AWWA JAW56600

In October 2001, the US Environmental Protection Agency decided to move forward with implementation of a 10- ug/L standard for arsenic (As) in drinking water. Given this more stringent As standard, water facilities, especially smaller treatment systems, need up-to-date information on the ability of existing treatment technologies to remove As from drinking water. A yearlong study was conducted at two ion-exchange (IX) and two activated alumina (AA) water treatment plants in New England to evaluate the performance of these full-scale systems for consistently removing As from raw water. The source water contained 34-87 ug/L of total As, consisting primarily of As(V), except for one system in which 0.3-28.8 ug/L of As(III) was measured. Sampling results from these real-world conditions indicated the IX and AA systems could remove As to < 5 ug/L in the treated water, but only if IX resins were properly regenerated and AA media were changed out in a timely manner. IX and AA processes offer water suppliers ease of operation as well as low operations and maintenance costs. For small water treatment facilities and point-of-entry plants, they represent two appealing options for meeting the challenges of upcoming regulation requirements. Includes 43 references, tables, figures.