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Blackstone River
The Blackstone River in Massachusetts
CountryUnited States
StateMassachusetts, Rhode Island
RegionNew England
Physical characteristics
 • locationWorcester, MA
 • location
Seekonk River, at Pawtucket Falls in Pawtucket, Rhode Island
 • coordinates
41°52′38″N 71°22′56″W / 41.8771°N 71.3822°W / 41.8771; -71.3822
Length48 mi (77 km)
Basin size540 sq mi (1,400 km2)

The Blackstone River is a river in the United States that flows through the states of Massachusetts and Rhode Island. It is 48 mi (77 km) long with a drainage area of 540 sq mi (1,400 km2) and drains into the Seekonk tidal river at Pawtucket, Rhode Island. Its long history of industrial use has caused significant pollution, with the United States Environmental Protection Agency describing it as the most polluted river in the country because of high concentrations of toxic sediments."[1]


The original Native American name for the river was the "Kittacuck", which meant "the great tidal river". The "Kittacuck" used to be plentiful with salmon and lamprey in pre-colonial and colonial times.[2]

In English, the river is named after William Blackstone (original spelling William Blaxton), who arrived in Weymouth, Massachusetts in 1623 and became the first European settler of present-day Boston in 1625. He relocated to Rhode Island in 1635 and built his home on the river, in what would become Cumberland.[citation needed]


The river is formed in South-central Worcester, Massachusetts, by the confluence of the Middle River and Mill Brook. From there, it follows a rough southeast course past Worcester city and Northbridge. It then flows through Millbury, Sutton, Grafton, Northbridge, Uxbridge, Millville, and Blackstone. It continues into Rhode Island, flowing past Woonsocket, Cumberland, Lincoln, Central Falls, and Pawtucket, where it then reaches Pawtucket Falls. Following this, the river becomes tidal and flows into the Seekonk River just north of Providence. Other tributaries join the Blackstone along the way, such as the West River and Mumford River in Uxbridge, Massachusetts; and the Branch River, in North Smithfield, Rhode Island.[3]


In addition to many unnamed tributaries, the following brooks and rivers feed the Blackstone:


Blackstone River at Ashton, RI (Ashton Viaduct)
Below is a list of crossings over the Blackstone River. The list starts at the headwaters and goes downstream.
  • Worcester
  • Millbury
  • Sutton
    • Blackstone Street
    • Depot Street
  • Grafton
    • Pleasant Street
    • Main Street (MA 122A)
    • Depot Street
  • Northbridge
    • Sutton Street
    • Providence Road (MA 122)
    • Elston Avenue
    • Church Street Extension
  • Uxbridge
  • Millville
    • Central Street
    • Cam's Street
  • Blackstone
    • Bridge Street
    • St. Paul Street
  • Woonsocket
  • Cumberland
  • Central Falls
    • Broad Street (RI 114)
    • Roosevelt Avenue
    • Cross Street
  • Pawtucket
    • Exchange Street (RI 15/114 Southbound)


Along with the Providence River, the Blackstone served as the northeastern border of Dutch claims for New Netherland from Adriaen Block's charting of Narragansett Bay in 1614 through the Hartford Treaty of 1650.

Slater Mill in Pawtucket, along the Blackstone River

In 1790, Samuel Slater opened the first successful water-powered cotton mill in America: Slater Mill, at Pawtucket Falls. This mill was powered by the waters of the Blackstone River. Many other mills appeared along the Blackstone River over time, making it a significant American industrial location and contributing to the river becoming the main cause of the Narragansett Bay pollution by the end of the 20th century.[4]

In August 1955, severe flooding on the Blackstone caused extensive damage to Woonsocket, Rhode Island. Whereas the river is usually 70 ft (21 m) wide, it swelled to over 1 mi (1.6 km) in width.[5] The flooding of the Blackstone was the result of a succession of dam breaks, which were caused by rainfall from Hurricane Connie and Hurricane Diane a week later. 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.[6] This lead 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.[7]

The river, together with the Woonasquatucket River to the south, was designated an American Heritage River in 1998.

