Valve Fugitive Emission Monitoring Programs (LDAR)

ted wang
Jun 4
2 min read

What Is an LDAR Program

Leak Detection and Repair (LDAR) programs are regulatory requirements for facilities handling volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). LDAR requires regular monitoring of valve stems, pump seals, flanges, and other equipment components to detect and repair leaks above threshold concentrations. Programs are mandated under EPA regulations including 40 CFR Parts 60, 61, and 63.

Monitoring Methods

EPA Method 21: organic vapor analyzer (OVA) probe placed at component interface, reading in ppm
Optical gas imaging (OGI): infrared camera visualizes VOC emissions without contact measurement
Permanent continuous emission monitors: real-time sensors for high-value or high-risk valves
Leak definition varies by regulation: 500 ppm or 10000 ppm depending on component type and standard
Bagging method: used to quantify leakage rate from an individual component

Component Identification and Tracking

Each regulated component must be identified with a unique tag number, component type, service classification (light liquid, heavy liquid, gas or vapor), and location. A site inventory database tracks monitoring history, leak findings, repair dates, and reinspection results. Typical LDAR monitoring frequencies range from monthly to annually depending on component type and regulatory subpart.

Repair and Reinspection Requirements

Leaking components must be repaired within 15 calendar days of detection
Difficult-to-repair components can receive delay of repair designation pending shutdown
After repair, component must be reinspected within 24 hours to confirm repair success
Three repair attempts within 45 days may qualify component for difficult-to-repair status
Annual review of repeat leakers triggers valve replacement consideration

Record Keeping and Reporting

LDAR regulations require detailed records of all monitoring events, leak detections, repairs, and reinspections. Annual reports submitted to regulatory agencies summarize leak rates, emission estimates, and program performance. Modern LDAR software integrates with plant asset management systems to automate scheduling, data capture, and regulatory report generation.