Site Description
On November 3rd, 2006, a Puget Sound Energy (PSE) generator above ground storage tank (AST) was overfilled when automatic shutoff valves failed. The storage tank is filled by three 12,000 gallon underground storage tanks (UST’s). It is estimated that 18,000 gallons of diesel fuel spilled onto the generator pad and drained downhill into a drainage ditch which flows under Crystal Mountain Drive to Silver Creek and the diesel fuel spilled down an access road close to ¼ of a mile in distance. The fuel spilled at a rate of approximately 18 gallon per minute.
Temporary containment measures were implemented in an attempt to minimize fuel moving offsite towards Silver Creek. Containment measures include a series of trenches, use of absorbent materials, and construction of an underflow dam with PVC pipes and an earth. Additional interceptor trenches have been excavated to collect remaining product seeping down gradient of the generator site.
Current Activities
11/9 through 11/12:
• PSE removed several of the containment dams that were placed below the generator pad, due to drilling operations. These dams wer were no longer holding back any free product. The remaining containment dams(along Silver Creek)are being inspected for petroleum products on a regular schedule.
• PSE has contracted a drilling company and collected soil boring samples to determine site specific geology. This data will be used in conjunction to ground penetrating radar (GPR) which began data collection on 11/12.
• PSE has contracted a surveying firm to conduct a detailed topographic survey of the site and surrounding area.
• A soil sampling team has collected soil samples to determine the extent of soil contamination along the power line access road. Additional soil samples will be collected in the near future to provide a better picture of the extent of soil contamination.
• 7 surface water samples are being collected daily, including bacground.
• 5 drinking water samples are being collected daily from community well heads, and residential.
Initial sample results have indicate no detectable levels of petroleum. Daily water samples near the residential wells and Silver Creek Watershed will continue to be collected. PSE has offered to sample additional residences if the homeowner requests their services.
• PSE has filled the test pits with straw and pea gravel. Jute fabric was applied to prevent erosion from occurring.
• EPA has issued a PRFA to USDA/USFS for spill response costs.
Daily Progress:
• 190-200 tons of soil removed, from approximately 200 linear feet of the power line access roadway.
• Two bags of absorbent materials, and approximately 1 quart of product was collected.
• Clearing of trees and vegetation in the location of the interceptor trench is approximately 80% complete.
• 2 drill borings were completed, one reached bedrock at 55 feet of depth.
• 3 preforated pipe wells have been installed in trenching along Crystal Mtn. Blvd.
• GPR is onsite and operational, data will be avaliable 11/13/2006.
• 12 soil, and 1 core samples were collected. Samples will be delivered to the labortory on 11/13/2006.
• OSC updated natural resource trustees- Puyallup, Muckleshoot, NOAA Fisheries, USFWS.
• Ensure that personnel decon (boots) and equipment decon has been implemented.
Planned Removal Actions
• PSE will continue to recover product from the ground and maintain all spill control measures.
• PSE will place an interceptor trench between Crystal Mountain Boulevard and Silver Creek.
• PSE will continue surveying, collecting soil borings, and using GPR on site.
• A recovery system will be implemented by PSE to recover product from the interceptor trenches.
• PSE plans to continue daily water sampling for both drinking water and surface water.
• Excavation of contaminated surface soils along the power line access road.
Next Steps
• Excavation of interceptor trench will start on 11/13/2006.
• Continuation of soil borings and site geology characterization.
Key Issues
• Awaiting results of geophysical site investigation in hopes of identifying large pockets of petroleum product.
• Ensure oversight of PSE and contractors during cleanup operations.
• Bucket loader did not arrive until 11/12/2006, delaying removal operations on 11/11.
• Crystal Mountain is scheduled to open for commercial skiing on 11/15/2006. Removal operations will NOT close Crystal Mtn. Blvd.
• Executive from PSE plan to visit site at 11/13/2006.
• Natural Resource Trustees are expected to visit on 11/14/2006.
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