WASHINGTON | In the face of mounting criticism, BP is "moving ahead" with its Whiting expansion plans and use of a controversial wastewater discharge permit, the company told lawmakers Wednesday.

BP executives, including Bob Malone, chairman and president of BP America, met with members of Indiana's congressional delegation and Gov. Mitch Daniels' staff in Washington on Wednesday.

"We thought that it was important that the Indiana congressional delegation had the same information that their colleagues in the Great Lakes region," BP spokesman Tom Keilman said of the "very productive session.

BP officials described the $3 billion Whiting plant expansion project, and process involved in obtaining a state permit, according to Justin Kitsch, spokesman for U.S. Rep. Pete Visclosky, D-Ind.

The meeting came the day after the U.S. Environmental Protection Agency called the permit compliant with the Clean Water Act, and said the agency wouldn't impugn Indiana for issuing it.

"Congressman Visclosky felt it was important to bring together officials from BP and the state to brief the Indiana Congressional Delegation," Kitsch said.

Visclosky was one of 387 U.S. House members who voted July 25 to urge Indiana to reconsider the waste discharge permit.

The company has said it needs the permit -- allowing 54 percent increased daily ammonia output and 35 percent more suspended solids -- for its plans to process heavier Canadian crude oil.

The increased discharges fall within federal limits.

Keilman said BP is not halting its plans for the Whiting plant, noting that its permit is valid.

"It's important that our congressional delegation understands that the process was an open process, with regards to public participation, and that BP followed all the regulatory requirements," Keilman said.

The company is seeking approval for the first step in the project -- construction of a $110 million asphalt facility -- from Hammond's Board of Zoning Appeals at the end of the month.