By the OGJ Online Staff
HOUSTON, July 20 -- A sulfuric acid spill is no longer leaking through the cement containment around damaged storage tanks at the Motiva Enterprises LLC refinery in Delaware City, Del., officials said Friday.
But emergency response personnel from the company, the US Coast Guard, the US Environmental Protection Agency, and the Delaware Department of Natural Resources & Environmental Control are still working around the clock.
Four of the five tanks within the containment area are believed to be holding their original volumes of acid, although at least one shows damage, officials reported. The fifth tank appears to have leaked all of its contents following a fire Tuesday at the refinery.
Efforts were underway Friday to assess the condition of the remaining tanks and to begin safe removal of the acid stored in them.
Meanwhile, a hazardous material team is making a "grid pattern" for a missing contract maintenance worker around the outside perimeter of the acid tank farm. Officials said the team would search inside the containment area as soon as personnel can enter safely. The worker has been missing since the fire Tuesday afternoon. Company officials earlier reported that fire was extinguished within 40 min.
The cause of the fire and the leak is still under investigation by company and government officials.
Workers also are sealing the concrete dike around the tank farm, constructing additional earthen barriers in that area, positioning pumping and vacuuming systems, and continually monitoring the acid levels and integrity of the metal tanks.
Remaining runoff from earlier fire fighting efforts -- water mixed with acid, caustic soda, and ash -- is being processed normally through the refinery's wastewater treatment facility. That facility Thursday treated 8 million gal of runoff and wastewater from normal refining operations, Motiva officials said.
Tests of water samples taken from the Delaware River near the refinery's intake and outflow channels still indicate normal pH levels, authorities reported. Although access to one adjacent road remains restricted, they said, air monitors around the perimeter of the refinery have registered no detectable levels of sulfur dioxide.
Cleanup efforts have temporarily reduced the 152,000-b/d refinery's operating rates, said company officials.
Motiva Enterprises, Houston, is a joint venture of Texaco Inc., Shell Oil Co., and Saudi Refining Inc.
