EPA works to clarify difference between closure devices and equipment
What’s the difference between “equipment” and “closure devices”? That’s the question EPA is trying to answer in relation to organic air emissions from hazardous waste tanks, containers, and surface impoundments. EPA will accept comments and information from the public on the topic until October 3.
It’s important to understand the difference between equipment and closure devices because they are regulated differently. Equipment is regulated at 40 CFR 264/265 Subpart BB and closure devices are regulated in 40 CFR 264/264 Subpart CC.
EPA says it wants to improve how it enforces the hazardous waste Organic Air Emissions Standards at hazardous waste treatment, storage, and disposal facilities and large quantity generators. In 2017, the agency launched a national compliance initiative called “Reducing Hazardous Air Toxic Emissions at Hazardous Waste Facilities.” Right away, EPA began receiving questions about the difference between equipment and closure devices, in part because closure devices are so similar to certain equipment, including valves and pressure relief devices.
Subparts BB and CC standards in 40 CFR 264/265 differ in several ways. Subpart BB establishes organic air emission controls for equipment leaks, while Subpart CC establishes controls for tanks, surface impoundments, and containers. Other differences apply to applicability thresholds, operation, inspection, monitoring, and repair requirements. For instance, Subpart BB requires facility owners and operators to monitor for leaks using instrument readings. Subpart CC allows for visual inspections.