San Joaquin Valley Air Basin 2016 vs. ’15 ozone update

Ozone exceedances in the San Joaquin Valley in California’s interior, preliminarily speaking, in 2016 numbered 88. This is six exceedances more than the year before. 2015’s numbers are preliminary also.

The ozone season in the Valley roughly lasts from March through October.

So, why the increase? Keep in mind that a big part of the Valley’s ozone problem is on account of emissions released from mobile sources. Driving all over California is up and that includes in the San Joaquin Valley.

But, the weather can be a factor, too. If there are more days when air stagnates and hence leads to smog formation, then the opportunity for ozone to stay present in the air, is greater.

Smog in the air forms in the presence of sunlight, heat and from the mixing of smog-forming emissions such as oxides of nitrogen (NOx), hydrocarbons (HC) and Volatile Organic Compounds (VOC) – reactive gases, in other words, which could be from solvents, paints, etc. Regardless of source (mobile or stationary) responsible for releasing smog-contributing elements or gases into the air, they, each and every source, factor in smog’s creation.

The scourge that ozone is can cause lung irritation, trigger asthma attacks and lead to other lung and respiratory-related conditions and ailments.

Meanwhile, anytime the Air Quality Index reaches above 100, the air is considered to be in the unhealthy category. An AQI of 101 corresponds to ozone in the atmosphere at a level of 76 parts per billion (ppb) of air.

The Valley is required to meet the newest standard – 70 ppb – by 2037. The real question then is: will the Valley be able to meet this? Several very important factors to consider: population growth, implementation – presumably – of California’s high-speed rail system, greenhouse gas emissions mitigation measures statewide, possible continuation of global temperature rise, a possible continued increase of CO2 emissions concentration and transboundary drift, to name several.

Sprawl development also has an impact and it’s huge!

With each new housing subdivision that goes in Valleywide, this means additional miles vehicles travel. More miles traveled mean more pollution. Statewide, vehicles comprising either near-zero or zero-emissions types make up roughly 3.5 percent of all vehicles on the road. The number of registered vehicles on the roads in the Valley is roughly about half the population or about 2 million. Registered vehicles in California number about 31 to 32 million. California’s population is now 39 million. So, using a conservative 31 million registered motor vehicles, this translates to 1.33 people per vehicle, while in the Valley, there is a vehicle for every 2 people on average.

To this add that each year Californians drive in excess of 300 billion miles.

Furthermore, for the first three quarters of 2016 driving in the U.S. is up over the same three quarters last year. If the amount of time behind the wheel is going up, this means as well, presumably, that emissions from driving are rising too.

Without significant advances in technology, more work-related telecommuting, greater use of public transportation, improved farming methods, further reduction in waste, increased energy production using renewable sources, added green building projects, and implementation of programs and practices designed to save energy, reduce waste and pollute less, then one can and should expect one absolute: even more exceedance days of ozone in the Valley. That’s the reality.

The numbers bear this out.

California’s expansive and agriculturally fertile yet often air-polluted San Joaquin Valley

This post was last revised on Nov. 21, 2020 @ 5:12 p.m. Pacific Standard Time.

Published by Alan Kandel