Indianapolis, Indiana - CVOC remediation adjacent to occupied building with sheet pile electrodes - Case Study

0

Courtesy of TRS Group, Inc.

Standard Fixed Price Remediation of TCE and VC in soil and groundwater

Project Summary

TRS Group, Inc. (TRS) provided a Standard Fixed Price Remediation (SFPR) of trichioroethene (TCE) and vinyl chloride (VC) in soil and groundwater using Electrical Resistance Heating (ERH) for AECOM at a confidential site located in Indianapolis, Indiana, Unique aspects of this project included the installation of paired-sheet pile electrodes, conveyance piping and wiring below ground surface. Rapid installation was also required to minimize impact to tenants occupying the adjacent warehouse complex. Sixty-seven of seventy-two electrodes were installed using sheet-pile techniques. Over 10,000 pounds of volatile organic compounds (VOCs) were removed from soil and groundwater. The remedial goals were to reduce TCE and VC in soil and groundwater to 25,730 |jg/kg and 130 |jg/kg and 260 pg/l and 10 |jg/l, respectively.

Background

The former warehouse and manufacturing facility is located in Indianapolis, The source area was located under a parking lot adjacent to a building containing several small businesses, The land sale agreement with the current tenant and property manager required the former property owner to clean-up the area of concern to Indiana Department of Environmental Management (IDEM) guidelines.

Site Characteristics & Design Parameters

The treatment area was approximately 30,200 square feet, The shallow portion of the remediation depth interval extended from 2 to 22 feet below ground surface (bgs). The deep portion of the remediation depth interval extended from 2 to 44 ft bgs. The resulting target remediation volume was approximately 28,400 cubic yards. The site lithology in the remediation area consisted of five layers of sand and clay. A confining clay layer was located at approximately 42-ft bgs. Groundwater was encountered at 7 ft bgs. Maximum, pre-ERH TCE and VC concentrations in soil (clay/sand layers) were 7,300,000/26,000,000 pg/kg and 6,000/9,000 pg/kg, respectively. Maximum, pre-ERH groundwater concentrations forTCE, cis-l,2-DCE and VC were 900,000 pg/l, 8900 pg/l and 270 pg/l respectively.

System Construction

Paired-sheet pile electrodes were selected to allow for rapid installation of the below ground portions of the ERH system, thereby significantly reducing the impact on the tenants located in the adjacent building. The use of sheet pile electrodes also reduced the amount of soil cuttings generated versus standard drilling techniques, resulting in reduced soil disposal costs. Sixty-seven sheet pile pairs were installed across the site, The two piles were connected to achieve an electrode width of 44 inches and were cut to length to match the treatment depth interval. Vapor recovery was performed using horizontal wells installed above each electrode. Due to the tight interbedding of clay layers at this site, a small chimney well was drilled prior to sheet pile installation and backfilled with a permeable, conductive material.

Customer comments

No comments were found for Indianapolis, Indiana - CVOC remediation adjacent to occupied building with sheet pile electrodes - Case Study. Be the first to comment!