The Massachusetts Department of Conservation and Recreation (DCR) embarked on a project to restore Blair Pond in Cambridge, Massachusetts. Blair Pond is a man-made urban pond dating back to the early 1900’s when a brick manufacturing company mined the pond for clay until it was depleted.
A “pit” was left and transformed into a steep sided pond with depths between eight and ten feet. Since that time Blair Pond has experienced extensive sediment loading from its watershed. The area surrounding the pond is densely populated with residential and commercial structures.
SAK prepared and implemented a Sampling and Analysis Plan to characterize upland soil and sediment in the pond for proper management under COMM-97 for soil and MassDEP’s dredged sediment policy for sediment. Up to 14,000 cubic yards of material were removed. The project was subject to MassDEP 401 permitting requirements. Sampling was performed in-situ where the project area was divided into “cells” with each cell represented by a soil boring sample.
Urban contaminant including polyaromatic hydrocarbons (PAHs) and metals were detected in the subsurface. Areas of upland soil were found to contain up to 30% solid waste that included metal, asphalt, brick, concrete, and partially burnt wood. Wooden blocks were subsequently found in limited areas that were found to contain elevated concentrations of PAHs and could negate the reporting exemption previously established for the project. Material Shipping Records were prepared for material to be disposed at Massachusetts Lined and Unlined Landfills, material suitable for unrestricted reuse, and ABC waste to be recycled.
SAK's work streamlined the management of contaminated excavated material to ensure cost control and regulatory compliance.