San Joaquin Valley air quality improvement reflected in annual report

The San Joaquin Valley Air Pollution Control District (District) has rolled out its “Annual Report to the Community 2013-14 Edition” (Report).

From the Report on page 3, there is this: “For the first time in recorded history, the San Joaquin Valley in 2013 had zero violations of the hourly ozone standard established under the federal Clean Air Act, down from 281 violations in 1996. In 2004, EPA [U.S. Environmental Protection Agency] classified the Valley as ‘Extreme’ non-attainment for this standard, meaning that reaching the standard, at that time, was deemed impossible. San Joaquin Valley is the first and only region in the nation with ‘Extreme’ classification to attain the standard.”

As encouraging as this news appears, there is more to this than that which is presented above.

For example, “The District’s request for an attainment finding by EPA will include extensive technical support information. Special issues such as transboundary ozone from Asia, the District’s ozone saturation study to address the Arvin monitoring station relocation, and an exceptional event whereby the Valley experienced an exceedance of the 1-hour ozone standard due to a large industrial fire and wildfires will also be addressed,” the District added.

What all this tells me is that the San Joaquin Valley has only “unofficially” attained the standard meaning the extra $12 added to my yearly vehicle registration fee I pay as a result of Valley 1-hour standard ozone non-attainment, will remain in effect, that is, until such time it is “officially” declared said standard attainment has been realized. In all, Valley motorists are responsible for coughing up $25 million yearly all due to non-attainment of the standard.

For more perspective on this, see: “No end in sight to Valley, fed old ozone standard fight.”

Okay, that’s just regarding the 1-hour standard. What about the 8-hour national ozone health standard? How is the Valley faring in this regard?

In this case there are two different standards to consider: the 1997 standard of 84 parts per billion of ozone and the 2008 standard of 75 parts per billion of ozone, the latter of course being the more healthful or more stringent of the two standards.

According to Report data, the Valley had about 400 what are called “County Days” exceeding the 1997 federal 8-hour ozone standard in 2002 and dropped to approximately 240 such exceedances in year 2008. Hence, there has been improvement.

As it has to do with the 2008 federal 8-hour ozone standard, that year in the Valley there were around 425 such exceedances, decreasing to right around 275 “County Days” exceedances in 2013.

In both cases, the decline has not been linear. Between 2002 and 2013, regarding “County Days” exceedances in ozone pertaining to both the 1997 and 2008 standards for the Valley, it’s been an up-and-down trend. For more on this, see “Ozone Trends” on page 7 of the Report.

Ozone is one thing. Now keep in mind that the problematic pollutant of note during winter is fine particulate matter (PM 2.5). Wood-smoke from fireplaces and woodstoves and farming activities are two primary PM 2.5 sources. Other inputs according to the Air District include road and fugitive wind-blown dust, heavy-duty diesel truck and other mobile source exhaust, smoke from the burning of agricultural waste as well as that produced from other stationary sources. For more, see: “Sources of Pollution” in the Report on page 43. Other pollutants and their listed sources are Volatile Organic Compounds (VOC) and Nitrogen Oxides (NOx).

On particulate matter, the “PM2.5 Trends” to pay particularly close attention to in my view are: “Annual PM2.5 Design Value Trend” and the “County Days over Federal 24-hr PM2.5 Standard (Nov – Feb).”

Regarding the former, between 2002 and 2013, the overall trend is negative. In 2002, the “Annual PM2.5 Design Value Trend” reading was roughly 23 micrograms per cubic meter of air. This declined to approximately 19 micrograms per cubic meter in 2005 and then remained that way again in 2006 before peaking at about 22.5 micrograms per cubic meter in 2009 before falling to roughly 16 micrograms per cubic meter in 2012. However, due to meteorological factors in 2013 (read: “many, many days where the air was stagnant”) apparently, the “Annual PM2.5 Design Value Trend” reading for that year was just above 18 micrograms per cubic meter. Not at one time between 2002 and 2013 did the readings drop below the 1997 PM 2.5 standard of 15 micrograms per cubic meter of air. The standard for 2013 is even more stringent: 12 micrograms per cubic meter of air.

Meanwhile, for the “County Days over Federal 24-hr PM2.5 Standard (Nov – Feb),” in 2002-2003, there were almost 50 days where that standard was exceeded while in 2005-2006, there were easily over 60 days where the 1997 standard of 65 micrograms per cubic meter of air was breached, and this is between the months of November and February only (Nov. 1 to Feb. 28). With a more stringent standard of 35 micrograms per cubic meter of air in effect in 2006, the up-and-down story was repeated. In 2006-2007, the number of “County Days over Federal 24-hr PM2.5 Standard (Nov – Feb)” was roughly 340. This dropped to around 155 in 2010-2011, rising to just above 250 in 2011-2012 and then sharply retreated to about 140 such days in 2012-2013. For more on this, see: “PM2.5 Trends” in the Report on page 8.


– Alan Kandel