Approval for a controversial sewer line in Big Cottonwood Canyon is expected to generate some added development pressure in the area, but officials believe the size of the line will limit that development sufficiently to allay concerns of environmentalists.

A group that has expressed concern about the line says, however, that the final approval, granted Tuesday by the U.S. Forest Service, should have been delayed until Salt Lake County completes work on a master plan for the canyon.Michael Budig, co-chairman of Save Our Canyons, said his group wants to see development controlled by the master plan and not the availability of sewer service. "We believe the master plan draft is an excellent start with the kinds of guidelines needed to concentrate growth in the right area," Budig said. "The question is whether the final plan will maintain those guidelines."

The line was first proposed in 1982 with plans for a 320-unit condominium project at Solitude Ski Resort. Forest Service officials project the cost at $3 million and the 10-inch line will provide capacity for 850 more housing units in addition to the condominium project.

They believe this limitation will moderate development in the canyon. Officials decided against a 12-inch line because it was felt that size would have generated the kinds of development pressures opposed by environmental groups.

Salt Lake City officials have supported the sewer line project to protect the water quality of Big Cottonwood Creek, an important drinking-water source for the city. Officials had worried that continued use of outhouses and septic tanks could jeopardize that water quality.

Cabin owners in the canyon may be urged to connect to the line, but that will not be required unless ordered by the county Health Department to correct violations affecting existing systems.

However, installation of the line will not occur soon. Officials project it will take between two and four years to complete planning work and construction.

Forest Service officials said they recognize the concerns raised about intensive development in the canyon but believe the county can adequately control that development while protecting the watershed and other resources of the canyon.

The line will be installed along the shoulder of the road to limit the impact on the existing canyon vegetation.