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<br />Draft Feasibility Study Recommended Alternative:
<br />. Site A Unit I: Continue containment pwnping and monitoting of the groundwater; utilize institutional
<br />controls; undertake air stripping treatment or discharge, Rice Creek discharge, source characterization and
<br />remediation.
<br />. Site A Soils: Undertake excavation, soil washing/leaching, handling of other materials, backfilling.
<br />
<br />Site B is located along the northern boundary ofTCAAP. Before 1940, this portion of the site was occupied by
<br />farmsteads. Material was dumped in the farmstead building foundations. It is believed that sewage sludge was
<br />disposed here before 1966. Contaminants of concern include PCBs, pesticides, VOCs, semi-volatiles, explosives
<br />and heavy metals. However, no significant contamination has been found at this site.
<br />
<br />Interim Remediation: No remediation has been performed at this site. The Feasibility Study recommends no
<br />further action since significant contamination has not been found here.
<br />Draft Feasibility Study Recommended Alternative: Remedial alternatives for Site B were not recommended
<br />because contaminants did not exceed preliminary clean-up goals.
<br />
<br />Site C is located immediately east of Mounds View Road within the central portion ofTCAAP. It was used for
<br />burrting lumber, solvents, oils, maizo (com cobs), and possibly other production materials. The site was also used
<br />as an open storage area. Contaminants of primary concern include solvents, oil, grease, dioxins, explosives,
<br />propellants and metals. Soil contamination has been docwnented. Low levels of groundwater contamination have
<br />been detected sporadically.
<br />
<br />Interim Remediation: No remediation has been performed at this site.
<br />Draft Feasibility Study Recommended Alternative: Undertake excavation, soil washinglleaching, handling of
<br />other materials, backfilling
<br />
<br />Site D is located 220 feet west of Snelling A venue, south-southeast of the reservoir in the south-central part of
<br />TCAAP. Several pits on the site were used to dispose of powder water, oil, grease, solvents, rags and neutralized
<br />cyanide. Other materials disposed at Site D include primer and tracer powder, scrap propellant, thinner, varnish and
<br />swnp waste. Western ball powder, solvent, contaminated rags, scrap chemicals and oil were disposed of in the rag
<br />pit. Oil and grease were reportedly burned daily in the oil pit. Contaminants of concern include VOCs, PCBs,
<br />solvents, heavy metals, semi-volatiles, thinners, oils and cyanide. Soil and groundwater contamination are present.
<br />An eighteen-inch clay cap was laid over the site to prevent precipitation infiltration.
<br />
<br />Interim Remediation: In February 1985, 1400 cubic yards of PCB-contaminated soils were excavated and
<br />stockpiled; in 1989, this soil was incinerated on-site. A soil vapor extraction system was installed on the site in
<br />Fcbruary 1986 to remove VOC contamination and is still in operation today. Studies indicate that most of the
<br />VOC soil contamination has been removed.
<br />Draft Feasibility Study Recommended Alternative: Continue existing SVE operation, expand with deep vents,
<br />impose institutional controls.
<br />
<br />Site E consists of approximately 7.6 acres located in the central portion of TCAAP. This site was formerly used as a
<br />non-combustible landfill and as a burning area for combustible and explosive wastes. Contaminants of primary
<br />concern include VOCs, semi-volatiles, explosives, dioxins, furans and heavy metals. VOC contamination and low
<br />concentrations of metals have been detected in the groundwater. Metals were detected in a nurnber of soil samples
<br />from the site.
<br />
<br />Interim Remediation: No remediation has been conducted at this site. Soil washing is a recommended clean-up
<br />alternative in the Feasibility Study.
<br />Draft Feasibility Study Recommended Alternative: Undertake excavation, soil washing/leaching, handling of
<br />other materials, backfilling.
<br />
<br />Camiros, Ltd.lSEH, Inc./LHDL, Ltd.
<br />
<br />TCAAP Framework Plan
<br />Page 26
<br />
<br />Chapter 11
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