The Environmental Protection Agency has put a road block in plans to expand an oil refinery in Illinois. The plant is operated by Conoco Phillips.

"Right now we're in the process of digesting all the pieces of this decision to determine how it's going to impact the refinery," the St. Louis Dispatch quoted ConocoPhillips spokesman Bill Graham.

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The effort is part of a plan to process more Canadian oil in the U.S. the Wall Street Journal reports

In fact, it would have boosted the plant's Canadian oil imports by up to 460,000 barrels a day. But environmentalists convinced the EPA to reject air permits for the project.

The agency says Conoco did not plan to use the best technology for cutting emissions.

"Our intention is not to stop the expansion project, but to ensure that the refinery lives up to the standards of the Clean Air Act and its protections for the people who live and work nearby," Natural Resources Defense Council Attorney Ann Alexander insisted.

"ConocoPhillips simply ignored the requirement to find and use the best available pollution control technology," he told the Dispatch.

But the company says it was planning to install "state-of-the-art technology." No one knows how long this will delay the expansion.

Source: Wall Street Journal, St. Louis Dispatch