LEWISTON - Councilors will back an effort to get state environmental protection officials to recognize water quality improvements in the Androscoggin River.

They directed staffers Tuesday to draft a letter urging the state to increase the river's classification from a C rating to a B. Durham, Brunswick and Topsham have already sent similar letters to the state.

Ed Friedman, chairman of the Friends of the Merrymeeting Bay, said his group's test data shows water quality in the Androscoggin River from Durham downstream has improved enough to meet Class B standards. The group has asked the state Department of Environmental Protection to reclassify that section.

"I do envision a day when you'll be able to see Atlantic salmon migrate up past the Great Falls," Friedman said. "The days of the river being a sewer are in the past."

The DEP reviews classification changes to Maine's waters every three years. The classifications, from highest to lowest, are AA, A, B and C. Friedman said the public comment period on the Androscoggin's classification closes Thursday.

The Androscoggin is rated Class C from its source in Errol, N.H., to its mouth, 173 miles away in Bath. But according to the Friends, the river's water quality stays well above Class C, except during heavy rainstorms. Pollution from storm sewer overflows are to blame, and both Lewiston and Auburn have worked hard to limit those instances, Friedman said.

Friedman's group monitors and promotes recreation in and conservation of the watershed created where several rivers, including the Androscoggin and the Kennebec, empty into the Atlantic Ocean. He was joined by Neil Ward, executive director of the Androscoggin River Alliance.

Councilors' biggest concern was if the change could raise water treatment standards for city.

"My concern would be added costs to the city if we suddenly have to make changes at our treatment facility to maintain those new classification standards," said Councilor Denis Theriault.

But Public Services Director Dave Jones said the Lewiston Auburn Water Pollution Control Authority treatment plant meets the tougher standards now.