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Learn about the Air District’s special purpose air quality monitoring project in Cupertino, California.
Cupertino residents were concerned that the Lehigh Cement Plant and its diesel truck traffic could be affecting the air quality in nearby neighborhoods. The Air District monitored air quality in Cupertino from September 2010 to December 2013 to determine whether residents were exposed to high pollution levels that may not reach other Bay Area monitoring stations.
The Cupertino air monitoring station was located at Monta Vista Park, about one mile east of the Lehigh Cement Plant. Pollutants continuously measured included ozone, sulfur dioxide, particulate matter, nitrogen oxides, nitrogen dioxide, hydrocarbons, and carbon monoxide. Every sixth day, 24-hr samples of ambient air were collected and analyzed for toxic gases and metals.
After collecting three years of air quality data at the Cupertino site, the Air District reviewed the data and developed a Summary and Analysis of Cupertino Air Monitoring Results (PDF).
Cupertino residents had been concerned that the Lehigh Cement Plant and its associated diesel truck traffic could have significant air quality impacts on nearby neighborhoods. Consequently, the study measures pollutants in ambient air specific to those emissions from Lehigh and its associated truck traffic.
After collecting an entire year of data from September 2010 through August of 2011, Air District staff reviewed the data and developeda Summary and Analysis of Cupertino Monitoring Results – Revised Including 2012 Data(835 Kb PDF, 11 pgs, revised 11/20/14).
The Air District’s Cupertino air monitoring equipment is housed in a trailer at Monte Vista Park, in a residential area about one mile east of the Lehigh Cement Plant and two blocks south of Stevens Creek Blvd. Pollutants continuously measured include ozone, sulfur dioxide, particulate matter, nitrogen oxide, nitrogen dioxide, hydrocarbons, and carbon monoxide. Hourly averages for these pollutants can be viewed and compared with other locations on the Air District’s Real Time Air Quality Data web page. Hourly winds and temperature are also measured in the park.
In addition, 24-hour samples of ambient air are collected every sixth day and analyzed for toxic gases and metals.The samples are collected in canisters and on filtersfor later analysis at the Air District and contract laboratories.Toxics and metals data(599 Kb PDF, 9 pgs, revised 02/22/12) are available for viewing.Further information about air toxics can be found at the California Office of Environmental Health Hazard Assessment (OEHHA) web site.For comparison, toxics data summaries for other monitoring sites throughout Californiacan be found at the California Air Resources Board (CARB) web site. It is important to note theaveraging and reporting time frameson these websites to ensure that the data are comparable.
In addition to the special Cupertino monitoring site, the Air District operates 24 permanent air monitoring stations within the Bay Area. The closest permanent monitoring station to Cupertino is 9.8 miles east in downtown San Jose. Air quality measurements at the San Jose station are comparable to measurements taken at other stations around the Bay Area: most pollutants are well below state or federal ambient air quality standards, with the exception of ozone and fine particulates. Air quality measurements at the Cupertino station have also been well below state or federal ambient air quality standards, including measurements of ozone and fine particulates.
Table 1 below lists the pollutants measured at Cupertino and the sampling frequencies.
No Spare the Air Alert in Effect
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Last Updated: 5/24/2015