Agricultural chemicals at the outlet of a shallow carbonate aquifer
A groundwater catchment, located in Woodford and Jessamine Counties in the Inner Bluegrass of Kentucky, was instrumented to develop long- term flow and water quality data. The land uses on this 1 620-ha catchment consist of approximately 59% in grasses consisting of beef farms, horse farms, and a golf course; 16% row crops; 6% orchard: 13% forest; and 6% residential. Water samples were analyzed twice a week for, Ca++, Mg++, Na+, Cl-, HCO3-, O4=, NO3-, total solids, suspended solids, fecal coliforms, fecal streptococci, and triazines. Flow rate and average ambient temperature were also recorded. No strong linear relationship was developed between chemical concentrations and other parameters. The transient nature of the system was emphasized by one event that drastically deviated from others. Pesticide data were summarized and the 'flushing' phenomena accredited to karst systems was discussed. The total solids content in the spring was consistent at approximately 2.06 mg/L. Fecal bacteria contamination was well above drinking water limits (fecal coliform and fetal streptococci averages were I 700 and 4 300 colony-forming-units/100 mL, respectively) and the temporal variation in bacterial contamination was not linked to any other variable.