Colorado Reg. 7 2014 Revisions Storage Tank Emission Management Jul 10 | 2014 Marley Bain

Reg. 7 Revisions – Overview Revisions to Reg. 7 adopted February 2014, effective April 2014 AQCC Regulation Number 7 – Control of Ozone Via Ozone Precursors and Control of Hydrocarbons Via Oil and Gas Emissions (VOC regulation) Section XII and XVII focus on Oil and Gas emissions XII: Ozone non-attainment area XVII: State-wide Enforced by CDPHE

Reg. 7 Revisions - Outcome Expansion of several non-attainment area requirements statewide Low bleed or intermittent bleed pneumatics Control of storage tank emissions at lower thresholds New requirements not previously included in Section XII Definition of ‘hydrocarbon’ includes methane/ethane Leak detection and repair (LDAR) requirements Audio, visual, olfactory (AVO) checks Well unloading and maintenance Storage tank emission management (STEM)

STEM Overview Purpose: Develop a Plan(s) to meet the storage tank “without venting” requirements. Required for storage tanks with VOC emissions > 6tpy (rolling 12-month uncontrolled actuals) NOT required for storage tanks containing stabilized liquids or tanks controlled during the first 90 days of production Implementation of STEM Plan Construction Date Compliance Date On or after May 1, 2014 Within 90 days of commencing tank operation Prior to May 1, 2014 May 1, 2015 Increase in VOC emissions to > 6 tpy Within 60 days of discovering increase

STEM Plan (XVII.C.2.b.(i)) Selected control technologies Monitoring practices Operational practices and/or other strategies Procedures for evaluating ongoing storage tank emission capture performance Monitoring with “Approved Instrument Monitoring Method” (AIMM) Specific implementation schedule for AIMM Certification by the owner or operator that the STEM strategies are designed to minimize emissions from storage tanks and associated equipment Additional requirements in Statement of Basis and Purpose

AIMM Frequency – new tanks AIMM is a defined term in the rule Tanks constructed on or after May 1, 2014 VOC Emissions (tpy) Initial Monitoring Subsequent Monitoring > 6tpy Within 90 days of commencing operation > 6 and < 12 -- Annual > 12 and < 50 Quarterly > 50 Monthly

AIMM Frequency – new tanks AIMM is a defined term in the rule Tanks constructed on or after May 1, 2014 VOC Emissions (tpy) Initial Monitoring Subsequent Monitoring > 6tpy Within 90 days of commencing operation > 6 and < 12 -- Annual > 12 and < 50 Quarterly > 50 Monthly

Recordkeeping (XVII.C.3) STEM Plan, updates, and certification Records of monitoring (kept for 2 years) Tank AIRS ID Date and duration of any period of thief hatch, prv, or other access point venting (except as allowed) Date and duration of periods when control equipment is not operating Timing of and efforts made to eliminate venting, restore operation of control equipment, and mitigate visible emissions List of equipment associated with tank that is designated as unsafe, difficult, or inaccessible to monitor – including explanation of designation and monitoring plan