Excessive Rain Overwhelms Sewage Systems In Merrimack Valley, Leading To River Pollution

Rainfall in eastern Massachusetts has been one to two inches above normal for November. That's having a really unfortunate impact in the Merrimack Valley, where sewage systems are so overwhelmed that towns are having to dump raw sewage into the Merrimack River — hundreds of millions of gallons worth.

Why is this happening, and what does it mean for the health of the river and the towns that line it?

David Epstein, WBUR's meteorologist. He tweets @growingwisdom.

Rusty Russell, executive director of the Merrimack River Watershed Council.

Robert Ward, deputy director of the Department of Public Works for the City of Haverhill.