The Trump administration is ending federal protection for many of the nation’s millions of miles of streams, arroyos and wetlands. It’s a sweeping environmental rollback that could leave the waterways more vulnerable to pollution from development, industry and farms. The new rule narrows the types of waterways that qualify for federal protection under the half-century-old Clean Water Act.  The Trump administration says it’s providing “regulatory certainty and predictability for American farmers, landowners and businesses.” But environmental advocates and public health officials say the change will make it harder to maintain a clean water supply for the American public.