AVO: (Audible Visual Olfactory) – Leaks that can be seen, heard or smelled. Leaks detected in this manner demand immediate repair. The repair schedule is usually not treated like a leak found during normal Method 21 audits. The question has been raised as to whether or not leaks seen with an infrared camera qualify as AVOs.

CARBON OFFSET: (Carbon Credit) – Offsets of various greenhouse gasses are traded in units of equivalent carbon dioxide (CO2e). One metric ton of methane (CH4) = approximately 20 metric tons of CO2e.

CDM: (Control Development Mechanism) – A preapproved project method for reducing CO2 emissions that applies directly to Kyoto Treaty participants. Projects are used by developing countries to reduce emissions and gain certified emission reduction (CER) credits. These credits are sold to industrialized countries to offset their production of GHGs.

CHRONIC LEAKER: A component that is found to leak above a mandated leak definition twice during four consecutive quarters. Chronic valve leakers fall under special rules for repacking and replacement.

DOR: (Delay of Repair) – If a component is leaking and is justified as not repairable within the prescribed 15-day period, it can go on the DOR list. There is a list of conditions to be met before the component can on the DOR list. The state of California Air Quality Management Districts do not allow DORs. Some recent consent decrees put a cap on the number of components that can be on DOR. If the number is exceeded a plant may be forced to shut down to perform repairs.

ELP: (Enhanced LDAR Program) – A Leak Detection and Repair program being promoted via consent decree that focuses on preventive measures as the way to lessen and eliminate fugitive emissions. Enhanced LDAR requires the use of certified low-leak valves and packing technology.

INJUNCTIVE RELIEF: This is a court-ordered set of actions to be performed or prohibition against certain acts or condition requested to remedy violations of regulations. In a consent decree action these are ordered by judicial decree, are not the result of a trial and are usually negotiated by the parties involved.

LDAR: (Leak Detection And Repair) – A program that dictates monitoring, repairing and recording data of regulated components in a process plant.

LEAK DEFINITION: The leak level at which compliance is determined. This can change depending on the component, regulations and consent decree.

OPEN-ENDED LINE: (OEL) – Pipelines or valves that do not have functional plugs or blind flanges. Fines are levied for OELs.

PROCESS EMISSIONS: Emissions that are an expected part of the process.

REGULATED COMPONENT: A component covered by consent decree, federal, state or local laws (regulations). Some components are outside the scope of the law and are unregulated components.

TVA: (Toxic Vapor Analyzer) – Used for Method 21 monitoring. Analyzers are of the FID-flame ionization detector or PID-photo-ionization detector types.

VOC: Volatile Organic Compound – An organic (carbon containing) substance that is in gas form (vapor) at ambient atmospheric conditions.

The terms and definitions for this glossary were contributed by Jim Drago, P.E., Garlock Sealing Technologies, a provider sealing and leak detection systems for process fluid applications. Mr. Drago can be reached at jim.drago@garlock.com.