Tubewell water was collected and used immediately for this treatability study without the addition of sample preservatives. The tubewell water was fortified with arsenic to yield 2.0 mg of As(III)/L. One liter aliquots of fortified tubewell water were delivered to 1 L borosilicate glass beakers. Chlorinated lime (a locally available oxidant, aCa(OCl)2·bCaCl2·cCa(O H)2·dH2O) was added at rates of 4, 6, 10, 15, and 20 mg/L. The solutions were mixed for 1 minute. Ferric chloride hexahydrate (an effective coagulant, FeCl3·6H2O) was added at rates of 100, 150, 200, and 250 mg/L. Each solution was mixed for 1 minute, allowed to settle for 24 hours, then the water column above the precipitate was analyzed for total arsenic.