Less than a week before he is scheduled to announce officially his candidacy for governor, Mayor William Donald Schaefer is repudiating reports of his comments on the Chesapeake Bay cleanup and is meeting with environmentalists in an effort to put the controversy behind him.

Two weeks ago, during a Montgomery County campaign appearance, Schaefer upset environmentalists when he said that regulations passed by the General Assembly this year to restrict development along the Chesapeake Bay could stand to be weakened in "maybe a year or 18 months." He also said at the time that a 16-month-old ban on harvesting rockfish could be lifted "a couple of years from now."

But Monday night, in a speech at Western Maryland College in Westminster, he said that he had meant that the bay regulations might be relaxed in 50 years, rather than 18 months, and he emphasized that he shares environmentalists' concerns for the state's resources.

"If 50 years from now you can adjust the [critical areas] law, we'll look at it," said Schaefer. " . . . In a world of reality and not a world of nonreality, fishermen might be told someday . . . we might take the rockfish ban off.

"I breathe the same air as the environmentalists and nonenvironmentalists," he added. "I drink the same water they drink. So it's not that I don't want the air clean or the water clean."

Today, Schaefer's campaign manager, Mark Wasserman, laid out the mayor's case in a private meeting with Ajax Eastman, a past president of the Maryland Conservation Council. Schaefer has asked for a briefing in his offices Wednesday with state Department of Natural Resources Secretary Torrey Brown, Chesapeake Bay Critical Areas Commission Chairman Solomon Liss, Chesapeake Bay Foundation President William C. Baker and other environmentalists to set the record straight.

"The record has become muddled and distorted," said Wasserman. "It's crucial to the mayor personally . . . to convince the electorate of Maryland that he . . . can point proudly to his record on the environment."

Schaefer's aides said that mayor has overseen the creation of 400 acres of parkland during his 16 years in City Hall and point to the new Middle River park here as an example of his commitment to preserving shoreline open space.

Schaefer, in his remarks in Westminster, said that he intended his original comments in Rockville to reflect a willingness on the part of government to change laws when the occasion warrants such action. "I did not say I was going to lessen controls," he said.

Liss, who championed the strict new shoreline development restrictions in the General Assembly this year, said that he planned to explain to Schaefer during the Wednesday meeting that the bay protection program may not even be completely in place within two years.

"We're hoping that [the meeting] will clear the air," said Liss. "Obviously you don't decide what to do with a program until it goes into effect."

Some environmentalists who have been following the mayor's comments, however, are more skeptical about the meaning of his original statements.

John Kabler, political director of the League of Conservation Voters, also criticized Schaefer for opposing the statewide phosphate detergent ban that was imposed in 1985. "It'll take more than backpedaling on some irresponsible statements on the bay to prove that he is in favor of cleaning up the bay," he said.

Schaefer's chief critic and Democratic gubernatorial opponent, state Attorney General Stephen H. Sachs, accused the mayor of doing a "major flip-flop."

"He seems to be making up his environmental policy as he goes along," Sachs said.