Address: 2100 Highway Y
                Foley, MO 63347Photograph of Foley
County: Lincoln
Pollutant monitored: Ozone (O3)
Date established: 03/01/2017
Site coordinates:
    * Latitude: 39.04577
    * Longitude: -90.84927
Site ID: 29-113-0004

The air monitoring station at the Foley West location began operating on March 1, 2017 — the beginning of ozone season. The department relocated its original Foley monitor to this new site earlier in 2017 because of a property transfer. The original site and the current site are less than a mile apart, and they share the same air mass. The Foley West site helps the department characterize ground-level ozone concentrations extremely downwind of the St. Louis area and monitor attainment of the ambient air quality standards.

Ozone (O3) Data*

The federal ozone season runs from March 1 through October 31.
Ground-level ozone forms when pollutants emitted by cars,
factories, power plants and other sources react chemically in the presence of heat and sunlight. Ozone at ground level
is a harmful air pollutant as opposed to ozone in the upper atmosphere, which protects us from ultraviolet light.

As of 2015, the federal standard for ground-level ozone is 70 parts per billion, or 0.070 parts per million.
An area is in compliance if the design value is at or below this standard. A design value for ozone incorporates data
from three years. The department and EPA calculate the design value by 1) ranking the daily eight-hour ozone values
for three consecutive years; 2) extracting the fourth-highest value for each year; and 3) averaging the three figures.

Weekly summary of preliminary data from all ozone sites

Preliminary one-hour averages from Foley West
   • Ozone data in third and fourth columns
   • "P" stands for primary monitor. "S" stands for secondary monitor.
   • Data from 10 days ago through current date
   • Central Standard Time
   • Concentrations of pollutant in parts per million (ppm)

Preliminary eight-hour forward-rolling averages from all ozone sites
   • Hourly data equal to average of that hour and the following seven hours.
   • Data from 10 days ago through current date
   • Central Standard Time
   • Concentrations of ozone in parts per million (ppm)

Preliminary one-hour ozone averages from all sites

   • Data from 10 days ago through current date
   • Central Standard Time
   • Concentration of ozone in parts per million (ppm)

2016 list of exceedances

Graph of design values for ozone sites in the St. Louis area, beginning in 2003

Additional information about ground-level ozone

*Technical issues can affect ability to deliver quality data.
Click to access a table of symbols indicating technical issues.

Related Links

Missouri's mapped network of air monitoring sites

The 2016 Monitoring Network Plan provides information
on the development of the Foley West monitor, which replaced another one in Foley.

National standard for pollutants

Real-time views from cameras in Kansas City and St. Louis

Daily Air Quality Forecast (AirNow) shows how current readings
at air monitoring sites rate on the EPA's Air Quality Index.
Click on Missouri in the state box at the top of the home page
to access information.

EPA's Air Sensor Toolbox for Citizen Scientists