Consultants say a $3.6 billion expansion of the Wood River Refinery should produce a strong economic stimulus to the communities of northwestern Madison County, Ill. 

Work began last year on a project that will enable the 92-year-old refinery to process heavy crude oil from Canada and increase refining capacity to 360,000 barrels per day. The expansion should make the refinery the nation's sixth largest by 2011.

A study conducted by RSN Economic Group and announced today says contracts with local construction companies should boost local economic activity by an estimated $1.5 billion. It says spending by workers from outside the region are expected to produce an additional $35 million stimulus.

The study says the expanded refinery operations should provide an ongoing $1.9 billion yearly boost to the area's economy. The refinery is expected to add about 100 workers to the 800 refinery employees and 600 contract workers who now work there.

Houston-based ConocoPhillips and EnCana Corp. of Calgary, Alberta, are partners in WRB LLC, which owns the refinery. The study was commissioned by WRB, the Illinois Department of Commerce and Economic Opportunity and the River Bend Growth Association.

About 2,000 construction workers are currently working on the expansion project. Refinery spokeswoman Melissa Erker said that number is expected to increase to about 3,800 by the end of this year.

Copyright (c) 2009, St. Louis Post-Dispatch. Distributed by McClatchy-Tribune Information Services.