Photograph of Farrar Site

Address: County Road 342
Farrar, MO 63746

Pollutant monitored: Ozone (O3)

Date established: 1/22/2004

Site coordinates

  • Latitude: 37.70264°
  • Longitude: -89.69864°

County: Perry

EPA Site No: 29-157-0001

Farrar's design value for ozone peaked at 80 parts per billion (ppb) during the 2005-2007 monitoring period. Its design values did not fall below the current standard of 70 parts per billion until the relatively cool monitoring period of 2013-2015. As of early July 2016, preliminary data show that the Farrar site has had one exceedance of the standard; however, one exceedance does not mean that the site's design value for 2014-2016 will exceed the standard. The Missouri Department of Natural Resources will not be able to determine the ozone design value for 2014-2016 until March 2017 because of the need to quality-assure data. A site's design value determines whether an area is in attainment of a federal standard.

Ground-level ozone is formed 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 the sun's harmful ultraviolet rays.

Please note that the current standard of 70 parts per billion equals 0.070 parts per million (ppm).

Ozone Data *

Preliminary data for current date plus previous 10 days
Central standard time
in parts per million (ppm)

Weekly summary of all ozone sites
Ozone design values for outstate sites, 2003 - 2015
Design values indicate a region’s air quality. They are calculated by averaging the fourth-highest eight-hour ozone concentration over three consecutive years.

* Technical issues can affect the ability to deliver quality data.
Click here to access a table of symbols and the problems they represent.

Related Links

National standards for pollutants

Health effects of ozone and historical information

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

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

EPA Air Sensor Toolbox for Citizen Scientists