Blog

May 25, 2023

Blackstone River still suffers from pollution 50 years after massive cleanup

On Sept. 9, 1972, about 10,000 people descended on the banks of the Blackstone

On Sept. 9, 1972, about 10,000 people descended on the banks of the Blackstone River. Flowing 48 miles south through Central Massachusetts and Rhode Island, the Blackstone at the time was considered one of the most polluted rivers in the country — smelly and toxic from raw sewage, industrial chemicals and other debris regularly released into it.

Using helicopters, cranes and other heavy construction equipment, the volunteers along with the National Guard removed more than 10,000 tons of debris from the river in one day — everything from washing machines to a school bus. Operation ZAP, as it was called, made headlines across the country and jumpstarted more efforts to restore the river.

"Even today, [something like that] is pretty much unheard of," said Ray Kelley, whose late grandfather David Rosser organized the cleanup. "Why would 10,000 people do anything except maybe go to a sports arena?"

Fifty years after the ZAP event, the Blackstone River and the water bodies that flow into it are cleaner than they used to be. Still, scientists and environmental activists say the watershed is less healthy than the organizers of the 1972 cleanup had hoped it would be by now.

The sediments at the bottom of the river remain contaminated from the industrial pollution released into the water decades ago. Dirty stormwater carrying nutrients from fertilizer and chemicals from motor oil also regularly runs off streets into the river, leaving the waterway hazardous for recreational swimming and compromising the health of fish. Trash continues to line parts of the river and its tributaries.

During a recent cleanup of a Worcester stream at the northernmost point of the Blackstone watershed in Massachusetts, volunteers came across an old rusty cash register, a basketball hoop rim and a street sign pole, in addition to more than a hundred plastic bottles and miscellaneous wrappers.

The plastics break down over time into smaller, hard-to-remove pieces that fish can easily ingest, said Worcester State University professor of earth science Laura Reynolds, who led the cleanup with her students.

"There's a constant influx," Reynolds said. "It's a losing battle" trying to pick it all up.

The Blackstone River, which leads into the Narragansett Bay off Rhode Island, began suffering from a lot of pollution during the Industrial Revolution in the 1800s. Steam-powered mills producing everything from textiles to paper started operating along the river, using the water as a source of energy. The factories regularly released industrial waste into the river, including heavy metals and dyes that would turn the water different colors.

With the mills came residential development and the need to dispose of waste and sewage. Kelley, the grandson of David Rosser — the organizer of the 1972 Operation ZAP event — said people saw the Blackstone as a convenient dumping ground, not a habitat for wildlife or haven for outdoor recreational activity.

"It was just, ‘Throw it down by the river. No big deal,"’ Kelley said.

By 1971, Audubon Magazine identified the Blackstone as one of the most polluted rivers in the country. That's when Rosser began organizing Operation ZAP and convinced Rhode Island's state government, National Guard and construction worker unions to help with the massive cleanup.

The passage of the 1972 Clean Water Act was another victory for the river and its advocates. The federal bill regulated discharges of industrial waste into water bodies and forced localities to start cleaning sewage before releasing it into rivers and streams. Rosser was hopeful that the new water protections and more efforts to restore the Blackstone would help the river become clean enough for recreational swimming within a few years.

That still hasn't happened, because the river remains polluted for several reasons.

"In terms of river quality, he would not be satisfied and would really continue to push for more," Kelley said.

In addition to the trash still around the watershed, some sewer systems in nearby cities are old and have a tendency to overflow into the Blackstone after heavy rainfall.

The sediment behind dozens of dams on the river also remains contaminated. Blackstone River advocates want the sediment to be removed, but that process is expensive and time-consuming and would require finding somewhere else to put the sediment.

Watch a 1974 short documentary about Operation ZAP:

Another main source of pollution involves stormwater running off streets into the Blackstone and the water bodies that flow into it.

When rainwater drains in communities such as Worcester, underground pipes eventually release it into the Blackstone and other nearby waterways. As it runs down impervious surfaces like asphalt, the stormwater picks up motor oils as well as nutrients from fertilizers and animal waste that can fuel the growth of toxic algae in water bodies. When the algae die and decompose, bacteria break them down, sucking up oxygen from the water and effectively suffocating nearby fish.

"I worked with an engineer once who said, ‘If aliens arrived on our planet and looked at our stormwater system, they would think we’re doing a highly effective job of polluting our waterways as quickly and efficiently as possible,’" said Stefanie Covino, who leads the Blackstone Watershed Collaborative, a network of groups working to restore the river.

Climate change could exacerbate the problem, Covino said. As temperatures warm, storms produce more rainfall because hotter air can hold more water vapor. That results in a higher volume of polluted stormwater running off into waterways.

Covino said the solution must involve greater consideration of how sprawling development with lots of concrete and asphalt leads to more polluted runoff into the Blackstone River. Communities should prioritize replacing impervious surfaces that contribute to the runoff problem with more green infrastructure that cleans stormwater, she said. Rain gardens and wetlands, for example, capture stormwater and naturally filter out the pollutants as the water seeps through the soil before it heads into rivers and streams.

"If someone's coming [into a town around the watershed] to build something, is the town saying … ‘Have you considered green infrastructure?’" Covino said. "Let nature do its job."

City officials in Worcester agree polluted stormwater runoff is a problem. They’re trying to address it with about 85 underground devices called hydrodynamic separators that remove pollution from stormwater.

Jacquelyn Burmeister, a senior environmental analyst for Worcester, said the Green Worcester Plan — a roadmap for the city's response to climate change — also involves adding more trees and greenspace to areas that are mostly concrete and working with private property owners to do the same. Burmeister noted that more tree canopy comes with the extra benefit of additional shade and less heat around Worcester.

The city also has been trying to improve its combined sewer system to avoid future sewage overflows during heavy rainfall events, Burmeister said.

"We have come a really long way," she said. "There's a lot more work that needs to be done."

She said it could take some time, but the hope is to accomplish what the organizers of Operation ZAP set out for: a clean and healthy Blackstone River.

Produced with assistance from the Public Media Journalists Association Editor Corps funded by the Corporation for Public Broadcasting, a private corporation funded by the American people.

Sam Turken is the Worcester reporter for GBH News, covering housing, the environment and other social justice and economic issues.