Photograph of Farrar Site

Address: County Road 342
Farrar, MO 63746
County:
Perry
Pollutant monitored: Ozone (O3)
Date established: Jan. 22, 2004
Site coordinates
*
Latitude: 37.70264°
* Longitude: -89.69864°
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. Note that the current standard of 70 parts per billion equals 0.070 parts per million (ppm).

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 the sun's harmful ultraviolet rays.

As of 2015, the federal standard for ground-level ozone is 70 parts per billion. 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 Farrar in parts per million
• Ozone data in third and fourth columns
• "P" stands for primary ozone monitor. "S" stands for secondary monitor.
• Data from 10 days ago through current date
• Central Standard Time

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

Preliminary one-hour averages from all ozone sites in parts per million

• Data from 10 days ago through current date
• Central Standard Time

Graph of ozone design values for outstate sites, beginning in 2003

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