Of 85 unregulated and, in some cases, unknown chemicals found in samples of the Potomac prior to it becoming our drinking water, 35 were still in there after it was “purified” at the aqueduct. This tasty takeaway—-plus: hermaphrofrogs!—-comes from the latest Frontline on PBS, “Poisoned Waters,” which examines both the Chesapeake Watershed and the Puget Sound. It was on last night and it’s online. Happy Earth Day.