70-92 Boston Street - Supplemental Site Investigation Summary Report - Appendix E - November 2005 ,
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APPENDIX E
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DATA USABILITY ASSESSMENT
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Supplemental Site Investigation Summary Report November 2005
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Former Flynntan Manufacturing Site
70-92 Boston Street
Salem,Massachusetts
Supplemental Site Investigation
Data Usability Assessment
The data associated with soil samples collected 6/14/05 and 6115105 and groundwater samples collected
6/23/05 and 6/24/05 were reviewed. In general, the data appear to be valid as reported and may be used
for decision-making purposes with the exception of the cautions and/or limitations listed below.
• Potential low bias exists for the arsenic result in soil sample B 104-2-4 due to low recovery in the
matrix spike (MS) analysis. This result falls below the Method 1 S-1/GW-2 and S-1/GW-3
standards by a minimal amount. Caution should be used with this result for decision-making
purposes as the actual result may be potentially higher and above the applicable Method 1
standard.
• Potential uncertainty exists for-the benzo(a)anthracene, benzo(b)fluoranthene, benzo(a)pyrene,
and indeno(1,2,3-cd)pyrene results in sample B101-4-8 due to variability in the field duplicate
results. It should be noted that these compounds were detected in the field duplicate sample at
concentrations which were above the Method 1 S-1/GW-2 and 5-UGW-3 standards and these
compounds were not detected in the. original sample. The results of the field duplicate sample
should be used for decision-making purposes in order to remain conservative.
The following discussion summarizes the issues which were noted:
1. Soil Data Issues
A. Presumptive Certainty
The data associated with the VOC analyses of all soil samples do not have. Presumptive Certainty, as
defined under the MADEP Compendium of Analytical Methods (CAM) because the laboratory did not
spike surrogates into the sample using the procedure required in the CAM. The overall decision-making
process was not adversely affected by this method deviation.
B. Low-Biased Results
Potential low bias exists for the MTBE result in soil sample B 107-2-6 due to low recoveries in the LCS
and LCS Duplicate. The overall decision-making process was not adversely affected as the result was
significantly below the Method 1 S-1/GW-2 and S-1/GW-3 standards.
Potential low bias exists for isopiopylbenzene and 1,3,5-h imethylbenzene in .soil sample B 107-2-6 and
for tert-butylbenzene in the field duplicate sample for B107-2-6 due to.calibration range exceedances: In
all cases, the detected results were about 2 orders of magnitude below the Method i S-11GW-2 and S=
1/GW-3 standards and therefore the decision-making process was most likely not adversely affected by
this nonconformance.
Potential low bias exists for VPH results in soil samples B101=4=8, B102-4-8, and B110-4-8 due to.low
surrogate recoveries., The overall decision-making process was not adversely affected as the results were
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significantly below the Method 1 S-1/GW-2 and S-1/GW-3 standards and therefore most likely not
adversely affected by this nonconformance.
Potential low bias exists for the antimony, arsenic, and zinc results .in all soil samples due to low
recoveries in the MS analysis. The decision-making process was not adversely affected for antimony and
zinc as these results were significantly below the Method 1 S-1/GW-2 and S-1/GW-3 standards. The
decision-making process may be adversely affected for arsenic in soil sample B 104-2-4. since this result
i falls below the Method 1 S-1/GW-2 and S-1/GW-3 standards by a minimal amount. Caution should be
used when using this result for decision-making purposes as the actual concentration may be higher.
C. High-Biased Results
Potential high bias exists for the VOC results in soil sample B 107-2-6 due to high surrogate recoveries.
Overall data usability was not affected since the detected results were still below the MCP Method 1 S-
1/GW-2 and S-1/GW-3 standards.
Potential false positives exist for acetone and methylene chloride in soil sample B 107-2-6 and silver in
soil samples B 107-2-6 and B 109-2-6 due to trip blank or method blank contamination. Overall data
usability was not affected since the detected results were still below their respective Method 1 S-1/GW-2
and S-1/GW-3.standards.
D. Potential Uncertainty in Results
Potential uncertainty exists for select VOCs in the field duplicate of soil sample B 107-2-6 due to slightly
low recovery of one internal'standard. All of the affected results were significantly below the Method 1
S-1/GW-2 and S-1/GW-3 standards and therefore,the overall decision-making process was not adversely
affected.
