Leak Detection and Repair (LDAR) Requirements and Oil and Gas Operations - revised 28 Nov. 2019
April 22, 2016

(Updated 28 November 2019)

The oil and gas (O&G) industry uses Leak Detection and Repair (LDAR) programs to reduce methane and VOC emissions from their operations. Existing federal and state regulations require LDAR at O&G production facilities. Also, voluntary industry programs are an integral part of the effort to reduce methane and VOC emissions form O&G facilities and equipment.

HY-BON/EDI IR camera user conducting IQR survey (Identify, Quantify and Rectify) for leaks. 

 IQR picture.png


Reasons for LDAR

Some reasons to monitor for leaks include:

  • Safety considerations to minimize leaks of flammable gases, H2S and other potentially harmful hazardous air pollutants such as benzene.
  • Federal and state regulations requiring leak monitoring.
  • Ensure leak free operation of the closed vent system (piping) serving emission control systems (e.g., vapor recovery unit, vapor combustion units). NSPS OOOO/OOOOa has requirements to monitor emission control closed vent systems for storage tanks.
  • Implement voluntary methane reduction programs such as ONE Future.
  • Obtain emission reduction credits based on using emission factors that are lower than facilities not using a LDAR program. The Texas Commission on Environmental Quality (TCEQ) has a model Emission Reduction Credit Program for ozone nonattainment areas that includes LDAR for reducing fugitive leaks.
  • Minimize wasteful leaks and increase product sent to sales
  • Minimize odors from impacting nearby public areas and landowners


Component Types Covered under LDAR

LDAR programs typically apply to equipment in VOC service, such as:

  • Storage tanks
  • Compressors
  • Connectors and flanges
  • Open-ended lines
  • Instruments, meters
  • Pressure relief devices
  • Pumps
  • Sampling connections
  • Valves


LDAR Program Requirements 

Most LDAR requirements include:

  • Approved methods for detecting natural gas leaks
  • Definition of a leak
  • Equipment and components required to be monitored
  • Monitoring frequency (e.g., monthly, quarterly, semiannually, annually)
  • Leak repair requirements
  • Recordkeeping and reporting


Regulations and Programs for LDAR

Examples of regulations and programs that require or encourage the use of LDAR for O&G production facilities upstream of gas processing facilities include:

  • 40 CFR 60 Subpart OOOOa – affects oil and gas facilities constructed on or after September 18, 2015. Requires the monitoring of equipment components in based on
  • 40 CFR 60 Subpart OOOO – affects oil and gas (O&G) facilities constructed after August 23, 2011, and on or before September 18, 2015. This rule only requires leak monitoring for tank hatches and closed vent system for OOOO required emission controls. This regulation does not require the detailed component equipment leak monitoring required by NSPS OOOOa.
  • 40 CFR 98 Subpart W – Mandatory Greenhouse Gas (GHG) Reporting rule.
  • Texas Commission on Environmental Quality (TCEQ) oil and gas Standard Permits and Permits by Rule (PBR).
  • Colorado Department of Health and Environment – CDPHE Regulation 7
  • Pennsylvania Department of Environmental Protection (DEP) Exemption Category No. 38 and GP-5 LDAR program


Typical and New Monitoring Methods for Leaks

Some typical leak monitoring methods are listed below. Always review the regulatory requirements to determine the approved leak detection methods.

  • Audio, visual, olfactory (AVO) for certain components – no instrument required.
  • EPA Method 21 using volatile organic analyzer (VOA) meter reading in parts per million by volume (ppmv). The concentration varies from a VOA meter reading of 500 ppmv to 10,000 ppmv depending on the regulation.
  • Optical gas imaging (OGI) using “InfraRed Cameras” such as FLIR, Rebellion OGI, Picarro.
    • Hand held sensors
    • Land vehicle mounted sensors
    • Unmanned aerial vehicle (UAV) or “drone” mounted sensors


Definition of a Leak

Leaks are normally defined in terms of leak thresholds. The leak threshold depends on the method used to survey for leaks. Existing and past regulations have required fugitive emissions to be monitored using sensory monitoring (e.g., audio, visual, olfactory) or EPA Method 21 meters to determine if a leak exceeded a set threshold (e.g., the leak concentration was greater than the leak definition for the component).

  • For audio, visual, olfactory (AVO) methods a leak is typically considered any detectable emissions.
  • EPA Method 21 monitoring has leak thresholds ranging from 500-10,000 ppm. Proposed NSPS OOOOa is considering leak thresholds of 500 ppm, 2,500 ppm and 10,000 ppm.
  • For OGI cameras, the leak threshold is normally considered to be detection of visible emissions (i.e., emissions that can be seen using OGI cameras).


LDAR Monitoring Frequency

Monitoring frequency varies depending on the regulatory programs. This can include:

  • Weekly audio, visual, olfactory (AVO) methods
  • Quarterly, semiannual or annual monitoring using Method 21 or OGI camera.
  • Operators may reduce monitoring frequency if the leak rates are less than a set percentage of the total number of components. This can vary from 2% to 5% of the total.
  • For most programs, if the monitored leak percentage is below the set percentage, the operator can skip a monitoring period; skipping monitoring normally will only reduce the frequency to an annual basis – provided the leak percentage stays below the set percentage. If leaks are detected over the set percentage, then the monitoring frequency can increase – depending on regulatory or program requirements.


LDAR Recordkeeping

Monitoring records must be kept on location or other approved location and available for inspection by the regulatory agency. Typical recordkeeping includes all monitoring records such as:

  • Monitoring dates
  • Monitoring equipment used
  • Calibration records
  • Listing of components monitored
  • Number of leaks detected
  • Date(s) of successful repair of the leak(s)
  • Deviations from the monitoring plan


LDAR Reporting

Most programs do not require copies of the LDAR monitoring to be reported to the regulatory agency. NSPS OOOOa requires submittal of an annual report of the results of LDAR monitoring.


Concerned about Venting of Natural Gas?

Let HY-BON/EDI assist your company with your LDAR needs. Using our Identify, Quantify and Rectify (IQR) services and our ongoing Vent Gas Management (VGM) system, we can help you stay in compliance with LDAR requirements. HY-BON/EDI’s vent gas management (VGM) system is a cost effective way to take this issue off of your plate. We use “best in class” vapor recovery units (VRU), Vapor Recovery Towers (VRT) and enclosed combustion devices (ECD or VCU) to comply with storage tank emission control requirements. 

Avoid regulatory compliance issues by remotely monitoring the state of tank hatches, gates, valves, and other mechanisms. HY-BON/EDI’s. Hatch Sense is the only safe, wireless thief hatch alert system with monitoring capabilities. Since we meet the UL Class 1 Div 1 requirements for intrinsically safe equipment Hatch Sense can be deployed now at your production facilities and solve problems. Operators can use Hatch Sense to demonstrate to regulators their proactive approach to minimizing leaks and increasing compliance.


Cimarron Energy Acquisition of HY-BON/EDI

Cimarron’s acquisition of HY-BON/EDI in July 2019 means that our environmental product and services offered to our oil and gas customers are further strengthened. This includes the following:

  • BTEX combustor unit for glycol dehydrators
  • Tankless facilities
  • Mobile glycol reclamation system
  • Vapor Recovery Units (VRU)
  • Vapor Recovery Towers (VRT)
  • Flares
  • Enclosed Combustion Devices (ECD)
  • Leak Detection and Repair (LDAR) services
  • Vent gas measurement services
  • Field service
  • Parts

For more information on our products and services, you can contact us at +1 (844) 746-1676 or visit https://www.cimarron.com.