Regulatory Developments, Special Topics in Environmental Management

EPA Rule Amends Leak Threshold for Site Remediation Facilities

In a final rule, the EPA has issued its Residual Risk and Technology Review (RTR) for the Site Remediation source category regulated under the Clean Air Act’s National Emissions Standards for Hazardous Air Pollutants (NESHAP).

The NESHAP applies only to active remedial operations at sites that are major sources with facilities subject to another maximum achievable control technology (MACT) standard. Site remediations subject to the Resource Conservation and Recovery Act (RCRA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) are not subject to the Site Remediation NESHAP. The EPA says 30 facilities must comply with this NESHAP. Another 33 site remediation facilities do not meet the compliance trigger. However, these facilities must have documentation to support the determination that the total annual quantity of the hazardous air pollutant (HAP) contained in the remediation material excavated, extracted, pumped, or otherwise removed at the facility is less than 1 metric ton per year.


RTRs comprise two parts. The intent of the first, or residual risk, part is to determine if the existing NESHAP protects public health with an ample margin of safety and, taking into consideration costs, energy, safety, and other relevant factors, prevents adverse environmental effects. Should the Agency find that these criteria are not being met, the NESHAP must be amended, typically with more stringent emissions standards. For the Site Remediation NESHAP, the Agency determined the public health and environmental criteria are being satisfied and no changes are necessary.

The second part of the RTR considers developments in practices, processes, and control technologies. If the EPA determines that these developments are cost-effective—that is, if the emissions reductions that adoption of the development would produce are worth the cost—the Agency must insert them into the applicable regulations.

For the Site Remediation NESHAP, the EPA did find one cost-effective development related to the leak detection thresholds for valves and pumps. A leak is detected and must be repaired whenever the measured concentration exceeds the threshold. The Agency is requiring facilities to use the leak detection thresholds of 40 CFR part 63, subpart UU for valves and pumps rather than those of 40 CFR part 63, subpart TT. The Agency says the additional reductions in HAP emissions resulting from this change will be approximately 4.7 tons per year.

Exemption During Routine Maintenance

Also, when the EPA proposed the rule in September 2019, it stated its intention to eliminate an existing exemption from the requirement that emissions control devices must be operated whenever gases or vapors containing HAP are vented through the closed-vent system to the control device. However, based on comments received on the proposal, in the final rule, the Agency revised this part of the proposal as it applies to storage tanks. Specifically, the final action continues to allow a facility to bypass control devices on storage tanks for up to 240 hours per year so that planned routine maintenance of the closed-vent system or control device can be performed. Facilities are restricted from filling the tanks for those 240 hours. Also, the final rule adds a work practice standard that requires no working losses from the tanks during the planned routine maintenance.

SSM and Electronic Reporting

The rule also removes the exemption from meeting the NESHAP during periods of startup, shutdown, and malfunction (SSM) to be consistent with a 2008 court decision—that is, the standards are applicable at all times. Finally, the rule requires electronic submittal of required performance tests and compliance reports through the EPA’s Central Data Exchange using the Compliance and Emissions Data Reporting Interface.

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