An SBA Certified 8(a), WBE, SBE, DBE Company
Contractors License #827022
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Remediation of Chlorinated Solvents in Soil - Dry Cleaning Facility
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Services Provided
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Oversight Agency
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Project Details
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Soil vapor extraction
Feasibility testing
Construction services
Equipment installation
Electrical services & hookup
Carbon services
Remediation report
Soil closure in 90 days
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Los Angeles County Fire
Department (LAFD)
Regional Water Quality
Control Board, Los Angeles
Region (RWQCB)
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Start Date: 5/05
End Date: 12/05
Total Contract: $110,000
Amount Spent: $95,000
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PROJECT HIGHLIGHTS
- Remediation of soil contaminants
- Soil closure in 90 days with LAFD
- Installed four triple-nested SVE wells
- Installed a 500 cfm blower skid & two
1,000 lb vessels
- Collection of wellhead vapor samples
and O&M
- Documentation of ROI of underground
vapor flow
- Detailed remediation reporting
The site is a former dry cleaner facility with chlorinated compounds in soil and groundwater beneath the
site. The project required an expedited soil remediation in order for financing. Northstar was the remediation contractor
to design, install, and operate a soil vapor extraction (SVE) system. Northstar designed 4 triple-nested SVE screened at in
order to isolate specific zones for remedation. The wells were piped to a common manifold at the equipment compound with
underground trenching so as not to disturb property tennants. Northstar also installed groundwater conveyance piping for
possible future groundwater remediation. Northstar provided remediation equipment consisting of a positive displacement
blower capable of 500 scfm flow at 12 inches of mercury vacuum, two 1,000 pound activated carbon vessels, and a various
locations AQMD permit for chlorinated compounds. Northstar performed feasibility testing, step and steady state extracted
vapor flow tests, and radius of influence testing. Northstar collected extracted well vapor data and monitored flow, percent
oxygen content, and contaminant concentration for each well screen interval. Soil vapor samples were analyzed weekly for
contaminant compounds and concentrations, and data was updated weekly for calculation of contaminant mass removed. Northstar
performed three rebound tests to document reduction of soil vapor influent concentrations. Northstar installed additional
push probe wells to further document the radius of influence at the request of the LAFD, and demonstrated asymptopic levels
of soil vapor influent concentrations. The remediation system was shut down within 90 days. Northstar reported on the
results of remediation and requested a "No Further Action" (NFA) letter from the LAFD with respect to the soil contamination,
which was granted. The site was referred to the RWQCB, Los Angeles Region for assessment of groundwater which will commence in
2007.
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