Groundwater Monitoring

Gravity is a measurement of mass: the greater an object's mass, the stronger its gravitational pull. By measuring changes in gravity over time, inferences can be made about changes in mass. In hydrology, this can be used to study water in the subsurface. If the amount of groundwater in a particular area increases over time, through processes such as infiltration of rainfall or aquifer recharge...

The Arizona Water Science Center collects water-quality data from stream and aquifer sites in networks that are part of the National Water-Quality Program (NWQP) and the National Stream Quality Accounting Network (NASQAN).

In the United States, the Colorado River Compact of 1922 apportions the waters of the Colorado River between the upper basin States and the lower basin States (U.S. Congress, 1948, p. A17-A22). The requirement for participation of the U.S. Geological Survey (USGS) and the Bureau of Reclamation (BOR) is stated in Article V. Water in the lower Colorado River is apportioned among the States of...

The Navajo Nation, the City of Flagstaff (COF), and the U.S. Geological Survey (USGS) maintain a cooperative monitoring program with other local and State agencies for groundwater in the C aquifer (Coconino aquifer) in the Little Colorado River Basin. The goal of this program is to determine baseline groundwater conditions in the C aquifer and other water-bearing zones before significant...

The U.S. Geological Survey water-monitoring program in the Black Mesa area began in 1971 and provides information about the long-term effects of groundwater withdrawals from the N aquifer for industrial and municipal uses. The monitoring program includes measuring potential recovery in the N aquifer as a result of the reduction in industrial pumpage by Peabody Western Coal Company.

Industrial activity at Air Force Plant 44 (AFP 44), a manufacturing facility located on property owned by the U.S. Air Force and operated by a major defense contractor, resulted in extensive contamination of groundwater with the industrial solvent trichloroethylene (TCE) and other organic compounds. The sole-source regional aquifer underlying AFP 44 provides potable water for municipal, commercial...