EXXONMOBIL PIPELINE CO

Incident Narrative

ON JANUARY 2, AT 2PM THE PASADENA SCHOOL DISTRICT NOTIFIED A THIRD PARTY OF A STRONG HYDROCARBON ODOR COMING FROM THE STORM DRAIN/RETENTION POND. AT APPROXIMATELY 4:40PM THE EXXONMOBIL PIPELINE OPERATIONS CONTROL CENTER RECEIVED A CALL FROM AN EMPLOYEE OF THE THIRD PARTY INQUIRING ABOUT A HYDROCARBON ODOR AND A SHEEN ON THE RETENTION POND AT THE DOBIE HIGH SCHOOL IN HOUSTON, TEXAS. THEY NOTICED THE EMPCO PIPELINE SIGNS ON THE PIPELINE ROW IN THE AREA. THE EMPCO OPERATIONS CONTROL CENTER SHUTDOWN THE SAN ANTONIO REFINED PRODUCTS PIPELINE SYSTEM AT APPROXIMATELY 5:05PM. AT APPROXIMATELY 5:30PM EMPCO OPERATIONS PERSONNEL ARRIVED ON SITE TO INVESTIGATE AND FOUND DISCOLORED GRASS AND PROBED THE AREA, AND CONFIRMED THE PRESENCE OF FREE HYDROCARBON AT 7:09PM. AT 7:42PM A CALL WAS MADE TO THE NATIONAL RESPONSE CENTER TO REPORT THE INCIDENT. SUBSEQUENT NOTIFICATIONS AND COMMUNICATIONS WERE MADE TO THE TEXAS RAILROAD COMMISSION, TEXAS COMMISSION ON ENVIRONMENTAL QUALITY AND TEXAS GENERAL LAND OFFICE, UNITED STATES COAST GUARD AS WELL AS THE GREATER HOUSTON LEPC AND HOUSTON HAZMAT, WHICH RESPONDED TO THE SITE. ENVIRONMENTAL CREWS RESPONDED TO THE SITE FOR ENVIRONMENTAL ASSESSMENT AND CLEAN UP. THE SPILL LOCATION WAS EXCAVATED AND A REPAIR CLAMP WAS APPLIED TO THE AFFECTED PIPE. THE PIPELINE SEGMENT WAS THEN DISPLACED WITH NITROGEN AND APPROXIMATELY 25 FEET OF PIPE WAS REPLACED. THE CAUSE OF THE INCIDENT WAS DETERMINED TO BE EXTERNAL CORROSION CONFIRMED BY METALLURGICAL EXAMINATION AND TESTING BY A THIRD PARTY. THE THROUGH-WALL FEATURE, PRACTICALLY IMPERCEPTIBLE TO THE NAKED EYE, APPEARED TO BE A SEPARATION COINCIDING WITH AN AREA OF THIN WALL THICKNESS (0.004') CAUSED BY CORROSION. IN ORDER TO DELINEATE THE AREA IMPACTED BY THE RELEASE, 49 SOIL BORINGS WERE COMPLETED TO DEPTHS UP TO 25 FEET. SOIL FROM EACH BORING WAS SCREENED WITH A PHOTOIONIZATION DETECTOR (PID), AND SOIL SAMPLES WERE COLLECTED FOR THE INTERVAL WITH THE HIGHEST PID READING. FOR THE BORINGS WHERE GROUND WATER WAS ENCOUNTERED, ADDITIONAL SOIL SAMPLES WERE TAKEN IN THE ZONE JUST ABOVE THE GROUND WATER. ADDITIONAL SOIL SAMPLES WERE COLLECTED FROM THE EXCAVATED SOIL AND SIDEWALLS OF THE EXCAVATION. ALL SAMPLES COLLECTED WERE THEN SENT TO THE LABORATORY FOR TESTING TO CONFIRM THE TOTAL PETROLEUM HYDROCARBONS (TPH) IN EACH SAMPLE. IN ADDITION, LASER INDUCED FLORESCENCE (LIF) WAS USED IN SOME BORINGS TO CHARACTERIZE IMPACTS BELOW THE GROUND WATER TABLE. TOGETHER THE TPH, LIF, AND RECOVERED HYDROCARBON INFORMATION WAS USED TO ESTIMATE THE TOTAL VOLUME RELEASED. 2/26/19 AT PHMSA'S REQUEST, UPDATED PART A.4 TO 14:00 FROM 19:09 BASED ON WHEN THE PASADENA SCHOOL DISTRICT NOTIFIED A THIRD PARTY OF A STRONG HYDROCARBON ODOR COMING FROM THE STORM DRAIN/RETENTION POND. ALSO AT PHMSA'S REQUEST UPDATED PART C.3A TO 8 INCH NOMINAL SIZE FROM 8.625 INCH. UPDATED PART A.11 WITH AN ESTIMATED VOLUME OF COMMODITY RECOVERED TO 87 BBL'S. FROM 76 BBL'S., AND UPDATED NARRATIVE.