A hedonic cost function is used to isolate the operation and maintenance costs for water treatments. For small systems, costs are substantial for some technologies, but not for others. When regional differences in input costs are accounted for, small systems located in rural areas may have a cost advantage over similar systems closer to urban centers; however, costs of water treatment to meet Safe Drinking Water Act amendments may still be substantial.The ability of small public water systems to com-tionwide serve populations under 3,300 people. ply with monitoring and treatment requirements Many believe that systems below this size are ununder the Safe Drinking Water Act (SDWA) con-able to take advantage of economies of size and/or tinues to be an open question for national, state, have insufficient resources to finance SDWA reand local policymakers and government officials. quirements at a reasonable cost to consumers Based on EPA's recent survey of the need for im-(Boisvert and Schmit 1996; EPA 1993b). Current provements in the public water system infrastruc-and future costs for both treatment and distribution ture (1997), the nation's 55,000 community water are substantial. Thus, policymakers need specific systems must invest about $140 billion (1995 dol-information about the cost implications of the lars) over the next twenty years to install, upgrade, regulatory requirements and potential dramatic inor replace infrastructure to insure the provision of creases in water rates for system users, particularly safe drinking water. Estimates of average costs per for small systems. household range from $970 for large systems to This research contributes to an understanding of $3,300 for small systems, those serving fewer than public water system treatment costs by accounting 3,300 people.for size, population densities, factor prices, and Just over half of this total investment is needed water treatment in estimating public water utility for treatment or distribution expenses related to the cost functions. The differential costs of alternative SDWA. About $12 billion is needed immediately water treatments (including aeration, ion exchange, to comply with current SDWA regulations. Total to comply with current SDWA regulations. Total and several filtration processes) are accounted for twenty-year costs for SDWA and SDWA-related twenty-year costs for SDWA and SDWA-related in a hedonic fashion. This model specification is needs, including proposed regulations of the En-