Arsenic Overview Series - Part 4
As seen in Section Section I, the federal legislative history for revising the existing drinking water standard on arsenic has been a roller coaster ride. In 1942, the UNITED STATES Public Health Service set the drinking water standard at 50 parts per billion (ppb), which was adopted by the EPA in 1975, as a result of the passage of the Safe Drinking Water Act. While this treatment standard still is in place today, it has been the subject of debate and controversy in the federal government for more than 20 years. Many deadlines and opportunities for revision have come and gone. (To see figure click on link on side bar).
Most recently, in the final days of President Clinton’s administration, the EPA posted a final rule in the Federal Register on January 22, 2001, lowering the standard from 50 to 10 ppb. Ten ppb is the accepted standard adopted by both the World Health Organization (WHO) and the European Union (EU). However, on March 22, 2001, the EPA, under the new leadership of the Bush administration, withdrew the rule, citing the need for additional research on cost and health effects. Although the EPA under the Bush administration has refused to implement the final rule of 10 ppb, they have publicly recognized the need to lower the standard somewhere to a level between 3 and 20 ppb. The EPA now is accepting comment on these levels. A final rule is anticipated on February 22, 2002.
As a result of the continued delays by the EPA on this issue, several states have initiated their own legislation to implement a more stringent standard than the current 50 ppb. State government agencies in New Hampshire and New Jersey have drafted new laws that will bring the MCL from 50 to 10 ppb. These proposals currently are under review by the state’s respective legislative committees. The state government of Delaware has passed a new standard. On September 1, 2001, the new MCL of 10 ppb will go into the books, and water systems state-wide have until September 10, 2006, to meet compliance.
EPA estimates approximately 2,526 of 2,912 (86 percent) of small community water systems will be impacted at a 10 ppb MCL. Because small water systems will be the most heavily impacted by a new standard for arsenic in water, POU treatment options likely will play a larger role in compliance. POU is proving to be a more cost-effective solution for systems serving 4,000-5,000 end users or fewer.
One of the more significant issues required for POU implementation is revision of existing legislation that was designed only with centralized systems in mind. In many cases, new legislation will be required to allow the central system to delegate the responsibility of treatment and monitoring to a POU service provider. Other issues surrounding the POU approach that may require legislative action include identification of clear lines of responsibility for the utility and the water consumers, the acceptance of POU options as approved technology and access to the POU unit located inside the end user’s home.
The current enforceable MCL for arsenic in water, established in 1942, is 50 ppb. This limit is enforced through the state government agencies and, on occasions, directly by the EPA when violations are considered to be of a more serious nature. In these cases such as the violation currently occurring in Fallon, Nevada, the EPA has stepped in to ensure a plan is put in place to prevent future violations. Repeated violations are punishable by fine and, in some cases, criminal and civil suit.
On January 22, 2001, the EPA established a health-based, non-enforceable Maximum Contaminant Level Goal (MCLG) for arsenic of zero and an enforceable Maximum Contaminant Level (MCL) for arsenic of 10 ppb. This regulation will apply to non-transient, non-community water systems, which presently are not subject to standards on arsenic in drinking water and to community water systems.
On May 22, 2001, the EPA published in the Federal Register (66 FR 6976) a final rule delaying the effective date of the arsenic rule until February 22, 2002, in order to conduct reviews of the science and cost analyses. In the process of extending the effective date for the arsenic rule, the EPA has not changed the compliance date for the MCL issued in the January 2001 rule. Until January 23, 2006, the enforceable MCL for arsenic is 50 ppb.