3.A: Colorado

The gasoline standard required across most of Colorado (i.e. areas outside of the Denver/Boulder metro area) is a conventional formulation. The state has adopted NIST Handbook 130, by reference, as its quality standard for conventional gasoline. The Handbook, in turn, adopts ASTM D4814 Standard Specification for Spark-Ignition Engine Fuel, also by reference, as the applicable standards for parameters outside the purview of EPA’s federal conventional gasoline quality regulations. The applicable federal parameters and limits are listed in Fig. 1 of Part 1 of this report, whereas the applicable ASTM D4814 parameters and limits are listed in Fig. 3 of Part 1 of this report.

Oxygenate blending with gasoline is allowed in the state, in accordance with the EPA’s “substantially simila