Earth Log

We drive 110 million miles a day in Valley? Really?

Folks in the San Joaquin Valley drive nearly 110 million miles per day -- like circling the globe at the equator 2,700 times each day.

The thought makes me a little dizzy, and I have no idea how the mathematical model works for that estimate. But, trust me, it's an estimate. Nobody is counting these miles.

The number comes from the state Air Resources Board's 2013 Almanac of Emissions and Air Quality, the latest one available. The almanac tells us the air pollution trends around California. 

So with that many miles being driven, what's the trend in the Valley? The air is improving even as the population expands and drives more miles, thanks to cleaner vehicles, advanced rules and billions of dollars invested in clean-air technology. 

But don't be lulled. We're years away from achieving federal eight-hour ozone standards.

A lot of the problem is connected to vehicles -- diesel trucks, buses and cars. Vehicles put out the majority of nitrogen oxides, a key ozone-forming gas. So the state's almanac always mentions miles driven and population growth. 

Valley air leaders are aiming at 2023 to comply with the eight-hour ozone standard. The standard was set in 1997 at 84 parts per billion averaged over eight hours

A newer, tougher standard was set in 2008 at 75 parts per billion. It's just a few parts per billion lower, but making the 2032 deadline for this standard looks nearly impossible, even with 18 years to reach it.

Things do change, though.

It looked pretty impossible to make the old one-hour ozone standard in the 1990s. Yet it might have happened last year.

The Environmental Protection Agency is still studying the numbers to see if this region is now in compliance with the old standard.

The bottom line? The Valley's air is cleaner than it was 10 years ago, but it is not healthy.

People still need to reduce driving, keep the children indoors during ozone spikes and pay attention to the real-time air monitoring online from the San Joaquin Valley Air Pollution Control District.

And if you get a minute, check out that almanac.