Country
Assessment
Rule 903 of the Environmental Impact Prevention 900 Series, 2021 , requires a 98 percent design efficiency for the combustion of flare gas. This requirement is in line with the Environmental Protection Agency’s national legislation (see section 20 of the case study on US federal offshore production).
US environmental law includes detailed requirements for flare design. Title 40 CFR § 60.18 provides general requirements for flares; other subparts include more details. Title 40 CFR § 63.987 requires a flare compliance assessment, provides certain technical details, and refers to other sections of the law for submitting flare compliance assessments (§ 63.999(a)(2)) and keeping records (§ 63.998(a)(1)). Title 40 CFR § 63.11 provides detailed performance requirements for flare design. For example, there should be no visible emissions, except for periods not to exceed a total of five minutes during any two consecutive hours; a flame should always be present; and the heat content of gas and the exit velocity must be calculated using the formulas provided in § 63.11. Taken together, environmental regulations require that flares be operated and maintained in a manner consistent with “good air pollution control practices,” typically interpreted to mean a combustion efficiency of 98 percent. Title 40 CFR § 63.11 also provides alternative practices for monitoring leaks. Standard practices for monitoring leaks are provided in other parts of Title 40, including § 60, which apply to any stationary source subject to the NSPS, and § 61 and § 63, which apply to hazardous air pollutants. Appendix A-7 of § 60 details calculation methodologies for all regulated emissions, including volatile organic compound leaks, that are applicable for a diverse set of facilities. The proposed EPA NSPS rule also has performance requirements such as continuous monitoring of the pilot flame. If a flare failure causes a “super-emitter” methane event, the operator is required to bring the flare into compliance promptly under the Super-Emitter Response Program.
Section 20 of the preceding case study, on US federal offshore production, covers national environmental regulations with performance requirements applicable to flares. For onshore operations, Title 43 CFR § 3179 required operators to find and repair leaks at least twice a year. However, a court vacated Subpart 3179 in 2020. One of the litigants’ concerns was that the cost of adding equipment for leak detection would be too high for many small operators. The proposed rule reinstates Subpart 3179, which has performance requirements with respect to safe operation of flares, limits on flared and vented volumes under various circumstances such as well completions. Subpart 3179.301 of the proposed rule requires operators to maintain a leak detection and repair program, which will be subject to annual (or more frequent) inspections. Any leak must be repaired as soon as practicable but no later than 30 days after its discovery (Subpart 3179.302). Operators must provide a report on each inspection as well as an annual report (Subpart 3179.303).
The NDIC regulations are designed to provide operators maximum flexibility to manage their drilling, operation, and gas capture plans within the gas capture goals . The standards are applied state-wide, then at the county level, field level, and well level. The enforcement mechanism provides that if the operator cannot attain the capture goals at the maximum efficiency rate, wells will be restricted to 200 barrels of oil a day if at least 60 percent of the monthly volume of associated gas produced from the well is captured. Otherwise, oil production from such wells should not exceed 100 barrels of oil a day. Because of the unique properties of the geologic formations in Bakken, DAQ has developed guidelines and regulations related to the air quality requirements of facilities producing and processing oil and gas from these formations. More efficient pollution control is required for tanks located on sites where the emissions of volatile organic compounds from tanks are greater than 20 tonnes a year, and such controls must be in place and operational within 60 days of production starting. Companies need to meet certain performance requirements to qualify for a DAQ air permit (see section 10 of this case study). NDAC Section 33.1-15-20, 2019 , focuses on preventing significant deterioration of air quality as a result of emissions from oil and gas well production facilities and refers to many other sections of Chapter 33.1-15 on Air Pollution Control. NDAC Section 33.1-15-20, 2019, provides a formula to calculate emissions, which should meet ambient air quality standards as outlined in NDAC Section 33.1-15-02, 2019. Flares must have automatic ignitors or continuously burning pilots, and the flare stack must be tall enough for adequate dispersion of emissions. NDAC Section 33.1-15-07, 2019 , bans the release of organic compounds in gaseous and vapor forms except in emergencies or when flared or combusted in another effective control device approved by the NDIC. NDAC Section 33.1-15-03, 2019 , restricts the opacity of emissions from flares. According to DAQ, equipment at oil and gas facilities in North Dakota may be subject to Title 40 Code of Federal Regulations (CFR) § 60 and § 63. DAQ has also implemented the national New Source Performance Standards, as outlined in Title 40 CFR 60 Subpart OOOO and Subpart OOOOa. Flares on federal and Indian lands must meet federal performance requirements (as detailed in section 20 of the case study on US federal offshore production).
The TCEQ provides guidance on how flares must be designed and operated, based on the specifications of Title 40 Code of Federal Regulations (CFR) § 60.18. Among other requirements, it requires flares to be always operated with a flame present or have a constant pilot flame, which should be continuously monitored by a thermocouple, infrared monitor, or ultraviolet monitor. There should be no visible emissions, except during periods not exceeding a total of five minutes during any two consecutive hours.