The REAL story behind Trump and clean water

During Obama's reign, he extended the Clean Water Act to small streams, some of which only contain water for some months of the year. Trump's rollback of this rule would only roll back that addition: small streams that would be covered under the Clean Water Act.

The Obama rule tried to expand the definition of "navigable waters", waters where you can travel on a boat on them, to included 1 inch deep streams, and stream beds that didn't even have have water in them for parts of the year! This includes drainage ditches on the side of the road.

The claim behind the hysteria: 117 million people in the US get their drinking water from small streams. (The footnote says "Streams classified by the U.S. Geological Survey as intermittent, ephemeral or headwater streams.") Intermittent, and ephemeral, mean the stream is not even there the whole year! From the USGS PDF:

• Intermittent: "Contains water for only part of the year, but more than just after rainstorms and at snowmelt."
• Ephemeral: "Contains water only during or after a local rainstorm or heavy snowmelt."
• Headwater from here: "(1) the source and upper reaches of a stream; also the upper reaches of a reservoir. (2) the water upstream from a structure or point on a stream. (3) the small streams that come together to form a river. Also may be thought of as any and all parts of a river basin except the mainstream river and main tributaries."

The claim: 117 million people get 100% of their water from these sometimes-dry streams. The 2009 EPA map classified counties according to the percent of people in that county that use these types of streams for drinking water. In fact, the 2009 EPA study that EWG used shows somecounties use these streams for 87-100% of their drinking water.

Since "headwaters" were grouped with temporary streams in the 2009 EPA study, this makes the 72 million number suspicious.


Sources

1. EPA 2009 study about drinking water from streams. This has a similar map to the EWG map. PDF of data by county.
2. EWG article. 
3. EWG analysis.  They provide an interactive map of US states and counties.