This report on sewage flows into the Charles River. and into two other area rivers, was commissioned in consideration of the Charles as a source of drinking water for Boston.
A report on the sewage systems which emptied into the Charles and Mystic Rivers, as well as early experiments on the treatment of sewage with chemicals.
This 2007 article by Brett Hansen relates the story of the Charles River Dam (1910), which transformed the river's polluted tidal mudflats into a recreation area for pedestrians and boaters.