California Department of Transportation, District 1
HUM 254 Culvert Rehab Geotechnical Drilling
NOE - Notice of Exemption
Caltrans proposes to drill ten geotechnical borings into the pavement or gravel shoulder of State Route 254. The estimated maximum depth for the 4.75-inch diameter, vertical borings would be approximately 75 feet below ground surface but would vary according to the site conditions. Stand-pipe piezometers (groundwater monitoring wells) will be installed in three of the borings, one at each of the trenchless culvert installation sites. These instruments will be periodically monitored over a period of up to 12 months before being destroyed in accordance with Humboldt County Environmental Health agency requirements. The purpose of geotechnical drilling is to characterize the subsurface conditions. Geotechnical drilling is needed to support the design and construction of the proposed HUM 254 Culvert Rehab project bridges and trenchless installation culverts. All geotechnical drilling will be within the Caltrans right of way.