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EXVIRBQHMENTAL 888 CIVIL EHGINEE BING
December 6, 2017
Jaime Colby, PE
New Hampshire Department of Environmental Services
Waste Management Division
Permitting & Design Review Section
29 Hazen Drive, PO Box 95
Concord, New Hampshire 03302-0095
RE: Type IB Modification to Solid Waste Management Facility Permit
Temporary Permit DES-SW-TP-95-004; Webster Square — Guitar Center
Dear Ms. Colby:
Enclosed please find three copies of the signed application for a Type IB modification to the
referenced permit. The modification is requested to allow 1) drilling of mini-piles through the
buried Construction & Demolition (C&D) debris, and 2) temporary disturbance of the landfill
cap and, possibly, shallow C&D debris, during construction of the associated pile caps.
Background - Consolidation of the C&D debris underlying the site has imposed unacceptable
stresses on the structure. In 2013 and 2014, the permittee performed similar projects in other
areas within the same complex. This project, though smaller in scope and shorter in duration,
will include less landfill disturbance and restoration but similar environmental monitoring and
regulatory reporting. The location of the proposed work with respect to the limits of the landfill
cap is shown on the Site Layout Pian portion of Figure 1.
Planned Work - The structural renovation is scheduled to begin in January 2018 immediately
following award of a construction contract. A system of drilled mini-piles has been designed to
extend to bedrock, as depicted on the attached drawings. Each mini-pile group is to be
completed with a concrete pile cap or grade beam. Given the urgency, tasks related to design,
permitting, work plan development, and contractor selection are being performed concurrently.
Construction of the pile caps will require shallow excavation. Excavations at interior columns
may extend 36” into the existing cap and, potentially, buried debris. The proposed pile cap
configuration is shown on the attached plans. Existing conditions are depicted based on best
available information from the 1990 landfill closure plan; cap thickness has not been verified.
Environmental Work Plan — An Environmental Work Plan (EWP) is being prepared and will be
submitted to NHDES along with the Notice of Intent to Construct (NOIC). It will be
substantially the same as the work plan for prior work at the shopping center, but some elements
of the safety program cannot be completed until the construction contract is awarded.
The EWP will include an overview of the work, a description of the means and methods,
including management of drill spoils, safety monitoring, asbestos monitoring and management,
solid waste disposal, and site restoration.
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