SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Ms. Lori Duncan November 11,2004 Page 2 of 3 Mr. Patrick Riddle, representing Gene Gabbard, Inc., requested that SJC/EHD direct Unifirst to conduct an investigation to determine if it is the source of PCE in the subsurface. Both SJC/EHD and Central Valley Regional Water Quality Control Board (CVRWQCB) staff indicated at the meeting that additional data would be required, specifically off-site monitoring wells, before Unifirst could be directed to conduct a subsurface investigation. Subsequent to the meeting,Ground Zero submitted a request to SJC/EHD and CVRWQCB to review files for several addresses related to the Unifirst facility. The file for the address listed as 819 N. Hunter Street was made available by SJC/EHD for review. The file included numerous documents summarizing soil sampling activities at the site between November 5, 2003 and January 16, 2004. Activities at the Unifirst site during that period included the following: • November 5-6,2003: Hydrocarbon impacted soil was encountered during grading activities south of the new Unifirst building. Site workers noted a"strong chemical odor, which increased with depth." Six surface soil samples were collected and analyzed for hydrocarbon constituents and chlorinated solvents. Elevated levels of petroleum hydrocarbon constituents and PCE were detected. PCE ranged from 5.2 to 340 ug/kg(ppb). • November 10-11,2003: Nine borings were drilled,reportedly to 25 feet bgs. The data table includes results of samples collected generally at 5-foot intervals to a depth of 20 feet for most borings. Soil samples from seven of the nine borings contained PCE. PCE was detected at a depth of 20 feet bgs in three borings. • November 13,2003: A"Site Mitigation"hearing was held at offices of SJC/EHD. No meeting notes were included. • November 17,2003: Contaminated soil was excavated. The final excavation was 30 feet by 60 feet, but only 8.5 feet deep. Eight confirmation samples were collected and analyzed for hydrocarbon constituents, metals, and VOCs. Three of eight samples contained PCE, as high as 32 ppb. Soil pile samples also had PCE up to 48 ppb. • December 11,2003: An oily substance was observed"flowing up out of rainwater" in the same area where the November 2003 excavation occurred. The perimeter of the site was bermed and approximately 22,000 gallons of oil/water mixture was pumped from the ground surface into Baker tanks. • December 12,2003: An excavation was conducted in the area of the spill to investigate the source of the oil. A 2,500-gallon UST and connected piping was uncovered and oil was leaking from the top of the UST due to continued rainfall raising the liquid level in the UST. SJC/EHD issued a permit to remove the UST. Sampling for VOCs was not required. • December 15-17,2003: The UST was removed. The report states that soil samples were analyzed for VOCs, but the laboratory report indicates that only oxygenated fuel compounds were analyzed, not a complete list of EPA Method 8260 compounds. The table in the report shows that PCE is ND in all but one sample(5 samples total),but the laboratory report has no results for PCE. • January 16,2004: A minor soil excavation was conducted to remove soil impacted by the December 2003 release of oil from the previously unknown UST. Only the upper I to 3 inches of soil was GAGROUNDZE\GABBARD\comspon\ehd_offsite.DOC