DCAM’s consultant circulated the following summary of the statekholders’ meeting that occurred on 8/19/11 at the behest of DEP –
From: Davis, Steven C. [mailto:email@example.com]
Sent: Wednesday, August 24, 2011 4:12 PM
To: ‘Purvi Patel’
Cc: ‘firstname.lastname@example.org’; Margaret Van Deusen; Michael Sullivan; William Massaro; Mark Baldi; Stella Tamul; John O’Donnell; ‘Meeker, Carol (DCP)’; Frank Ricciardi; Tony Zerilli
Subject: Medfield C&D Area IRA (EEA #14448R) Technical Meeting – August 19, 2011
As required by the Secretary’s Condition #1 under Hazardous Material in the August 10 2011 Draft Record of Decision, the Division of Capital Asset Management (DCAM) is providing the MEPA Office and the commenters on the Notice of Project Change with a synopsis of the Stakeholder meeting held at the Massachusetts Department of Environmental Protection’s (MassDEP’s) Central Office at 627 Main Street, Worcester on Friday August 19th, 2011. Attached are the meeting attendance sign-in sheets, a copy of the Agenda drafted by MassDEP, and the handouts from the meeting.
The intent of the meeting was to allow stakeholders, DCAM, and MassDEP to discuss technical issues regarding the proposed Immediate Response Action (IRA) plan for activities proposed for the contaminated sediments in the Charles River and for embankment remediation and stabilization on the eastern bank of the Charles River. In addition, the draft focused Phase III feasibility study was to be reviewed.
Mr. Frank Ricciardi, P.E., LSP (the LSP of Record) presented the proposed IRA Scope of Work and touched on each of the items that are listed on the attached agenda. The meeting was then opened for questions on the proposed Scope of Work. The major points of discussion were:
- Removal of contaminated fill;
- Relocation of the 24-inch high pressure natural gas line;
- Use of riprap between ordinary low and high water lines;
- Potential adverse impacts in addressing groundwater contamination;
- Use of a capping approach to address sediment contamination in the Charles River; and
- Phase III Remedial Alternatives.
Each of these points is discussed in the following paragraphs.
Removal of Contaminated Fill
Several stakeholders requested additional information on the limited removal of contaminated fill. Questions were posed requesting full removal of all fill within the Construction and Demolition (C&D) Disposal Area, including those materials within the easement of the natural gas line. Mr. Ricciardi responded, referencing text in MassDEP’s feasibility study guidance documents regarding active public utilities, that shutdown of a public utility even for a single day is considered infeasible and, therefore, contaminated material may remain in place within the easement. There was discussion between the stakeholders and MassDEP regarding the applicability of the guidance document. The result was that MassDEP indicated that the feasibility document applied to the C&D Disposal Area. The Chairman of the SHERC indicated that he disagreed with MassDEP’s decision regarding the applicability.
Several stakeholders questioned that since the contaminated material within the natural gas line easement would remain, could additional fill be excavated to reduce the area of the C&D Disposal Area and the associated risk from contaminated material left behind. DCAM and its consultants explained that for the northern portion of the C&D Area, the distance between the River and the gas line easement, combined with the need to create a more stable slope, constrained the amount of contaminated fill that could be safely removed without risk to the gas line.
For the remaining portion of the C&D Disposal Area, DCAM and its consultants indicated that, due to the contaminated fill remaining within the easement, the site could not be completely remediated (removed). Some contaminated material will be left behind and regardless of quantity or location; the “risk” level remains the same. Thus, the economics of removing thousands of tons of contaminated fill with negligible reduction of risk was not a fiscally responsible expenditure of taxpayers’ money. Mr. Ricciardi indicated that for every 10 feet landward that the contaminated fill was removed, the cost was approximately $1,000,000. The cost of total removal, even if it were feasible, would be about $20 million.
