Spatial and Temporal Variability of Ground-water Quality in a Shallow Aquifer in North-central Oklahoma

Abstract

The spatial and temporal variability of the chemical quality of shallow ground water was determined by evaluating data obtained from several monitoring wells over a nine- month period. The investigated aquifer is located in Stillwater, Oklahoma. The 21 monitoring wells lie within an area of about 11,000 square feet and a vertical interval of 5.5 feet. Nitrate was the main tracer used in the study and is applied to the land surface in the form of fertilizer three times annually and thus was routinely monitored. Nitrate has been found to vary temporally, particularly on the short-term during recharge events. Nitrate, and all other monitored parameters, have also shown rather large spatial variations.