Groundwater Remediation
A recently delivered report indicates that the cleanup at the Gerrish Motors/Woodstock east site is making progress towards the eventual cleanup of the site.

Matrix Environmental Technologies of Orchard Park, NY submitted the August 2008 Remedial System Operation and Groundwater monitoring report to the Vermont Department of Environmental Conservation (VTDEC) in early October. The report is available at the Norman Williams Public Library and on the VTDEC Gerrish Motors internet site. (click here)

It states that after 9 months of continuous operation the oxygen injection system has reduced the size of the contamination plume at the site by approximately 60 to 70%. Remediation of the former underground storage tank area is almost completed. However, elevated petroleum compound concentrations were measured in monitoring wells located in the vicinity of the Route 4 entrance to the site.

As a result of the information in this report, Matrix performed a supplemental subsurface investigation in October 2008 to collect additional data regarding the distribution of petroleum contaminants. The results of that investigation should be available shortly. The report will be posted on the VTDEC Gerrish Motors internet site and will be available for review at the Norman Williams Public Library in Woodstock. A summary of the results will be included in the next edition of this newsletter. Matrix has also increased the flow of oxygen to the most affected area in an effort to reduce contaminant concentrations prior to the next monitoring event, which is scheduled to take place in February 2009. Matrix will continue to visit the site monthly to monitor the remediation system and make adjustments as necessary to optimize its performance.

In August, an excavation contractor was on-site to relocate the pile of clean soil and debris that was stockpiled on the site during Matrix’s 2007 excavation activities. The soil was used to fill an existing excavation. Once the groundwater cleanup goals have been reached in the five (5) compliance monitoring wells that measure groundwater quality as it leaves the site, the oxygen injection system will be operated for an additional three months before being shut down. Groundwater samples will then be collected every two months for one year to demonstrate that the cleanup goals are maintained without active remediation.