General Siting Criteria

The air monitors that provide these readings are located strategically throughout the City of Richmond. These secure monitoring locations were selected in a year-long collaborative process that involved neighborhood council and City of Richmond input in addition to a number of other factors, including Environmental Protection Agency (EPA) and California Air Resources Board (CARB) criteria.

There are three fence line air monitors located strategically on the perimeter of the Chevron Richmond Refinery. There are also three community air monitors, located in monitoring stations and trailers in the three residential communities of Atchison Village, North Richmond and Point Richmond. These community air monitors involve a more complex set of equipment that samples a wider variety of chemicals than the fence line monitors. The substances selected for these readings are based on consultations with the City of Richmond and the Bay Area Air Quality Management District (BAAQMD).

The following considerations, consistent with guidance from the EPA and CARB, were made in selecting our monitoring sites:

Logistical Requirements

  • Does the site have access to power the monitoring equipment?
  • Does the site have the capability to access the Internet for real-time data reporting, on-line troubleshooting and remote access for emergency response activation?
  • Does the site have adequate security?

Environmental Requirements

  • The site should have no large scale sources between the monitor and the Chevron Refinery.
  • The site should be located away from local minor sources, such as furnace or incineration flues.
  • The site should be located 20 meters away from the drip-line of tree(s) and/or 10 meters away from trees that act as an obstruction.

Sampling Requirements

  • If the site is set on a building there should be unrestricted air flow 270 degrees around the sampler or 180 degrees if the sampler is on a side of a building
  • The distance from sampler, probe, or 90% of monitoring path to obstacle, such as a building, must be at least twice the height the obstacle protrudes above the sampler, probe, or monitoring path.

Although difficult to meeting all of the above criteria for fence line and community monitoring stations in complex urban environments, every effort has been made to minimize the impact of obstructions and secondary sources.

CARB Air Handbook

CARB Siting Criteria

EPA Siting Criteria