[6] In August 1955, severe flooding on the Blackstone caused extensive damage to Woonsocket, Rhode Island.

In some parts of Rhode Island and Massachusetts, these hurricanes resulted in a combined amount of more than 20 in (510 mm) of rain within a week.

[8] This led to the highest water mark on record for the Blackstone river in Woonsocket at 21.8 ft (6.6 m), a full 12.8 feet (3.9 m) above flood stage.

The Blackstone Canal played a significant role in the economic development of the region, allowing for the efficient movement of raw materials and finished products.

While environmental activists in the Blackstone River Valley were already organizing clean-up efforts locally, in 1971, a formalized plea for action was made to the then Governor of Rhode Island, Frank Licht.

While the CWA did not specifically mention The Blackstone River by name, it stated that the act "establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters.

The condition of the stream is likely to grow worse until effective measures are completed for removing from the river much of the pollution which it now receives.

A 2005 report written by the Rhode Island Department of Environmental Management said, "... [the] UBWPAD, North Attleboro, and Attleboro WWTFs play a significant role in the ability to improve water quality in the Providence and Seekonk River system [into which the Blackstone discharges], and efforts to reduce their nitrogen inputs should be initiated as soon as possible.

"[16] In September 2010, the Conservation Law Foundation, citing this report, filed a lawsuit claiming that the discharge permit issued to the UBWPAD by the Environmental Protection Agency was not "sufficient to meet state water quality standards".