Lessons From Aliso Canyon CDAWG Conference Las Vegas

Lessons From Aliso Canyon CDAWG Conference Las Vegas November 16, 2016 LAKI TISOPULOS, PH. D, P. E. , DEPUTY EXECUTIVE OFFICER ENGINEERING & PERMITTING

Aliso Canyon Natural Gas Storage Facility • State’s largest natural gas storage facility, located in Los Angeles county Aliso Canyon • Spans over 3, 600 acres, working storage capacity of 86 billion cubic ft. (BCF) • Sufficient to provide natural gas for roughly 2 million households for a year Greater Los Angeles N • Owned and operated by Southern California Gas Company (So. Cal. Gas) 2

Aliso Canyon Operations • Reservoir is filled with natural gas between April and October • Withdrawn between November and March • Facility comprised of 114 injection/withdrawal wells • Wells draw from a reservoir located ~8, 500 feet below ground level 3

Leak Overview • Leak discovered at Well SS-25 during odor inspection on October 23, 2015 • Experts believe casing was leaking from the well ~500 feet below the surface • SCAQMD started to receive odor complaints due to Mercaptan odorant added to natural gas on October 24, 2016 4

Initial Attempts to Stop the Leak • First initiated efforts to stop the gas leak on October 24 • Pumped brine solution down the well to stop the leak • Seven attempts to plug the leak from the top were unsuccessful 5

Relief Well • Drill relief well to intercept and permanently cut off Well SS-25 from the reservoir ◦ Work on first relief well started on Dec 4 & used magnetic ranging to find SS-25 ◦ Reached the base of the well on Feb 10 ◦ Pumped mud down the relief well on Feb 11 ◦ Cementing operations began on Feb 12 ◦ Well SS-25 containment confirmed by DOGGR on Feb 18 6

Key Events Date Event Oct 23, 2015 Natural gas leak from well SS-25 discovered by So. Cal. Gas. Oct 24, 2015 SCAQMD received and investigated the first of more than 2, 300 air quality complaints due to Mercaptans odor from the natural gas leak. Oct 26, 2015 SCAQMD began ongoing air sampling and monitoring activities in the local community. Nov 5, 2015 SCAQMD issued Notice to Comply to So. Cal. Gas to abate mercaptan odors impacting the local community. Nov 23, 2015 SCAQMD issued Notice of Violation to So. Cal. Gas for creating a public nuisance. 7

Key Events Date Event Dec 10, 2015 SCAQMD petitioned the SCAQMD Hearing Board for an Order for Abatement requiring So. Cal. Gas to abate the natural gas leak, monitor the leaking gas, and reduce its nuisance impacts on the local community. Jan 9, 2016 Jan 16, 2016 Jan 20, 2016 Jan 23, 2016 The SCAQMD Hearing Board heard public testimony from local community members about the impacts of the natural gas leak. Following deliberation on January 23, 2016, the Hearing Board issued the Order for Abatement. Jan 26, 2016 SCAQMD filed a civil penalty lawsuit against So. Cal. Gas in LA Superior Court for creating a public nuisance. 8

16 20 2/ 6/ 16 /2 0 30 1/ 16 /2 0 23 1/ 16 /2 0 16 1/ 16 20 1/ 9/ 16 20 15 /2 0 1/ 2/ /2 6 12 15 /2 0 /1 9 12 /1 2 12 15 15 /2 0 /5 12 /2 8 11 /2 1 11 /1 4 11 15 15 /2 0 /7 11 /3 1 10 /2 4 10 Community Impacts OVER 2, 300 AIR QUALITY COMPLAINTS RECEIVED BY SCAQMD FROM ALISO CANYON AREA OCT 24 2015 - FEB 10 2016 90 80 70 60 50 40 30 20 10 0 9

Community Impacts • Community concerns about benzene, mercaptans, oil residue, hydrogen sulfide, radon • Reports of dizziness, headaches, nausea, nose bleeds • Over 5, 000 households, and about 2, 000 students in two local schools relocated SCAQMD map of odor complaints 10

Public Outreach • SCAQMD website (www. aqmd. gov) with ongoing updates ◦ Ambient air sampling and monitoring activities ◦ Health impacts estimates ◦ Compliance and enforcement activities, including: ◦ Issuance of Notice to Comply and Notice of Violation ◦ Order for Abatement hearings and exhibits ◦ Filing of civil lawsuit • Participation in community meetings 11

