<_x0034_01026287>

401026287 19 2016-04-14T17:01:44.923-06:00 47120 KERR MCGEE OIL & GAS ONSHORE LP

P O BOX 173779

DENVER CO 80217-3779 Erik Mickelson 303 929.4306 Erik Mickelson Senior HSE Representative 2016-04-14T17:01:44.923-06:00 2016-04-14T17:01:44.907-06:00 445453 in process bkieding 2016-04-12T12:23:03.547-06:00 bkieding erik.mickelson@anadarko.com 0.00000 erik.mickelson@anadarko.com bkieding bkieding 2016-04-14T17:01:42.28-06:00 401024607 401026287 CANFIELD, CHRIS 2016-04-05T00:00:00-06:00 TANK BATTERY ADAMS SWNE 14 1S 68W 6 N NON-CROP LAND Sunny, windy, 60 degrees F 0 0 On April 5, 2016, a release was discovered at the Green 61S68W/14SWNE facility (Location ID 320310). An estimated 45 barrels of crude oil was released into the unlined secondary containment berm, from a hole located just above the base of the oil tank. The compromised storage tank was removed from service and excavation of impacted soil commenced on April 6, 2016. Groundwater was encountered within the excavation pit at approximately 5 feet below ground surface (bgs). Groundwater and soil confirmation samples are being collected from the excavation, and surface water samples have been collected from the adjacent surface water feature, located approximately 120 feet to the east of the facility. Remediation and assessment activities are ongoing and further information will be provided in a forthcoming Form 19 Supplemental report. A regional topographic facility location map is provided as Figure 1. 320310 401024607 true 2016-04-05T00:00:00-06:00 39.966631 -104.966438 Thornton FEE 1 0 0 false <_x0032_7_approved>false S false >=5 and <100 0 0 0 0 true false false true false 0 2016-04-08T09:55:50.767-06:00 401026287 401026287 FORM 19 SUBMITTED 401026287.pdf 401026287 401028508 TOPOGRAPHIC MAP Green_61S68W_14SWNE_Fig1_area_20160406.pdf 465123 401026287 401028509 SITE MAP Green_61S68W_14SWNE_Fig2_dig_20160412.pdf 422535 401026287 401028510 ANALYTICAL RESULTS SiteClearance_Green61S68W14SWNE_Soil_Table1.pdf 16217 401026287 401028511 ANALYTICAL RESULTS SiteClearance_Green61S68W14SWNE_GW_Table2.pdf 28800 401026287 401028512 ANALYTICAL RESULTS Analytical Reports_Combined_Green 61S68W-14SWNE.rpt.pdf 1605052 401026287 1 SPILL 2016-04-05T00:00:00-06:00 Adams County Gordon Stevens

email forwarded to Jen Rutter

-email 401026287 2 SPILL 2016-04-05T00:00:00-06:00 City of Thornton Lori Hight

email forwarded to Robb Kolstad

-email 401026287 1 2016-04-14T00:00:00-06:00 0 0 true true false false false false 6 false Between April 6 and April 13, 2016, soil excavation and groundwater extraction activities were conducted following the discovery of the release. On April 6, four surface water samples (Green 1 through 4) were collected from the adjacent water feature, Big Dry Creek. On April 7, four confirmation soil samples (North1@5', West1@5', South1@5' and East1@5') were collected at the sidewall extents of the excavation, at 5 feet bgs. On April 7, groundwater sample Groundwater1@6' was collected from the excavation, at 6 feet bgs, and on April 13, groundwater sample Groundwater2@6' was collected from the excavation, at 6 feet bgs. Due to groundwater extraction activities, groundwater levels were drawn down relative to static levels. All samples were submitted to Origins Laboratory in Denver, Colorado, for analysis of constituents of concern. Surface water and groundwater samples were analyzed for benzene, toluene, ethylbenzene, and total xylenes (BTEX) by USEPA Method 8260C. Soil samples were analyzed for BTEX and total petroleum hydrocarbons (TPH) - gasoline range organics (GRO) by USEPA Method 8260C, TPH - diesel and reduced range organics (DRO and RRO) by USEPA Method 8015C, electrical conductivity (EC), and pH. Laboratory analytical results of the surface water samples indicated that BTEX concentrations were below laboratory detection limits and less than COGCC Table 910-1 allowable levels. Analytical results of groundwater sample Groundwater1@6' indicated that benzene and toluene exceeded the applicable COGCC Table 910-1 standards for groundwater, at 774 micrograms per liter (µg/L) and 2,770 µg/L, respectively. Analytical results of groundwater sample Groundwater2@6' indicated that benzene and toluene exceeded COGCC Table 910-1 standards, at 255 µg/L and 798 µg/L, respectively. The general facility layout, excavation location, and laboratory results are shown in Figure 2. Analytical results are summarized in Table 1 and Table 2, and laboratory reports are provided. Sandy clays grading to siltstone/claystone bedrock. 5 5 398 120 120 3410 525 For the soil samples collected at the sidewall extents of the excavation, laboratory analytical results indicated that BTEX and TPH were below laboratory detection limits and below COGCC Table 910-1 allowable levels. For EC and pH, soil sample laboratory analytical results indicated that concentrations were below COGCC Table 910-1 allowable levels. The final extent of the excavation spanned approximately 32 feet (west-east) by 41 feet (north-south). Approximately 360 cubic yards of impacted material was excavated and transported to Front Range Landfill in Erie, Colorado, for disposal. Approximately 768 barrels of impacted groundwater were removed via vacuum truck, and transported to Kerr-McGee's licensed injection facility for disposal. To stimulate the hydrocarbon degradation process, on April 13, 200 pounds of a carbon-based bio-stimulant and oxidizer was applied to the groundwater within the excavation, prior to backfilling. During excavation activities, apparent remnant staining from a former release was observed. COGCC Remediation Project #485, which was assigned to the former release that occurred in 2000, was closed by the COGCC in 2003. A Form 27 will be prepared and submitted for the subject release. 45 0 0 0 0 0 0 0 0 0 false false 0 0 false false false false false false false false false false false true 32 41 72 401026287 1 2016-04-14T00:00:00-06:00 false true false false The release resulted from a sidewall seam failure, located just above the base of the oil tank. The oil tank was removed from service. 360 true false false 768 0 Thread was being aborted.