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What are MCLs (Maximum Contaminant Levels) in California Water Quality and Drinking Water Standards?

A fantastic resource is available on the environmental standards page of the website to search and use environmental standards and guidelines. Environmental Standards are available for air, water and soil for the United States, Canada, Australia, New Zealand, United Kingdom, Holland and from the World Health Organization.

EPA Environmental Standards

The Environmental Protection Agency (EPA) is an agency of the United States federal government whose principal mission is the protection of human and environmental health. Having been established in 1970, the agency has made significant steps in the protection and conservation of the natural environment, regulating the manufacturing, handling, supply, and use of chemicals, and establishing the safe tolerance levels for chemicals and pollutants in food, animal feed, and water. The agency has been successful in enforcing its findings mainly through fines and sanctions (Gillespie, 2016).

Maximum contaminant levels (MCLs)

Maximum contaminant levels (MCLs) are defined as the highest degree of a contaminant that is permissible in drinking water (Ranasinghe et al., 2018). These standards are set by the United States Environmental Protection Agency. They are important because they ensure the amount of any contaminant in drinking water is beneath which there is no known or anticipated danger to human health (Ranasinghe et al., 2018). Even though in most cases, EPA uses MCLs, for some contaminants, it institutes a Treatment Technique (TT).

The role of the United States Environmental Protection Agency (EPA) in conservation and protection of water is crucial. Under the Safe Drinking Water Act (SDWA), the EPA has been mandated to establish the levels for drinking water quality and supervise states, localities, and water suppliers who execute the standards. The SDWA has allowed EPA to set standards and regulations that are binding to all public water systems in the United States.

All states have a duty to comply with the standards set by EPA. However, the States also have the option to establish strict standards that ensure the water is safe for human consumption. It is important to note that States can create a drinking water standard that is less protective than those set by the US EPA. MCLs (maximum contaminant levels) in California Water Quality and Drinking water standards can be found on the website. 


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