Laura M. Bexfield (Former Employee)

The Southwest Principal Aquifers consist of many basin-fill aquifers in California, Nevada, Utah, Arizona, New Mexico, and Colorado. Demands for irrigation and drinking water have substantially increased groundwater withdrawals and irrigation return flow to some of these aquifers. These changes have increased the movement of contaminants from geologic and human sources to depths used to...

Seasonal variability in groundwater pumping is common in many places, but resulting effects of seasonal pumping stress on the quality of water produced by public-supply wells are not thoroughly understood. Analysis of historical water-quality samples from public-supply wells completed in deep basin-fill aquifers in Modesto, California (134 wells) and Albuquerque, New Mexico (95 wells)...

The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post- 1950s) containing...

The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) is conducting a regional analysis of water quality in the principal aquifer systems across the United States. The Southwest Principal Aquifers (SWPA) study is building a better understanding of the susceptibility and vulnerability of basin-fill aquifers in the region to groundwater contamination by

The National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey began a series of groundwater studies in 2001 in representative aquifers across the Nation in order to increase understanding of the factors that affect transport of anthropogenic and natural contaminants (TANC) to public-supply wells. One of 10 regional-scale TANC studies was conducted in the Middle Rio...

This fact sheet highlights findings from the vulnerability study of a public-supply well in Albuquerque, New Mexico (hereafter referred to as “the study well”). The study well produces about 3,000 gallons of water per minute from the Rio Grande aquifer system. Water samples were collected at the study well, at two other nearby public-supply wells, and at monitoring wells installed in or...