What's in Your Water? The United States has had some of the best drinking water in the world, although recent reports reveal that one in ten Americans exposed to dangerous chemicals such as Lead, MTBE, Round-Up, pharmaceuticals. and possible carcinogens in the tap water of major cities. The Clean Water Act is not being well enforced. Only 3 percent of violations result in fines! State agencies responsible for enforcement aren't testing for many unhealthy contaminants.