Elevations of bench marks, observation wells, and production wells at Mather Air Force Base, Sacramento County, California, 1988

Abstract

Precise and accurate elevations of water-level-observation wells on Mather Air Force Base near Sacramento, California, were needed to determine the direction of groundwater flow at and near the base. A total of 19 miles of primary survey lines were run on or near Mather Air Force Base. The datum of these surveys is based on National Geodetic Survey bench mark Y952 about 1.5 miles south of the base at the intersection of Jackson Highway (State Route 16) and Excelsior Road. The accuracy of these levels, based on National Oceanic and Atmospheric Administration standards, ranged between first and third order. Elevations of 41 bench marks, 76 observation wells, and 15 production wells on Mather Air Force Base were determined by differential leveling during June 1988. Levels were run to a designated measuring point on observation wells, to the pressure valve of production wells, to the land surface adjacent these wells, and to selected bench marks, some of which are on runways or taxiways.