NITRATE LEVELS IN THE WOODBINE AQUIFER, NORTH-CENTRAL TEXAS

The Woodbine aquifer is an important source of groundwater in northcen tral Texas. In a survey of 63 wells located within or near the aquifer 's recharge zone, nitrate concentrations ranged from less than 0.22 mg /L to 102 mg/L. Only one observation exceeded 45 mg/L. In general, nit rate concentrations were higher in shallower wells, and there was no s ignificant correlation between nitrate and chloride concentrations. Po tential sources of nitrate in the study area include fertilizers used on crops and lawns, animal waste from feedlots, and household wastewat er. Results of this study suggest that nitrate concentrations are loca lly elevated above background levels, shallow groundwater is more susc eptible to nitrate contamination, and fertilizer is a probable source of groundwater pollution. The use of deep wells and careful land use p lanning may alleviate future contamination of groundwater supplies.