|
Documents: LettersBGwT comment letter to BRA re: The Gatehouse Project |
 |
|
|
February 18, 2005 Ms. Maria Faria, Assistant Director of Housing
Subject: The Gatehouse Project Small Project Review Application Dear Ms. Faria: The Boston Groundwater Trust was established by the Boston City Council to monitor groundwater levels in those sections of the city where wood pile supported foundations are threatened with deterioration because of lowered groundwater levels and to make recommendations to solve the problem. As such, our comments are limited to groundwater related issues. In the Application for Small Project Review, the proponent included a section on Geotechnical Engineering Studies prepared by the The Geotechnical Group. In this study, recommendation is made for an underslab drainage system which would relieve groundwater uplift by draining groundwater to storm drains. They also proposed that ground surfaces around the building be designed to divert water away from the building and toward storm drains. This design would likely result in lowered groundwater levels in the immediate area and threaten nearby wood pile supported buildings. I am in receipt of a letter from The Geotechnical Group to ESS Group, dated Feb. 11, 2005, that was furnished to me by the project architect. This letter revises the foundation recommendation to a concrete mat foundation with fully waterproofed below grade walls and slabs that would resist earth pressures and hydrostatic pressures based on the design groundwater level. The letter further recommends that groundwater monitoring wells be installed at the site to establish preconstruction levels and assess the effects of construction on groundwater levels. I have been assured by the architect that this letter will be forwarded to the Authority and made a part of the application. We very much appreciate the responsiveness of the proponent to concerns about groundwater that we expressed at the public meeting held by the BRA about this project. The modified foundation design alleviates much of our concern about the project. We further appreciate their intention to coordinate with the Trust the locations and installation of the wells. After construction, the wells should be turned over to the City to be incorporated into the Trust's monitoring network. The Trust will furnish specifications to the proponent for well construction that will assure that the wells can provide long term service to the City. In order to assure that the design continues to successfully meet its intention that groundwater not penetrate the building, we ask that there be an annual certification by a registered professional engineer that groundwater has not been removed from the site in the previous year by pumping or by a drainage system. I appreciate the cooperation of the Authority in encouraging proponents to meet these important criteria for assuring that new construction does not make the groundwater situation worse, and most especially that of the proponent in modifying their planned construction design. Thank you for the opportunity to comment on this proposal. Very truly yours, Elliott Laffer
Cc: John Walser, BRA
|