On May 17, 2012, the only area in the Central Valley to record a violation of the 8-hour ozone standard was the foothill region represented by an air monitor that used to be called “Ash Mountain”. This monitor is run by Kings Canyon National Park and is located next to the community of Three Rivers, just inside the park entrance and a short distance below the park headquarters. The elevation is approximately 1700 feet. The Sierras quickly climb towards the east in this area to over 10,000 feet.
Several foothill communities similar to Three Rivers dot the east side of the Central Valley. Thousands of people live in these communities. The Ash Mountain monitor basically measures the pollution produced near cities like Fresno, Visalia, and Bakersfield. This pollution is pushed to the east by prevailing winds and up into the hills where it sits during the atmospheric inversion episodes common to San Joaquin Valley summers.
This drawing illustrates the position of the Ash Mountain monitor relative to the flat valley floor and the surrounding mountains.So why is the violation on May 17 so infuriating to the Air Board? Because last year there were approximately 15 solo violations at Ash Mountain that added to the 109 violations attributed to the Central Valley. The Air Board is charged with protecting the public from the health damaging air pollution represented by these violations. The Air Board has attempted to discount these Ash Mountain violations by saying they did not occur on the valley floor where most of the population lives. They claim they will no longer add these violations at this monitor to the total for the valley when making reports and analyzing trends in air pollution. They even had the name of the monitor changed to read “Sequoia and Kings Canyon National Park” and they describe this monitor as being “high in elevation”.
The reality is this monitor is far closer to the valley floor than it is to the high ridges of the Sierras. The reality is the pollution at Ash Mountain is representative of the pollution on the valley floor and not representative of forest fires in the Kern Canyon as the Air Board claimed in a blatant lie last fall.
Since the Air Board removed the Bear Mountain monitor near Arvin at the end of 2010, the Ash Mountain monitor has become the place with the highest number of violations per year. Bear Mountain actually had 150 more violations than Ash Mountain over the ten years from 2001 thru 2010. Ash Mountain now has more solo violations than in the past because of the removal of the Bear Mountain monitor.
This monitor is bad news for the Air Board because it shows how poorly they are doing in protecting the health of the breathing public. Unfortunately, saying violations there no longer count does not make the air in people’s lungs any cleaner.