The Nashua River,Is a tributary of Merrimack River in Massachusetts and new Hampshire in the united states.it is formed in eastern Worcester County,Massachusetts,by junction of its north and south branches near Lancaster, and flows generally north northeast past groton to join the Merrimack at Nashua.

The Nashua River was heavily used for industry during the colonial period and the early united states.During the late 18th century and early 19th century,the heavy concentration of paper mills and the use of dyes near Fitchburg resulted in pollution tjat

In the mid 1960s,Marion Stoddart started a campaign to restore the Nashua River and its tributaries.She built coalitions with labor leaders and business leaders,in particular the paper companies who were the worst polluters of the river.

From its Impoundment at the wachusett reservoir in Clinton,Massachusetts, the South Branch of the Nashua river flows southeast from Fitchburg and Leominster, Massachusetts,to Lancaster. The Nashua river flows northward from Lancaster, meandering its way through the north central Massachusetts towns towns of Harvard,Groton, Dunstable, and Pepperrell,before eventually emptying into the Merrimack River at Nashua, New Hampshire.

1969-1979 Nashua river Watershed Association founded on October 16, 1969. Petition with 13,000 signatures sent to President Nixon, Governors Sargent and Peterson,Congressmen and Legislators seeking assurance that federal monies be appropriated to help with the construction of waste water treatment plants.