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

Remedial Action Completion Report
June 2008
3.4.1 Designation of Work Zones Boundaries
Remediation of Soils and Dry Sediments at RVAAP 08-11 (LLs 1-4)
Page 3-12
Prior to initiating excavation activities, Shaw established the work zone boundaries by the
placement of barrier fences and the appropriate signage. The work zones were living boundaries
and the size and configuration of these work zones increased or decreased based upon conditions
encountered in the field.
3.4.2 Soil Excavation at all Load Lines
Excavation of the contaminated soils and dry sediments typically proceeded in the following
sequence and methodology:
1. The corners of the excavation design limits identified in the RAWP (Shaw 2007b) load
line excavation drawings were surveyed utilizing a Trimble GeoXHTM 2005 Series
Handheld Global Positioning System (GPS) with an accuracy determination capable of
within one foot and staked.
2. Initially, an approximate 20-foot by 20-foot area was excavated from the area of highest
COC concentration and moved outward from the assumed source location.
3. After reaching the design limit of contamination or removal of “hot spot” areas, field test
kits and/or screening equipment for the applicable COCs were implemented as an initial
check to determine whether all contaminated soils were removed. Collection and
analysis of field screen samples is discussed in Section 3.5.
4. If the field test result(s) indicated that contaminated soils still remained, excavation at
that location continued until the field test result(s) specified that contaminated soils had
been removed to below the cleanup goals.
5. Once the field test results identified that the contaminated soils had been removed,
multi-increment samples were collected from the completed excavations for off-site
processing and confirmatory laboratory analysis to verify that contaminated soil above
the clean-up criteria was removed in accordance with cleanup goals. Multi-increment
confirmatory sample process and analysis is discussed in Section 3.6.
6. Excavated material was stored temporarily on-site at designated stockpile locations at
each load line. The soils were placed accordingly in stockpiles based on the COCs within
the excavation. At the end of each workday the stockpiles were covered and secured
prior to leaving the site.
7. Once received from the laboratory, confirmatory analytical results were reviewed by the
Shaw Project Chemist and submitted to the USACE and Ohio EPA project managers for
approval prior to backfilling the excavations. A discussion of the analytical results for
the multi-increment samples is presented in Section 3.6.
8. Once approval to backfill was given, Shaw collected an as-built survey of the excavation
area using the aforementioned GPS in Step 1. The excavation was then backfilled with
clean fill from an approved off-site source. Site restoration activities following backfill
of the excavations are discussed in Section 3.8.
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