AWWA JAW56578

The US Environmental Protection Agency's (USEPA's) new arsenic (As) standard of 10 ug/L is expected to affect 5% of community water systems (CWSs), but 77% of these CWSs serve 1,500 or fewer customers. Point-of-use (POU) treatment, recently approved by USEPA for permanently complying with drinking water standards, may be an economical alternative to As removal by centralized treatment for these smaller CWSs. Lack of guidance from USEPA regarding design of POU treatment programs and how to ensure compliance with federal regulations has resulted in few CWSs implementing POU treatment programs. Thus, the costs and logistical difficulties involved are not well documented. This study describes three (base-case, high-cost, and low-cost) POU scenarios to treat drinking water to meet the 10-ug/L As standard and calculates the per-household cost for each one. These per-household costs were compared with those of the least expensive centralized treatment methods for removing As presented in published studies. The authors found that POU treatment costs varied significantly with the monitoring and maintenance schedule adopted by the CWS; annual As monitoring of each POU device coupled with frequent maintenance and filter replacement increased the POU costs to the point at which centralized treatment was more cost-effective. The published costs of centralized treatment, however, also varied significantly, and these discrepancies may mask the economic advantage of POU treatment. The results of this study point out the difficulties in designing and running a POU treatment program. For a POU program to be successful, CWSs must get cooperation from their customers. This may discourage CWSs from implementing POU treatment, even when centralized treatment is not feasible. In these cases, the authors suggest providing bottled water to customers as a temporary compliance measure. Includes 24 references, tables, figures.