Draft Project Impact Report - Boston Redevelopment Authority

Exeter Residences/888 Boylston
\\Mabos\projects\09916.00\docs\Permits\DPIR\Text\DPIR Chapter 5
Environmental.docx
coatings, color and reflectivity of the glazing, and mullion depth and orientation will
be carefully selected with an eye to decreasing reflected sunlight.
5.6 Geotechnical and Groundwater Analysis
Subsurface Soil Conditions
Groundwater
Subsurface soil conditions at the Project Site consist of the following based on data
from test borings completed at the site:
Table 5-5 Subsurface Soil Conditions
Groundwater Conservation Overlay District
General Description Typical Thickness of Strata (ft) Depth (ft) 1
Granular Fill 5 to 9.5 0
Organic Silt 0 to 10 5 to 10
Marine Sand 10 to 15 10 to 20
Marine Clay 100 to 125 25 to 30
Glacial Till 5 to 10 125 to 130
Bedrock - 125 to 150
1. Refers to depth below lowest level of Prudential Garage slab (existing).
Groundwater levels at and near the Project Site are measured within a large network
of groundwater observation wells monitored periodically by the Proponent.
Measured groundwater levels at wells located within the lowest level Prudential
Center garage slab range from approximately El. 1 to 2 BCB, and are directly below
the slab. The existing lowest level garage is at about El. 2.5 to 3. Groundwater levels
measured at existing monitoring wells in city streets located outside of the Project
range from about El. 3 to 7 depending on location. The locations of the wells
surrounding the Project are indicated on Figure 5-41.
The Prudential Center is located within the Groundwater Conservation Overlay
District (GCOD) and will need to comply with the associated requirements relating
to infiltration of rainwater and no negative impacts to groundwater levels within the
DRAFT - Environmental Protection 5-40