Answer:
Explanation: One of the potential consequences of groundwater overdraft is water-quality degradation. The USGS has characterized many linkages between water use and water quality and found that the processes affecting water quality vary widely and depend on a complex suite of factors. These factors can include natural geology and local aquifer conditions, human activities related to land use, and well construction and operation. Determining changes in groundwater quality over time involves systematic monitoring of constituents of concern, coupled with an understanding of the dynamics of a groundwater-flow system.
Groundwater quality can be assessed using both existing wells installed for water supply and wells installed specifically for monitoring. Groundwater monitoring-well networks and related data are developed based on the characteristics and needs of each groundwater basin.
Photo of a USGS hydrologist preparing equipment during groundwater sampling in Jurupa Valley, California.
A USGS hydrologist prepares equipment during groundwater sampling in Jurupa Valley, Calif. Photo: USGS.
Water-quality data for principal aquifers may be available based on information from existing technical studies or regulatory programs. The USGS has a wide body information, data, and tools to support water-quality assessments statewide. Combining USGS data with other quality-assured data can assist water managers and GSAs with basin-wide assessments and water quality mapping. Links to data are indicted at the conclusion of each section, for the example studies described below.
