Recipient proposes to examine the EX post benefits, costs and distributional impacts of the safe drinking water act's (sdwa's) 2001 arsenic rule, which lowered the maximum contaminant level (MCL)…

Recipient proposes to examine the EX post benefits, costs and distributional impacts of the safe drinking water act's (sdwa's) 2001 arsenic rule, which lowered the maximum contaminant level (MCL) for arsenic (as) from 50 to 10 micrograms per liter (micro; g/l), with compliance required for all systems by 2006. Our project leverages existing data from EPA's six-year review of drinking water standards, as well as other sources that are under-explored by economists. EPA's EX ante regulatory impact analysis (RIA) suggested that the rule's monetized benefits did not exceed its costs (ABT associates, INC. 2000), which (along with political timing) made IT the subject of public controversy. This project will contribute to a very thin literature on the economics of the sdwa. Lack of information in the peer-reviewed literature on the act's health and other benefits may have contributed to critiques on the basis of cost, especially for small communities (belzer 2020). Their work will also contribute to our understanding of relatively low benefit-cost ratios for water quality rules relative to air quality rules in the united states (keiser ET AL. 2019). One reason for the thin economics literature on the sdwa is that, until recently, the only available data for assessing regulatory impacts were violations data. These data have been used to demonstrate that sdwa violations may increase health care expenditures (alzahrani ET AL. 2020) and induce bottled water purchases (graff zivin ET AL. 2011), and that the sdwa's information disclosure requirement has reduced violations, particularly of microbial standards (baker ET AL. 2023, bennear and olmstead 2008). Violations are infrequent, however, and they are a noisy measure of water quality concerns. To quantify the benefits and costs of mcls under the sdwa, data capturing spatial and intertemporal variation in the actual contaminant levels in public drinking water systems are needed. They will reconsider the benefits and the costs of the arsenic rule EX post and compare our results to the EPA's EX ante RIA (ABT associates, INC. 2000). Their benefits comparison will use a multi-step process that allows US to demonstrate how several different types of new information affect our estimates of the rule's effects on human health outcomes. For cost estimates, they will consult new evidence from the literature on the costs of the arsenic rule, updating those as necessary (morgan and simon 2014). Finally, they will consider how costs and benefits of the standard may have differentially accrued to small community water systems, as well as water systems primarily serving low-income and marginalized populations. Activities:the research project proposes to develop the following information and perform a series of analyses of the data. They include: to estimate the benefits of the arsenic rule, the researchers will use sdwa compliance samples from 1980 to 2011. We assemble these samples from three sources: the occurrence analysis for the rule itself, the six year review 2, and the six year review #3. These data include sample information from 25, 45, and 48 states over the periods 1980-2000, 1998-2005, and 2006-2011, respectively. The researchers will also collect ambient as concentrations from source water in rivers, streams and aquifers from the water quality portal (WQP), an online platform that collects sampling data from 900 federal, state, and other agencies, including the US EPA and USGS. We match as monitoring stations with drinking water systems by taking into account the hydrologic unit code (HUC)12 watershed where both the monitoring station and the drinking water intake are located. Health effects associated with exposure to arsenic in drinking water, include cancers of the bladder, lung, skin, kidney, nasal passages, liver, and prostate (ABT associates, INC. 2000). The research project will expl