Samples of materials at the AvalonBay site tested negative for PCBs, but metals and chemicals known as polycyclic aromatic hydrocarbons (PAHs) were detected that exceed NJDEP residential standards, town officials said.
Because of the findings, AvalonBay is required by the New Jersey Department of Environmental Protection (NJDEP) to develop a remedial action work plan. Avalon Bay has already provided the plan to the state and the town.
The remedial action work plan requires that the site be capped. Capping involves placing a cover over contaminated material. AvalonBay’s remediation plan includes various kinds of caps including concrete slabs, crushed stone, shredded rubber, and one to two feet of clean soil added to the top of the surface in some areas. The surplus stockpile of recycled concrete site material will be removed from the site for disposal.
AvalonBay will be required to file a deed notice indicating the existence of contaminants capped on the site. In addition, Avalon Bay will be required to obtain a remedial action permit from the NJDEP. The NJDEP permit will require continual monitoring and semi-annual inspection of the cap.
Municipal staff members and the Whitman Environmental Firm have reviewed both the site investigation report and remedial action plan and finds that they meet the standards set forth by NJDEP and will provide appropriate safeguards to public health, town officials said. Once construction resumes, Avalon Bay will conduct appropriate air monitoring and dust control measures.
“In our continued efforts to ensure the health, safety and welfare of our residents, staff will continue to monitor the site to ensure the required safeguards are in place including the dust control measures and air monitoring,” said Princeton Administrator Marc Dashield in a written statement to the press. ”
A summary of the site investigation report and remedial work plan, including details about the capping materials, has been placed on the municipal website. The full report including attachments will be available in the municipal clerk’s office, Dashield said. AvalonBay hired EcolSciences, Inc.to prepare the plan.
Construction work at the site stopped about a month ago after concrete material at the site tested positive for PCBs.
Concrete and brick from former structures and site improvements had been crushed with other site materials (including sub-base beneath foundations, walkways, and roadways, site soils, and a limited amount of pavement) for reuse at the site. The reused materials are spread throughout the site as “site soil” at a depth of between zero and seven feet depending on the location. Some surplus reworked site materials were stockpiled for offsite disposal.