The October whiplash is in full swing. The San Joaquin Valley’s dirty air suddenly made a comeback in the last 10 days, then just as quickly vanished in a storm Monday.
Just a few weeks ago, I had written that the Valley has a good shot at the lowest-ever recorded number of federal eight-hour ozone exceedances. With a rash of exceedances — eight since Oct. 19 — it’s going to be close.
The total now is 91. The record is 93.
South Coast Air Basin in Southern California has 94 exceedances right now. The region has had only one ozone November exceedance in the last five years.
It’s possible the Valley could wind up with more than South Coast this year. That would mean the Valley would have the most in the nation.
There’s another issue in the Valley. A reader points out high hourly readings for tiny particle pollution, wondering why the residential wood-burning ban doesn’t start in October. Right now, the rule kicks in Nov. 1 each year.
As I understand it, the tiny particle threshold — known as the standard for PM-2.5 — is an average over 24 hours. So hourly readings, by themselves, are not considered exceedances.
But the reader pointed out some pretty high hourly readings, saying October is known for these problems. It might be worth taking a longer look at this point.
Remember, wood-burning restrictions begin Friday. Check with the San Joaquin Valley Air Pollution Control District’s web site to see if wood-burning is allowed in your county before you light up.
I’m still thinking about ozone and the summer of 2013. I think the good news in California is also the bad news.
The good? Both the San Joaquin Valley and the South Coast Air Basin are poised to set all-time records for the least number of bad days — 86 in the Valley and 90 in South Coast, so far.
The bad? South Coast’s lowest-ever number of eight-hour ozone exceedances is still the worst in the country this year. The Valley’s lowest-ever is second worst. And third place is not even close to South Coast or the Valley.
Antelope Valley is third with 64 exceedances. Coachella Valley is fourth with 48. Houston is fifth with 20.
I checked the number of exceedances for the one-hour ozone standard, too. The Valley has not breached the standard this year, which would be a first if it holds up through the end of the warm season.
South Coast, which includes Los Angeles, Riverside, San Bernardino and Orange counties, had four exceedances of the one-hour standard. Houston had one. I found no others.
Fresno’s gritty skyline this September.
The San Joaquin Valley might not exceed the eight-hour federal ozone standard 100 times this year — not exactly a success story anywhere in the country except here or Southern California.
But it is news. It has only happened twice here, according to the records. In 2009, the count was 98. In 2010, it was an all-time low of 93.
The only problem is the weather can be cruel in late September. The last four days of September 2010 were triple-digit nightmares.
The heat continued sporadically that year. There were 10 exceedances after Oct. 1 in 2010 — two of them after Nov. 1.
Flash forward to this year. The total is 77 on Sept. 13. It was 74 on that day three years ago. So there’s a chance the total will be below 100 exceedances this year.
I usually add something about the target being zero exceedances. For now, I’d settle for a shutout for the rest of September, October and November.
Pop quiz: When the Valley’s air breached the federal ozone standard earlier this month, was it an exceedance or a violation?
In federal air-speak — a legal language invented over the past few decades — it was an exceedance, not a violation
Air quality was a concern during this Cross City Race several years ago.
I called it a violation, which I think is easier to understand when we’re speaking in general terms. I sparingly use the term exceedance when I’m explaining the law or its consequences.
But maybe it’s time to start using both exceedance and violation, and explaining the difference each time for clarity. What do you readers think?
So, let’s talk about difference. You need three exceedances at a monitor to get an official violation. You can see why people who know the difference are upset when I write that the Valley’s two March breaches — now I’ve invented my own air-speak — are violations.
In the legal world, it’s an important distinction. Exceedances are cause for concern. Violations can knock your community out of compliance with the standard. That can lead to penalties and expense for the community involved.
How does a community achieve the federal standard? A federal official emailed me this several years ago:
“A community will meet the eight-hour standard when the three-year average of the annual fourth highest daily maximum eight-hour ozone concentration measured at each monitoring site is less than 76 parts per billion (ppb).”
I’ve just been writing that we need zero violations. I’m pretty sure that would work — for both exceedances and violations.
Honestly, I’ve never been able to write a sentence about the “three-year average of the fourth annual highest daily maximum” and really make it sing.
But I am now seriously thinking of switching from my conversational use of “violations” to the combination of exceedances and violations. Maybe there is value in making the distinction each time I refer to it.
For those who are still awake after reading this, let me know what you think.