3.40 OTHER40 Building 650 - Base Laundry and Dry Cleaner
No rationale is provided for sampling locations.
No site specific historical information was obtained during investigation.41 Sample locations were placed at the south and east side of Building 650 only.
Potential sources of contamination from Dry Cleaning facilities were not evaluated.
Sample locations should be selected based on locations of the drain lines from dry-cleaning equipment, Building 650 sewer laterals, areas potentially impacted by deposition from equipment stacks (particularly near rain gutters), potential disposal locations for solvent still sludge, and potential disposal locations for spent solvent. The EQS sampling does not appear to target these potential source areas.
Soil samples did not target most likely areas of contamination.
It is unlikely volatile organics would be found in shallow soil samples. Many of the potential sources of solvent contamination such as sewer pipes would be located below the depths at which these samples were collected.
Vinyl chloride exposure needs to be fully evaluated.
Vinyl chloride was detected in a February 28, 1996 groundwater sample at a concentrations of 116 µg/L. Vinyl chloride is a gas at ambient temperatures. Inhalation exposure to vinyl chloride in indoor and outdoor air was not evaluated during the risk screening.
Vinyl chloride is a product of chlorinated solvent spills.
Vinyl chloride is a degradation product of plastics and chlorinated ethenes. Vinyl chloride has a significantly higher cancer potency than the dry cleaning solvents, perchloroethylene and trichloroethylene, from which it is formed. Vinyl chloride also has a significantly high vapor pressure than perchloroethylene and trichloroethylene from which it is formed. The continued formation of vinyl chloride will result in an increasing risk of exposure and an increasing risk of cancer from Site 40 conditions. Efforts should be immediately taken to reduce the potential for exposure to vinyl chloride by investigating and remediating the dry cleaning solvents. This site has been recommended for further action only if a change in site use occurs.
3.41 OTHER41 Binictican Golf Course Pesticide Storage/Mixing Area
History of agricultural chemical use at the golf course.
The interviews identified the current agricultural chemical uses at the golf course but did not discuss past usage. The single sample collected from Site 41 targeted a storm water ditch that drained the pesticide mixing area. No information on the storage and disposal practices for the pesticide mixtures and rinse waters is provided in the EQS.
Chemical of Concern, Carbaryl, not included in analysis scope.
A review of analysis results, indicate that Carbaryl, trade name Sevin, was not included in the scope of analysis of the sediment sample despite being identified as a contaminant of concern. Analysis was performed for organophosphate pesticides. Carbaryl is from the Carbamate class of pesticides.
3.45 OTHER46 Existing Monitoring Wells
Wide-spread pollution from petroleum fuels evident.
Five monitoring wells installed in previous studies were sampled during the EQS. These wells are located at the High Speed Refueling Area, Coastal Refueling Tank Farm, Boton Valley Fuel Farm, Subic/Clark Pump House, and the POL Pier Compound. Each of these sites contain petroleum contamination in groundwater. These five sites were not included in the list of 44 sites which were investigated in the EQS.
3.46 OTHER47 Sediment Samples
Wide-spread sediment contamination requires further investigation.
A review of analysis results, indicate that sediments, particularly around the Ship Repair Facility, are heavily contaminated with petroleum, tri-butyl tin, metals, and PCBs. The EQS makes no recommendations for further investigation or remediation of sediment contamination.
Ocean Disposal Area needs to be investigated.
Analysis results indicate wide-spread sediment contamination by US Navy activities. It is reported that the US Navy routinely dredged areas around the Freeport Zone and disposed of dredged sediments in the South China Sea or in reclamation project areas. Based on contaminant levels in sediments these disposal areas warrant investigation to evaluate human health and environmental impacts.
Mangrove sediments recommended for assessment.
Volume IV of the EQS recommends collection of sediment samples from the mangrove areas of the Freeport Zone to assess for contamination. The EQS sediment sampling that was performed did not target these areas.
