Final Remedial Action Completion Report for the ... - Rvaap.org

Remedial Action Completion Report
June 2008
3.6.4.4 Load Line 4
Remediation of Soils and Dry Sediments at RVAAP 08-11 (LLs 1-4)
Page 3-21
At LL 4, there were a total of nine (9) discrete areas (LL4ss-106-cs through -114-cs) that
required excavation (Figure A-4). The COCs at LL 4 consisted of Aroclor-1254 and the metals
aluminum, lead, and manganese. One excavation location, LL4ss-108-cs, did require
re-excavation due to a manganese concentration of 5,300 mg/kg that was above the cleanup goal
of 1,800 mg/kg for manganese in surface soils (0 to 1 foot). After the removal of the additional
soils, a follow-up multi-increment sample was submitted for analysis for manganese and the
result was below the applicable cleanup goal. All the laboratory results for the confirmatory
multi-increment samples collected at LL 4 indicate that COCs have been removed to below
cleanup goals at all excavation areas.
3.7 DECONTAMINATION
During excavation activities at each load line and loading of trucks for off-site disposal of soils,
the heavy equipment and trucks were thoroughly inspected and decontaminated to remove all
loose soil from buckets, tracks, and undercarriage prior to leaving the controlled area.
Decontamination methods for heavy equipment between excavation areas and trucks during soil
load out consisted of dry removal of soils and debris and wet brush washing depending on the
extent of residual soils on the equipment. Final decontamination of the heavy equipment
following the completion of excavation activities consisted of steam cleaning. Fabricated
decontamination pads capable of collecting wash water, including overspray, and loose soil were
mobilized to the site prior to construction activities to avoid cross-contamination of clean areas
during decontamination procedures and to collect decontamination liquids. As discussed in
Section 3.3.6, Shaw provided all water for construction use, including decontamination of heavy
equipment and vehicles. All decontamination liquids generated were pumped into and stored in
55-gallon drums for characterization and off-site disposal. Disposal of this waste liquid is
discussed in Section 4.0.
3.8 SITE RESTORATION
Backfill and restoration was performed at each excavation area after approval of the
multi-increment laboratory data by USACE and the Ohio EPA. Backfill activities began in
October 2007 after the receipt and approval of the initial multi-increment samples. Site
restoration was performed to return the disturbed areas to prior conditions and was
“replace-in-kind”.
Restoration included backfilling with clean soil from Route 5 Sand & Gravel, an off-site source
that passed the chemical and physical requirements outlined in the RVAAP facility-wide plans.
Due to the relative shallow depths of the excavations, the backfill was directly offloaded into the
excavation or placed by the Shaw excavator. The backfill material was compacted by the
excavator bucket or tracks. There were no changes to site elevation or drainage features. Once
backfilled, an approved seed mix was applied, weather permitting, to the restored area.
3.8.1 Grass Seed
Shaw coordinated the required seed mixes with the RTLS Environmental Supervisor, Mr. Tim
Morgan, prior to mobilizing. Re-vegetation of disturbed areas was conducted in accordance with
the requirements of the RTLS Integrated Natural Resources Management Plan (INRMP) as
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