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Technical Memorandum on Soil Boring Investigation
Section 9 - SWMU Oxidation Pond (O-1)
Four soil borings were drilled at this former evaporation and oxidation pond for waste liquids and sludges generated from the bluing operation (Figure 9.1).
9.1 - Geology and Hydrogeology
No surface soils were observed at this site. Two feet of fill material was noted in boring OX-SB3 and four feet in OX-SB2. The fill material consisted of clay, limestone fragments, sand and waste material.
The lithology was described as interbedded marly limestone and hard massive limestone. Vertical fractures were recorded in three of the four soil borings. The fractures in OX-SB1 from 11 to 15 ft bgl were filled with calcite. Caliche was also observed within the first four feet of limestone bedrock. Solution cavities were noted in OX-SB1 and OX-SB3 from 6 to 8 ft bgl.
Fossils found in the limestone cores include foraminifera, gastropod, and pelecypod steinkerns, and crinoid stems.
No perched groundwater samples were collected at this site. Ponded surface water samples were collected on two separate occasions.
9.2 - Observed Waste Material in the Borings
Waste material was observed in boring OX-SB2 and OX-SB3 which included black plastic liner and charred material.
9.3 - Soil/Rock Analytical Results
Fifteen soil/rock samples were collected for analysis. Analytical results are presented in Table O1-1. Four samples collected contained PCE, three of the samples were collected from two borings at a depth of 0 to 2 ft bgl. Toluene, PCE, and m,p-xylenes were detected in OX-SB1 (26.5-27.5 ft). Di-n-butylphthalate, a common laboratory contaminant, was detected in five samples. Chromium was detected in thirteen samples. Lead was detected in fourteen samples, and nickel was detected in all the samples. All concentrations for cadmium, except OX-SB2 (0-2 ft) and (0-2 ft dup), were qualified as nondetect.
9.4 - Groundwater Analytical Results
No groundwater samples were collected at this site.
9.5 - Surface Water Analytical Results
Three surface water samples were collected at the oxidation pond and analyzed for VOCs (Table 9.2). The shallow puddles of water were noticed following a rain event. Two surface water samples were collected by Parsons ES on March 3, 1995 and analyzed by the contracted laboratory. A second surface water sample was collected on March 7, 1995 by Parsons ES and analyzed by Armstrong Laboratories/OEB laboratory. In OX-1, collected on March 3, 1995, toluene was detected at a concentration of 0.034 mg/L. The remaining samples, OX-2, and the sample collected by Armstrong Laboratories were nondetect for VOCs.
9.6 - Statistical Comparison with Background Metals and Risk-Based Closure Criteria
PCE, toluene, and m,p-xylene were detected at the oxidation pond. None of the concentrations exceeded MSCs. Of the metal constituents of concern, only two samples exceeded the statistical background levels for cadmium. The remaining samples did not exceed the comparison concentrations. Figure 9.2 shows the locations and concentrations of the samples that exceeded comparison criteria.