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Ravell Call, Deseret News
Colors show brilliantly on both sides of the causeway for Union Pacific in the Great Salt Lake west of Promontory Peninsula on Wednesday, June 8, 2011. Water flows through a culvert from right to left (south to north).

SALT LAKE CITY — Repairs proposed to the aging Union Pacific causeway have landed as a "hot" issue that a state team of experts says needs more study because of what is at play with the Great Salt Lake.

The U.S. Army Corps of Engineers is ready to suspend a national permit that would have allowed those repairs to go forward absent any depth of public scrutiny.

"We are proposing to suspend authorization of the permit due to our concerns, concerns from other public agencies, industries on the lakes and others that there are unknown effects" the fixes could cause, said Jason Gipson, chief of the Utah/Nevada regulatory branch for the U.S. Army Corps of Engineers.

"The Great Salt Lake is a very dynamic system," he said. "Right now, we don't have enough information to say that if Union Pacific does this, this will be the effect."

At issue is the annual contribution of $1.3 billion into Utah's economy by the Western hemisphere's largest inland body of salt water, the industries it supports and the millions of waterfowl and migratory birds that use its ecosystem.

The Union Pacific Railroad wants to replace its concrete box culvert system that was installed as part of causeway construction in the 1950s because the system is sinking into the lake bed. One of those culverts already failed last year and was repaired under emergency circumstances authorized by the Corps of Engineers, Gipson said.

Ultimately, the railroad wants to replace the culvert system with a bridged, 150- to 180-foot opening that will be structurally sound, but according to the railroad, will still allow the same directional flows between the north and south arms of the lake.

Those assurances, however, have failed to assuage the fears of lake advocacy groups, the brine shrimp industry, or the state agency that owns the lake bed and is ultimately one of the long-term caretakers of the system.

"There is a lot of information that we don't know, that we should know, before anyone makes a decision," said Laura Ault, a program manager with the state Division of Forestry, Fire and State Lands.

The agency recently solicited study proposals on multiple issues confronting the lake, such as mercury, proliferation of invasive phragmites and those possible implications of causeway modifications.

One of eight study pitches received this month dealt with the modification issue, with the grant committee planning to make a final selection in June.

"The causeway is a hot topic for everybody who deals with the Great Salt Lake," Ault said.

The causeway northwest of Ogden grew out the need to replace a wooden trestle completed in 1904 and part of a route called the Lucin Cutoff.

With the installation of the causeway and subsequent reinforcement of the fill on the vital east-west railway line, a tale of two vastly different lakes began to emerge over the decades.

Even with culverts in place and seepage through the fill, a salinity difference began to build, with the north section reaching a saturation point with its saline content.

"It acts like a dam to an extent. While water seeps through, the north is so hyper saline compared to the south," Gipson said.

A report by the Utah Geological Survey noted that the causeway's history is a compelling story that illustrates how human attempts to re-engineer nature produce unexpected impacts.

Advocacy groups such as the Friends of the Great Salt Lake see the causeway modification as an opportunity for the Union Pacific to do more to correct those imbalances caused by the 20-mile structure.

The federal government, the railroad and the state have been wrestling with the issue for a couple of years now, and the state and railroad have yet to settle a difference over an easement dispute.

Gipson said the federal regulatory agency is waiting on additional information from the railroad before the process moves forward in any fashion.

"Not being able to say definitely to the public that this will have no more than a minimal impact prevents us from being able to issue that nationwide permit," he said. "It's become more evident that we don't have the necessary information on the impacts."

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