But other pollutant controls may keep most of Arizona in compliance.
The closure was extended until next Sept. 30 or until rescinded.
Coronado National Forest will start work next month to clean up at least 300 tons of lead-contaminated soil from three recreational target-shooting sites in Redington Pass northeast of Tucson.
Pima County’s air quality has reached unhealthful levels, thanks to high winds and blowing dust.
An Asarco mining operation has agreed to pay a $60,000 fine and take preventive steps valued at $50,000 to resolve water-quality violations caused by a June 2010 pipeline spill at the Silver Bell Copper Mine near Marana, state regulators said Tuesday.
WASHINGTON - In its first major regulation since the election, the Obama administration on Friday imposed a new air quality standard that reduces by 20 percent the maximum amount of soot released into the air from smokestacks, diesel trucks and other sources of pollution.
LOS ANGELES — In a finding that points to a link between environmental toxins and autism, a new study shows that children who were exposed to the highest levels of traffic-related air pollution during gestation and in early infancy were three times more likely to be diagnosed with the neurod…
PHOENIX - State officials want to force a federal agency to stop dumping sewage loaded with heavy metals into the Santa Cruz River.
Arizona Public Service said it may be forced to close down one of the units at its Cholla power plant near Holbrook if the EPA rules go into effect.
PHOENIX - State officials and utilities are trying to kill a plan by the U.S. Environmental Protection Agency to force owners of three coal-fired power plants to install expensive pollution-control equipment to improve visibility.
Another air quality advisory was issued today by the Pima County Department of Environmental Quality because of the elevated levels of smoke and ground-level ozone.
The state Senate easily approved a bill Tuesday that would allow companies to keep secret environmental audits they conduct of their operations.
The opening question at Thursday's Congressional District 8 GOP debate was a hard-hitter: If you were born an animal, what would you be?