Blackstone River

• 1. Introduction

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  The Blackstone River flows 48 miles from central Massachusetts into Rhode Island. It drains an area of 475 square miles, or 1,229 square kilometers. In 1990, the United States Environmental Protection Agency delivered a blunt verdict. It called the river "the most polluted river in the country because of high concentrations of toxic sediments." A modest New England waterway had earned that grim distinction. How did water running past small mill towns come to carry that label? And what does the name Blackstone even reveal about who lived along this river first?

• 2. A River Named Twice

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  Long before English settlers arrived, Native Americans called this water the Kittacuck. The name meant "the great tidal river." Narragansett speakers used a related term, Mishkittacook se'pe, meaning "the great long wide river." In pre-colonial and colonial times, both names fit water that ran thick with salmon and lamprey.

  William Blaxton, later spelled Blackstone, arrived in Weymouth, Massachusetts, in 1623. Two years later, in 1625, he became the first European settler of what is now Boston. In 1635 he relocated to Rhode Island. There, he built his home directly on this river, on land that would become Cumberland. Within a few miles of that homestead, the same current would later turn a mill wheel and reshape New England industry.

• 3. From Confluence To Tide

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  The Blackstone begins in south-central Worcester, Massachusetts, where the Middle River meets Mill Brook. From there it runs southeast, threading through Millbury, Sutton, Grafton, Northbridge, Uxbridge, Millville, and the town of Blackstone. Crossing into Rhode Island, it passes Woonsocket, Cumberland, Lincoln, Central Falls, and Pawtucket, reaching Pawtucket Falls. Below the falls, the river turns tidal, flowing into the Seekonk River just north of Providence.

  The West River and Mumford River join the Blackstone in Uxbridge, Massachusetts. Further downstream, the Branch River adds its flow in North Smithfield, Rhode Island. Smaller contributors, like the Quinsigamond River and Abbott Run, feed the system as well.

  In the early 19th century, builders added the Blackstone Canal running parallel to the river itself. The canal carried goods between Worcester, Massachusetts, and Providence, Rhode Island. It moved raw materials and finished products efficiently, feeding the region's growing economy. That parallel channel foreshadowed a far larger transformation already underway along the riverbank.

• 4. Borders And The First Mill

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  In 1614, the Dutch explorer Adriaen Block charted Narragansett Bay. That survey made the Blackstone, together with the Providence River, the northeastern edge of Dutch claims to New Netherland. The border held until the Hartford Treaty of 1650 redrew the line.

  In 1790, Samuel Slater opened Slater Mill at Pawtucket Falls. It was the first successful water-powered cotton mill in America, and the Blackstone's current powered it directly. Other mills soon followed along the river's length.

  By the end of the 20th century, industrial use had made the Blackstone the leading cause of pollution in Narragansett Bay. The same mills had also turned the river into a major American industrial site. Decades of dams built to power them were about to fail all at once.

• 5. The Flood Of 1955

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  In August 1955, floodwaters tore through Woonsocket, Rhode Island, causing extensive damage across the city. The Blackstone normally runs about 70 feet wide. During the flood it swelled to more than a mile across.

  Hurricane Connie, followed a week later by Hurricane Diane, triggered a succession of dam breaks along the Blackstone. In parts of Rhode Island and Massachusetts, the two storms combined dropped more than 20 inches of rain within a single week.

  The Blackstone reached its highest recorded water level in Woonsocket during that flood, at 21.8 feet. That mark stood a full 12.8 feet above the river's flood stage. The wreckage those waters left behind would outlast the floodwaters themselves by decades.

• 6. The Fight To Clean It

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  Since the 18th century, textile mills had discharged dyes directly into the Blackstone. Metal and woodworking industries added heavy metals and solvents on top of that. Traces of those metals still turn up in sediments near the river today.

  Earth Day, celebrated for the first time in 1970, boosted public support for cleaning up the river. Activists in the Blackstone River Valley were already organizing local efforts. In 1971, they formalized a plea for action to Rhode Island's governor, Frank Licht.

  By December 1971, political support for cleanup had been pledged at the state level. The Blackstone River Watershed Association, only two years old, was designated to lead the effort. Public backing kept growing, and by April 1972 support for cleaning the river had increased further.

  In 1972, Congress passed the federal Clean Water Act. The act never named the Blackstone specifically, but it declared that it "establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters." In 1983, the EPA identified continuing water quality problems and established the Peterson/Puritan Superfund Site.

  In 1998, the Blackstone earned a different kind of recognition. Alongside the Woonasquatucket River to the south, it was designated an American Heritage River. Recognition and reality, it turned out, were not the same thing.

• 7. Still Impaired

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  A 1990 report from the Massachusetts Department of Public Health did not mince words. It described the river's condition as "offensive throughout its course, from Worcester to the state line at Blackstone." The same report warned conditions were "likely to grow worse" without further cleanup measures.

  Recent pollution has been traced partly to the Upper Blackstone Water Pollution Abatement District, the wastewater treatment plant serving Worcester and its surrounding communities. A 2005 report from the Rhode Island Department of Environmental Management flagged that plant, along with the North Attleboro and Attleboro treatment facilities, over nitrogen discharge into the river system. In September 2010, the Conservation Law Foundation filed a lawsuit citing that report, arguing the EPA's discharge permit for the district was not sufficient to meet state water quality standards.

  As of 2010, assessors rated the Blackstone in the worst possible category, "impaired," for every use they measured. That covered aquatic life, fish consumption, swimming, boating, and general aesthetics, all the way up to its start at Middle River.

  In 2022, processing problems at the Woonsocket sewage treatment plant sent solid waste flowing into the river. That failure triggered no-contact advisories across the Rhode Island stretch of the Blackstone, keeping people out of water still being shaped by choices made generations earlier.