In this week's paper we reported on what's been a surprising and unwelcome development for Portland bar owners in recent months: In January, as part of several tweaks to its administrative rules, the state of Oregon quietly changed the rules for legal outdoor smoking areas.

In the spring, bars began to receive notice that their smoking patios now qualify as "enclosed" spaces under the state's Indoor Clean Air Act, and that they could face a $500 fine anytime patrons were caught smoking there. Since that enforcement is complaint driven, it's picked up over recent months, to the point that bar owners are forming a coalition.

One attorney involved tells the Mercury there are ground to sue the state over the rule change.

Portland lawyer Sonia Montalbano says she represents a coalition of roughly 15 restaurants and bars that want to push back on the Oregon Health Authority (OHA), and that she's researching what legal options exist.

As we laid out in our story, the public record suggests that the state was less-than up front about its intentions to change the rules around smoking patios. Notice of a possible rule change only mentioned new regulations on vaping, food service, and medical pot. It also included a mention of amending and adding "definitions," but didn't offer any specifics.

What the state wound up doing was upending regulations that had been in place for seven years—a period in which some bar owners say they've poured thousands into their outdoor smoking spaces. As of January, a patio counts as enclosed if it's walled in on two sides and has a ceiling. Here's part of an informational flyer the state created:

Bar owners that have been forced to comply with the new rules say they're losing business while other, also-illegal patios are allowed to remain in business. Montalbano says the state gave insufficient warning about the powerful rules change, and so didn't get to hear from bar owners about how their business would be impacted.

"You have to provide notice to people who might be impacted," she says. "It has to be notice that might be sufficient to help them understand what’s going on."

The state, both in written documents and in officials' communications with the Mercury, has described the rules change as "clarifying" the definition of an enclosed space, when it actually materially changed that definition. That's another thing Montalbano takes issue with.

"I understand if there’s ambiguity and you need to clarify something," she says. "In this case they changed the definition of enclosure. It’s from three walls to two walls. That is almost architecturally impossible to do."

Bars are considering a number of options, Montalbano says. They might seek an injunction from a court to stop the rule from being enforced. They might also sue to have the rule overturned.

Either option would be costly, Montalbano concedes. If a suit is filed, shes says she'd hope the state would voluntarily suspend enforcement of the rule, and re-open it for public comment.

For its part, the OHA has stood behind the rule change. Karen Girard, manager of the agency’s Health Promotion and Chronic Disease Prevention Section, acknowledged to the Mercury that the public notification could have been better. But she says limiting exposure to second-hand smoke is in everyone's interest, and argues that the new regulations won't hurt businesses in the long run.

That last argument is based on the state's experience in 2009, when Oregon bars were forced to disallow indoor smoking across the board. Portland bar owners say this is different: The rule is being enforced on a complaint-driven basis, meaning some bars are losing smoking clientele while others aren't.

"It's a significant economic impact for many small businesses," Montalbano says.