Answer:
The authority of EPA set several standards for drinking water quality,water suppliers,localities etc.
Step-by-step explanation:
The regulations are-
1) National Primary Drinking Water regulations-
This regulation is legally possible which is applied in public water system.Primary standards protect public health by controlling the contaminants present in drinking water.
2)National Secondary Drinking water Regulations-
These regulations don't set any proper guideline to control contaminants present in water.
3)Unregulated Contaminants-
The Safe Drinking Water Act (SDWA) is a process through which EPA have to enlist the unregulated contaminants that are require in National drinking water regulations.EPA uses there unregulated contaminants and collect data that will help us to determine that whether we have to regulate that contaminants or not.