The nondetect results for :1,2-dichloroben2ene, 1,2-dibromo-3-chloropropane, 1,2,4-trichlorobenzene,
hexachlorobutadiene, naphthalene, and 1,2,3-trichlorobenzene were reported from the high-level analysis
for.the field duplicate of soil sample B 107-2-6 due to significantly low recovery of the internal standard.
With the exception of hexachlorobutadiene, the elevated reporting limits were still below the Method 1 S-
1/GW-2 and S-1/GW-3 standards and therefore the nonconformance did not affect the overall.data
usability. Although the elevated reporting limit for hexachlorobutadiene exceeded the Method 1 S-1/GW-
2 and S-1/GW-3 standards; the overall decision-making process was not adversely affected as the result
for this compound in.the original analysis fell below these standards.
Potential uncertainty exists for select VOCs in soil sample B 107-2-6 and select EPH analytes in soil
sample B101-4-8 due to significant variability in the field duplicate results. With the exception of
benzo(a)anthracene, benzo(b)fluoranthene, benzo(a)pyrene, and indeno(1,2,3-cd)pyrene in sample B101-
4-8,both the original and field duplicate results were significantly below the Method 1 S-1/GW-2 and S-
1/GW03 standards and therefore the variability did not adversely affect the decision-making process. The
I end-user of the data should use the results of the field duplicate sample for benzo(a)anthracene,
benzo(b)fluoranthene,benzo(a)pyrene, and indeno(1,2,3-cd)pyrene in sample B101-4-8 in order to remain
conservative.
Potential uncertainty exists for arsenic, lead and zinc results in all soil samples due to variability in the
laboratory duplicate analyses. The overall decision-making process was not adversely affected as results
for these metals in both analyses fell below.the Method 1 S-1/GW-2 and S-1/GW-3 standards.
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E. Other Issues
C5-Cg aliphatics in soil samples B 101-4-8, B 102-4-8, and B 110-4-8 are not due to a.petroleum product
and most:likely due to an elevation in the baseline. This baseline elevation was also seen in the method
blanks and trip blank. Since these results are significantly below the Method 1 S-1/GW-2 and S-1/GW-3
standards, the overall decision-making process was not affected by this nonconformance.
It.should be noted that the pH'and oxidation-reduction potential(ORP)data for all soil samples indicated
that the samples were reducing in nature and therefore the tendency for hexavalent chromium to exist in
these samples was very low. Due to the concentrations of total chromium in the soil samples below the
Method 1 S=1/GW-2 and S-1/GW-3 standards for hexavalent chromium combined with the pH and ORP
results, further hexavalent chromium analysis of these soil samples was not warranted.
II. Groundwater Data Issues
A. Low-Biased Results
Potential low bias exists for the VPH results in the field duplicate of groundwater sample MW-101 due to
low surrogate recoveries. Since all results were significantly below the Method 1 GW-2 and GW-3
standards and since all results compared well with the original sample, the overall data usability was not
adversely affected.
Potential low bias exists for the aliphatic EPH results in groundwater sample MW-101 due to a low
surrogate recovery. Since.all results were significantly below the Method 1 GW-2 and GW-3 standards
and since all results compared well with the field duplicate sample, the overall data usability was not
adversely affected.
Potential low bias exists for C9—C18 aliphatics, naphthalene, 2-methylnaphthalene, and acenaphthylene in
all groundwater samples due to low recoveries in the LCS Duplicate analysis. Since the results for these
analytes were significantly below the Method 1 GW-2 and GW-3 standards in all samples, the overall
data usability was not affected.
B. 'Other Issues
Ci9-C36 aliphatic hydrocarbons in groundwater samples MW-101, MW-102, and MW-104 and a portion
of the C9-Ct$ aliphatic hydrocarbons in groundwater sample MW-104 are not due to a petroleum product
and are more likely due to contamination in the fractionation cartridges.. This contamination was also
seen in the method blank at a similar concentration but not reported-since the concentrations detected
were below the reporting limit. Since the concentrations :detected in these samples were below the
Method 1 GW-2 and GW-3 standards,the overall decision-making process was not adversely affected.
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