Quantitative evaluation of tracers for quantification of wastewater contamination of potable water sources.

Quantitative criteria for selection of tracers for assessment of mixing of wastewater and pristine water are proposed and evaluated for leakage from a wastewater effluent recharge system to nearby pristine water wells and the dilution of the effluents in a reclamation well by pristine water from the surrounding aquifer. Two molecular tracers were compared: carbamazepine, an organic drug whose refractory behavior was evaluated on-site, and chloride, a widely used conservative tracer. The mixing ratios and the corresponding uncertainty levels in their calculation were evaluated using actual field data.