SF6 (Sulfur Hexafluoride)
Federal Regulation 40 CFR Part 98 Subpart DD
EXECUTIVE SUMMARY
The Environmental Protection Agency (EPA) regulates greenhouse gas (GHG) emissions. Sulfur Hexafluoride or SF6 gas is an electrical insulator commonly used in circuit breakers, pressurized cylinders, gas-insulated substations, and switchgear (including closed-pressure and hermetically sealed-pressure switchgear and gas-insulated lines). SF6 has the potential to be emitted or leaked to the atmosphere from aging equipment or during equipment maintenance, servicing, and installation. As of 2011, mandatory annual greenhouse gas reporting to EPA is required for electrical transmission and distribution “facilities” with a combined total nameplate capacity of all equipment containing SF6 over 17,820 lbs. “Facilities” below this threshold do not have to report to the EPA, but still have some record keeping requirements. Presently, AECI annually submits the greenhouse gas report to EPA for its member-owners who are above the reporting threshold by March 31. Please note, AECI asks that member-owners supply information needed for reporting by February 1 each year.
DEFINITIONS
Distribution miles: length of lines carrying voltages at or below 35 kV.
Facility: an electric power system that is comprised of all electric transmission and distribution equipment insulated with or containing SF6 that is linked through electric power transmission or distribution lines and functions as an integrated unit, that is owned, serviced, or maintained by a single electric power transmission or distribution entity (or multiple entities with a common owner).The facility also includes servicing inventory for such equipment that contains SF6. AMEC/AECI Legal Counsel has further defined a “facility” subject to SF6 reporting requirements (as described herein)as one that is both owned and controlled by AECI and is also ≥161 kV.
Transmission miles: length of lines carrying voltages above 35 kV.
FACILITIES BELOW THE 17,820 LBS SF6 THRESHOLD
If the combined total nameplate capacity of all equipment containing SF6 at a “facility” is ≤17,820 lbs., then the facility owner must keep an up to date SF6 inventory. An annual review of a facilities SF6 inventory is recommended. There are no other record keeping requirements.
FACILIITES ABOVE THE 17,820 LBS SF6 THRESHOLD
If the combined total nameplate capacity of all equipment containing SF6 at a “facility” is >17,820 lbs., then the following requirements pertain:
- Must have a Monitoring Plan;
- Required to maintain equipment information;
- Required to weigh Cylinders; and
- Submit an annual report to EPA.
Note: Presently, AMEC Members with facilities above the 17,820 lbs. SF6 threshold annually submit equipment information to AECI by February 1. In turn, AECI submits the mandatory annual report to EPA for all member-owners subject to greenhouse gas reporting by its due date of March 31.
Monitoring Plan Requirements
Facilities above the SF6 reporting threshold are required to have an SF6 Monitoring Plan in place. It is recommended that Monitoring Plans are reviewed annually and updated as needed. The Monitoring Plan must include the following:
List of relevant definitions (e.g., Facility);
Identification of job functions and roles and responsibilities for all individuals involved in the tracking and maintaining of equipment and records;
Explanation of processes and methods, equations for making calculations, and references to other existing documents;
Quality Assurance / Quality Control (QA/QC) and verification procedures; and
Transmission miles and distribution miles.
Note: AECI has developed the required SF6 Monitoring Plan and will send to member owners, as applicable.
Equipment Information Requirements
Facilities above the SF6 reporting threshold are required to maintain equipment information. It is recommended that equipment information is reviewed annually and updated as needed. The following information must be maintained:
Nameplate capacity of each individual piece of SF6 containing equipment in pounds.
Pounds of SF6 stored in containers but not energized both at beginning and end of year.
Pounds of SF6 purchased in bulk from producers, distributors, equipment manufacturers, and equipment with SF6 already inside.
Pounds of SF6 sent offsite for recycling, returned to suppliers, sold, or destroyed.
Cylinder Requirements
Facilities above the SF6 reporting threshold must perform the following on SF6 cylinders:
Weigh all cylinders at the beginning and end of the year on scales that are certified to be accurate and precise within two (2) pounds of true weight; and
Periodically recalibrate the certified scales used to measure SF6 quantities using the scale manufacturer’s instructions / specifications.
RECORDKEEPING
Retain all required records for at least three (3) years from the date of submission of the annual greenhouse gas report for the reporting year in which the record was generated. Records must be maintained in a way that allows them to be readily available in the event of an EPA inspection and/or review. The following records must be retained:
- A list of all units, operations, processes, and activities for which GHG emission were calculated; [member-owner responsible]
- The data used to calculate GHG emissions for each unit, operation, process, and activity, categorized by fuel or material type (i.e., SF6 in this instance); [AECI responsible]
- The annual GHG reports; [AECI responsible]
- Missing data computations; [member-owner and AECI responsible]
- A written GHG Monitoring Plan; [AECI responsible]
- Scale accuracy certification, recalibration, and maintenance records; [member-owner responsible] and
- Equipment information. [member-owner responsible]
AECI compiles data received annually by February 1 from each member-owner, calculates the annual SF6 emissions, and submits the greenhouse gas report, which is due to the EPA annually by March 31. AECI will send completed reports to member owners for their records.
Rob LeForce, AECI, revised August 18, 2014.