Safe Drinking Water Act of 1974
The Safe Drinking Water Act (SDWA) of 1974 is a key federal legislation designed to safeguard the quality of public drinking water in the United States. It specifically targets public water systems that serve more than twenty-five people, addressing concerns raised by the discovery of harmful organic chemical compounds in drinking water and the inconsistencies in state regulations. The act established national drinking water standards through a two-part implementation process, initiating interim regulations based on existing public health guidelines and followed by a comprehensive scientific study to revise these standards.
The Environmental Protection Agency (EPA) is tasked with setting maximum contaminant levels (MCLs) for various harmful substances, including specific organic and inorganic compounds, as well as guidelines for water clarity and microbial presence. The SDWA also empowers states, territories, and tribes to enforce these standards, provided they meet federal requirements, thus fostering a cooperative federal-state relationship in water quality management. Additionally, it mandates regular water sampling and transparency regarding water quality information to the public, contributing significantly to the improvement of the nation’s drinking water supply and public health protection.
On this Page
Subject Terms
Safe Drinking Water Act of 1974
Identification U.S. federal legislation
Date Signed on December 16, 1974
During the early 1970’s, growing public awareness and media coverage of deteriorating water quality throughout the country led to the passage of the Safe Drinking Water Act of 1974, a landmark environmental and human health law that regulated certain contaminants in public drinking water systems.
The Safe Drinking Water Act (SDWA) of 1974 is the primary legislation at the federal level that protects the public drinking water system. Public water systems that supply drinking water are defined as those systems that serve more than twenty-five people. Discovery of organic chemical compounds in public drinking water systems, as well as the variance in regulations from state to state, prompted the passage of the SDWA.
The initiation of national drinking water standards as specified in the SDWA called for a two-part implementation process. Interim regulations were established immediately after the passage of the act. The interim regulations, put into effect in 1975, were based upon United States Public Health Service guidelines established in 1962. The second step of the process outlined in the act was to revise those standards, which was done after a thorough scientific study conducted by the National Academy of Science. The study assessed the effects on human health by drinking water contaminants and the toxicology of those contaminants.
Maximum contaminant levels (MCLs) as defined by the Environmental Protection Agency (EPA) were set as interim standards in 1975. These standards included guidelines for six organic compounds, ten inorganic compounds, the cloudiness of the water (turbidity), and total coliform bacteria. MCLs were set for chemicals such as the herbicide 2,4-D, as well as for arsenic and mercury. The act also required the EPA to set guidelines for contaminants that affect the aesthetic nature of drinking water but are not harmful to humans.
The SDWA of 1974 also delegated certain powers of enforcing the drinking water standards to the states. The federal-state arrangement allows states, U.S. territories, or tribes that meet specific requirements to have primary authority in enforcing the standards set by the national government for public drinking water systems. The SDWA authorized the EPA to offer grants to states for the purpose of regulating drinking water contaminants.
Under the SDWA, public water systems are required to collect water samples at specified times and locations. The results of these tests are reported to the state government, which has the primary authority to enforce the water quality standards. Besides setting and enforcing standards for drinking water contaminants, the act also required the EPA to protect wells and collection systems, to establish the integrity of distribution systems, and to ensure that qualified operators are employed to treat drinking water; it also stipulated that the information about the public water supply be made available to the individuals who use that particular water supply.
Impact
The far-reaching effects of the Safe Drinking Water Act of 1974 helped improve the quality of the nation’s public water supply and protect the health of those living in the United States.
Bibliography
DeZuane, John. Handbook of Drinking Water Quality. 2d ed. Hoboken, N.J.: John Wiley & Sons, 1996.
Dunlap, Riley E., and Angela G. Mertig, eds. American Environmentalism: The U.S. Environmental Movement, 1970-1990. Philadelphia: Taylor & Francis, 1992.
Kegley, Susan, et al. The Chemistry of Water. New York: University Science Books, 1997.