DFD Seismic Refraction Surveys (OM-DFD-2025-067)

The California Department of Water Resources will conduct seismic refraction surveys across the Delta Field Division of the State Water Project to support geotechnical characterization of critical water infrastructure. Field operations will involve deploying geophone arrays consisting of sensors in 5-inch plastic housings mounted on 6-inch metal spikes, with seismic energy generated using active sources such as sledgehammer impacts on metal plates or truck-mounted accelerated weight drop systems. Work will occur at five key sites including Clifton Court Forebay, Antioch Water Treatment Plant, CAAQ Check 4, CAAQ Orestimba Siphon, and Circle K Ranch, spanning Contra Costa, Stanislaus, and San Joaquin Counties, with Antioch, California designated as the primary place of performance. The project is classified under CEQA Class 6 as an exemption for information collection activities, indicating minimal environmental impact and no formal environmental review. All work will be performed directly by DWR staff using standard field equipment including seismographs, geophones, and hand tools, with no contractors involved. Deliverables will include processed seismic profiles and interpreted subsurface stratigraphy to inform engineering design and infrastructure risk analysis. No contract value, pricing, payment terms, invoicing procedures, accounting codes, or formal contracting officer details are specified in the available documentation. There are no prescribed packaging, marking, preservation, or bar-coding requirements, nor are there defined inspection criteria, quality standards, or acceptance thresholds. No formal evaluation factors, award basis, or proposal submission instructions are provided, and the project is presented as a forecast with no solicitation number or competitive procurement mechanism indicated. Key project contact is Todd Percival, Senior Environmental Scientist, with Sara Lowry serving as Environmental Program Manager for oversight.