Fence-line Monitoring

Petroleum refineries are some of the most significant stationary sources of criteria and hazardous air pollutants. A number of these refineries are located in the midst of residential neighborhoods with bordering schools and community services. Many local residents have a growing concern that air toxics may be crossing the refinery fence line into the bordering populace that could potentially pose a health risk to themselves and other community members In response to this concern, some states and local air districts have put regulations in place to measure and monitor toxic air gasses that may cross a refinery fence line. Following these requirements, Fence-line Monitoring Systems were installed to measure these hazardous air pollutants at the refinery perimeter/ fence line.

Fence-line Monitoring Technology

A traditional fence-line monitoring system utilizes a combination of both open-path and point monitoring to measure toxic air pollutants. An open-path air monitoring system utilizes beams of light to detect and quantify gases. The systems work by sending a beam of light into the open air and receiving it at a detector that is located a number of meters away (up to 900 meters). When gases are present in the beam, some of that light is absorbed and the detector can distinguish between a beam received in clean air, versus a beam in which gases are present.
The second type of air monitoring system used for fence-line monitoring programs are point sampling devices. The point-sample monitoring systems are suited for use in areas where the concentrations of gases are below the detection limits of open-path technologies, for pollutants such as particulate matter that cannot be detected by open-path technologies, and for areas where the sample path is too short for open-path systems


Typical Emissions Measured with a Fence-line System:

Measurements with an Open-path UV DOAS (Differential Optical Absorption Spectroscopy) include:

  • SO2
  • BTEX (Benzene, Toluene, Ethylbenzene, Xylene)

Measurements with an Open-path FTIR (Fourier-Transform Infrared Spectroscopy) include:

  • Volatile Organic Compounds (VOC’s)
    o Non-Methane Hydrocarbons
    o Formaldehyde
    o Acetaldehyde
    o Acrolein
    o 1,3-Butadiene
    o Styrene

Measurements with an Open-Path TDL (Tunable Diode Laser) and Point Monitors:

  • H2S

Measurements with a Point Monitor:

  • Black Carbon

Real-Time Websites and Data Acquisition

After air toxics are detected by the open-path or point-monitor systems, the raw data is stored within a Data Acquisition and Handling System (DAHS). This DAHS stores the data for many years and can provide a report format of the data that can be submitted to a local air district, if required. A real-time website is typically also required. This real-time website will display the toxic air emissions at a refinery fence line on a real-time basis for complete transparency to the neighboring residents and community.

CEMTEK KVB-Enertec – Fence-line Monitoring DAHS:

  • Systems are set up with local workstations to collect and analyze data.
  • Data is analyzed and recorded on a real-time basis.
  • Data is sent to a website that can be viewed from the internet on a real-time basis.
  • Raw data is archived for final QA/QC.
  • Monthly and quarterly reports are generated that summarize data.

Rules and Regulations that Require Fence-line Monitoring Systems

Although many petroleum refineries have elected to install fence-line, open path and point- monitoring equipment on their own, some states and local regulatory agencies are now requiring the installation of these systems. Listed below are some of the Rules and Regulations driving the installation of fence-line systems for compliance:

  • CARB (California Air Resources Board) Rule 617
  • California Local Air District: BAAQMD (Bay Area Air Quality Management District) Regelation 12, Rule 15
  • California Local Air District: SCAQMD (South Coast Air Quality Management District) Rule 1180
  • California Local Air District: SJVAPCD: (San Joaquin Valley Air Pollution Control District) Rule 4460

Key Advantages of Fence-line Monitoring Systems:

  • Real-time results are generated for each target gas found in the ambient air.
  • Low detection limits are in place to reveal air toxics below health impact standards.
  • Raw data can be stored and viewed at a later date for unknown gasses in the air.
  • The presence of each target gas can be easily verified.
  • On-stream efficiency is over 99%.
  • The systems are calibrated once each month.

CEMTEK KVB-Enertec™ Services Offered:

  • Development of Air Monitoring Plans
  • Work with refinery and local air districts to minimize overall project costs
  • Design, build and install fence-line monitoring systems
  • Operate and maintain systems after installation
  • Reduce overall resource impact on the refinery

CEMTEK KVB-Enertec™ Difference:

  • Cemtek projects are professionally engineered and executed, resulting in minimal impact on operations, personnel.
  • Cemtek has the resources to provide compliance-based systems and satisfy all rules and regulations.
  • Cemtek has over 50 years of monitoring experience to simplify complex regulations, systems and projects.
  • Cemtek will engineer, build, test, install, certify, and support the best equipment available to ensure long-term superior performance, including the peace of mind that comes with doing the job right.
  • Cemtek will answer and address all questions and concerns utilizing our vast project experience.
  • Cemtek provides top quality, high performing, reliable Fence-line Monitoring Systems.
  • Cemtek provides Air Monitoring Plans (AMP), Quality Assurance / Quality Control Plans (QA/QC) and robust, reliable Fence-line Monitoring Systems to meet stringent regulations.
  • Cemtek provides long-term maintenance and operation of Fence-line Monitoring Systems including:
    o Service contracts (Preventive maintenance and necessary audits)
    o Annual QA/QC audits required by local air districts
    o 24/7 Emergency Support
    o 24/7 Phone Support
    o Onsite Training