June 25, 2008
Mr. Jay Rourke, Senior Project Manager
Boston Redevelopment Authority
One City Hall Square
Boston, MA 02201-1007
Subject: Grand Marc at St. Botolph Street
Dear Mr. Rourke:
Thanks you for the opportunity to comment on the Draft Project Impact Report for the Grand Marc. The Boston Groundwater Trust was established by the Boston City Council to monitor groundwater levels in sections of the City where the integrity of building foundations is threatened by low groundwater levels and to make recommendations for solving the problem. Therefore, my comments are limited to groundwater related issues.
I am pleased with the response of the proponent to the groundwater related issues that I raised in my comments on the Project Notification Form. The project has committed to meeting the standards required in the Groundwater Conservation Overlay District. According to the DPIR, they plan no excavation below Elevation 7 except to remove some existing obstacles, and in fact plan to fill in existing basement space below that level. They plan to utilize space formerly occupied by basement under the existing gymnasium structure to house the required recharge system. In addition, they plan to install new groundwater observation wells; I look forward to the promised consultations on where best to locate them.
As is noted in the DPIR, the portion of the Hastings Wing that the proponents plan to maintain is supported on wood pilings, as are the portion of the YMCA that is to remain and the adjacent New England Conservatory of Music. Therefore, it is especially critical that all possible measures are taken to maintain or increase groundwater levels at this site. I am gratified that the proponent recognizes his responsibility to do so. It would be very helpful in understanding the adequacy of these measures if the proponent could provide the cutoff elevation of the pilings for the YMCA and NECM buildings. If possible, it would be helpful if they could provide those elevations for other nearby wood piling supported buildings.
While, according to the DPIR, there is expected to be only a limited amount of dewatering during construction, the proponent should investigate the feasibility of recharging that water adjacent to the site rather than sending it to the BWSC system.
The proponent has pledged to monitor a network of new and existing wells through foundation construction. These wells should be monitored before construction to establish a baseline level and then frequently during construction. Readings should be provided to the Authority and to the Trust shortly after they are taken. Plans should be in place to address any reductions in groundwater level that may be attributable to the construction.
I look forward to working with the proponent and the Authority to assure that this project can have only positive impacts on area groundwater levels.
Very truly yours,
Elliott Laffer
Executive Director
Cc: Kathleen Pederson, BRA
Maura Zlody, BED