A concern was raised that leaving contaminated materials within the Zone II of the Town’s well No. 6 could jeopardize a public drinking water supply. MassDEP indicated that the constituents present within the C&D Disposal Area had little risk of being conveyed by groundwater to Well No. 6. The SHERC Chairman indicated that he was more concerned with the chlorinated solvents detected in groundwater at the Site. DCAM responded that the groundwater issues would be addressed separately as part of the Special Project Designation (SPD) Phase II and Phase III process. This meeting was strictly to address the C&D IRA according to the agenda drafted by MassDEP.
Relocation of the Natural Gas Line
A resident of Medfield indicated that he was not satisfied that sufficient efforts had been made to relocate the gas line outside of the limits of the C&D Disposal Area. He requested that a listing of the Spectra Energy representatives and their positions be provided together with meeting notes from discussions between DCAM’s consultants and Spectra Energy. He insisted that additional efforts be made to have the gas line relocated. This will not be done, since Spectra Energy has refused to consider relocating the gas line.
Riprap between ordinary low and high water lines
Several stakeholders expressed concerns that the use of riprap between ordinary low and high water was unacceptable due to aesthetics and adverse impacts to fauna that may migrate from the uplands to the River. It was suggested that a bio-stabilization approach, such as brush layering, would allow vegetation to grow below high water and would be more satisfactory to fauna movements. DCAM’s consultants indicated that due to its location, approximately 200 feet of embankment could be subject to high velocity currents during storm events and that erosion in the form of scour could undermine this area. In addition, the liner that underlies the riprap is included to prevent a continuing release of contaminated fill to enter the River. Without stable, robust protection, there is a high potential for a release in the future. A suggestion was made that perhaps coconut logs could be used as the protection. DCAM’s consultants indicated that the logs may not have the mass to withstand the forces in the River as well as needing to be replaced every six to ten years. It was also presented by DCAM that the total frontage in question is 200 feet out tens of miles of river frontage. Fauna will still have other avenues of accessing the banks of the Charles, which are currently so steep at the proposed location that no fauna could navigate them as they currently are. There will also be a construction fence around the Site, prohibiting upland fauna from accessing the banks for at least a year. By the time the fence is removed and construction is complete, the riprap will have been in place for a period of time and vegetation will have taken hold, and the fauna will be able to navigate the reduced-slope banks and the vegetated riprap.
MassDEP requested DCAM to reconsider the proposed riprap armor and CWRA offered contact and provide information from the environmental firm the BioEngineering Group, whom they have been in contact with. DCAM agreed to review any information provided by CRWA on this issue, but still believes that rip rap is the appropriate approach.
Potential adverse impacts in addressing groundwater contamination
Several stakeholders expressed concern that construction of the geomembrane and riprap would impede groundwater remediation, if required. DCAM’s consultants indicated that lateral distance of twelve feet for the riprap and approximately 40 horizontal feet of geomembrane would not impede groundwater assessments or remediation activities. (The 40 feet of geomembrane includes the 12 feet of geomembrane under the riprap.) In addition, the sources of the chlorinated solvents in the groundwater are outside of the C&D Area and those locations are critical in accessing the groundwater for remediation.
MassDEP indicated that additional groundwater assessment activities would be required and may include passive diffusers and/or piezometers installed within the Charles River. DCAM agreed that these types of sampling approaches may be warranted to address the chlorinated solvent issue.
A concern was raised that leaving of contaminated fill within the Zone II of Town Well No. 6 posed a threat to the drinking water supply of the Town of Medfield. Please see the last paragraph above under the heading Removal of Contaminated Fill.
Capping Approach to Address Sediment Contamination in the Charles River
Several stakeholders expressed concerns that the use of a cap over the 800 square feet of contaminated sediment in the Charles River was unacceptable as the Commonwealth might place this material and not perform any additional response actions. DCAM reiterated that initial decision to use the cap was to streamline the approval process through the US Army Corps of Engineers (USACOE) as only two to three months of permitting time could elapse before the seasonal low groundwater and Charles River levels would begin to rise. Although initially this cap was considered as possibly being the final remedy for the contaminated sediment, further examination of the constraints associated with the Charles River indicated that the long-term operation and monitoring of the cap was cost prohibitive. DCAM believes that the final remedy will consist of hydraulic dredging.
