2010 March 31: AZ Maricopa County: targets unhealthy dust (wood-burning stoves included) in Northwest Valley air
18 commentsby Cecilia Chan – Apr. 1, 2010 11:18 AM
The Arizona Republic
Reducing unhealthy dust in Maricopa County’s polluted air is the goal of a policy that is in the works.
The county Air Quality Department staff recently presented the draft, which would affect small- to medium-size stationary sources that emit particulate pollutants no larger than 10 microns in diameter, smaller than the tip of a needle.
Windblown dust from industry, construction sites, wood-burning stoves and vehicles driving on unpaved roads contribute to high emissions of dust particles, called PM10.
The sand-and-gravel industry opposed the policy during a workshop in Phoenix, while some in attendance said it doesn’t go far enough.
Complaints have been filed in Surprise and elsewhere in the Northwest Valley about air quality in the region. Industry representatives said there is no scientific basis to claims that their companies contribute to respiratory problems.
The guidelines propose that applicants for new and modified permits conduct an impact analysis of dust emissions on air quality. If the emission is equal to or exceeds a significant impact level then a cumulative analysis kicks in.
The emissions from the project in question and any nearby, off-site sources would be looked at collectively. The county does not expect many applicants to trigger a cumulative analysis.
The policy "will give us the authority to deny permits," said Doug Erwin, county Permit Division manager. "If an applicant can’t show it won’t have an adverse affect, we will deny."
Erwin said the policy could take effect before the end of the fiscal year on July 1.
Maricopa County exceeds the federal standard for such dust emissions and risks losing millions in federal transportation funding. The policy is part of a county "five percent plan" submitted to the Environmental Protection Agency for approval.
It outlines how particulate pollution will be reduced by 5 percent each year in the Valley until the standard is met. The emissions can cause adverse health effects, including respiratory infections, when the particulates are inhaled into the lungs.
Northwest Valley concerns
Although the proposed policy would be countywide and not target one particular source, Northwest Valley residents directed their focus on the concentration of sand-and-gravel companies mining the Agua Fria River bed, where more than 20 operators mine in an eight-mile stretch.
While any individual mine may put out a safe level of emissions, residents say the clusters of mines emit a cumulative level that is unhealthy.
Resident Skip Knolle said Coyote Lakes in Surprise is surrounded on three sides by mining operations. He wanted to know if the plants clustered along the riverbed were operating in compliance. He called for a moratorium on the county issuing new permits until the policy takes effect.
Sun City West resident Shirley McDonald, who chairs the Joint Environmental Task Force, opposes the policy because she said it should include more pollutants than just PM10.
Debate over dust
The policy’s concepts and much of its substance could be extended to other pollutants in the future, according to Maricopa County officials.
County resident Richard Wehbe said the policy doesn’t take into consideration such emissions from portable permits and from diesel fumes in trucks ferrying material out of the mines.
"This policy must be based on science and not assumptions," said Steve Trussell, spokesman for Arizona Rock Products Association, a lobby group for the mining industry. "We are absolutely opposed to it because of what it will unintentionally create."
Trussell said if the county is trying to reduce certain dust emissions that it should look at unpaved roads, which are larger contributors of particulate dust.
Trussell said sand-and-gravel operations mine where the material is. Proximity to the consumer means cost savings and reduction in diesel emissions, he said.
"If we use this to solve one problem it may cause unintentional consequences in other things we might not have taken into consideration," Trussell said.
Sun City West resident Gene Zulk called the policy "past due."
"We have people from our community who will support you 100 percent," Zulk told county staff. "We are here to support anything you can do to protect us."