APCD skews report on Nipomo Mesa air quality

April 4, 2013
Larry Allen

Larry Allen


A member of the San Luis Obispo County Air Pollution Control District Board discovered last week that district staff used incomplete data sets to compile a report which inaccurately portrays escalating pollution levels on the Nipomo Mesa.

Prior to the March 27 presentation of the APCD report on county air quality trends for the years 1991 through 2011, board member and Pismo Beach Councilman Ed Waage told district staff that they used an incomplete set of data in their analysis. In a response to the initial report, Waage showed that the incomplete data set skewed the conclusion of the study such that levels of particulate matter, or solid particles smaller than a human hair in diameter, on the Nipomo Mesa appeared worse than they would have if the report included all the data available.

The APCD is currently battling the California Department of Parks and Recreation over the implementation of a set of fees it plans to impose on the Oceano Dunes State Vehicular Recreation Area based upon the conclusion of a previous study that off-road activity at the dunes is causing particulate matter pollution on the Nipomo Mesa. The APCD regulation, known as the “dust rule,” is the subject of three current lawsuits.

The March 2013 report, authored by Air Quality Specialist Karl Tupper, concluded that, over the years 1991 through 2011, particulate matter pollution improved throughout the county, but worsened on the Nipomo Mesa. But, the Nipomo Mesa study used a season in which particulate matter levels are low as a starting point and compared it to full years of pollution data that followed.

Instead of beginning the study with data from January 1991, Tupper used October 1995 as a starting point. Particulate matter pollution on the mesa varies by season, with spring generating the highest levels. In 1995, levels of PM10, particulate matter 10 microns or less in diameter, only exceeded state limits in the months of January through September. Since Tupper only used data from the final three months of 1995, he reported that PM10 levels never exceeded state limits that year. However, data from a July 2005 APCD report showed that 4 percent of PM10 samples taken on the Nipomo Mesa in 1995 exceeded state standards.

1995 was the only year in Tupper’s report in which particulate matter never exceeded state standards. Between 1996 and 2011, the percentage of samples that exceeded state standards each year ranged from 5 percent to 14 percent. Including the incomplete set of samples from 1995, the overall data from the mesa particulate matter samples for the years 1995 through 2011 produced “a statistically significant upward trend,” meaning the report faultily concluded air quality is worsening on the mesa.

In advance of the March 27 meeting where Tupper presented the report, Waage produced his own graph that included the pre-October 1995 data that the APCD omitted. He included complete data for the years 1990 through 2011, excluding 2005, for which the district only had a partial year’s worth of samples. Waage’s graph produced a slight downward trend in particulate matter, and the Pismo Beach councilman concluded that air quality on the mesa is neither improving, nor worsening in notable manner.

“I do not believe PM 10 levels are declining,” Waage said. “There is too much uncertainty to tell. But, by the same token, there is not enough evidence to make any summary conclusion about what is happening as the staff report originally stated.”

Air Pollution Control Officer Larry Allen said the air district did not include the pre-October 1995 data in its report because the data did not appear in the Environmental Protection Agency database that the APCD uses.

“We pulled data from the EPA federal air quality database,” Allen said. “We made a decision to only use federal data.”

The data Waage used to complete his graph came from a July 2005 APCD particulate matter report. In 2005, APCD staff gathered that data from California Air Resources Board statistics. Allen told Waage in an email that CARB often posts data on its website without validating it. He did not, however, explain why district staff used the CARB statistics in its own July 2005 particulate matter report.

Prior to the March 27 board meeting, APCD staff issued a revised version of the Tupper report stating that the data it used from 1995 was incomplete. The updated report included descriptions of two new graphs, one of which removed all data from 1995 and the other eliminated all data from both 1995 and 2005. Still, staff only used the EPA statistics and concluded that air quality is worsening at the mesa, although not in a very significant manner.

While Waage disputed the revised conclusion, he said at the board meeting that his acknowledgement of the incomplete data set for 1995 at least led to an improvement upon the initial report.

“If I hadn’t raised that point, this report would continue to state that this was a significant particulate matter increase on the mesa,” Waage said.


Audio record disappears

In the days following the meeting, members of the board and public noticed that the archived audio of the board discussion on the air quality trends report did not exist.

The APCD provides live and archived audio and video feed of all of its meetings. Archived video of the March 27 meeting is available in entirety on the district website, but the audio cuts out just prior to beginning of the discussion on the particulate matter report. The archived audio only version also cuts out at the same moment.

Just prior to Tupper’s presentation of his report, Allen requested that the board take a break in the meeting. When the meeting reconvened, the audio feed cut off.

In an email to the members of the board, Allen said a mishap involving the livestream platform used by the APCD caused the loss of audio.

“The audio problem was caused by the unmute button for the microphones not activating properly after the board returned from the break – either because the button didn’t respond or Kim, our board clerk, could have pushed the wrong button,” Allen wrote.

Allen said district staff would monitor the online feed of future meetings and alert the board if an issue arises. The air district chief also said that he took notes on the discussion of the trends report, and that he would submit them into the minutes, along with the notes taken by the board clerk and the other staff members present.

But, critics say the disappearance of the audio feed removes from the permanent record critiques of an air quality report that held political significance.

The APCD currently faces a lawsuit filed by California Attorney General Kamala Harris on behalf of state parks alleging that the district used a scientifically flawed study to pass its Oceano Dunes dust rule. The dust rule levies fines of $1,000 per day on the Oceano Dunes State Vehicular Recreation Area if it does not reduce particulate matter blowing toward the Nipomo Mesa. The district is also awaiting judgments on suits filed by Friends of the Dunes and Kevin Rice and is simultaneously battling state parks to implement the dust rule.

Still, Allen said politics did not factor into the Tupper report concluding that particulate pollution is getting worse on the mesa.

“It’s not a political report,” Allen said.


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Do you know what sits squarely between the Oceano Dunes and the APCD monitoring station? A big old frickin refinery. Nobody ever questions what comes out of those stacks at night but I have seen them belching tons of stuff into the air late at night. Granted most of it is supposedly steam but is anybody checking on that? I’d be interested in knowing if they are contributing anything to this so called problem. If so why isn’t APCD looking into that?

APCD needs to be shut down.

The fact that we actually have an ‘air quality’ group s a joke…. who are they trying to fool?

From my perspective, this little group grows and grows and continues to try to justify their existence… often with apparently less than accurate statements.

The county can solve this problem… but they have to want to.