Seismic Monitoring Station


SCH Number
Public Agency
California Governor's Office of Emergency Services (OES)
Document Title
Seismic Monitoring Station
Document Type
NOE - Notice of Exemption
Document Description
These new stations will contribute to the CA Earthquake Early Warning System (CEEWS) designed in accordance with the mission of the USGS, this station could help protect against loss of life and property during a large earthquake. It will also help to 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 of immense scientific, engineering and public safety value. Under a ten-year lease with property owner, USGS plans to install and operate an outdoor seismic monitoring station at the Lat/Long location noted above. Three-day installation will take place in a roughly 36-sq.-ft. area, to install two small structures: 1. 4’x3’x10” sensor vault set on a 6” concrete base, with two attached PVC-pipe postholes (10” diameter) running from center of vault, to a maximum of 10’ into the ground, leading to two seismometers (1 strong motion accelerometer and 1 broadband seismometer); 2. 4’x3’x6” concrete base on which a battery box, solar panel equipment, antenna mounts, and communications equipment are housed; and 3. 10’x15’x5’ fence around site, with fence posts placed 1’ deep in 4" diameter holes. A flexible conduit 1’ deep and 5” wide will connect the two 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 and fence 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

Nate Ortiz
Agency Name
Emergency Services, Office of
Contact Types
Lead/Public Agency


Los Angeles
Southern California
Other Location Info
Five locations on the Angeles and San Bernardino United States National Forests Lat/Long: Sunset Peak at 34.21048 -117.69394, Dot Map ID: NS540; Crystal Lake at 34.296004 -117.861578, Dot Map ID: NS565; Soledad Canyon Fire Camp at 34.437383 -118.287932, Dot Map ID: NS531; Pine Mountain 34.16689 -117.87009, Dot Map ID: NS530; Butler Peak at 34.25698 -117.00521, Dot ID: NS560

Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
Class 3, CEQA Guidelines Section15303, Class 4 Section15304 and Class 6 Section 15306
Reasons for Exemption
This project is exempt in accordance with Class 3 as described above; construction of new small weatherproof enclosures to operate seismic sensor equipment for the purpose of data collection (Class 6). In accordance with Class 4, the project described above consists of minor public or private alterations in the condition of land and/or vegetation which do not involve removal of healthy, mature, scenic trees. None of the exceptions to a notice of exemption apply.
County Clerk
Los Angeles


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