About the Fence-Line Methane Monitoring System
The methane monitoring system utilizes a laser-based open path technology composed of four sensors strategically located near each of the corners of the facility, or “fence-line.” [1] These sensors are being continuously monitored 24 hours a day, seven days a week by SoCalGas Operations staff who oversee the system and respond accordingly as needed. Baseline conditions have been established to determine response levels.
The four monitors installed at Ventura Compressor Station measure the concentration in parts per million (ppm) of methane in the air across all four fence-lines of the facility. Methane readings can potentially be impacted by weather conditions, such as rain, wind, fog and dust, that may interrupt the beam and appear offline by displaying an “O”.
See Frequently Asked Questions for more information on baseline conditions and response thresholds.
Ventura Compressor Station Fence-Line Methane Monitoring Dashboard Tutorial
Fence-Line Methane Monitoring Interactive Dashboard
As part of our continued commitment to maintain clear and transparent communication with the community, we’ve developed an interactive dashboard to allow public access of methane monitoring data collected at the Ventura Compressor Station. This interactive dashboard can be used to view the concentration levels of methane being detected in the air at each of the monitoring stations we’ve placed at the facility.
*The dashboard is intended for desktop mode usage
Communications Log Link
SoCalGas will automatically record and post an entry into the Communications Log if the methane levels are elevated for 20 minutes or more. The log entry can be found here and will include updates after the investigation has been completed.
The fenceline monitoring equipment and website is for informational purposes only and does not replace existing guidance for gas leak detection. If you suspect a natural gas leak, evacuate the are immediately, and from a safe location call SoCalGas at 1-800-427-2200. If you experience any issues with this number, please call 911.
[1] This methane monitoring site is maintained and operated by SoCalGas.
Frequently Asked Questions
What is the purpose of the system?
- The system monitors the amount of methane in the air at the perimeter of the facility. We installed the fenceline monitoring system to provide greater transparency to the community about our ongoing operations at the facility.
How does the fence-line system work?
- The four monitors installed at Ventura Compressor Station measure the concentration in parts per million (ppm) of methane in the air across all four fence-lines of the facility.
- The interactive web page displays a map indicating the location of the fence-line methane monitoring devices. By clicking on any of the fence-line monitor icons, the viewer can view a chart with data showing monitored methane levels in parts per million, recorded in ten-minute increments over the previous 24 hours.
- In addition to methane levels, the online tool displays data from the weather station at the facility. Clicking on the weather station icon or moving the computer mouse over the methane data charts allows you to see weather data, including wind speed and direction.
- There is a help guide on the right side of the screen to assist with understanding of the system. If a monitor is offline due to maintenance or inclement weather, the screen shows an “O” for offline.
Who monitors the fence-line data?
- The data from our fence-line system is monitored around-the-clock, 365 days a year by SoCalGas’ operations center.
Does SoCalGas change the data before it is displayed online?
- No. The data is collected every 30 seconds, averaged each minute from the monitors and goes directly into the system, which is then displayed on a ten-minute interval on the website. We do not alter the data.
Why does the system often show a steady reading at 2 parts per million?
- SoCalGas worked with its Air Quality Consultant for more than a year to test and calibrate the methane monitoring system. The consultants determined that 2 parts per million (ppm) is the background level of methane at Ventura Compressor Station. Therefore, a flat line at 2 ppm means that the monitors do not detect any methane above background levels. For comparison, the Rose Bowl holds approximately 93,000 people. If you had five completely sold-out events, almost 500,000 people, 2 ppm is equivalent to one person not in attendance.
What actions does SoCalGas take if the readings increase?
- If our fence-line system detects elevated levels of methane concentration a technician will respond to the facility and conduct an investigation. The technicians use company approved leak detection methods and devices.
- We investigate to determine if there is a leak. Methane readings can potentially be impacted by weather conditions, such as rain, fog, and dust, which may interrupt the laser beam. A temporary increase in the readings on one monitor may not necessarily mean that elevated levels of methane are present.
- If we detect a leak, we will begin our normal process of addressing the leak and follow our notification requirements which are aligned with the safety codes mandated by the State.
- A recorded entry to the Communications Log webpage will be made if the methane concentration exceeds 10 ppm for 20 or more minutes. The log entry will be updated after the investigation has been completed.
What does it mean when the readings show at 0 ppm?
- If the monitor is offline due to maintenance or weather, it will display an “O” on the interactive map and will return a result of zero parts per million (ppm).
- Readings can be impacted by weather conditions, such as rain, fog, and dust, which may interrupt the laser beam and cause a monitor to appear offline.
Where can I get additional information?
For more information on the fence-line system, please visit our website at www.socalgas.com/ventura.