Scope the waste.
Then scope the equipment.

Begin with the waste determination

Equipment cannot be scoped correctly from a piping and instrumentation diagram alone. The facility first needs to identify the hazardous waste, its point of generation, composition, organic content, volatile-organic concentration, physical state, and the units in which it is accumulated or managed.

The Subpart BB and CC thresholds measure different things and use different applicability structures. A conclusion for one subpart should not be copied into the other without a separate evaluation.

Subpart BB follows components

Subpart BB applies to specified equipment that contains or contacts hazardous waste with the organic concentration described by the rule. Potentially covered equipment includes pumps, compressors, pressure-relief devices, sampling connection systems, open-ended valves or lines, valves, flanges, and other connectors.

The equipment list should be created in the field. Small lift stations, double-diaphragm pumps, conservation vents, pressure-relief devices, drain valves, sample ports, flexible connections, and cabinet piping are easily omitted when the review relies only on design drawings.

Subpart CC follows management units

Subpart CC addresses tanks, surface impoundments, and containers that manage hazardous waste meeting the rule’s volatile-organic criteria unless an exclusion or exemption is supported. The evaluation must consider the waste at the regulatory point of waste origination, the unit type and capacity, how waste is added or removed, openings and closure devices, vapor pressure or service conditions when relevant, and the selected control level.

A closed-looking unit is not necessarily a compliant unit. Hatches, gauge openings, vents, conservation devices, transfer connections, and drum bungs may have their own inspection, closure, monitoring, or recordkeeping implications.

Drawings, tags, and records must agree

A practical program connects the process-flow diagram, piping and instrumentation diagram, equipment list, field tags, monitoring route, inspection forms, waste profile, and applicability memorandum. Each component and unit should have a durable identifier that can be followed from the drawing to the field and into the monitoring record.

When the facility uses an alternative standard, exemption, or concentration determination, the underlying data and assumptions should be retained. The compliance position should be understandable to someone who did not perform the original evaluation.

Startup and change management are critical

The best time to scope Subpart BB and CC is before the system starts. The review should be triggered by a new waste stream, new tool, larger container, revised collection route, added tank, new vent, changed operating concentration, or new off-site profile. Waiting until annual monitoring begins can reveal that equipment was never tagged, records were never created, or the selected closure design cannot meet the intended standard.

A defensible scoping sequence

1. Document the waste determination and regulatory point of waste origination.
2. Determine the separate concentration and applicability basis for Subpart BB and Subpart CC.
3. Walk the entire system from generation through final accumulation or removal.
4. Tag every potentially regulated component, opening, and management unit.
5. Select and document the applicable control, inspection, and monitoring standards.
6. Build the monitoring route and records from the verified equipment list.
7. Require a scope review whenever the waste, equipment, or operating conditions change.