AWWA JAW71678

A two-phase study investigated thesource of high arsenic at consumers' taps ina small water system and the effectivenessof treatment to resolve the problem. Thecommunity used the common practice ofchlorination and polyphosphate addition tocontrol iron. A relatively low water velocitywithin the system may have allowed arsenic-boundiron particles to settle, only to bemobilized by the opening of a faucet andsubsequent rapid change in water velocity.Replacing polyphosphate treatment with anoxidation/filtration unit and adsorption unitinstalled in series reduced arsenic concentrationsto < 1 µg/L.Arsenic (and potentially other contaminants)can accumulate in the distribution system,and their release back into the watermay result in elevated levels at consumers'taps. The water industry should be awarethat changes in such processes as treatment,operation, and system maintenance can affectthe release of any contaminants present in thedistribution system. Includes 22 references, tables, figures.

Product Details

Edition:

Vol. 102 - No. 3

Published:

03/01/2010

Number of Pages:

12

File Size:

1 file , 670 KB