AWWA QTC98391

This paper outlines the Indiana-American Water Company's (INAWC) effort to initiate water treatment for arsenic removal. INAWC has provided groundwater treatment for arsenic using various processes including oxidation, coagulation, and filtration since 1976. The treatment steps as outlined in this paper yielded drinking water that surpassed all drinking water regulations using a treatment process greater than 90% effective for removing arsenic. In 1986, a pilot study indicated that ferric sulfate provided better water treatment for arsenic, which resulted in being 95% effective. In 1991, a new 9 mgd groundwater treatment facility was constructed that uses high rate adsorption clarifier/filter units which allows for blending and treatment of all available groundwater resources. The remaining chemical treatment processes consist of corrosion control with orthophosphate and fluoridation prior to distribution. Frequent testing for arsenic confirms that the current treatment process for arsenic is very effective for consistently reducing arsenic to less than 5 ppb. This represents an arsenic removal efficiency of 98%. After the finished groundwater and surface water supplies are blended the arsenic is diluted to less than 2 ppb. INAWC uses a Supervisory Control and Data Acquisition (SCADA) system for monitoring water quality, which utilizes continuous analyzers for free available chlorine residual, pH, instantaneous corrosion, particle counting, as well as turbidity monitoring for raw, settled, filtered and finished water. Manual water quality monitoring is also done daily. Further details of the processes are discussed.

Product Details

Published:

01/01/1998

ISBN(s):

0898679796

Number of Pages:

4

File Size:

1 file , 17 KB