Petroleum refineries carry some of the densest, most heavily regulated component counts in the country — and the most scrutiny. Between Refinery MACT, the benzene fenceline program, and a decade of consent decrees, there is no margin for a sloppy LDAR program. AIM™ EH&S runs Leak Detection and Repair (LDAR) at refinery scale, with crews who have walked the units they monitor.
Which Rules Apply at Refineries
Refinery equipment leaks fall under NSPS Subpart GGGa (500 ppm for valves, 2,000 ppm for pumps) and Refinery MACT (40 CFR 63 Subpart CC). Subpart CC also requires fenceline benzene monitoring — a network of passive monitors sampled every two weeks against a 9 µg/m³ annual-average action level, with a 45-day root-cause and corrective-action clock when you cross it. Many refineries also operate under consent-decree LDAR terms that run stricter than the federal floor. We read the applicable subpart and decree language for your units instead of guessing.
What We Do
Method 21 component monitoring, OGI surveys where allowed, pressure-relief-device and flare monitoring, repair tracking against the regulatory clock, fenceline data QA, semiannual report preparation, and audit-grade recordkeeping — from a single unit to a full refinery component inventory. We build programs that keep the fenceline number down, not just paperwork that looks clean.
Why Refinery Operators Call Us
Refinery-scale experience, calibrated instruments, and defensible data every time. We have stood up programs under consent-decree scrutiny and survived the audits that follow. No fluff, no padded headcounts.
Refinery LDAR FAQs
Which regulations govern refinery LDAR?
Refinery equipment leaks fall under NSPS Subpart GGGa (500 ppm for valves, 2,000 ppm for pumps) and Refinery MACT (40 CFR 63 Subpart CC), which also adds fenceline benzene monitoring. Many refineries run stricter terms under a consent decree. See our LDAR compliance overview for how the rules fit together.
How does refinery fenceline benzene monitoring work?
A network of passive samplers around the unit perimeter is collected every two weeks and averaged over a rolling year against a 9 µg/m³ action level. Cross it and a 45-day root-cause and corrective-action clock starts. We handle sampler siting, chain of custody, lab QA, and the corrective-action paperwork.
Do you use optical gas imaging (OGI) or Method 21?
Both. We run Method 21 component monitoring for compliance counts and OGI surveys where the applicable subpart allows it, then track every repair against the regulatory clock.
Can AIM run an LDAR program under a consent decree?
Yes. We have stood up and run programs under consent-decree scrutiny and the audits that follow — we read the decree language for your units instead of guessing.
Which regions do you cover?
Nationwide, with deep coverage of the major refining corridors — including Texas and the Gulf Coast. See all regions we serve.
Get an LDAR Program That Holds Up
Whether it is a turnaround, a new unit, or a decree obligation, we scope it straight. Talk to someone who has walked the unit.
Two tools that keep refineries ahead of the rule
The same regulatory engine we run for clients, put in your hands.