Final Remedial Action Completion Report for the ... - Rvaap.org
Final Remedial Action Completion Report for the ... - Rvaap.org
Final Remedial Action Completion Report for the ... - Rvaap.org
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<strong>Remedial</strong> <strong>Action</strong> <strong>Completion</strong> <strong>Report</strong><br />
June 2008<br />
Remediation of Soils and Dry Sediments at RVAAP 08-11 (LLs 1-4)<br />
Page 3-17<br />
capable of analyzing specifically <strong>for</strong> hexavalent chromium, total chromium was used as <strong>the</strong><br />
screening contaminant <strong>for</strong> this COC.<br />
As a proactive measure, <strong>the</strong> Shaw field crews continued excavation <strong>for</strong> all in<strong>org</strong>anic COCs,<br />
including those not previously identified, that were found to exceed cleanup goals at each of <strong>the</strong><br />
discrete excavations. Excavation of soils continued until <strong>the</strong> XRF field screen results identified<br />
all in<strong>org</strong>anic COCs to be below <strong>the</strong> applicable cleanup goal levels. The locations where<br />
previously unidentified COCs were detected and removed are presented in <strong>the</strong> data summary<br />
tables (Table B-3) in Appendix B.<br />
3.6 CONFIRMATORY SAMPLING<br />
Confirmatory samples were collected from each of <strong>the</strong> excavation areas using multi-increment<br />
sampling in accordance with <strong>the</strong> Guidance <strong>for</strong> Multi-Increment Sampling procedures included in<br />
Appendix A of <strong>the</strong> Shaw FSP (Shaw 2006b).<br />
3.6.1 Sample Collection<br />
As indicated in Section 3.4.2, excavation began in <strong>the</strong> area of <strong>the</strong> highest COC concentration(s)<br />
previously detected and moved outward from <strong>the</strong> assumed source location. Once field screen<br />
test results identified an excavation area to be below <strong>the</strong> applicable cleanup goals <strong>for</strong> <strong>the</strong> COC(s),<br />
multi-increment samples were collected from a pre-determined number of stratified random<br />
sample locations from <strong>the</strong> excavation area using disposable sample trowels. The random<br />
samples were placed into a clean plastic lined bucket and combined to make a single sample.<br />
The sample was homogenized by manual mixing and a maximum of 1 kilogram (kg) of <strong>the</strong><br />
sample was removed from <strong>the</strong> plastic bag and placed into a labeled pre-cleaned container. Each<br />
multi-increment sample consisted of random samples combined from <strong>the</strong> floor and sidewalls of<br />
<strong>the</strong> excavation areas. In general, 20 random samples were collected from excavation areas less<br />
than 100 square feet (ft 2 ) and 30 random samples were collected from excavation areas greater<br />
than 100 ft 2 . For <strong>the</strong> most part, excavations were greater than 100 ft 2 and 30 random samples<br />
were collected from <strong>the</strong> majority of <strong>the</strong> excavations. The excavation dimensions and locations at<br />
which <strong>the</strong> random samples were collected <strong>for</strong> <strong>the</strong> multi-increment sample were noted by <strong>the</strong><br />
Shaw field sample technicians and documented in <strong>the</strong> field log sheets presented in Appendix E<br />
in <strong>the</strong> electronic attachment to this RACR. It should be noted that <strong>the</strong> reduction of <strong>the</strong> sample<br />
volume to 1 kg prior to shipment deviated from <strong>the</strong> methodology outlined in <strong>the</strong> RAWP but was<br />
approved by USACE and <strong>the</strong> Ohio EPA prior to implementation in <strong>the</strong> field.<br />
The sample containers were secured, packaged, and shipped to <strong>the</strong> designated off-site laboratory<br />
<strong>for</strong> drying, processing, and analysis, along with <strong>the</strong> appropriate chain-of-custody documentation<br />
as outlined in <strong>the</strong> FSP (Shaw 2006b). The off-site laboratories used by Shaw as part of <strong>the</strong><br />
remediation of soils at LLs 1-4 were approved by USACE and <strong>the</strong> Ohio EPA prior to shipment<br />
of <strong>the</strong> samples.<br />
3.6.2 Sample Processing and Analysis<br />
In all, a total of 125 multi-increment samples, including duplicate and MS/MSD duplicate<br />
samples, were submitted <strong>for</strong> analysis at ei<strong>the</strong>r of <strong>the</strong> two off-site laboratories contracted by<br />
Shaw: Test America in North Canton, Ohio and Kemron in Marietta, Ohio. Shaw contracted<br />
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