A proposed railroad connection near wetlands in northwestern DuPage County has Forest Preserve District officials concerned about potential contamination from hazardous-material spills.

Canadian National Railway hopes to buy the Elgin, Joliet & Eastern Railway, but a federal study on the impact of the acquisition predicts a slightly higher rate of spills because of increased freight traffic. The chances of such a accidents are still remote, the report notes, predicting they would occur less than once a year.

“One contamination of our groundwater will have a long-term effect,” said John Oldenburg, director of natural resources for the Forest Preserve District of DuPage County. “One time is too many as far as the Forest Preserve District is concerned.”

The federal Surface Transportation Board’s draft environmental impact study, released late last month, predicts a 28 percent increase in rail accidents along the EJ&E if train traffic is increased as a result of the buyout.

As part of its plan to buy the EJ&E, Canadian National plans to connect its existing east-west running tracks with the north-south running tracks it hopes to acquire. Both sets of rails run through Pratt’s Wayne Woods  Forest Preserve in Wayne. The EJ&E runs in an arc from Waukegan to Joliet to northwest Indiana.

Canadian National previously approached the district about buying a 1-acre parcel of land to construct the spur, but district officials made it clear to the railway that selling the land was not an option. The railway is now considering an alternate plan to build a smaller connection in the same area on a right-of-way owned by Commonwealth Edison.

Oldenburg said the district will seek to enter into negotiations with Canadian National to ensure that if the deal goes through, the railway foots the bill for measures that would contain spills of hazardous materials.

The district expressed its hope to negotiate with Canadian National on Tuesday, a few days after the railway indicated that it is seeking a speedy end to the federal approval process.

The railway announced Friday, that it wants the Surface Transportation Board to make a decision before on the proposed buyout by Oct. 15. A decision is not expected until spring.

Canadian National officials are asking the board to decide on the transportation merits of the proposal so the railway can close the deal before the new year. The EJ&E’s current owner, U.S. Steel Corp., has said it will not extend its $300 million purchase agreement beyond Dec. 31. The railway is suggesting the federal board maintain its current schedule for evaluating the environment impacts of the proposal.

Canadian National and its supporters contend that purchasing the little-used rail line will reduce freight-train congestion by allowing some trains to bypass the overcrowded rails leading into Chicago. Local leaders in DuPage County and other suburban areas argue that the acquisition would dramatically increase train traffic along the EJ&E tracks and negatively effect communities through which they run.

One of those opponents is U.S. Rep. Judy Biggert, R-13th District, of Hinsdale. The congresswoman released a statement Friday, shortly after the railway’s announcement.

“Once again, Canadian National  is trying to pressure federal regulators into making rash decisions about the safety and quality of life of suburban residents,” Biggert said in the written statement. “They’re asking the Surface Transportation Board to make a mockery of the public comment process. That’s completely unfair to those who are being asked to pay the price so Canadian National can add to their bottom line.”

Supporters of the plan, including U.S. Rep. Dan Lipinski, D-3rd District, of Western Springs, Riverside Village President Harold Wiaduck and North Riverside Village President Richard Scheck plan to hold a news conference Thursday morning at North Riverside Village Commons to talk about the benefits of the purchase.

“Should this controversial transaction be approved, Chicago and many of its suburbs could benefit from a reduction or even elimination of Canadian National train traffic in certain corridors,” Lipinski said in a written statement. “For many communities this could mean fewer blocked crossings, a reduction in idling trains and fewer train whistles in the middle of the night.”