A valley air district proposal that could increase restrictions on residential wood burning in the San Joaquin Valley will not become official until at least 2016 or 2017, air district officials said Monday.

An article in Monday's Californian, based on an Associated Press report, was unclear on when the new restritions might take place.

The still-fluid proposal by the San Joaquin Valley Air Pollution Control District -- which governs emissions in the valley portions of Kern County -- could sharply increase the number of no-burn days for fireplaces and other wood-burning heaters and outdoor devices.

The new rules would double the no-burn days in many counties, with Kern's increasing from an average of 47 per season to 78, or nearly two-thirds of the 120 days the "Check Before You Burn" program is in effect from Nov. 1 through the end of February.

The restrictions do not apply to homes where wood burning is the only source of heat.

Jaime Holt, a spokeswoman for the air district, said Monday that her office received a flood of phone calls from residents up and down the valley who were concerned the rules would be "shoved down their throat" at a meeting of the district board Dec. 20.

But Holt was adamant that won't happen -- that it can't happen without proper public review.

"There is zero chance the wood burning rules will change Dec. 20," Holt said.

On the contrary, the official public workshops and comment period for any proposed rule changes will not begin before 2016, Holt said, and any new wood-burning rules would likely not be implemented until 2017. Even then, the final version may not look exactly like the proposal published last week in the district's "strategy evaluation" of its PM-2.5 particulate control plan.

The 216-page report addresses all kinds of stationary sources of PM-2.5, which is microscopic dust and soot particles smaller than 2.5 microns that harm sensitive lungs, aggravate asthma and are known to cause lung cancer.

The fireplace restrictions are just one part of a developing plan to bring the valley in line with federal clean air standards. The report also addresses incinerators, steam generators, stationary gas turbines and engines, cotton gins, commercial charbroiling and other pollution sources.

The valley "faces significant challenges in meeting the National Ambient Air Quality Standards," the air district states in the report.

Indeed, it's not uncommon for the district to exceed federal standards.

"Tough and innovative rules, such as those for ... residential fireplaces, glass manufacturing, and agricultural burning have set benchmarks for California and the nation," the report continues.

The air district, which covers an eight-county area from Kern in the south to San Joaquin County in the north, argues in the report that restricting wood burning "is the most cost-effective rule for reducing PM-2.5."

But the rule has met with resistance from some residents who use wood burning as a cheap supplement to their overall home heating -- or simply for the beauty, ambiance and tradition of a fire in the home hearth.

Although details may change before 2016, the recommendation as it now stands would lower the curtailment threshold from the current 30 micrograms of particulate matter per cubic meter of air to 20 micrograms per cubic meter. While significantly below the federal standard of 35 micrograms per cubic meter, establishing the curtailment threshold at this proposed level, the report argues, "will reduce the buildup of emissions during the long stagnation periods characteristic to the valley."

The district says it will consider allowing the use of cleaner Environmental Protection Agency-certified wood burning devices during these buildup periods.

Also in the report, there is discussion about expanding the restriction period to include October, March or both.

And if the EPA finds that the valley has failed to attain standards by 2019, a contingency plan could be enacted that would reduce the particulate threshold even lower to 15 micrograms per cubic meter. If that happened, fireplace restrictions in Kern County would nearly be a total prohibition, allowing use during just 20 days of the 120-day burning season.