2011

Prior to 2010, gasoline sold in the Larimer and Weld area during the summer ozone season (June 1 to September 15) was subject to a national RVP limit of 9.0 psi; 10.0 psi for ethanol–blended fuels. On March 1, 2010, EPA approved extending this regulation to the full 8–hour ozone nonattainment area as part of the Federal Volatility Control Program in the Denver–Boulder–Greeley–Fort Collins–Loveland, Colorado, 1997 8–Hour Ozone Nonattainment Area (75 FR 9107). This included expanding the low RVP fuel requirement to portions of Larimer and Weld counties and into the remaining portions of Arapahoe, Adams, Boulder and Broomfield counties.

The 2011 study evaluated four scenarios:

1.  Retain the current 7.8 RVP summertime standard, but eliminate the one psi ethanol waiver
2. Adopt a 7.0 RVP summertime standard and retain the one psi ethanol waiver
3. Adopt a 7.0 RVP summertime standard and eliminate the one psi ethanol waiver
4. Opt‐into the federal Reformulated Gasoline Program (RFG).

Ultimately the 7.8 RVP standard was retained with the one pis ethanol waiver, and expanded to the entire nonattainment area.

2018

As part of the serious SIP development the RAQC evaluated more stringent methods for fuel standards throughout the entire nonattainment area.

The 2018 study evaluated four scenarios:

1. Maintain the current 7.8 psi (pound per square inch) RVP (Reid Vapor Pressure) summertime standard, but eliminate the one psi RVP ethanol waiver
2. Adopt a 7.0 psi RVP summertime standard and retain the one psi RVP ethanol waiver
3. Adopt a 7.0 psi RVP summertime standard without the one psi RVP ethanol waiver
4. Eliminate summertime ethanol blending

2018 Fuels Study (Energy Analysts International, Inc – March 2019)

2017 RFP – Update Fuels Study  (Deadline August 25, 2017)

2011 Fuels Study (Energy Analysts International, Inc – March 2011)