California Air Resources Board

Quarterly/Annual Reporting Data

The Greenhouse Gas Emission Standards for Crude Oil and Natural Gas Facilities (Oil and Gas Methane Regulation) requires operators of natural gas underground storage facilities to submit ambient methane data gathered by the continuous monitors by July 1 of each calendar year for the previous calendar year’s data.

Additionally, leaks identified during either daily or continuous wellhead screening, that are above the minimum allowable leak threshold, must be reported to the California Air Resources Board (CARB) quarterly.

For questions regarding the Annual Report for Natural Gas Underground Storage Facilities, contact Oil and Gas Section.

2021 Annual Report

Monitoring Plans

In accordance with the Oil and Gas Methane Regulation, continuous ambient methane monitoring plans for natural gas underground storage facilities were required to be submitted to CARB by January 1, 2018. CARB received draft submittals from 12 facilities, conducted a review process, and conditionally-approved all monitoring plans by March 2019.

With conditional-approval, operators of those 12 facilities had 180 days to: (1) install the ambient monitoring systems, and (2) begin the 12-months continuous monitoring period to collect baseline data for ambient methane.

In September 2019, all operators had notified CARB that their ambient monitoring systems were installed and operational for baseline monitoring. Upon completion of the baseline monitoring period, operators had established the baseline ambient methane concentrations and alarm thresholds for each continuous monitor, in consultation with CARB.

In 2021, all 12 monitoring plans for the natural gas underground storage facilities were formally approved by CARB for full implementation (i.e., alarm thresholds programmed in monitoring systems). The continuous ambient methane monitoring and alarm systems at the following facilities are currently in operation with the approved baselines and alarm thresholds.

Note: "Date of Implementation" is the effective date when the continuous ambient methane monitoring system was fully operational with alarm mechanisms programmed. It is also the start of data collection that is required to be reported annually to CARB under the Oil and Gas Methane Regulation.