The U.S. Environmental Protection Agency’s (EPA) lower ozone standard poses a challenge to Arizona based on the state’s unique geography, climate and mixed emissions sources, the Arizona Department of Environmental Quality (ADEQ) announced Oct. 2 in Phoenix.
The combination of strong sun, the fact that “air pollution does not recognize political boundaries” -- referring to the state’s proximity to California -- and limited reduction options in rural areas create a high hurdle for Arizona’s revised compliance goals.
Currently, ADEQ and its partners monitor ozone concentrations. According to EPA, most areas already see ozone levels below 70 parts per billion on most days. And industry-wise, the state is not a significant producer of internal combustion gases from vehicles.
However, nine out of Arizona’s 10 monitored counties report ozone concentration levels in excess of EPA’s new standard too frequently, with Navajo County being the sole jurisdiction consistently in compliance with the new standard.
“Implementation of this new, lower standard will be difficult in Arizona,” ADEQ Air Quality Division Director Eric Massey said. “Emissions and options to reduce them are few, particularly in rural areas like La Paz County.”
Arizona has one year in which to make a proposal to EPA whether to classify its monitored counties’ air quality as being in or out of attainment with the new, lower ozone standard.
Established in 1986, the Arizona Department of Environmental Quality is the state agency responsible for protecting and enhancing the state’s public health and environment.
ADEQ will engage in a stakeholder process and invite public participation in the recommendation process.