PROVIDENCE — A new park recently opened in the middle of a concrete jungle.

Hidden off Reservoir Avenue, behind a fast-food joint and an all-but-vacant strip mall and its shuttered gas station, and across a polluted pond from a 117-acre industrial park, the swath of newly minted green space was for decades brown, as in a toxic brownfield.

Mashapaug Pond Park, more than a decade in the making, has been capped with a geotextile barrier and covered by 12 inches of clean fill. The site, including wetlands, has been revegetated with native plants and the Department of Parks plans to plant a 64-square-foot wildflower garden in the park’s northeast corner. It’s now the fourth park around Mashapaug Pond, and there has been preliminary talk about creating a trail system to connect them.

The remediation of the Reservoir Triangle neighborhood park and the ongoing cleanup of the urban pond were long championed by Amelia Rose, now the executive director of Groundwork Rhode Island, and Holly Ewald, who for years made Mashapaug Pond the focal point of the annual Urban Pond Procession (UPP).

ecoRI News spoke to Ewald two days after the park’s official ribbon cutting and on the morning of day the community fellow at Brown University’s John Nicholas Brown Center for Public Humanities was flying to England, to give a presentation about the project at a landscape conference at the University of Derby.

She called the June 21 event “awesome,” “amazing,” and “wonderful.”

“The public interest in addressing the causes and cleaning up the area, and all the wonderful work done by so many, it was amazing to see,” said Ewald, founder and executive director of UPP Arts. “It was gratifying that the arts can really work to create change. The arts community really had an impact.”

Before the project shut down two years ago, after a decade of activism, UPP Arts had introduced thousands of students and residents to Mashapaug Pond via school and community-based workshops and projects. It encouraged people to learn about Mashapaug Pond and its history, and to take on the role of citizen-conservationists, artists, and cultural historians.

Mashapaug Pond is the centerpiece of an often-ignored neighborhood, basically a liquid brownfield surrounded by homes, a high school, and acres of underused impervious surface. Legacy contaminants trapped in sediment and polluted stormwater runoff, much of it delivered by six storm drains on the pond’s west side, have turned the pond into a toxic soup. The pond is a regular on Rhode Island’s list of impaired waters, because of phosphorus, low dissolved oxygen, excess algal growth, and pathogens.

Fish from Mashapaug Pond are still unsafe to eat and swimming is prohibited. The pond is now an Environmental Protection Agency research site for bacterial blooms in urban waters.

The Gorham Manufacturing Co., on the banks of Mashapaug Pond where the remediated park now sits, began operating in 1890. At its height, the 37-acre facility had 30 buildings and was one of the largest silver manufacturers in the world.

As a result of the various manufacturing processes used at the factory for nearly a century, much of the land and water on the Adelaide Avenue site were significantly contaminated. Chemical solvents, such as trichloroethylene and perchloroethylene, that were used to clean metal and machine parts in the factory seeped into the land and created underground pools. These chemicals are volatile organic compounds, meaning they can turn into a gas that people might breathe in. They also are known to be human carcinogens.

The cleanup of the Gorham site was a complex situation fraught with 15 years of controversy, which intensified in 2006 when the city hastily decided to build Dr. Jorge Alvarez High School, a public school that educates most mostly low-income students and children of color, on top of dirt contaminated with industrial pollutants. The school opened long before the site was completely remediated. Local residents were, understandably, upset.

Relentless resident and activist pressure eventually forced the city to install venting and monitoring systems to prevent the buildup of toxic vapors inside the school.

The recent event to celebrate Mashapaug Park’s opening, which included the Urban Pond Procession, the Extraordinary Rendition Band, and representatives from the indigenous community, marked perhaps the final chapter for local residents who long fought to have a say in what their community should look like.

The park’s new walking path begins behind the school and overlooks Mashapaug Cove. The path follows the cove before ending at the northeastern shore of the pond. It includes four wood benches and 10 interpretive signs designed by Central and Alvarez High School students with the support of local artist Anna Snyder. The signs contain information about Mashapaug Pond and its social, industrial, Indigenous, and environmental significance and legacy.

The area was once a thriving Narragansett Tribe settlement. In the early 1800s, its shores became home to an ice-harvesting company owned by the Carpenter family, and by the late 19th century it was the heart of American silver manufacturing.

Mashapaug Pond, the city’s largest freshwater body, is part of the Pawtuxet River watershed. It’s fed by the waters of nearby Tongue and Spectacle ponds in Cranston and in turn feeds into the Roger Williams Park ponds. From there, the water ultimately drains into Narragansett Bay.

As for the new park, Ewald said it would be a “great place for a rock concert.”