They know when summer ozone levels are spiking in Arvin or wintertime particulate pollution is off the charts in Bakersfield.
And vice versa.
But they've never had a tool to help understand whether the air in their neighborhood is cleaner or dirtier -- at any given time, day or night -- than the air quality in other parts of town. Or even a few blocks away.
But all that may be about to change.
By the end of this year, residents of the valley, from Mettler to Manteca, Taft to Turlock, will be able to check real-time air quality levels for their neighborhoods just by entering an address online.
"We're trying to put together something for valley residents that has never been tried or done by anyone else in the nation," said Seyed Sadredin, the executive director of the eight-county San Joaquin Valley Air Pollution Control District.
The air district is developing a website called the Web-Based Archived Air Quality System, or WAAQS, which initially will allow residents to examine historical air quality information for their neighborhood, and compare different years and different parts of a city, county or region.
Once launched, the website will allow residents access to a variety of statistics, including the number of days with good air quality, the number of days with unhealthy air quality, days over federal standards for ozone and particulate pollution -- known as PM2.5 -- and neighborhood air quality compared to trends for the county and the San Joaquin Valley.
A beta version of the website containing historical data is expected to be made available to the public on March 1, Sadredin said. Comments and recommendations will be collected to better help the air district improve the information provided on this site.
The real-time data, which is more difficult and complex, is expected to be online by the end of the year.
But how, with a limited number of air monitors dotted up and down the valley, can the district provide air quality information in specific neighborhoods?
Last year, the air district developed a computer modeling technique to quantify neighborhood ozone and PM2.5 concentrations. The data generated from the new model will serve as a foundation for the project.
"We're trying to use science and technology to simulate having an air monitor in every neighborhood," Sadredin said.
A single air monitor costs between $200,000 and $500,000 to install, and about $65,000 per year to operate and maintain, Sadredin said. The valley has 37 monitors operated by various agencies, with nine in the valley portion of Kern County. Installing hundreds or even thousands of monitors would be cost-prohibitive and logistically impossible.
Instead, air district engineers and technologists divided the valley's 25,000 square miles into 3,600 grids, each one 4 kilometers by 4 kilometers. Four kilometers is about 2 1/2 miles.
By doing an "emissions inventory" in each grid, the developers of the algorithm and modeling techniques can take into consideration topography, weather conditions, including temperature, air movement, height of the inversion layer, and other data to establish a strong estimate of pollutant levels in any given grid.
When residents see a colored flag flying over a school in Bakersfield, the air district errs on the side of caution by using the worst reading in the area. But in reality, Sadredin said, one part of town might have slightly better air quality than another.
The air district covers a vast geographical area, Sadredin said, and its governing board felt providing the worst-case air quality measurements may not accurately reflect the actual conditions of certain neighborhoods.
This effort is an attempt to provide residents with more accurate information about the air they breathe.
©2015 The Bakersfield Californian (Bakersfield, Calif.) Distributed by Tribune Content Agency, LLC
