State of Colorado Public Utilities Commission — Pipeline Safety Interpretation

Page 1February 20, 2009 Mr. Stephan Pott, PE Chief, Gas Pipeline Safety State of Colorado Public Utilities Commission 1560 Broadway, Suite 250 Denver, CO 80202 Ref. No.: PI-08-0010 Dear Mr. Pott: The Pipeline and Hazardous Materials Safety Administration (PHMSA) reviewed your December 11, 2008, letter transmitting an October 22, 2008, petition received by the Colorado Public Utilities Commission (CO-PUC) from DCP Midstream for a finding that the endpoint of the gathering designation for an intrastate gas pipeline should be extended beyond a gas processing plant. Specifically, DCP Midstream requested a finding that the gathering designation for a rural section of the ANGI intrastate pipeline be extended an additional 7.8 miles from the DCP Midstream Greeley Plant to the DCP Midstream Mewbourn Gas Plant, both of which are located in Weld County, Colorado. Per 49 CFR § 192.8 (a)(2) and Section 2.2 (a)(1)(A) of API RP 80, DCP Midstream included documentation they feel demonstrates that extending the gathering designation an additional 7.8 miles from the Greely Plant to the Mewbourn Plant was justified based on sound engineering principles. Additional correspondence with DCP Midstream determined the following: • The Greeley Plant separates the methane out and sells it there; the liquids are placed in tanks at the facility and eventually transported to the intended destination via truck. • The remainder of the gas, including 90% ethane, 5% methane, and 2% CO2 is then transported to the Mewbourn Plant for additional processing. • The normal operating pressure of the line is approximately 300 psig, down to approximately 150 psig when delivered to the downstream plant Based on the information provided in DCP Midstream’s petition, the additional correspondence, and your recommendation, PHMSA finds that extending the endpoint of the gathering designation for the ANGI gas pipeline an additional 7.8 miles to the Mewborne Plant is warranted as long as the current operating parameters and operating pressures remain the same. Accordingly, to the extent this condition is met, PHMSA grants the petition. If DCP Midstream makes any significant changes to the operation of this line, such as increasing the pressure to where the ethane might be in a liquid super critical phase, DCP Midstream will be required to contact the CO-PUC and/or PHMSA’s Western Region to make a new determination.#

Page 2Sincerely, Signed/JAG/2-20-09 John A. Gale Director, Office of Regulations#