Address:

 806 West Queen St

 Southington, CT 06489

 Contact Information:

 Phone: 860-621-3630

 Fax: 860-621-0067

 E-mail: info@desct.com

Client: New England Telephone (NYNEX)

Location: South Kingstown, Rhode Island

Project: Hydrogeologic Investigation, Remedial Design, and Groundwater and Soil Remediation System Installation

Description:

  In accordance with a Consent Order issued by the Rhode Island Department of Environmental Management (DEM), a hydrogeologic investigation, soil gas survey, and hydraulic conductivity tests were performed on a site contaminated by a leaking underground gasoline storage tank. The tank had been previously removed and initial subsurface investigations performed. The investigation was performed to determine the vertical and horizontal extent of soil and groundwater contamination, the soil permeability -hydraulic conductivity, and the potential remediation alternatives. Soil contamination was discovered over a 6,000 square foot area, and groundwater was found to be contaminated in the bedrock aquifer, after the installation of six deep bedrock monitoring wells. The source of the deep aquifer contamination was determined to be from fractures in the bedrock surface with a hydraulic connection between the shallow and deep aquifers.

  A comparison of various remediation alternatives was performed and a design of a soil vapor extraction and air stripping pump and treat system were chosen, based on timeliness, costs, and regulatory agency influence. Six 4-inch vapor extraction wells were installed, a pilot test run, and a soil vapor extraction system installed. Two 6 inch groundwater recovery wells were installed, pump tests run, and a groundwater pump and treat system installed with an iron removal system and low profile air stripper to treat up to 10 gallons per minute. All water discharge permits were obtained in order to operate the system. Air discharge calculations were performed, and air permits were not required due to the level of emissions.