Seismic Monitoring Station - Hole in the Wall, Mojave Preserve


SCH Number
Public Agency
California Governor's Office of Emergency Services (OES)
Document Title
Seismic Monitoring Station - Hole in the Wall, Mojave Preserve
Document Type
NOE - Notice of Exemption
Document Description
This new station will contribute to the CA Earthquake Early Warning System (CEEWS) designed to potentially save thousands of lives during a large earthquake, prevent critical infrastructure damage and expedite recovery following a large earthquake. The network to which this sensor is connected will contribute real-time data to accurately record and warn people of strong shaking due to earthquakes in the region, and help provide records of ground motion that would be immense scientific, engineering and public safety value. Caltech/USGS plan to install and operate an outdoor seismic monitoring station at the Lat/Long location noted above. One-day installation will take place in a 20x20 ft. area (site footprint at finish 5'x5'), to install three small structures: 1. 3'x3'10" sensor vault set on a 6" concrete base, with an attached PVC-pipe posthole (10" diameter) running from center of vault to a maximum of 6' into the ground, leading to a seismometer; 2. 4'x4'x6" concrete base on which a battery box, solar panel equipment, and communications equipment are housed; and 3. Antenna mounted on a 2'-diameter pole supported by a 4'-deep concrete base. A flexible conduit 1' deep and 5" wide will connect the three structures. Grounding rods will be inset next to the equipment to protect the site from lightning strikes. Holes for the vault, solar panel mount, and antenna poles will be dug by a small backhoe or hand-operated auger. Access to site is entirely by existing roads and trails. There are no hazardous substances involved. If needed, a small generator (~8 KW) will be used to power a hand-loaded concrete mixer and any other tools needed for the work.

Contact Information

Ryan Arba
Agency Name
Office of Emergency Services, California
Contact Types
Lead/Public Agency


San Bernardino
Other Location Info

Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
S:15303,4,6, Class 3, 4, 6
Reasons for Exemption
New Construction or Conversion. Minor Alterations to Land. Information Collection.

Disclaimer: The document was originally posted before CEQAnet had the capability to host attachments for the public. To obtain the original attachments for this document, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at or via phone at (916) 445-0613.

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