DCP MIDSTREAM — Gas transmission and gathering — incident on 2019-04-02

Gas transmission and gathering incident in Not Within a Municipality, WELD County, CO. Reported cause: OTHER OUTSIDE FORCE DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 533 NATURAL GAS released, $1,000 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20190049.

Operator ID: 31130.

Reported incident date: 4/2/2019 10:00.

Location detail: 6+176

Cause detail: OTHER OUTSIDE FORCE DAMAGE

Cause detail: DCP GAS CONTROL RECEIVED A CALL FROM A PROPERTY OWNER ON APRIL 2, 2019 AT APPROXIMATELY 10:00 AM MST REPORTING A SUSPECTED GAS RELEASE. DCP PERSONNEL ARRIVED ON SITE AT APPROXIMATELY 10:15 AM MST AND CONFIRMED A GAS RELEASE AND ISOLATED THE LINE. DCP PERSONNEL BLEW DOWN REMAINING PRESSURE IN THE LINE. INITIAL INVESTIGATION INDICATED A CRACK IN THE PIPE AT APPROXIMATELY THE 6-O'CLOCK POSITION IMMEDIATELY ADJACENT TO A GIRTH WELD TO BE THE SOURCE OF THE RELEASE. BASED ON INVESTIGATION AND METALLURGICAL ANALYSIS, DCP HAS DETERMINED THAT THE BZ-7-1-2-EXT CLASS 2 GAS GATHERING PIPELINE FAILED DUE TO CYCLIC FATIGUE CAUSED BY EXTERNAL LOADING. THE BZ-7-1-2-EXT PIPELINE RUNS PARALLEL TO A COUNTY ROAD AND UNDERNEATH AN INTERSECTION WITH A SECOND COUNTY ROAD. AS PART OF A COUNTY ROAD EXPANSION PROJECT IN AUGUST 2015, A HEAVY CONCRETE PRE-FABRICATED DRAINAGE CULVERT AND SUPPORT BRACE WERE INSTALLED DIRECTLY OVER AND WITHIN A FEW INCHES OF THE TOP OF THE PIPELINE AT THE INTERSECTION. DCP HAD LOCATED AND MARKED THE PIPELINE IN JULY 2015 IN RESPONSE TO AN 811 NOTIFICATION FOR THE ROAD PROJECT, BUT DCP WAS NOT PROVIDED WITH THE COUNTY'S CONSTRUCTION PLANS PRIOR TO THE WORK BEING DONE, AND WAS NOT AWARE NOR MADE AWARE OF THE CONFLICT BETWEEN THE CULVERT INSTALLATION AND THE PIPELINE. FREQUENT HEAVY VEHICLE TRAFFIC AT THE INTERSECTION SUBSEQUENTLY APPLIED REGULAR CYCLIC LOADING TO THE CONCRETE CULVERT AND CONCRETE SUPPORT BRACE UNDER THE ROADWAY, WHICH CYCLIC LOADING CAUSED A BENDING FRACTURE AND THEN FINAL DUCTILE OVERLOAD TEAR OF THE GATHERING PIPELINE IMMEDIATELY BELOW, RESULTING IN THE FAILURE OF THE BZ-7-1-2-EXT PIPELINE ON OR IMMEDIATELY BEFORE APRIL 2, 2019. THE AFFECTED PIPELINE SEGMENT HAS BEEN PURGED OF ALL HYDROCARBONS, PHYSICALLY DISCONNECTED FROM ALL SOURCES OF GAS, AND CAPPED. DCP HAS FURTHER RESPONDED TO THE FAILURE BY CONDUCTING AN EXTENSIVE SOIL AND GROUNDWATER INVESTIGATION ON THE SURROUNDING PROPERTIES, AND IS PURSUING REMEDIATION OPTIONS WITH THE PROPERTY OWNERS UNDER THE OVERSIGHT OF THE COLORADO OIL AND GAS CONSERVATION COMMISSION.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: OTHER OUTSIDE FORCE DAMAGE — OTHER OUTSIDE FORCE DAMAGE.

PHMSA indexed costs: $381,431 reported total cost, $179,533.01 in 1984 dollars, $440,303.837 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.