The topic isn’t sexy. Attending something called the “Landfill Forum” sounds like an act of desperation, what you do if there are no more openings in the lecture series on Best Compost Practices.

But Monday morning’s forum (8:30 a.m. , Santa Rosa City Council chambers) happens to involve a decision that could have lasting economic and environmental consequences.

In Sonoma County, we brag about our devotion to a sustainable lifestyle, but if we get this wrong, we will have a lot of explaining to do.

The story begins with the Board of Supervisors’ plan to sell the county’s central landfill on Mecham Road, south of Cotati.

Supervisors say they want to get out from under the costs and liabilities associated with repairing a plastic liner that is leaking bad stuff into nearby groundwater. Officials say it could cost $50 million to abandon the landfill, or $100 million to make it operational again.

But environmental groups and the county’s largest solid waste hauler, North Bay Corp., warn that the sale could leave local consumers at the mercy of a private monopoly, a corporation that would raise rates, discourage recycling and import garbage from other counties.

In a September letter, the Sierra Club urged supervisors to reconsider their plan, noting: “Public ownership of the landfill guarantees that the environmental values of this community, as reflected by our elected leaders, will come before the profits of corporate executives and shareholders.”

In this conflict, the exchanges are not always friendly.

In December, former county Supervisor Ernie Carpenter, a consultant to North Bay Corp., accused county officials of inflating cost estimates, violating the state’s open meeting law, and applying “heavy-handed pressure tactics and threats. . .”

In reply, Phillip Demery, county director of transportation and public works, denied the allegations and concluded, “The comments in Mr. Carpenter’s letter are what one might expect from someone who has a vested competing financial interest in seeing this process fail.”

Ironically, both sides claim their solution would promote recycling and reduce the current practice of shipping Sonoma County garbage to distant locations.

Since the landfill was mothballed in 2005, the county has spent $15 million a year to transport 300,000 tons of garbage to somewhere else. That’s 65 truck-and-trailer rigs every day – trucks that burn energy, spew greenhouse gases into the atmosphere, add to traffic congestion and contribute to the deterioration of highways.

So, which side is right? And why isn’t this decision the subject of a broader public debate?

Enter a consortium of civic and environmental groups that includes the League of Women Voters, the Leadership Institute for Ecology and the Economy, the Sierra Club, Sonoma County Conservation Action, the Sonoma Ecology Center and the Climate Protection Campaign.

Not all the sponsors of Monday’s forum oppose the sale of the landfill. Tanya Narath, executive director of the Leadership Institute for Ecology and the Economy, and Ann Hancock, executive director of the Climate Protection Campaign, told me their groups haven’t take a position.

“We’re not seeking a specific solution or trying to bludgeon the county,” said Hancock, “but to bring people together to have them talk about it.”

But Narath and Hancock agreed that their participation reflects their organizations’ concern that this decision is fast approaching without a serious conversation about the consequences.

It doesn’t help that the proposed sale is being reviewed behind closed doors. The county says a real estate deal involving rival bidders can’t be negotiated in public, but the secrecy leaves the public in the dark about the broader policy issues.

The situation also highlights the problems associated with California’s scatter-shot approach to regulation. In this case, a single-purpose agency, the North Coast Regional Water Quality Control Board, wields the authority that is pushing the county toward a decision to sell the landfill.

But what if reducing the risk to groundwater near the Mecham Road landfill means more air pollution, lower recycling rates and climate change? Which is worse for the environment?

Whatever the outcome, a coherent society would establish a forum for weighing the inevitable trade-offs.

Meanwhile, no one has yet explained why a for-profit company would be so eager to shoulder the financial liabilities that the county is so eager to jettison.

And, whether publicly or privately owned, success may depend on the capacity of the county and the nine cities in Sonoma County to share the obligations associated with operating a landfill.

For now, what we know for sure is that a credible decision will require greater transparency from local government, plus a regulatory approach that recognizes that real life is complicated.

Note: The begins at 8:30 a.m. Monday in the Santa Rosa City Council Chambers. The session will be telecast live on Santa Rosa community-access channel 26 (and re-broadcast throughout the week.) If you want to learn more, a list of speakers and panelists, plus an impressive collection of reports, letters and other information is available at the Leadership Institute’s Web site. Click here.