Emergency Services, Office of
(Office of Emergency Services, California)
New Seismic Monitoring Station Installation
NOE - Notice of Exemption
The state-of-the-art earthquake recording and telemetry equipment proposed to be installed at this station will contribute continuous seismic data to the CA Earthquake Early Warning System (CEEWS) and ShakeAlert, designed to potentially save thousands of lives during a large earthquake, prevent critical infrastructure damage, and expedite recovery following a large earthquake.
With permission from the property owner secured, USGS plans to upgrade and operate the seismic monitoring station at the Lat/Lon location. The station is within the footprint and fencing of a pre-existing geodetic station run by UNAVCO. Two aluminum enclosures (2'x3'x21"H) will be mounted to 6" thick concrete pads: one concrete pad at grade (max 6" depth) and the second concrete pad at a depth of typically 16" below grade. An ~8' tall steel pipe will be mounted to one enclosure and concrete pad and hold the 2'x4' solar array and telemetry antenna. The two enclosures will be connected by flexible conduit in a shallow trench (6" deep, 6" wide) about 25 ft long; this trench will be filled to grade after installation. A ground rod will be driven to a depth of 8' proximate to the battery/radio enclosure; additionally, a 2-gauge wire will be buried in a 12" deep, 6" wide trench around the exterior of the enclosure; additionally, a 2-gauge wire will be buried in a 12" deep, 6" wide trench around the exterior of the enclosure. All excavation will be dug by hand or mini-excavator, depending on site accessibility. There are no hazardous substances involved during construction nor as components of the site. If necessary, a small generator will be used to power a hand-loaded concrete mixer and any other tools needed for the construction. Construction/installation takes 3 days and covers a total of 175 sf (5'x35').
This project is exempt in accordance with class 3; construction of new small weatherproof enclosures to operate seismic sensor equipment for the purpose of data collection. The project 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.