Which act passed in 1986 prohibits the discharge of toxic chemicals into state waters?

The Safe Drinking Water and Toxic Enforcement Act, also known as Proposition 65, was passed in California in 1986. This significant piece of legislation aims to protect the state's drinking water sources from being contaminated with chemicals that are known to cause cancer, birth defects, or other reproductive harm. It requires the state to maintain a list of chemicals that are deemed hazardous, and businesses are required to provide warnings to consumers if products contain any of those listed chemicals.

This law not only addresses the protection of drinking water sources but also extends its focus to include broader public health concerns regarding the discharge and exposure to toxic chemicals. By regulating the release of harmful substances, this act plays a crucial role in safeguarding both environmental health and public welfare in California.

The other options involve different aspects of environmental management: the California Environmental Quality Act primarily focuses on environmental review processes for state and local projects, the Clean Water Act governs water pollution on a national level but is not a California-specific state law, and the Water Resources Development Act pertains to water resources development and policies at the federal level, not specifically the prohibition of toxic chemicals in state waters.