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Maintenance Areas in Oregon

Maintenance areas are those geographic areas that had a history of nonattainment, but are now consistently meeting the National Ambient Air Quality Standard. Maintenance areas have been re-designated by EPA from "nonattainment" to "attainment with a maintenance plan," or designated by the Environmental Quality Commission. Legal descriptions of these areas are listed in Oregon Administrative Rules, Chapter 340, Division 204-0010.

Maintenance areas in Oregon


Under authority of the Lane Regional Air Protection Agency (LRAPA). Contact LRAPA for information on this area.​
​​Because of topography, weather and a large number of woodstoves, the Klamath Falls area has a long history of identifying problems with particulate pollutions and working to solve them. With increased understanding of the health effects of particulates, EPA has made the standards more protective over time, addressing smaller sized particles that are the most hazardous but more difficult to control. Since 1994, the Klamath Falls area has attained the larger or coarse (PM10) particulate matter standard. In 2009, with the adoption of a fine particulate (PM2.5) matter standard, EPA changed the legal status of the Klamath Falls Area from attainment (meeting air quality standards) to nonattainment (not meeting air quality standards) for fine particulate matter (PM2.5). DEQ has adopted an attainment plan with associated regulations to ensure that the Klamath Falls area meets the current PM2.5 standard.

2012 Klamath Falls Fine Particulate Matter Attainment Plan
Adopted Dec. 6, 2012

For more information on the 2012 Klamath Falls Fine Particulate Matter Attainment Plan, contact Rachel Sakata, Air Quality Planner, 503-229-5659


1991: The EQC adopts a PM10 attainment plan which includes emission reduction strategies for: Woodstove and open burning curtailment, winter road sanding controls, public education programs, and agreements with Forestry and Agriculture agencies. The Klamath Falls Urban Growth Boundary is in nonattainment for PM10.

1994: Klamath Falls is in compliance with the standards.

1999: DEQ establishes a PM2.5 monitor in Klamath Falls and monitors high levels of PM2.5 in the airshed.

2002 DEQ prepares and the EQC adopts a PM10 Maintenance Plan for Klamath Falls:
2003: EPA approves the Maintenance Plan and associated rules for the Klamath Falls Maintenance area for coarse particulate matter (PM10). The legal status of the Klamath Falls area changes from nonattainment to attainment for PM10. The Urban Growth Boundary is now in attainment for coarse particulate matter (PM10).

2006: EPA revises PM2.5 standard.

2007: Klamath County revises its Clean Air Ordinance which further limits the use of woodburning devices inside the home and outdoor burning during the winter months when high levels of PM2.5 are evident. Woodstove replacement programs are implemented to help low income individuals replace their uncertified woodstoves with cleaner units.

2009: Klamath Falls along with Oakridge are designated Nonattainment for fine particulate matter (PM2.5) by EPA. PM2.5 concentrations are high enough to cause a violation of the 24 hour air quality standard also known as the National Ambient Air Quality Standard.

2011: DEQ conducted monitoring for Toxic Air Pollution and found that many toxic air pollution tracked with days of high wood stove pollution. See Fact Sheet describing Air Toxics in Klamath Falls.

2012: The EQC adopts the Klamath Falls PM2.5 Attainment Plan for Klamath Falls. The plan is submitted to the EPA.


Under the 1990 Clean Air Act Amendments, the Rogue Valley (Jackson County, Ashland, Phoenix, Talent, Medford, Jacksonville, Central Point, White City, and Eagle Point) became a nonattainment area for particulate matter (PM10). These communities shared a common airshed, known as the Medford-Ashland Air Quality Maintenance Area. During the 1980s, particulate pollution in the AQMA reached some of the highest levels in the nation and violated the federal air quality health standards also known as National Ambient Air Quality Standard. This violation meant two things:
  1. DEQ needed to write a plan to bring the Medford-Ashland AQMA back into compliance with the standard; and
  2. Added restrictions would be placed on Rogue Valley communities to limit new and expanding industries and significant transportation projects would need to be reviewed to determine their compliance with the plan.
The plan and rules addressing industry and residential woodstove curtailment were prepared by DEQ in 1991. The Environmental Quality Commission adopted the plan and rules shortly thereafter. All emission reduction measures adopted by the EQC were successfully implemented and air quality monitoring in the AQMA demonstrated that the PM10 standards were met in 1992. The Medford-Ashland AQMA currently meets the PM10 standards and EPA’s tougher new standards for fine particulate (PM2.5).

On Dec. 10, 2004, the EQC approved an updated PM10 attainment and maintenance plans. This plan continues all of the PM10 strategies from the 1991 attainment plan and continues the strictest requirements for managing emissions growth from future new and expanding major industry under the New Source Review program. EPA approved the plans in 2005.

Supporting documents




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