dredging is to be conducted. Industrial debris related to marine activities has been identified within the Marine Area, including old piles, tires, bricks, cables, lines, and timber and scrap metal debris. The remnants of the abandoned marine railway at Maritime Gloucester will also be removed during this phase of work. Proposed debris management is described in Section 9.30 of this Phase IV and in Specification Section 02 61 00 – Removal and Disposal of Excess Materials.

The debris survey will be coordinated with a pre-dredge bathymetric survey to establish baseline conditions prior to the start of remediation. This pre-dredge survey represents one of a series of surveys that will be conducted throughout the Phase IV in accordance with Specification Section 02 21 00 – Surveys. The baseline survey will be compared to post-dredge surveys to verify dredge depths reached and volumes removed in each area. The survey results will be used to prepare Final Conditions plans that will be submitted as part of the Phase IV Final Inspection Report (FIR).

7.10.6Installation of Marine Resuspension Controls

As described in Specification Section 01 57 30 – Marine Resuspension Controls, a number of in-water controls will be installed prior to the initiation of in-water or waterfront activities that may generate silt (i.e., turbidity) or sheens. These controls, which will be deployed as shown on Drawings C-3 and C-4, will generally consist of the following elements as shown on Drawing C-7:

• A Mobile Resuspension Control System will be installed prior to dredging in the Nearshore and/or Offshore Areas. This system will be comprised of an enclosed moon pool surrounded by permeable turbidity curtains. Reefing lines will be used to accommodate varying water depths due to tidal fluctuations, and to maintain the curtains between one and three feet above the sediment surface. Billow controls will be used to limit drifting of the curtain due to tidal currents. Sorbent booms will be secured to the inner and outer edge of the system to absorb potential sheens that may be released during the work.
• A Modified Mobile Resuspension Control System will be installed prior to dredging in portions of the Nearshore Area where the system described above cannot be used due to access limitations associated with the system geometry or shallow water depths. The modified system includes the same components (i.e., turbidity curtain, reefing lines, billow controls, and sorbent booms) as described above. Work will be conducted off the back of the modified system, with additional permeable turbidity curtains installed from the mobile system to the shoreline as shown on Drawing C-4.
• Stand-alone permeable turbidity curtains will be anchored around the work area during suction dredging at USCG Pier 2 and steel pile installation for the City of Gloucester floating dock system (Drawing C-3).
• Both stand-alone impermeable turbidity curtains and stand-alone permeable turbidity curtains will be anchored around the work area during seawall removal and construction activities at Solomon Jacobs Park, National Grid, and Maritime Gloucester (Drawing C-3).

When left in place overnight, the marine resuspension controls will be lit to warn boaters in accordance with USCG and Harbormaster requirements.

The marine resuspension controls will be inspected at least twice daily, and will be modified as necessary to meet Site-specific conditions and the requirements of the Water Quality Certification (WQC). The controls will remain in place until sheen-generating and silt-producing activities are complete, and will then be decontaminated and disposed of in accordance with Specification Sections 02 51 29 – Surface Cleaning and Decontamination and 02 61 00 – Removal and Disposal of Excess Materials.

7.20UPLAND AREA SITE PREPARATION

Site preparation in the upland areas will be initiated with the installation of fencing around the work areas at each of the properties, as shown on Drawings C-13 and C-14 and in accordance with Specification Section 01 56 00 – Temporary Enclosures and Barriers. This will be followed by the installation of Erosion and Sedimentation Controls, as shown on C-3 and C-4 and discussed in Section 8.40 of this Phase IV RIP.

Existing features within Solomon Jacobs Park will then be removed as shown on Drawing CD-3, and the park will be cleared in anticipation of temporary construction features such as a containment area for temporary stockpiling of impacted materials, a staging area for clean materials, and a wheel wash station. Also during this stage of work, select monitoring wells in the Southern Area will be decommissioned in accordance with Specification Section 33 29 00 – Well Abandonment and Drawing R-9. These wells were selected based on routine monitoring efforts conducted during IRA activities; new DNAPL recovery wells will be installed at key locations as described below in Section 7.70.3.