Debate over Scheme Z has been heating up for almost two years now, ever since state planners added blueprints for the mammoth, 11-tier bridge across the Charles River to their designs for the new Central Artery highway system.

And in recent weeks the conflict between citizens' groups, environmental organizations and the state has reached the boiling point.

Early last month, the state Department of Environmental Affairs approved the final Environmental Impact Report that will allow the Central Artery package to seek federal funding. Three weeks later, the city of Cambridge and three environmental advocacy groups responded by filing intents to sue the state unless it backs down from its support of Scheme Z and the artery project as a whole.

Now, 37 of the foremost players in the ongoing dispute--representatives of groups with drastically different visions of the Central Artery's final form--are sitting down together at the bargaining table. They have a state mandate to draft a recommendation about the fate of Scheme Z by April 30.

The Bridge Design Review Committee, created by ex-Secretary of Environmental Affairs John P. DeVillars to advise the Department of Public Works, convened for the first time last Friday.

Private citizens and members of groups ranging from the Sierra Club to the Boston Transportation Department began to air the opinions and discuss the issues which they must eventually meld into a program of action for the state.

In his opening remarks, Secretary of Transportation Richard Taylor said the group's principal goal is to "examine ways to improve the Charles River Crossing as part of the design phase of the project."

But Stanley Miller '52, who will mediate the discussion, emphasized that the committee will consider new options in addition to looking for improvements to the plan. "We're not here just to beautify Scheme Z," Miller said in an interview yesterday. "We will be considering alternatives."

Miller added that although he anticipates a fair amount of dissent within the group, "my feeling is that 80 percent of the people in the room could be brought together with an equitable solution." He would not speculate as to what form that solution will take.

However, Cambridge Conservation Commission Director Elizabeth Epstein, the city's official spokesperson on the committee, was less optimistic, saying that "the city's position has not changed one iota" from its initial opposition to Scheme Z. She said she would be hard-pressed to consent to the River Crossing or any like variant and added that she has "good reason to believe that there are better alternatives."

But Assistant Secretary of Transportation Matt Kugin observed that "the basic problem of solving a safe road is pretty well handled [with Scheme Z]," despite its aesthetic and possible environmental shortcomings.

Cambridge architect Hugh Russell, a member of the committee, said he is uncertain whether the group will be able to make the compromises necessary to carry out its mandate. "It's going to be difficult to reach an agreement because people are coming from such different points of view and it's such a large and complicated thing," he observed. "On the other hand, we kind of have to."

Russell added that since the committee is only an advisory group and has no legal powers, even if the members do reach an agreement the state could easily ignore their recommendations