This slide presentation outlines a study with the objectives of: comparing pre-regulatory estimated compliance cost with post-regulatory costs (or cost estimates); comparing pre-regulatory predictions of compliance strategy with post-regulatory compliance plan. The presentation outlines points arguing that these two sources of information are not equivalent. Methods included: conducting a survey of progress towards meeting the new standard and estimated costs in fall of 2003; focus on six cases that study utilities from the Frey et al. (2000) report highlighting industry leaders and substantial progress toward meeting standard by 2003, and a detailed pre-regulatory study by Frey et al. (2000). Survey and compliance results are discussed along with capital and O&M costs, large system results, small water system treatment costs, capital cost comparison, and the benefits of following compliance behavior.