A question was raised as to why this work could not be performed next year’s low water conditions instead of proceeding with a cap at this time. It was pointed out that the contaminated sediment may have been present for a long period of time. MassDEP explained that once the condition was identified, remedial actions are required to address the issue. DCAM explained that the 800 square feet that is currently identified may extend further downstream from its current location and would require additional assessments to delineate the impacted area and determine the appropriate remediation.
The CRWA asked why we were not using the hydraulic dredging now instead of wasting funds with a temporary solution. DCAM explained that the USACOE had indicated in January 2011 that dredging was viewed as being the least desirable of potential options in addressing contaminated sediment and that a comprehensive review of other options need to be included to justify the dredging. When the IRA condition was identified in May 2011, a decision was made to proceed with a minimum invasive approach (i.e. capping) such that permit review by the USACOE could be completed during low water conditions in the early fall of 2011.
Phase III Remedial Alternatives
The discussions regarding the Phase III remedial evaluation focused primarily on the selected remedial alternative for the impacted sediment within the Charles River. Mr. Ricciardi presented the results of the initial and detailed evaluation of potential remedial alternatives and presented the selected alternative for the sediment, which was hydraulic dredging. This selection was reached following the detailed evaluation of effectiveness, implementability, protection of human health and the environment, and cost. Based on the results and primarily due to the long-term maintenance and monitoring costs associated with the temporary capping solution, the hydraulic dredging alternative was selected as the Permanent Solution. The stakeholders and meeting representatives preferred a vacuum approach rather than a barge dredging approach due to the minimal equipment needs and non-invasive nature of the vacuum dredge.
Until such time when a dredging approach can be permitted and implemented, the temporary sediment cap installed under the IRA would be in place. We discussed the extent, construction details, material selection, site preparation, schedule and maintenance and monitoring required for this approach. The schedule for moving forward was also discussed as being time critical and all approvals need to be in place by September 2, 2011 to meet the project milestone of October 15, 2011 for completion of all work between the ordinary high water and seasonal low water elevations. Consensus was reached that this temporary solution made sense provided that DCAM was committed to the permanent solution of hydraulic dredging. Mr. Baldi indicated that he would condition the approval of the IRA to require the removal of the impacted sediments via hydraulic dredging.
Based on the timelines associated with permitting the selected remedial alternative of hydraulic dredging, the preliminary schedule would be as follows:
- October 2011 – Implement preparation of the necessary permits including NOI, Army Corps General permit, and Chapter 91 Water Quality Certificate
- December 2011 – Design plans and specifications for implementation of selected remedy (to be implemented as the Phase IV Remedy Implementation Plan)
- April 2012 – Procure contractor under public bidding law for implementation of Phase IV remedy
- September/October 2012 – project completion
A discussion ensued regarding if additional excavation of fill material would also be conducted as part of the Phase IV RIP. DCAM and Weston & Sampson indicated that the approach presented under the IRA would most likely be the final remedial alternative for this aspect of the project. We also discussed the remediation of chlorinated volatile organic compounds (CVOCs) in groundwater and that the selected approach would not impede future groundwater remediation. The chairman of the SHERC requested additional groundwater monitoring to show that surface water/groundwater interactions would not impact the Charles River and/or Town Well #6. Weston & Sampson discussed that an evaluation of the Site hydrogeology would be included in the Phase II CSA report and that supplemental assessment activities would be required to further evaluate the these interactions and the extent of CVOCs at the Site. Groundwater concentrations will continue to be monitored on a quarterly basis to supplement the data and understanding of groundwater conditions at the Site for use in the design of the final groundwater remedial alternative.
Following completion of Phase IV activities at the Site, an Activity and Use Limitation would be established on the deed for the property for the area requiring restrictions to prevent unacceptable exposure to remaining impacted fill.
This email is copied to all of the commenters on the NPC. We understand that you will accept additional comment on the NPC until Monday, August 29, 2011. Please let me know of any questions that you may have on this summary or on any other aspect of the C&D Area IRA.
|Steven C. Davis, PE President
Rackemann Strategic Consulting, Inc.
160 Federal Street
Boston, Massachusetts 02110