SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Port of Stockton GrourieWater -3- •18 September 1987 present at 530 mg/1. This water sample also contained trichlorofluoromethane at 169 ppb, and 1,2-dichloroethane at 10.5 ppb. Another water sample collected here contained gasoline at 18 . 3 mg/L and diesel fuel at 1, 800 mg/L. Trichlorofluoromethane concentration in this sample was 20.5 ppb, and the 1, 2-dichloroethane concentration was 12 . 6 ppb. During an inspection on 7 Ju y 1987 I found that Tesoro had been emptying the water portion of an oil-water separator to the ground in the tank farm. This practice lad been followed for at least the past ten years, and probably sine the facility was constructed in the 19401s. SOUTHERN PACIFIC PIPELINES No information is available on the existence of soil or ground water contamination at this site. ST SERVICES On 5 May 1986 a 1, 000 gallon waste oil tank was removed from this site. The SJLHD inspection report states, "Water was noted at the bottom of the excavation. An oily appearing liquid was noted floating on this water. " Sampling conducted as part of this removal showed the following concentrations of chemicals in ground water: Benzene 1,600 ppb Toluene 2 , 000 ppb Xylenes 3 , 100 ppb Trichloroethylene 94 ppb PCBs 0.4 ppb Note that this tank did not bold gasoline, yet gasoline constituents accounted for much of the contamination at this location. On an inspection of the site on 15 July 1987, representative of the Regional Board, Department of Health Services (DHS) , and others observed visual evidence of spills on the site, fuel in sumps, and a pond filled with water discharged from an oil-water separator. DHS took soil samples near the pond which showed concentrations of several polynuclear aromatic hydrocarbons in the soil. Four soil samples from around the site tested positive for ethylene dibromide. On 4 December 1986 an underground tank belonging to Exxon was removed from the ST Services property. Analysis of a ground water sample taken from the tank excavation found total petroleum hydrocarbons at 240, 000 ppb. The lab identified the products present as diesel and gasoline. A soil sample taken at the time showed 1,900 mg/kg of diesel fuel in the soil. This would probably make this soil a hazardous waste since it contains diesel fuel above the 1, 000 mg/kg concentration level. Exxon wrote a letter to the SJLHD exp aining that this tank held only their proprietary additive which does not include gasoline or diesel. They believe their tank was not the source of the contamination found during its removal. On 4 .June 1987 the manager of sr Services terminal, Richard Zimmerman,