Extensive Coordination with Other Agencies • Daily Conference Calls with So. Cal. Gas & First Responding Agencies beginning November 2015 ◦ LA City Fire & Police; LA County Fire, Public Health, Office of Emergency Management & Unified School District; DOGGR; CPUC; CARB; U. S. EPA, etc. • Multiple inter-agency meetings ◦ LA County Fire, LA County Public Health, LA City, DOGGR, CPUC, CARB, U. S. EPA, etc. • Weekly conference calls on Air Monitoring Activities ◦ LA County Public Health, Fire & Unified School District; OEHHA; So. Cal. Gas, etc. • Methane measurement activities with CARB/JPL/DOGGR • Established criteria with CARB, and in consultation with other agencies, for determining typical ambient air concentration levels in the community 12

Inspections/Air Sampling & Measurement • SCAQMD field activities since October 24, 2015 • Near daily presence at or in the vicinity of the Aliso Canyon facility • Responding to community complaints • Conducting site inspections and surveillance at or in the vicinity of the Aliso Canyon facility • Conducting joint inspections with other state and local agencies at the Aliso Canyon facility • Conducting intensive air sampling & measurements in the community, nearby schools, as well as inside the Aliso Canyon Facility • • • Fixed Site and Mobile Platform Monitoring Continuous methane measurements Instantaneous grab samples 24 -hour integrated samples VOC, H 2 S, Total Sulfur, benzene, others 13

Fixed Site Measurements Continuous Methane Triggered VOC Triggered Sulfur 24 -hr Integrated VOC Passive VOC Continuous Methane Triggered VOC Continuous H 2 S 24 -hr Integrated VOC Passive VOC Continuous Methane Triggered VOC 24 -hr Integrated VOC Passive VOC 14

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Mobile Platform Measurements 16

Mobile Platform Measurements 17

Benzene Concentration Comparison to MATES IV 18

Community Air Monitoring • Real-time notification of the methane and benzene levels in the community • Data show a reduction in maximum hourly concentrations since February 11 19

Preliminary Total Emissions Estimate • Over 13 state-coordinated airborne measurements to estimate leaked methane emissions since Nov 7 • Highest methane leak rate: 58, 000 kg/hour (Nov 28) • Total estimated methane leaked: 95, 000 tons or 5. 4 bcf NG (20% of statewide emissions) 20

Post-Leak SCAQMD and CARB Monitoring Activities • Continued air monitoring for several months after the leak was plugged to ensure leak is controlled, and ambient air concentrations of methane, benzene, H 2 S, and mercaptans have returned to typical levels • At and around the site: • Infrared imaging • Aircraft measurements • Mobile monitoring • Continued community monitoring for methane. With improving air quality: • CARB gradually phased out monitoring in August 2016 • SCAQMD gradually scaled down monitoring to two fixed sites and mobile platform • Key elements of SCAQMD Order for Abatement • Sponsor Ambient Monitoring • Sponsor Health Study (pending) • Implement Enhanced LDAR • Public Notification Plan 21

Other Notable Post-Leak Activities • LA County Public Health Department concluded Indoor Air Quality testing prior to returning home • Over 100 Lawsuits (private & Public) Pending 22

Returning Home • As air quality returned to normal, residents started returning home over several months • Exterior cleaning to ~ 1, 200 homes, parks, schools, play grounds • Interior cleaning of ~ 1, 500 homes • 38, 000 air filtration systems installed in: – 10, 500 homes – 60 schools – 160 businesses • So. Cal. Gas relocation costs: $500 million 23

Post-Leak Facility-Wide Activities • Ongoing investigation to determine leak cause • CPUC (Safety Enforcement Division + DOGGR) • Extensive testing to assure integrity of all 114 wells prior to returning to service (8 separate tests) • Testing results to date: • 29 wells passed integrity testing • 7 wells in 2 nd phase of diagnostic testing • 78 wells temporarily and mechanically sealed off • So. Cal. Gas replaced inner metal tubing of every well (> 40 miles of new steel piping) • Casing around each inner tubing has been tested to ensure integrity under pressure 24

Recent Development • November 1, 2016 So. Cal. Gas requested regulatory approval to resume injection through approved wells 25

Monitoring Going Forward • Continuous pressure monitoring of each well by So. Cal. Gas • So. Cal. Gas to implement LDAR program • Including daily monitoring of each well with IR cameras • So. Cal. Gas to conduct Fenceline monitoring through eight Open Path IR monitors • Community notification procedures established • Community monitoring by SCAQMD at two fixed sites and through mobile platform 26

Regulatory Front • CARB proposed regulation for crude oil and natural gas facilities (including gas storage facilities) • GHG Emission Standards, LDAR and monitoring requirements • DOGGR proposed regulation for gas storage • New Standards for gas storage and well construction • Testing and monitoring standards, emergency response plans • CPUC efforts (NG transmission & distribution) • SCAQMD proposed rulemaking • Closely monitoring rulemaking by CARB/DOGGR/Others • Require tighter controls, if necessary 27

Thank You! Any Questions? 28