An updated mitigation monitoring and reporting program for contaminated soils at the McKinley Elementary School campus master plan project site will be broached by the Santa Monica-Malibu Unified School District Board of Education during Thursday’s meeting.
At the meeting, the board will look to adopt Resolution 23-56, which is the approval of an Environmental Impact Report Addendum as well as the amended monitoring and reporting program. The purpose of the addendum is to revise a Removal Action Workplan (RAW) and measures to mitigate "potential significant impact" caused by soil containing "naturally occurring arsenic and subsurface soils" that were found to be contaminated with dry cleaning solvent vapors emanating from an adjacent dry cleaner location at 2441 Santa Monica Boulevard.
Previously, the district adopted a mitigation monitoring and reporting program for the potential for chemicals (particularly chlorinated solvent perchloroethylene) to have affected soils at the project site. The initial mitigation measure, "MM HAZ-2," was approved by the board in June of 2023 and specifically required the removal of the contaminants from the school by excavating and hauling away the contaminated soils to an authorized disposal site.
However, after the district sought the Department of Toxic Substances Control (DTSC) to oversee investigation and remediation of the contamination, DTSC stated that it "would be appropriate" for the district to reuse the soil "so long as a mechanical barrier is maintained to separate school occupants from the soil," with the barrier consisting of concrete slabs and asphaltic pavement. The dry cleaning solvent vapors, DTSC added, could also be blocked from getting into the McKinley construction site through the use of a membrane and vapor extraction system beneath the new building, which is slated to be a two-story building with eight classrooms and a renovated front office. Both remedial methods are being separately reviewed and processed for approval.
To implement a RAW that does not dig up and haul away contaminated soils, MM HAZ-2 has been revised to include language adding that the district will be implementing a DTSC-approved cleanup selection document for "appropriate treatment of affected soils and soil vapor on-site." The revised MM HAZ 2, the district states, "does not reduce the effectiveness" of the mitigation plan and "would still not cause any significant environmental impact to occur."
"All recommendations in the cleanup selection, document regarding soil handling, treatment, and storage shall be implemented," the updated MM HAZ-2 states. "Soil vapors shall also be treated according to procedures outlined in the RAW."
Once the district confirms that the affected soils have been appropriately treated, contractor Placeworks will prepare a Removal Action Completion Report for DTSC that documents cleanup activities and presents analytical results for the confirmation samples, if required. The district will also prepare a long-term operation, maintenance, monitoring and reporting plan for DTSC "to ensure long-term effectiveness of the treatment system."
Perchloroethylene, or PCE, was banned for use at dry cleaners in California last year, though historical improper disposal caused the chemical and other contaminants to enter into groundwater and soil, with the potential to emerge as harmful vapors.
In addition to the new classroom building, poised to begin construction this summer, the McKinley project aims to result in 33 new classrooms ranging from kindergarten through fifth grade, as well as dedicated outdoor play areas for kindergarten students. The first phase of the project includes the two-story, 24,410 sq ft classroom building, as well as library renovations, the removal of nine portable classrooms and the creation of a new on-site pick-up and drop off lane along Chelsea Avenue.
Visit smmusd.org for more information about the upcoming meeting.
