Laserfiche WebLink
TABLE 5 <br /> SULFATES IN SOIL <br /> EPA METHOD 300.0 <br /> } mg/Kg (Ppm) <br /> 11 BORING DEPTH SAMPLEiID SULFATE - mg/Kg (ppm). <br /> MW-1 0.5 MW-113/0.5 9,400 <br /> MW-1 10.0 MW-lA/10.0 680 <br /> MW-1 10.0 MW-113/10.0 910 <br /> 1 <br /> Note: MW-lA/10.0 is a duplicate sample of MW-113/10.0 <br /> 1 <br /> y The concentration of Sulfates appears to decrease with depth. No regulatory standard presently <br /> exists for sulfates in soil. <br /> 4.2 DISCUSSION OF SULFATE VERSUS TOTAL SULPHUR RESULTS <br /> y <br /> j Based on comparison to total sulphur results, the above detections of sulfate in Parcel III soil <br /> _;• appear to be anomalous. Sulfate and total sulphur results should be comparable by reducing the sulfate <br /> results to determine the minimum total sulphur concentration. The concentrations of sulfate reported, <br /> when reduced, yield the following minimum total sulphur concentrations: <br /> Sample No. Proiected minimum total sulphur concentration Reported sulphur concentration <br /> MW-1B/0.5 3,133.02 mg/Kg 737 mg/Kg <br /> MW-IA/10.0 226.44 mg/Kg 162 mg/Kg <br /> MW-113/10.0 303 mg/Kg 187 mg/Kg <br /> In an attempt to resolve the discrepancy, several consultations with the analytical laboratory were <br /> made. The laboratory reportedly performed a detailed evaluation of the data and found no errors in the <br /> testing methods or quantifications. The EPA presently does not have a prescribed method for analyzing <br /> total sulphur. Although our prime laboratory contractor validated the total sulphur results, Dames & <br /> i <br /> Moore speculated that an error may have been made in the analysis. <br /> To further investigate the discrepancy, Dames & Moore retrieved the soil samples from the prime <br /> laboratory (D&M Laboratories) and resubmitted them to an alternate laboratory (Enseco, California <br /> i • <br /> SAC28.013 <br /> 1 15 December 20, 1991 <br /> 1 <br />