The valley's summertime air is dangerous at times 91 ozone violations and counting this year. And residents are paying a $29 million annual fine for failing to clean it up faster.
The best reasons to clean up the valley's air: The corrosive gas triggers asthma and other lung illnesses. Sometimes, it kills people before their time.
So, are you any better off than you were 10 years ago? Yes, say government watchdog agencies. Not really, say environmentalists, health advocates and community activist groups.
More than 40 percent of a key ozone-making gas, NOx, is gone. Also gone are terrible years such as 2002, when thousands of valley residents were affected by the terrible air.
Now, as this ozone season winds down, the air here still is not healthy.
Friday, the San Joaquin Valley Air Pollution Control District issued an unusual late-season alert for today through Wednesday, when temperatures are expected to climb into the low to mid-90s. To reduce emissions, people are advised to reduce driving or idling in their cars and use gas-powered lawn mowers early in the morning.
Fresno and Bakersfield continue to appear in the American Lung Association national rankings among the five cities most polluted by ozone. Merced is No. 10 on that list.
Unfortunately, the 25,000-square-mile San Joaquin Valley is a friend to ozone, more so than almost anywhere in the country.
The recipe for creating ozone reads like a valley profile: You need heat, sunlight, stagnant air, NOx (oxides of nitrogen) from cars and trucks, and pollutants coming from dairies, gasoline and other sources. And because the valley is a gigantic bowl, it often traps ozone for days.
The air quality in Modesto and Merced isn't as bad as in Fresno and other areas farther south because conditions get worse deeper into the valley, said Seyed Sadredin, executive director of the air district.
This year, Sadredin said, there were 33 violations of the eight-hour ozone standards in Stanislaus County, compared with 40 recorded a decade earlier. And the number of unhealthy air days in the county during the same period as defined by the Environmental Protection Agency dropped from five in 2002 to two in 2012, he said.
Despite the improvements, Sadredin said, people and businesses must do everything they can to comply with air quality rules not only for their good, but the good of their neighbors to the south.
The valley has a long way to go, said Kerry Drake, associate director of the U.S. Environmental Protection Agency's air division in San Francisco.
Still, he sees hope for meeting the cleanup deadline of late 2023 for the eight-hour ozone standard an average of ozone readings over eight-hour periods.
"I know it seems hard to believe that we could make it," he said. "But technology, pollution reduction and public awareness have come so far in the last 10 years. It is definitely better now in the valley."
The air district has passed many of the toughest rules in the nation, among them the pioneering control of pollution coming from agriculture, Sadredin said.
"Despite significant reductions in emissions and even with the toughest air regulations, our challenges are tougher than any other region in the nation," he said.
Activists agree about the challenge, but they say the groundbreaking rules for agriculture and other pollution sources were forced by environmental lawsuits.
Even so, the district wrote rules that are not so tough, said Kevin Hall, executive director of the Central Valley Air Quality Coalition, representing dozens of groups.
For instance, activists five years ago suggested banning the use of old, polluting trucks, cars, boats and commercial equipment on the smoggiest summer days. The district rejected the idea, saying it would be too harsh on business.
"There are too many times when the district board says we can't get something done," Hall said. "We need leadership that says it can be done."
There is also friction between the district and the federal government over the $29 million annual ozone fine, most of which is paid by registered vehicle owners.
The fine was triggered when the valley missed the 2010 cleanup deadline for the federal one-hour ozone standard.
Although the standard was abolished seven years ago, federal law still requires attainment. Sadredin said more than 90 percent of one-hour violations have been eliminated.
"We think it's unreasonable to make the valley pay $29 million for a few hours of readings over the standard," Sadredin said.