“…The sensors investigated were off-the-shelf commercial products designed to monitor standard drinking water parameters such as pH, free chlorine, ORP, dissolved oxygen, specific conductance, turbidity, TOC, chloride, ammonia, and nitrate. Sensors were mounted within a re-circulating pipe loop and challenged with contaminants including secondary effluent from a wastewater treatment plant, potassium ferricyanide, a malathion insecticidal formulation, a glyphosate herbicidal formulation, nicotine, arsenic trioxide, aldicarb, and Escherichia coli K-12 strain with growth media (Hall et al 2007 andSzabo (2010). Overall, the sensors that responded to the most contaminants were free chlorine, TOC, ORP, specific conductance, and chloride.…”