Dirty air caught up with the San Joaquin Valley on the last day of summer, triggering an ozone violation costing $29 million.
Motorists already were on the hook for a $12 vehicle registration fee to cover a $29 million ozone penalty next year. Now they're stuck with the same penalty in 2013.
The region had narrowly avoided the key violation for weeks. But on Thursday the Valley's prevailing northwest breeze died in the afternoon, allowing ozone to spike between 4 p.m. and 5 p.m. in Clovis, said the San Joaquin Valley Air Pollution Control District.
It pushed Clovis over the federal limit for one-hour ozone violations in a three-year period. In 2010, Clovis had three similar violations for one-hour readings – which are the highest daily readings at each monitor.
The sweltering heat and ozone spikes should begin to slowly fade over the next few days. The National Weather Service in Hanford predicts temperatures may drop below 90 degrees by Sunday.
All week long, the district has been using social media, radio and television alerts to encourage people to cut down on driving. The alerts ended Friday, but people shouldn't assume the problem has passed, officials said.
"We don't want another violation because it could help make the $29 million penalty continue beyond 2013," said district executive director Seyed Sadredin. "We want people to continue cutting back on pollution-making activities."
The ozone assault on Thursday also caused Fresno's second one-hour violation of the summer. If there are two more violations at that monitor in southeast Fresno over the next two years, the $29 million penalty will extend to 2014.
The U.S. Clean Air Act says the annual fine is extended if there are more than three violations at any monitor over a three-year period – 2011 through 2013, in this case. If the Valley gets through the warm seasons during that three-year span without four violations at any monitoring site, the fine will end.
Ozone is an invisible, corrosive gas that forms in sunlight and warm weather. It can trigger asthma and other lung ailments.
Air officials noted the Valley just completed its cleanest summer ever for the one-hour ozone standard, which they said is a sign of progress. But the region is among the worst in the country for the more protective eight-hour ozone standard, which reports readings averaged over eight hours.