<p> The Niles Cone Basin (NCB) within Alameda County, California, contains portions of the basin under perennial and ephemeral artesian groundwater conditions. This study used 349 wells installed throughout the basin’s four-aquifer system to delineate the spatial distribution of the 86 wells that have gone artesian between 1995 and 2015. Artesian wells within all four aquifers occur at elevations below 5.2 meters above sea level (MASL) but predominantly below 3.0 MASL. Even at lower elevations, artesian conditions do not occur in regions of major pumping owing to significant drawdown. Within topographically-low regions, wells may not be artesian where well-heads are located at higher elevations, such as on a levee or other elevated landforms. This can be observed throughout the Newark and Centerville aquifers where artesian wells are located near non-artesian wells during the same monitoring event. Precipitation influences artesian conditions with artesian events correlated with increases in precipitation generally during, but not limited to, the early spring months. The water levels of the shallow Newark Aquifer were found to respond independently from the three deeper aquifers. Those deeper aquifers were observed to be in hydraulic connection with one another, displaying synchronous water level changes with time across the basin.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10623614 |
| Date | 17 November 2017 |
| Creators | Fisher, Anthony W. |
| Publisher | San Jose State University |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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