With a decision expected by the end of the year from the Obama administration on the proposed Keystone XL pipeline, members of Congress have sent two letters to Secretary of State Hillary Clinton raising concerns over the State Department’s handling of a critical environmental review of the project.

A letter sent late last week by Senator Ron Wyden of Oregon and two Vermont senators, Patrick Leahy and Bernard Sanders, criticized the State Department for assigning the review of Keystone XL to a consulting firm with financial ties to the pipeline’s operator and urged the federal government to start the process all over again.

The letter cited a New York Times article published this month that said the State Department used Cardno Entrix, a Houston-based consulting firm, at the suggestion of TransCanada, which is seeking to build the 1,700-mile pipeline from Alberta to Texas.

As arranged with the State Department, Cardno Entrix was paid by TransCanada to conduct the study. TransCanada has also paid the company to conduct previous environmental reviews of its projects, one of which Cardno Entrix did not disclose to the State Department.



Although such practices have become commonplace over the years, some experts in environmental law have said the State Department should have been more cautious about whom it hired it for the environmental study to avoid the appearance of conflict of interest on a project that has created so much controversy.

The three senators agreed. “We find it inappropriate that a contractor with financial ties to TransCanada, which publicly promotes itself by indentifying TransCanada as a “major client,” was selected to conduct what is intended to be an objective government review,” they wrote. Mr. Leahy and Mr. Widen are Democrats, and Mr. Sanders is an independent.

A similar letter last week authored by Representative Earl Blumenauer of Oregon and signed by 32 fellow House Democrats cited the relationship between Cardno Entrix and TransCanada as well. It also noted recently released e-mails between State Department officials and lobbyists for TransCanada that appear to reflect a warm and friendly relationship.

“Rather than acting as fair arbiters of TransCanada’s application to build a massive pipeline across environmentally sensitive areas of the United States, State Department officials appear to have acted as little more than cheerleaders for the company’s bid,” the letter says.



Asked for comment, a State Department spokeswoman, Wendy Nassmacher, said, “We received the letters, and we are currently reviewing them.”

The department has vigorously defended its choice of Cardno Entrix, saying that it vetted the consulting firm and closely supervised its work and that the environmental study was robust.

In a recent interview with the Associated Press, Mrs. Clinton said she had no reason to believe the State Department was biased in favor of the pipeline.

“This is a very emotional decision, and you have people who feel very strongly on both sides,” Mrs. Clinton told the Associated Press.

“You have states that are welcoming it, states that are rejecting it,” she said. “This is an issue that raises very local concerns.”

Supporters of the $7 billion pipeline, which would pass through six states, say that it will create much-needed jobs and transport oil from a reliable ally. Environmental groups and some politicians argue that the heavy crude the pipeline would carry is environmentally harmful to extract and would pose more of a threat than other types of crude if spilled.

The State Department’s final environmental study on Keystone XL, released in August, found that the pipeline would have minimal environmental impacts if operated according to federal regulations.

That conclusion has been criticized by the pipeline’s opponents for not adequately taking into account the impacts of a major spill and for failing to sufficiently consider a route skirting the Ogallala Aquifer, a critical water source.

The Environmental Protection Agency, which plays only an advisory role in the process, found flaws in the first two drafts of the study. The agency has yet to weigh in on the final version.

TransCanada has maintained that it does not have a direct ongoing relationship with Cardno Entrix.