On Sunday afternoon, May 29th, EPA was notified that a tank had been overturned while attempting to move it from one property to another. The tank had an estimated capacity of 300 gallons and was believed to contain 100 - 200 gallons of oil. The oil released to the soil and then to 10 Mile Creek, a tributary to the Boise River. Attempts to have the responsible party hire a qualified contractor failed and the State of Idaho requested EPA's assistance in conducting the cleanup. EPA OSC Barber and 3 EPA contractors arrived on scene on Monday, May 30th, assessed the discharge, and began cleanup.
Sorbent boom and pads have been deployed in three locations at the spill site where oil is continuing to enter the creek. About 20 cubic yards of mostly oil-saturated soil have been excavated and placed in drums on-scene. A shoreline cleanup assessment was performed by OSC Barber, START Grojean, and IDEQ Representative Scheff for approximately 2.5 miles downstream on the creek. Trace amounts of silver or rainbow sheen were observed up to 1.5 miles downstream, but none in a practically recoverable quantity. Witnesses about 1 mile downstream claim to have seen heavy sheen covering the surface of the creek the evening of 5/29. They also claim to have seen several small dead fish of unknown species of about 3" in length, however, no injured or dead fish or wildlife have been recovered to date by response personnel. The creek does provide drinking water and/or habitat to a number of horses and other farm animals, canadian geese, ducks, and a variety of other non-migoratory birds. Approximately 3 water samples, 2 soil samples, and 1 oil sample (from the tank) have been taken so far.
Efforts will continue to control the source of the oil discharge. This will include finishing removal of contaminated soil on the adjoining shoreline and removal of a remaining 4" or so of oil in the tank. The storm drain free standing oil and oil soaked sediments in it that will need to be removed. Maintenance and removal of oil soaked absorbents and significantly contaminated vegetation and debris also needs to occur. Some oil collecting at the foot of the bank at the spill site will need to be removed and it will need to be investigated whether this accumulation is continuing or not. Wastes generated from the cleanup will be disposed of appropriately.
Next steps are to accomplish the planned removal actions, which are projected to take up to 2 work days to complete.
(1) If accumulation of oil at the base of the bank at the spill location continues, a consultation with Ada County Roads Department personnel will need to occur in regards to feasability of disturbing the area of the road and bridge in order to remove additional contamination. (2) Also, some organic sheeing was observed in a few places downstream near the spill location. The rainbow effect this biologically produced sheen causes could be confused by concerned citizens along the creek with actual petroleum contamination. This may require some additional community education effort to clarify.
|
