THE FALL AND RISE OF AN AQUIFER-- STAKEHOLDERS UNITE TO CONSERVE AND MONITOR THE SPARTA AQUIFER IN SOUTH ARKANSAS

The Sparta aquifer supplies the majority of water for industrial, municipal, and agricultural uses in Union County, Arkansas and the surrounding area with resulting water-level declines of more than 360 feet in some areas. Ground-water flow models developed by the U.S. Geological Survey (USGS) demonstrate that water levels may be maintained at or above the top of the aquifer by reducing withdrawals from the Sparta aquifer in Union County by 72 percent. Water quality has degraded in some areas as usage has increased. Recently Union County stakeholders united to petition the governor to appoint a water board with taxing authority, which began an education program, initiated conservation and reuse of ground water measures, and tapped a surface-water supply as an alternative source for certain industrial use to prevent further water-level declines in the Sparta aquifer.

A 5-year study by USGS is providing real-time water-level data on the internet and periodic water-quality sampling from a network of wells to document water changes within the Sparta aquifer. Real-time water-level monitoring is conducted using a pressure transducer connected to a digital data logger. Data are retrieved automatically every 6-hours via telephone modem, processed, and placed on the USGS website. Water-quality samples are collected two times per year for specific conductance and chloride.

The internet based real-time water-level data allows citizens and officials to quickly assess the changing water levels. Water conservation efforts have allowed ground-water levels to rise 2 to 3 feet in less than 2 years in areas centered in the greatest water-level declines. In the first 2.5-years (October 2004-April 2007) since surface water has been supplied to industry, water-level rises up to 49 feet have occurred in selected wells. Currently, average specific conductance ranges from 216 to 1,157 microsiemens per centimeter at 25 degrees Celsius, and average chloride ranges from 3.2 to 214 milligrams per liter in wells sampled.