GREENWICH, Conn. The most highly contaminated soil on the grounds of Greenwich High must be excavated, moved and disposed of before construction of the schools auditorium project can start again, the district announced late Thursday.
A total of 24 soil samples were taken in the area of Greenwich High School's auditorium project , known as "MISA." Of the samples, two had high levels of polychlorinated biphenyls, or PCBs. This classified them as PCB remediation wastes, according to a report made by AECOM, the environmental consultant hired by the town.
Soil must exceed 50 mg/kg to be classified as PCB remediation wastes, and none of the other soil samples exceeded 5 milligrams per kilogram. The highly toxic soil from these areas must be removed before any construction can begin. The rest of the soil removal should be completed as part of the projects process.
The problem started when workers began excavating parking lots for the project. They discovered soil that was darker than dirt found in July in the school's West Lot.
Immediate environmental tests began on the soil. Low levels of lead, arsenic, barium, volatile organic compounds, PCBs and petroleum hydrocarbons were found.
Athletic fields were closed, forcing high school teams to practice on middle school and elementary school fields. All work was stopped, and the contaminated area was covered and closed off.
The most recent testing done at the schools auditorium project site is separate from testing done on the athletic fields.
The report recommended more samples be taken after soil is removed to ensure the soil is safe and also recommended an air-monitoring plan to protect site workers as well as those who attend and work at the school.
The materials generated during testing are stored in 55-gallon drums and will be removed within the next several weeks, said Kim Eves, communications director for the district.
AECOM also recommended the district take groundwater samplings to see whether the cleanup has been effective. The town plans to conduct a well survey on properties within a 500-foot radius of the high school, even though Aquarion Water Co. has stated the area surrounding the school is served by public water. Nearby property owners will be sent information before the survey.
A remedial action plan has already been submitted to the federal Environmental Protection Agency and the state Department of Energy and Environmental Protection for work within the MISA project area, Eves said.
The district's 2012-13 capital budget includes $600,000 to remove contaminated soil. Public Works plans to update the Board of Estimate and Taxation by late winter or early spring with a cost estimate. The department has put together a 2012-13 funding request for $1.5 million for additional investigation and to prepare for remediation efforts.
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