Faced with the looming January 2006 deadline to comply with the tougher new drinking water standard for arsenic, New Mexico Rural Water Association members considered their options during their annual conference this week that featured presentations challenging the EPA’s risk assessment for the naturally occurring groundwater contaminant.
Steven H. Lamm, head of Washington-DC-based Consultants in Epidemiology and Occupational Health, presented his and other recent findings that question the applicability to the U.S. of the Taiwan arsenic cancer risk data EPA cited to support tightening the arsenic standard from 50 to 10 micrograms/L. He has argued that the Taiwan data inappropriately calculated overall risk from both artesian wells, which showed a relatively high correlation to bladder cancer, and nonartesian wells, which did not and are more typical of US shallow-aquifer wells.
Lamm recently urged EPA to consider recent research asserting that EPA has overestimated the cancer risk associated with relatively low arsenic exposures in the U.S. before finalizing its arsenic risk assessment for the Integrated Risk Information System (IRIS). He told NMRWA members that four recent US studies of arsenic risk "found no increased risk of bladder cancer with increased arsenic exposure" at levels below 50 micrograms/L, which he said "is consistent with" findings from Taiwan shallow wells and a recent case control study in Argentina.
The group also heard Mike Keegan of the National Rural Water Association and Don Munkers of the Idaho Rural Water Association, which has long disputed the revised arsenic standard, describe compliance-relief options for small communities, including EPA’s strategy for granting exemptions that can extend the compliance deadline for as long as nine years beyond 2006.
The two also challenged EPA’s finding that all arsenic treatment technologies are affordable, which precludes variances, arguing that the agency’s affordability determination based on a national water-affordability level equal to 2.5% of median household income "may not have adequately considered environmental justice issues, including the ability of low-income and rural populations to afford water service."
Asserting that EPA’s affordability decision "needs to be changed," Keegan and Munkers said EPA’s estimate that households can afford an estimated $1,000/year water bill increase to comply with the arsenic standard "is far too high" for low-income and rural residents.
Among several options they described to "improve" the arsenic rule were:
*Prohibiting USEPA from assessing enforcement penalties "to communities with levels over USEPA standards for naturally occurring contaminants if USEPA does not provide funding" to support compliance;
*Providing a legislative exemption along the lines of one that allowed New York State to extend Surface Water Treatment Rule compliance deadlines for small systems in select counties under certain conditions; and
*Delaying enforcement of the rule until USEPA identifies an affordable technology for small, low-income communities.