United States Environmental Protection Agency
Region X
POLLUTION REPORT

Subject: 

At approximately 0040 hrs on August 1st, a 40,000 gallon underground storage tank belonging to AT&T began pumping diesel fuel into three 250 gallon above-ground day tanks.  Over the next six hours 15,000 gallons of fuel overflowed from one tank onto the floor and flowed into the storm water system of the city of Bothell and into soils next to the tanks.

Fuel flowed down the storm water system but halted prior to reaching a storm water retention pond and wetland.  At this time there is no evidence that fuel has left the stormwater system.

Current situation:

There are two areas of operations:  the storm drain and the facility.  Fuel flowed into the storm drain which leads to a wetland pond, which in turn flows into the Par Creek, then to North Creek, and finally Sammamish River. Early in the response the storm drains were actively vaccuumed but we are now getting diminishing returns. Even after repeated flushing it is believed that there are pockets of fuel caught in swales along length of storm drains.  In addition, no fuel has entered the pond by virtue that the water level in the pond is high enough that water is backed up into the storm drain.  We believe fuel has made it to the backed up water and is trapped between the ceiling of the culvert and the water.  With the flow of water moving imperceptibly slow, the sloped storm drain is essentially serving as an oil/water separator.  

The second area of operation is the asphalt parking lot next to the above ground storage tanks.  It is believed considerable fuel may be under the asphalt as there was an opening in the concrete slab with the fuel tanks which leads down into the soil/pea gravel below the asphalt.

High VOC concentrations have been detected inside some manholes indicating presence of fuel still.

Soil in a planter next to slab with days tanks was saturated with fuel.  The soil has been removed.

One START was on site for part of the day Sunday.

Monday morning we will decide on how to address the problem of the trapped fuel at the end of the storm drain.  It is uncertain how much fuel is there and it is not easy to remove.  A number of options are being entertained.

AT&T is preparing to removal asphalt and begin probing, removal, and delineating of diesel beneath parking lot.  A "Super Sucker" truck is on scene for removal of soil and pea gravel under parking lot.  Beneath the asphalt lie the 40,000 gallon diesel storage tanks as well as communication and other utility lines.  Digging must proceed with caution.  So Monday AT&T will meet with engineers to confer on digging as well as long-term monitoring and remediation to ground water which is reportedly 10 feet below the surface.

Sunday we intended to send cameras down into the storm drains to look for fuel and especially to see if fuel is leaking into the facility storm drain from asphalt parking lot.

The section of storm drain on the facility property from where the fuel entered will be blocked off at the end leading into the main storm drain on North Creek Parkway as well as upstream to prevent clean water from entering.  Storm water will be diverted to a parallel storm drain or a baker tank.

Water/fuel removed off site will be analyzed to get a more exact number of fuel-water ratio.  In this way, we can better determine how much fuel has been recovered.

1)  Status meeting at 0800 Monday.
2)  AT&T planning meeting for work on ashpalt parking lot and long term monitoring.  North Creek is 1/8 to 1/4 mile due east.  The water table is high so there is threat to North Creek.
3)  Ecology will be providing options to AT&T for long-term cleanup, such as their Voluntary Cleanup Program.

1)  Removal of fuel trapped at end of storm drain close to the pond as well as fuel in pockets along the length of storm drain.

2)  How do we declare victory?  How clean is clean?