Law prof Margot Pollans has written Drinking Water Protection and Agricultural Exceptionalism, which you may want to read in light of the water crisis in Flint. Here's the abstract:
Providing safe drinking water is a basic responsibility of government. The US system is inefficient, unfair, and sets up local water utilities to fail. Under the Safe Drinking Water Act these utilities bear primary responsibility for providing safe water, but the Act provides few tools for utilities to engage in pollution prevention and instead emphasizes water filtration and treatment. At the same time, the Clean Water Act, which regulates water pollution, broadly exempts nonpoint source pollution in general and agricultural water contamination in particular from its strict requirements. As a result, water utilities are often the first line of defense against agricultural water contamination’s many human health harms. This allocation of responsibility is inefficient and unfair. It is inefficient because it prioritizes end-of-line clean up even where pollution prevention would be less expensive. It also fails to account for the ancillary benefits of pollution prevention, including, among other things, protection of aquatic habitats. This allocation of responsibility is inequitable not only because of its disparate impact on low-income and minority communities but also because of its arbitrary application of the polluter pays principle. Although there are some limited legal mechanisms by which water utilities can shift costs and clean up responsibility to farmers, the legal regime creates a default in favor of end-of-line cleanup. To address these concerns, this Article calls for a suite of legal reforms that would both empower water utilities to adequately protect their source waters and revoke the special status of farms in environmental law.