Boxer raises environmental concerns over Keystone XL pipeline

In a sign of hardening skepticism toward the controversial Keystone XL pipeline, a top Senate Democrat has sent a letter to the Obama administration asking about a possible conflict of interest between the pipeline operator and a company handling the environmental impact study of the project.

Sen. Barbara Boxer (D-Calif.), who chairs the Environment and Public Works Committee, wrote to Secretary of State Hillary Rodham Clinton last week cautioning that the environmental studies must be impartial.

“Following the nation’s worst oil spill and at a time when the effects of global warming become more apparent every day, it is imperative that we have thorough and objective environmental assessments so that the public can fully understand the impacts of proposed projects,’’ Boxer wrote.

The proposed 1,700-mile long Keystone XL must be approved by the State Department because it crosses a national border, running from Canada to Texas.

The Obama administration has said that it would make a decision on the issue by the end of the year, though that deadline could be stretched.

President Obama is coming under growing pressure from environmentalists and his liberal base to reject a permit for the project. As scrutiny matter intensifies, Obama appears to be taking ownership of the issue.

At one point, the White House had said that the fate of the permit rested with the State Department. But in an interview last week with a Nebraska television station, the president suggested that he would not outsource the decision and would instead make it himself based on the State Department’s recommendation.

He told the station he would take “the long view’’ in reaching a decision, taking into account public health and the possible effects on water supplies.

Boxer’s letter cited an article in the New York Times last month showing that the State Department allowed TransCanada, the company vying for the permit, to screen contractors for the environmental impact study. The firm chosen, Houston-based Cardno Entrix, had “financial ties” to TransCanada, the Times reported.

A relationship between Cardno Entrix and TransCanada was first reported in the Los Angeles Times in July.

Boxer’s letter zeroed in on the connection between the two companies. She asked Clinton to provide material addressing whether the State Department’s use of Cardno Entrix complied with federal law. Boxer also asked whether the relationship between Cardno Entrix and TransCanada ”created a conflict of interest,” and, if so, “how such conflict was disclosed.’’

Setting a Nov. 14 deadline, Boxer requested documents establishing whether State Department staff had looked into the “financial and business relationship’’ between the two companies.

Neela Banerjee of the Washington Bureau contributed to this report.