Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

Testing, Sampling, and Analysis Plan January 15, 2025 3 Zone 7 Water Agency and City of Pleasanton 3. SPINNER/FLOWMETER, AND DISCRETE DEPTH SAMPLING STANDARD OPERATING PROCEDURE, PACIFIC SURVEYS 3.1. Applicability The main application of Spinner/Flowmeter logging is subsurface characterization of the vertical fluid movement within the well-bore. The impeller or spinner flowmeter (spinner) uses an impeller that revolves in response to fluid flow. As fluid moves through the impeller blades, they rotate at a known speed based on the pitch of the impeller blades. The number of impeller revolutions per second is automatically recorded and used to calculate the velocity of the fluid. Spinner measurements can be made while ascending or descending in the opposite direction of the fluid movement to generate a continuous flow profile. Additionally, spinner stop count measurements can be recorded at a particular depth while the tool is held stationary to measure flow at a specific location in the well-bore. Once the flow profile of the well-bore has been identified, depth-specific samples can be collected at the identified flow zones. 3.2. Scope The geophysical logging contractor’s responsibility is to provide a qualified logging Engineer (a qualified person familiar with logging equipment, operations & procedures) and the following: x Properly calibrated logging tools. x Sufficient backup tools to ensure that all requested services will be successfully performed. x Ensure that all measurements have a common depth basis (i.e., depth-matched data). x Borehole corrected data. x Paper copy field prints of all logs at the proper depth and horizontal scales. x Paper and reproducible copy final prints of all logs at the proper depth and horizontal scales. x Log ASCII standard containing all digitally measured and processed log data. x Log PDF files of all logs at the proper depth and horizontal scales. 3.3. Data Collection Measurements are made as the tool is ascended or descended in the well-bore at a constant rate on a multi-conductor or coaxial armored cable (or wireline) using a power supply at the surface. Measurement depth is controlled by passing the cable over a calibrated sheave wheel. Downhole data is transmitted via the cable to a data acquisition system (i.e., processing system) and transmitted to a computer at the surface where the data is stored and processed. Geophysical logs are paper copy records of borehole measurements plotted with amplitude on the horizontal axis and depth on the vertical axis. Other information presented in the geophysical logs include: A. Borehole identification number B. Client name C. Borehole location (city, county, state GPS coordinates if available) D. Date