Sam Fletcher
OGJ Online
HOUSTON, July 19 -- Emergency teams at a Delaware refinery were still struggling Thursday to contain, control, and neutralize a sulfuric acid spill to reach the area where they can begin searching for a worker missing for 2 days.
No refining units were damaged by the brief fire and subsequent acid spill at the Motiva Enterprises LLC refinery in Delaware City, Del.
However, cleanup efforts have temporarily reduced the 152,000-b/d refinery's operating rates, officials said Thursday. They declined to comment on earlier reports that operations were down by a third.
Some 12 million gal of sulfuric acid, caustic soda, and water used in fighting the fire have been temporarily contained in three steel wastewater treatment tanks at the refinery. However, company officials responding to media inquiries Thursday could not say how much acid was spilled. Sulfuric acid is used as a catalyst in the alkylation process in refining gasoline, they said.
Interiors of those three holding tanks are lined with epoxy as an anti-corrosive barrier, and the thickness of their walls is being monitored by ultrasound to spot any deterioration.
Company and government officials plan eventually to process that mixture through the refinery's wastewater treatment facility.
Workers have neutralized at least part of the area where Tuesday's tank fire occurred. However, officials said, the containment area surrounding the damaged storage tanks continues to leak acid into the refinery's wastewater treatment system. Workers are pumping the leaking acid into an adjoining settling pond and damming the flow of runoff into the wastewater treatment facility. They are applying soda ash and caustic soda to neutralize the acid.
Once the spill site is neutralized, a hazardous materials team will attempt to search the area for the missing contract maintenance worker.
Officials of the Delaware Department of Natural Resources & Environmental Control reported that dead fish were found Wednesday in the Delaware River in the vicinity of the refinery's discharge area. However, officials said subsequent sampling of the river indicates that pH levels had returned to normal.
A small cloud of toxic gas was released at the time of the spill. However, officials said continuing monitoring of air samples outside the refinery's perimeter registered no detectable levels of sulfur dioxide.
Eight people, including two firefighters, were treated at a local hospital for varying injuries following that accident.
The cause of the fire is still under investigation by federal, state, and company officials, who also have cooperated in the cleanup effort.
Motiva Enterprises, Houston, is a joint venture of Texaco Inc., the Royal Dutch/Shell Group, and Star Enterprises, which in turn is a joint venture between Texaco and Saudi Refining Inc.
Contact Sam Fletcher at [email protected]
