BANGOR – Hoping to fend off future legal challenges, city officials here are revising a vague environmental ordinance that was ruled unconstitutional by a state judge last year as part of a Wal-Mart developer’s lawsuit against the city.

The revisions, which will go before the City Council on Monday for a first reading, change and elaborate on some of the unspecific language that allowed city planners to consider a project’s “effect on the scenic or natural beauty of the area or on historic sites or rare and irreplaceable natural areas” before issuing a permit.

In April 2001, the Planning Board cited the section when denying Widewaters-Stillwater LLC a permit to build a 224,000-square-foot Wal-Mart Supercenter near the southern tip of the environmentally sensitive Penjajawoc Marsh.

Three months later, Justice Jeffrey Hjelm struck down the ordinance as unconstitutionally vague, saying it gave a developer no specific criteria to meet. As part of his order, Hjelm required the Planning Board to grant Widewaters the needed permit.

The board did just that several weeks later, but that permit was invalidated when an appeals court, seeking additional information, vacated Hjelm’s decision.

The New York-based Widewaters is back in state court looking to have the permit reinstated. That lawsuit is pending.

City attorneys said Thursday they believed the ordinance’s new language would clarify what is required, or merely preferred, of a development near an environmentally sensitive site.

“The new language talks about encouraging the preservation of views,” said John Hamer, assistant city solicitor. “Because of that, we realize it’s unenforceable … but it’s an encouragement.

“This is saying that natural beauty is important and we want developers to consider it when submitting their projects,” he added.

But other sections of the ordinance are enforceable, Hamer said, with new standards for developers to meet.

The proposed ordinance specifies that a project cannot have an “unreasonable adverse impact” on a historic site, significant wildlife habitat or rare and irreplaceable natural area. The existing ordinance did not provide a standard, stating only that the city can consider a project’s “effect” on such areas.

Upon the City Council’s referral Monday, the Planning Board will review the changes at a future meeting.

The changes to the city ordinance roughly coincide with next week’s resumption of the Board of Environmental Protection hearings on the proposed project at the Spectacular Events Center on Griffin Road.

The hearings will run from 9 a.m. to 5 p.m. Monday. On Tuesday the hearings will begin at 9 a.m. and end when business is concluded.