Vapor control starts on tanks at BWT facility

Renovations at Alyeska’s Ballast Water Treatment (BWT) facility in Valdez achieved an important milestone on January 30 with the startup of the vapor recovery system for tanks 93 and 94—known as the 90s tanks. Prior to the renovations, the BWT system released volatile organic compounds (VOC) that could have been a safety risk in certain situations. This new Vapor Control System dramatically reduces the risk of fire or explosion and will cut the plant emissions to nearly zero in 2008.

“Five years ago we recognized the need to deal more effectively with the vapor in the 90s tanks. After careful study and risk assessments, we determined that an engineered solution was needed to reduce the risk and control vapors,” said Greg Jones, Valdez vice president. “We are all very proud to see this day come.”

With the first stage of renovations complete, vapors that once vented from the ballast water tanks now travel through piping to the Vapor Control System. That system already manages the crude oil tanks’ vapors and vapors from the tankers captured during the loading process. This summer, crews built infrastructure for this vapor piping system from welding pipes together, building supports for aboveground piping, and drilling a 30-inch diameter hole through the mountainside for the pipe’s predominant, belowground section.

“The operations and projects teams should be recognized for their hard work and commitment to completing this job,” said Jones.

The $91 million BWT renovation is one of Alyeska’s largest projects, second only to pipeline reconfiguration.

The BWT cleans ballast—water that tankers temporarily store for stability and control, keeping them low in the water until the vessels take on oil—and facility runoff and processes wastewater. With today’s lower throughput and decreased tanker traffic, and with more tankers carrying oil and ballast in separate tanks, there’s less ballast to process. This means the BWT facility is now too large and needs to be engineered to handle a wastewater stream that is more fresh water than saltwater.

The major renovation is the first of several large steps to adapt the BWT for lower ballast water flows, while also improving safety and decreasing emissions at the plant and the Valdez Marine Terminal.