Q503. In the onshore natural gas transmission compression industry segment and underground natural gas storage industry segment, is monitoring for compressor scrubber dump valve leakage required only for condensate tanks at the facilities?

Q503. In the onshore natural gas transmission compression industry segment and underground natural gas storage industry segment, is monitoring for compressor scrubber dump valve leakage required only for condensate tanks at the facilities (not other tanks at the facility or not at the facility)?

A503. Yes, as specified in 40 CFR 98.233(k) for facilities in the onshore natural gas transmission compression industry segment in all reporting years, only condensate storage tanks (water or hydrocarbon) require monitoring for compressor scrubber dump valve leakage and quantification of the leak rate if a leak is detected. Similarly, beginning in RY 2025, the same requirement applies to facilities in the underground natural gas storage industry segment. Note that only tanks within the facility boundary are subject to reporting. Also note that this answer pertains only to the compressor scrubber dump valve leakage monitoring requirements in 40 CFR 98.233(k) and not to equipment leak requirements in 40 CFR 98.233(q).