<_x0034_00883149>

400883149 19 2015-08-12T10:32:10.127-06:00 4680 DCP MIDSTREAM LP

370 17TH STREET - SUITE 2500

DENVER CO 80202 Sam Wood 970 590-6444 Sam Wood Compliance Coordinator 2015-08-12T10:32:10.127-06:00 2015-08-12T10:32:10.11-06:00 442347 in process SWood 2015-08-12T08:22:19.28-06:00 SWood swood@dcpmidstream.com 0.00000 swood@dcpmidstream.com SWood SWood 2015-08-12T10:32:07.437-06:00 400859200 400883149 CANFIELD, CHRIS 2015-06-24T00:00:00-06:00 PIPELINE WELD SWSW 31 3N 67W 6 Y OTHER Sunny and temps in the low 90's 0 0 A DCP pipeline was broken in the St. Vrain river just south of Highway 66 on WCR 13. An unknown amount of natural gas and condensate was released into the river. The line was immediately shut in and blown down to prevent any more release into the river. No sheen or evidence of condensate was visible, only the temporary bubbling of the natural gas. This incident is currently under investigation and corrective actions being planned. More information and a corrective actions report will be submitted in the 10-day follow up. 400859200 true 2015-06-24T00:00:00-06:00 40.182298 -104.941596 STATE 1 0 1 true <_x0032_7_approved>false S false River 0 >=1 and <5 0 0 0 false false false false true 0 2015-06-26T07:59:16.61-06:00 400883149 Please let me know if you have any questions or concerns, Thanks, 400883149 400883149 FORM 19 SUBMITTED 400883149.pdf 400883149 400883204 TOPOGRAPHIC MAP Graph01.pdf 23539 400883149 400883206 OTHER Image01.pdf 549975 400883149 400883207 OTHER image02.pdf 997253 400883149 400883208 OTHER Image03.pdf 495830 400883149 400883209 OTHER Image04.pdf 864862 400883149 400883218 OTHER St. Vrain Rupture Timeline.pdf 5201 400883149 1 SPILL 2015-06-26T00:00:00-06:00 Weld County LEPC Gracie Marquez

400883149 1 2015-08-12T00:00:00-06:00 0 0 false false true false false false 0 false At 10:15 a.m. on 6/24/2015, DCP Midstream (DCP) was contacted about a gas leak in the St. Vrain River by Anadarko P* C* (Anadarko). DCP immediately responded to shut in pipelines and visually inspect the damage (see attached timeline). Neither Anadarko, DCP, or any other party involved in this release noticed and sheen or evidence of liquids being released into the river. Using the most recent gas analysis from that pipeline and Promax simulations, we were able to estimate that less than 1 barrel of liquid* was released into the river. N/A 0 8 900 0 0 1100 A timeline of events leading up to investigation was formed during DCP's investigation of the event, please see attached timeline. 0 0 0 0 0 0 0 0 false false 0 0 false true false false false false false false false true false true 0 0 0 400883149 1 2015-08-12T00:00:00-06:00 false true false true Weather, flooding After a thorough investigation was conducted by DCP Midstream, it was determined the 4" pipeline was broken due to "fatigue failure." This "fatigue failure" was caused by several contributing factors. The first factor was on September 17th, 2013, Northern Colorado experienced a 1,000 year flood event which completely changed river bottoms and pathways in many rivers in Weld County including the St. Vrain (see Image01). During this re-shaping, many areas of the St. Vrain river bottom were altered, it is believed because of the altered river bottom a section of DCP pipeline that was originally installed well below the river bottom became exposed. Please see attached graph (Graph01) that shows depths of original installation of the pipe (blue line) and the original river bottom (orange line) in late 2011. With the pipeline exposed since September 2013, the pipeline experienced significant wear from the sands and sediments being moved by the St. Vrain River. This wear wore off the protective coating and started corroding the metal sidewall of pipe (see Image02). During the spring of 2015, Northern Colorado saw more significant flooding, which is believed to have bombarded this pipeline with more sand and larger objects such as rocks and stumps being carried by the high water levels and currents. As you can see, (Image03, Image04) the pipeline saw significant damage and thinning in the pipeline walls which then compromised the strength and durability of the line. Evidence shows the decreased strength and durability of the line caused it to flex back and forth until fatigue caused the pipeline to break, therefore causing the release. DCP removed the damaged pipeline section, replaced and re-bored the pipeline to safe depths below ground surface. DCP has drafted a revised Gas Pipeline O&M manual to reflect what was learned from this event to prevent further pipeline breaks from the 2013 flooding, 2015 flooding, and any future flooding that may occur in DCP’s areas of operation. A few main points of this drafted revision include the following: Identify all locations where pipelines cross or are adjacent to rivers or streams where severe flooding may occur. Evaluate each pipeline crossing at a river to determine if the installation method has the ability to withstand the risks of anticipated flood conditions. During flooding, position key operations personnel in locations where they will be able to respond for pipeline shut down and isolation as needed. After flooding, determine immediately if flooding has caused pipeline exposures or new river channels that impact the depth or cover of pipelines under or near the river. Also, after flooding, surveys of underwater pipelines and pipelines in areas adjacent to rivers will be conducted to determine new depth and cover. 0 false false false 0 0 Thread was being aborted.