RENO, Nev. - The Environmental Protection Agency raised new concerns about Reno's air quality Wednesday, proposing Washoe County's health rating for airborne dust be pushed from moderate to serious.
The EPA cited violations of federal dust standards in Reno and Washoe County last winter primarily as a result of excessive sand and dust left behind by road sanders and snow plows, which the wind whipped into the air before street sweepers could get to it.
The EPA noted Reno has had trouble with airborne dust in the past, violating federal air quality standards from 1992-94.
The shift from ''moderate'' to ''serious'' non-attainment of the standards would require Washoe County to adopt more stringent anti-pollution measures.
Washoe County officials said they expected the EPA's move and already are trying to find ways to pay for more expensive street sweepers and operate them more often.
They don't think the pollution has anything to do with wood-burning smoke, which caused high levels of small particulates in the past.
''We know that our violations are not coming from wood combustion,'' said Andrew Goodrich, director of Washoe County's Air Quality Management Division.
''We have to look at stricter regulations that target the sources of the pollution,'' he said, including guidelines for road-sanding procedures that don't grind down the material into such a fine mix.
The agency proposed the action for Washoe County in response to a lawsuit filed by an environmental group, EarthJustice, accusing the EPA of failing over the years to reclassify areas that have not met clean air standards.
''This problem is recurring in Reno. It's not just a one-time problem that occurred in 1994 and is gone,'' said Bill Curtiss, program manager for EarthJustice in San Francisco.
Failure to respond to the EPA's call for a new management plan could ultimately result in penalties ranging from tighter restrictions on emissions from new development to reduction in federal highway funds.
But EPA officials said neither is likely in Reno because county officials already are working to reduce dust.
''It sounds like they already have a plan to address this, which is a good thing,'' said Doris Lo, an environmental engineer in the EPA's Region 9 air planning office in San Francisco.
Goodrich said winter road dust caused pollution to reach an unhealthy level at two county air monitors last winter.
''We had measured violations of the federal standard for particulate matter and expected EPA to respond accordingly,'' he said.
''Washoe County has made huge strides in cleaning up our air, but according to federal law, we are trapped into this new designation, which will require us to look into some new regulations changes,'' he said.
The county mandated several years ago that road sand be used instead of a mix of soil and sand. But Goodrich said the sand often isn't swept up for several days, sometimes weeks.
''Everytime we have a snow storm, the streets become dirt roads after the snow melts,'' he said in a statement. ''This is truly unacceptable. There are other ways to control slippery streets.''
The latest air quality standards have been in place under the Clean Air Act since 1994. Reno-Washoe County was in violation of those standards when they went into effect in 1994. The area's air quality showed improvement from 1995-98 before the violations occurred last year, the EPA said.
If the new rating is adopted, the county would have to go three years without any violations before the EPA would reclassify the area again as attaining the standard.
Lo said other places, such as Southern California and Phoenix, suffer from a variety of problems that contribute to poor air quality.
''Their problems are much more complicated,'' she said. ''It sounds like this (in Reno) is a very primary-type problem directly coming from the roads.''