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  2. State and Local Transportation

Conformity Adequacy Review: Region 10

State Implementation Plans (SIP) Submissions that EPA has Found Adequate or Inadequate
Region 10: Alaska, Idaho, Oregon, and Washington

For more information about adequacy review, return to the main adequacy page.  

This page provides a list of state implementation plans that include motor vehicle emission budgets that EPA Region 10 has found either adequate or inadequate for the purposes of transportation conformity.

Contact:  Karl Pepple, (AK, ID, OR, WA) U.S. EPA Region 10, 1200 Sixth Ave., Seattle, WA  98101; phone: 206-553-1778. email: pepple.karl@epa.gov.

Alaska
Area Pollutant SIP Submission Finding (date budgets apply) Additional Information/ Comments
Anchorage carbon monoxide maintenance plan

Adequate

Alaska Adequate Letter (02/29/2012)
FR Notice (02/14/2012) (pdf) (2 pp, 147 KB)

Budgets found adequate through the adequacy review process.
Adequate
FR Notice (06/23/2004) (pdf) (147 KB)
SIP found adequate through SIP approval process.
attainment demonstration Adequate
FR Notice (09/18/2002) (pdf) (132 KB)
Budgets adequate by virtue of SIP approval.
Inadequate (05/14/1999) Determination made under old process.
Eagle River PM10 limited maintenance plan

Adequate

Alaska Adequate Letter (05/14/2012) (pdf)
FR Notice (04/27/2012) (pdf) (2 pp, 194 KB)

Budgets found adequate through the adequacy review process.
Fairbanks carbon monoxide maintenance plan Adequate (09/27/2004) Budgets adequate by virtue of SIP approval.
attainment demonstration Adequate (04/05/2002) Budgets found adequate through SIP approval process.
Inadequate (05/14/1999) Determination made under old process
Idaho
Area Pollutant SIP Submission Finding (date budgets apply) Additional Information/ Comments
Northern Ada County PM10 second limited maintenance plan Adequate
FR Notice (06/06/2013)
Idaho Northern Ada County Adequate Letter (06/21/2013)
Budgets found adequate through adequacy review process.
carbon monoxide limited maintenance plan Adequate (12/27/2002)
FR Notice (10/28/2002) (pdf) (148 KB)
Budgets found adequate through SIP approval process.
Pocatello PM10 maintenance plan Adequate
Idaho Adequate Letter (10/04/2004)
FR Notice (09/17/2004) (pdf) (142 KB)
Budgets found adequate through adequacy review process.
attainment demonstration Inadequate (8/14/2000)
Idaho Inadequate Letter (08/14/2000)
FR Notice (07/28/2000) (pdf) (215 KB)
 
Oregon
Area Pollutant SIP Submission Finding (date budgets apply) Additional Information/ Comments
Grants Pass CO limited maintenance plan Adequate (09/28/2015)
80 FR 44864 (07/28/2015)
Budgets found adequate through the SIP approval process.
PM10 limited maintenance plan Adequate (09/28/2015)
80 FR 45431 (07/30/2015)
Budgets found adequate through the SIP approval process.
Klamath Falls 2006 PM2.5 attainment plan Adequate (08/17/2015)
80 FR 45654 (7/31/2015)
Budgets found adequate through the adequacy review process.
Medford PM10 maintenance plan Adequate (08/18/2006)
FR Notice (06/19/2006) (pdf) (191 KB)
Budgets found adequate through SIP approval process.
carbon monoxide second maintenance plan Adequate
Oregon Adequate Letter (05/13/2016)
80 FR 54788 (04/28/16)
Budgets found adequate through the adequacy review process.
maintenance plan Adequate
Oregon Adequate Letter (04/26/2002)
FR Notice (04/11/2002) (pdf) (132 KB)
Budgets found adequate through adequacy review process.
Oakridge 2006 pm2.5 attainment plan

Adequate
FR Notice (06/16/2017)
Oregon Oakridge Adequate Letter (06/21/2017)

Budgets found adequate through the adequacy review process
Portland carbon monoxide maintenance plan Adequate
FR Notice (01/24/2006) (pdf) (150 KB)
Budgets found adequate through SIP approval process.
Salem carbon monoxide limited maintenance plan Adequate (3/02/2009)
FR Notice (12/30/2008) (pdf) (7 pp, 163 KB)
Budgets found adequate through SIP approval process.
Washington
Area Pollutant SIP Submission Finding (date budgets apply) Additional Information/ Comments
Kent, Seattle, and Tacoma PM10 Limited maintenance plan Adequate (08/20/2014)
79 FR 49239
Budgets found adequate through the SIP approval process.
Spokane PM10 limited maintenance plan Adequate (04/12/2016)
81 FR 21470
Budgets found adequate through the SIP approval process.
Adequate (08/30/2005)
FR Notice (07/01/2005) (pdf) (182 KB)
Budgets found adequate through SIP approval process.
carbon monoxide maintenance plan Adequate (08/29/2005)
FR Notice (06/29/2005) (pdf) (160 KB)
Budgets found adequate through SIP approval process.
attainment demonstration Adequate
Washington Adequate Letter (12/04/2002)
FR Notice (11/19/2002) (pdf) (133 KB)
Budgets found adequate through adequacy review process.
Inadequate (5/14/1999) Determination made under old process
Tacoma-Pierce County 2006 PM2.5 maintenance plan Adequate (2/10/2015)
80 FR 7347
Budgets found adequate through the SIP approval process.
Vancouver carbon monoxide limited maintenance plan Adequate
Washington Adequate Letter (12/04/2007)
FR Notice (11/19/2007) (pdf) (139 KB)
Budgets found adequate through adequacy review process.
Yakima PM10 limited maintenance plan Adequate
Washington Adequate Letter (11/29/2004)
FR Notice (11/12/2004) (pdf) (144 KB)
Budgets found adequate through adequacy review process.
carbon monoxide limited maintenance plan Adequate (12/31/2002)
FR Notice (11/01/2002) (pdf) (155 KB)
Budgets found adequate through the SIP approval process.

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Last updated on April 22, 2025
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