WORK PLANS - Laserfiche WebLink

Home Browse Search

Geo-Probe Soil Boring Sampling Results 2 9909 E. Woodward Avenue, Manteca 02/15/00 Soil samples were collected using a 1.5 foot long by 1.5 inch inside diameter drive sampler lined with a plastic sample sleeve. This device is activated by removing a retaining bolt from the top of the device by inserting rods through the hollow stem of the probe rods. Removing this retaining bolt allows the drive point to retract through the sampling tube and a sample to be collected. Groundwater samples were collected using the Geo-Probe's groundwater sampling device. This consists of a four foot long hollow rod fitted with a drive point which is attached to the end of the Geo-Probe stem. This rod is driven four feet into groundwater and retracted to expose the stainless steel screen inside of the device. Groundwater samples were obtained by oscillating a clean dedicated section of disposable polyethylene tubing, fitted with a stainless steel check valve, inserted inside of the hollow stem of the Geo-Probe. This causes groundwater to rise to the surface. During the collection of multiple groundwater samples from SB-10, rubber O-rings were installed above the threads of the Geo-Probe rods to insure that groundwater from intervals other than the one sampled was not entering the Geo-Probe. Resu Its Field Evidence Field evidence suggests that soil and groundwater contamination was evident in only three of the soil borings, namely S13-8, 9 & 10. None of the soil or groundwater samples from SB-11 and 12 exhibited any field discernible hydrocarbon impact, i.e., odor, discoloration or OVM readings. A faint hydrocarbon odor was noted at the 9-11 foot interval in SB-9 and in all of the soil sampled intervals from SB-10. None of the soil samples collected from S13-8 exhibited any hydrocarbon odor or staining, however, the groundwater sample exhibited a slight hydrocarbon odor. The only measurable OVM readings were from the 14-16 and 19-21 foot intervals in SB-10, with readings of 8 and 4 ppmv, respectively. Soil Samples Low levels of "Motor Oil Range" petroleum hydrocarbons were present in all of the soil samples submitted for analysis; one sample being submitted from the capilary fringe in each boring (9-11' bgs). The following table lists contaminant levels for each of the samples: Sample SB-8,9-11' SB-9,9-11' SB-10,9-11' SB-11,9-11' SB-12,9-11' Analysis 2.1 2.8 3.4 4.9 1.2 Units mg/Kg mg/Kg mg/Kg mg/Kg mg/Kg MDL=0.3 mg/Kg, (Samples in motor oil range but not typical of motor oil). These levels were beneath the normal detection limits for TEPH of 5.0 mg/Kg. Per a personal communication with the chemist who completed the analysis, the chromatographs for these samples were in the motor oil range but not indicative of motor oil. He indicated that the most likely possibility, given the shape and type of chromatogram peak, was that the detectable contamination was actually plastic from the Geo-Probe sampling tube scraped out when removing portions of the soil sample at the laboratory. 2937 Veneman Ave.,#B240 Geo-Phase Environmental Inc. Phone(209)569-0293 Modesto,CA 95356 Fax(209)569-0293