Freeway-planning group raises air-quality questions

Corinne Purtill
The Arizona Republic
Feb. 25, 2006 12:00 AM

When it comes to clean air, some involved in planning the South Mountain Freeway are starting to question whether meeting the minimum standards is still good enough.

At Thursday's meeting of the South Mountain Citizens Advisory Team, state and regional engineers said no data so far indicate that the proposed Phoenix bypass would push the area over acceptable limits for the most-harmful air pollutants.

But citing concern for schools close to the proposed 22- to 26-mile route, and the thickening brown cloud hanging over their homes, some in the volunteer citizens group wondered whether Arizona should use this project to set a new and better standard.

The air-quality worries come amid the Valley's worst air-pollution season in years, with record drought and multiple days in violation of federal pollution standards.

The freeway would complete Loop 202 and connect Interstate 10 in the west and east, circumventing central Phoenix. Building could begin as early as 2009.

According to the Arizona Department of Transportation and the Maricopa Association of Governments, the Valley will continue to meet federal standards on carbon monoxide, ozone and particulates 10 microns or less in size even if the South Mountain Freeway is built.

By the South Mountain Freeway's scheduled completion in 2015, there will be 134.1 million vehicle miles traveled per day in the Valley. However, emission-reduction technologies are improving faster than new cars are getting on the road, said Lindy Bauer, MAG's environmental director.

However, MAG is not required by the Environmental Protection Agency to plan for particulates of 2.5 microns or less in size, also known as PM 2.5.

Most particulates that come out of car tailpipes are PM 2.5, meaning they are small enough to travel into the lungs and the bloodstream when inhaled, said Cathy Arthur, MAG's air-quality modeling program manager.

A 1999 MAG study also revealed that most of the Valley's infamous brown cloud is composed of PM 2.5.

The proximity of several schools to the proposed freeway route, and the attending vehicle emissions, has several on the advisory team worried.

"It's a deadly issue," said John Rodriguez, a representative from Ahwatukee Foothills. "They need to bring in medical experts."

Some pointed to a June 2005 settlement between the Sierra Club and the Federal Highway Administration in which the government agreed to install air filters and relocate some classrooms and a playground to lessen children's exposure to emissions from a Las Vegas freeway.

Federal highway officials said then and now that the ruling does not set a precedent. However, federal officials in Phoenix said Thursday they will bring in experts to discuss new findings on pollutants.

Reach the reporter at corinne .purtill@arizonarepublic.com or (602) 444-7801.