Addressing Uncertainty and Conflicting Cost Estimates in Revising the Arsenic MCL

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• 作者：Patrick L. Gurian ; Mitchell J. Small ; John R. Lockwood ; and Mark J. Schervish
• 刊名：Environmental Science & Technology
• 出版年：2001
• 出版时间：November 15, 2001
• 年：2001
• 卷：35
• 期：22
• 页码：4414 - 4420
• 全文大小：254K
• 年卷期：v.35,no.22(November 15, 2001)
• ISSN：1520-5851

文摘

The current effort to revise the arsenic drinking waterstandard is one of the first times that the promulgation ofa Maximum Contaminant Level (MCL) for drinking waterhas been influenced explicitly by benefit-cost considerations.Different stakeholders have developed different estimatesof the costs, benefits, and appropriate decision-makingcriteria for a lower standard. In this study, alternative analysesprepared by the U.S. EPA and by independent researchersare compared. The large discrepancies in the aggregatenational cost estimates are shown to result largely fromdifferences in the engineering cost estimates for arsenictreatment processes. Further research is needed to resolvethese discrepancies. Alternative regulatory approaches,such as providing point-of-use treatment or exempting watersystems with high household compliance costs, yieldonly modest improvement in the overall cost-effectivenessof lower standards but are effective at addressingserious affordability problems for the small percentage of(primarily small) water systems where these problemsare predicted to occur. The U.S. EPA may wish to providemore explicit guidance to state regulators and to waterutilities as to the conditions under which these options willbe acceptable.