Brine contamination of ground water and streams in the Baxterville oil field area, Lamar and Marion Counties, Mississippi

A hydrologic investigation to define the extent of brine contamination in ground water and streams in the Baxterville oil field area was conducted from October 1984 through November 1985. The 260-square-mile study area includes the Baxterville oil field (approximately 12.5 square miles) in southwestern Lamar and southeastern Marion Counties, Mississippi. Since 1944, disposal of more than 1 billion barrels of brine pumped from the oil- producing zones has contaminated (increased chloride to greater than background concentrations) parts of the Citronelle and shallow Miocene aquifers and some streams that drain the oil field. Many domestic wells have been abandoned because of the presence of substantial quantities of brine in the ground water. Brine has moved laterally through the shallowest aquifers and discharged into Clear Creek and its tributaries. Although the presence of brine in surface water was greatest during periods of low flow when streamflow originated primarily from ground-water inflow, brine was also detected during high-flow periods when streamflow consisted largely of precipitation runoff.