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Enron Mail |
Soil sampling for waste characterization was completed on September 6th. Bill
Olson with the NMOCD was on-site to observe the sampling activities. Twenty-two soil samples were collected from the two former pit areas. Lab results indicate that the impacted soil samples do not trigger RCRA hazardous waste criteria, more specifically: ? for all 22 samples, all TCLP VOC constituents were non-detect ? for all 22 samples, all TCLP SVOC constituents were non-detect ? for all 22 samples, all TCLP Metal constituents were non-detect with only two exceptions. Arsenic was detected in the TCLP extract for two samples; one at 1.41 mg/L and another at 2.18 mg/L, both below the RCRA regulatory limit of 5.0 mg/L. ? for all 22 samples, the samples were determined to be "not-ignitable" ? for all 22 samples, reactive cyanide and reactive sulfide were non-detect with only one exception. Reactive sulfide was detected for one sample at 160 mg/kg; this is below the guidance level of 500 mg/kg. ? the measured pH for all samples was in the range of 6.9 - 9.1; this is within the RCRA regulatory limits of 2.0 - 12.5. Furthermore, the measured TPH for all samples was in the range of 131 - 9660 mg/kg with an average TPH concentration of 2429 mg/kg. Selected photos of the sampling effort are attached. There was a considerable amount of waste debris found in the pits, particulary at the east end of the larger pit area. I will be finalizing the excavation plan for the former pit areas over the next week or so. I will prepare cost estimates for two alternative excavation plans; one for a dig and haul option and one for a combination of dig and haul for the most heavily affected soil and on-site blending for less affected soil. We should try to have a work plan to the NMOCD by the week of October 1st. George C. Robinson, PE Contract Environmental Engineer Cypress Engineering ENRON Office: (713) 646-7327 ENRON email: george.robinson@enron.com
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