About EPA

EPA Issues 23 Final Drinking Water Standards

[EPA press release - May 19, 1992]

The U.S. Environmental Protection Agency today announced new standards to limit contamination of drinking water by 23 chemicals.

"With this action, the total number of federal drinking water standards will rise to 84 when these new standards go into effect in 1993," Reilly said. "Required by the Safe Drinking Water Act, the standards have a preventive thrust since most of the 23 contaminants are rarely found in drinking water. As the safe drinking water program matures," Reilly said, "it is increasingly important that EPA, the states and communities focus more attention and resources on the most serious risks to public health. Small communities, in particular, but larger communities, too, face extraordinary financial burdens for this and other public services. We must find ways to meet public health goals and implement the law that recognize this worsening situation."

These national standards will guide ground water protection and cleanup actions and help prevent pollution. Monitoring requirements provide an extra layer of protection for all community drinking water supplies.

The 23 chemicals include nine pesticides, five inorganic chemicals and nine synthetic organic chemicals. Five of the 23 contaminants are probable human carcinogens in drinking water and seven of the nine pesticides are in use today. Dioxin, beryllium, cyanide and antimony are a few of the affected chemicals.

The final standards announced today will require 80,000 public drinking water systems nationwide to meet the new criteria and to monitor for the contaminants. EPA estimates that when the regulations become effective, 260 of those systems, serving approximately 340,000 people, will have to treat their water for excess levels of any of the 23 contaminants.

Public water systems will have to monitor for these contaminants regularly to ensure that the standards are being met. Some public water systems have already begun initial monitoring.

Today's regulations are mandated by the 1986 Amendments to the Safe Drinking Water Act, which require EPA to publish MCLs [Maximum Contaminant Levels] for 83 specific contaminants. The original Safe Drinking Water Act was passed by Congress in 1974, and EPA began setting national standards in 1975.

EPA believes that the economic impact of this proposal on most water treatment systems and their customers will be small. The Agency estimates the total cost of the proposed regulations to be $46 million. EPA estimates that less than one-percent of the nation's drinking water systems will have to install new treatment equipment to meet today's requirements.

The impact of the regulations may be substantial for about 200 small systems (serving fewer than 500 persons) that may be out of compliance with specific contaminants. EPA has identified several approaches to lessen the economic impact on these small systems and their customers, such as phasing-in monitoring requirements and promoting the development of low-cost package treatment technologies.

A standard for sulfate, once included among the package of standards, has been deferred for additional consideration. Sulfate causes diarrhea in un-acclimated people, primarily travelers and newborns. Most people are believed to acclimate to sulfate in a short time and it has no known long-term effects.

Sulfate treatment is expensive, especially for small systems in small towns where sulfate is prevalent. During the deferral, EPA will explore innovative approaches to make compliance more affordable for small systems while still protecting health. EPA will also issue a health advisory identifying sulfate levels that may cause diarrhea.

EPA standards generally apply to any drinking water supply system that regularly serves at least 25 people. Of the 80,000 systems covered by the regulations, 60,000 are community systems serving customers year round and 20,000 are non-community systems, such as those that supply schools and factories.

The regulations establish federally enforceable standards, or maximum contaminant levels (MCLs), for the 23 pollutants. They also set non-enforceable health goals, called maximum contaminant level goals (MCLGs), at a level at which no known or anticipated health effects occur which allow an adequate margin of safety. The law requires that the MCLs be set as close to the MCLGs as feasible to ensure adequate protection of public health.

Today's standards also: identify the best available treatment technologies which can achieve the MCLs; stipulate language that public water suppliers must use to notify customers of standards violations; and establish requirements for monitoring, reporting and state implementation of the federal requirements.

The Agency generally delegates the authority to enforce all federal drinking water standards to the states, but can intercede when necessary. States may set standards more stringent than federal ones or establish standards for contaminants not regulated by EPA. States may not set standards less stringent than EPA's, however.

These regulations are among a continuing series of rules mandated by the 1986 Amendments to the Safe Drinking Water Act. EPA's development and promulgation of these rules are now being coordinated with a number of other EPA activities to ensure protection of public health while addressing the cumulative economic burden of the growing list of regulatory requirements on states, localities and water systems.

EPA recently convened a Governors Forum to review priorities under the Safe Drinking Water Act to identify the impact of growing fiscal constraints on implementation. Furthermore, EPA's Environmental Financial Advisory Board is developing alternative financing mechanisms with particular attention on small community concerns. In addition, EPA is in the third year of an initiative to identify and promote low-cost solutions to drinking water protection. These include consolidation of water systems to spread costs over a larger consumer base; pooling of several systems' water samples to reduce monitoring costs; and low-cost treatment technologies that can cut water bills in small water systems to as much as one-half the cost associated with traditional engineering solutions.

In addition, EPA is considering greater reliance on risk-based priority-setting within state compliance programs. That approach would focus limited state and federal resources on those elements of the public water supply supervision program, as well as on other environmental mandates, having the greatest potential for reducing risk and promoting the greatest benefits to public health protection.

The standards announced today should be published in the Federal Register soon. The MCLs and monitoring requirements will become effective 18 months after publication.

The affected contaminants are: Antimony, Beryllium, Cyanide, Nickel, Thallium, Dalapon, Dichloromethane, Dinoseb, Diquat, Di (ethylhexyl) adipate, Di (ethylhexyl) phthalate, Endothall, Endrin, Glyphosate, Hexachlorobenzene, Hexachlorocyclopenta diene (HEX), Oxamyl, PAHs, Picloram, Simazine, Dioxin, Trichlorobenzene and Trichloroethane.

The Safe Drinking Water Act Hotline is available to the public to answer questions on these proposed rules or on other drinking water questions. The toll-free number is 800-426-4791.