What’s In the Air We Breathe
The APCD has a network of 18 monitoring stations to find out what’s in the air we breathe. The data we collect is available on our Station Data page and reported each year in our Annual Air Quality Report. To view historical information on ozone and particle pollution levels at Santa Barbara County monitoring stations, and numbers of exceedances of standards by year, see the California Air Resources Board Air Quality Data Statistics.
Our air quality monitoring stations are small, portable structures containing electronic instruments used to measure and record the concentration of various air pollutants. Weather conditions such as temperature, wind speed, and wind direction are also recorded. This helps the APCD track air quality trends and evaluate the likely cause of high pollution levels.
Pollutants are measured continuously 24 hours a day. Twelve stations continuously measure concentrations of ozone, and are shown in our monitoring station network map. Particulate matter less than 10 microns in diameter (PM10) and particulate matter less than 2.5 microns in diameter (PM2.5) are both measured continuously at Santa Barbara, Goleta, Lompoc, and Santa Maria stations. PM10 is also measured continuously at two other stations: Las Flores Canyon and El Capitan. Data are recorded in real time by the APCD’s Data Acquisition System and posted on the APCD’s website.
For more information on ozone, particulate matter, other pollutants, and their health effects, see Air Pollutants and Your Health.
The stations require regular visits by technicians to calibrate equipment, change filters, and perform routine maintenance and repairs. Not every station measures every pollutant. Some measure just one pollutant plus weather conditions. Some measure up to ten pollutants plus weather conditions.
Ambient Air Monitoring Network
Each monitoring station is sited to meet one or more of the following objectives: (1) to determine representative concentrations of air pollution in highly populated areas; (2) to determine the impact of specific businesses or other sources of pollution; (3) to determine general background pollution levels in areas not directly affected by cars, businesses and other man-made pollution sources; and (4) to determine the highest pollution levels in the county. The network of all stations combined must meet all four objectives.
Each year the APCD prepares an annual air monitoring network plan for the county. The plan includes a statement of the purpose for each air monitor, and evidence that the siting and operation of each monitor meets the requirements of the federal regulations. A copy of the most current plan can be found here 2018 Air Monitoring Network Plan.
In 2018, The District evaluated the current monitoring network and submitted a request to the EPA to modify the network to maximize district resources and optimize monitor locations. Documents related to this request are provided here:
- 2018 Network Modification Request to EPA.
- EPA Response – 2018 Network Plan and Modifications.
- CARB – 2018 Network Modifications.
Every five years the APCD prepares a five year network assessment of the air quality surveillance system in Santa Barbara County. A copy of the most current assessment can be found here 2015 Five Year Network Assessment.
Types of Stations
Stations fall into two primary categories: SLAMS and PSD stations.
Six SLAMS (State and Local Air Monitoring Stations) measure urban and regional air quality. Two SLAMS stations are operated by the California Air Resources Board (Santa Barbara and Santa Maria) and four by the APCD (Lompoc, Santa Ynez, El Capitan, and Goleta). Five of these stations measure ambient concentrations of carbon monoxide, ozone, nitrogen oxides, PM10, and sulfur dioxide.
Twelve PSD (Prevention of Significant Deterioration) stations are used to determine baseline air quality and the impacts of specific operations, for example large oil and gas facilities. These stations are generally located in the vicinity of the facility, and measure specific pollutants emitted by the facility. Most PSD stations are operated by the facility; four are operated by APCD. Some PSD stations have been located in distant areas to measure background concentrations of pollutants, or to measure regional pollutants, such as ozone, in areas downwind from the facility.
Data collected are summarized in regular required reports to the California Air Resources Board and the U.S. Environmental Protection Agency, and in APCD’s Annual Air Quality Report. Data are also used for planning and permitting to help predict future pollution concentrations using computer models. In an emergency, data on wind speed and direction could help us predict the movement of a fire or toxic cloud, and determine whether an evacuation is necessary.
We also use the data to watch air pollution levels on a daily basis. If any monitoring station shows pollution levels above a certain threshold, the APCD is required to notify public officials, schools, hospitals, convalescent homes, radio and TV stations, and to advise people to curb their outdoor activities. Only rarely does the air in our county reach a level that would require the APCD to make these public notifications.