Check out this NPR interview with Hendrick Smith about his PBS Frontline documentary Poisoned Waters, which details the widespread pollution of America's water ways.
Smith reports that untreated toxins and chemicals from urban sprawl and development are damaging or destroying natural habitats in the Chesapeake Bay and the Puget Sound. In the Potomac River, chemical compounds are causing mutations in the genitalia of frogs, while high levels of Polychlorinated biphenyls (PCBs) in the Puget Sound have led to the endangerment of orca whales.
Yes, you read that correctly, they have found male frogs in the Potomac with ovaries.... SCARY
This affects people like you and me as residents of DC. Our drinking water comes from the Potomac River.
Take a listen, it's worth getting informed about!