Data for assessing the penetration depth post-1950s water in the Central Valley aquifer system, California (July 2022)

This dataset provides groundwater ages estimates that were used in an assessment of the penetration depth of modern groundwater in the Central Valley aquifer system (CVAL). Groundwater ages were estimated by calibration of environmental tracers (tritium, tritiogenic helium-3, chlorofluorocarbons, sulfur hexafluoride, carbon-14 and radiogenic helium-4) to lumped parameter models (LPMs) for samples from 650 sample locations. Groundwater samples were collected from wells (mainly drinking-water) in the CVAL between 2004 and 2017 as part of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment Priority Basin Project (GAMA-PBP) and the National Water-Quality Assessment (NAWQA) Project. Table 1 reports [...]