Pollution and remediation efforts

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The Blackstone River has been significantly impacted by industrial activities and resulting pollution since the 18th century. Early industries discharged a variety of pollutants into the river, including dyes from textile mills and heavy metals and solvents from metal and woodworking industries.[8] Much of this early pollution lies trapped in sediments behind historic dams on the river and continues to affect the ecosystem today.

The inaugural celebration of Earth Day in 1970 further increased public support for remediation projects. While environmental activists in the Blackstone River Valley were already organizing cleanup efforts locally, in 1971, a formalized plea for action was made to the then Governor of Rhode Island, Democrat Frank Licht. In December 1971, political support was pledged at the state level. The Blackstone River Watershed Association, just two years old at the time, was designated to lead the effort. By April 1972, support among the public for cleaning the river was increasingly widespread. Additionally, the 1972 federal Clean Water Act (CWA) was passed by Congress, offering more protections for the water quality of the Blackstone.

However, the effects of industrial wastewater discharge into the river were long-lasting: in 1990, the United States Environmental Protection Agency called the Blackstone "the most polluted river in the country concerning toxic sediments."[1] A 1990 Massachusetts Department of Public Health report said of the river: "The Department finds that the condition of the Blackstone River is offensive throughout its course, from Worcester to the state line at Blackstone. 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."[8]

Recent pollution can be partially traced to the Upper Blackstone Water Pollution Abatement District (UBWPAD),[9] the wastewater treatment plant for Worcester, Massachusetts and surrounding communities, which discharges into the Blackstone. 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."[10] 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 is not "sufficient to meet state water quality standards".[11]

River cleanup is ongoing and as of 2010 the Blackstone river was rated as the worst category ("impaired") for all assessed uses ("aquatic life", "fish consumption", "primary contact" (e.g. swimming), "secondary contact" (e.g. boating) and "aesthetics") up to its beginning at Middle River.[12]

Processing problems at the Woonsocket sewage treatment plant prompted no-contact advisories for the Rhode Island portion of the river in 2022.[13]

See also


  1. ^ a b "Blackstone River Watershed". Rhode Island Rivers Council. Archived from the original on 2012-03-16. Retrieved 2010-12-28.
  2. ^ source document: Metcalf, Annals of the History of Mendon, 1880.
  3. ^ The editors of Encyclopaedia Britannica. "Blackstone River". ((cite web)): |last= has generic name (help)
  4. ^ Blackstone River Watershed – Five-Year Watershed Action Plan, First Draft Archived March 3, 2007, at the Wayback Machine
  5. ^ Landrigan, Leslie (2014-08-17). "Hurricane Diane, 1st $1 Billion Hurricane, Wallops New England in 1955". New England Historical Society. Retrieved 2023-05-03.
  6. ^ "The Floods of Hurricane Connie and Diane". National Weather Service. Archived from the original on 2012-03-21. Retrieved 2011-02-23.
  7. ^ "Blackstone River Hydrograph". National Weather Service - Advanced Hydrologic Prediction Service. Archived from the original on 2011-07-21. Retrieved 2011-02-23.
  8. ^ a b Kerr, Meg (1990). "Rhode Island Sea Grant Fact Sheet: The Blackstone River". Archived from the original on 2010-06-12. Retrieved 2010-12-29.
  9. ^ Upper Blackstone Water Pollution Abatement District (UBWPAD)
  10. ^ "Plan for Managing Nutrient Loadings to Rhode Island Waters" (PDF). Rhode Island Department of Environmental Management. 2005-02-01. Archived (PDF) from the original on 2010-11-23. Retrieved 2010-12-29.
  11. ^ "Conservation Law Foundation Seeks Stricter Controls on Nitrogen Pollution in Upper Blackstone Water Pollution Abatement District to Restore Water Quality in Massachusetts and Rhode Island". 2010-09-28. Archived from the original on 2011-07-05. Retrieved 2010-12-29.
  12. ^ "Blackstone River Watershed 2003–2007 Water Quality Assessment Report" (PDF). Massachusetts Department of Environmental Protection Division of Watershed Management. March 2010. p. xi. Archived from the original (PDF) on 13 January 2011. Retrieved 12 September 2019.
  13. ^ "DEM: 'Substantial' solid waste from Woonsocket sewage plant released into Blackstone River daily". The Boston Globe. 10 June 2022.

General references