PAWTUCKET, R.I. — The stench was so robust that Holly Dygert couldn’t close her car door fast enough. She would have quickly driven away if she wasn’t waiting outside the International Charter School to pick up her daughter.

“I opened the car door and was knocked back by this strong toxic smell,” said Dygert, recalling that 2010 fall afternoon. After experiencing the overwhelming stink a few more times waiting on Pleasant Street to take her kindergartner home, she decided to investigate.

The in-your-face smell, she soon discovered, was coming from work being done at the nearby Tidewater Street gasification plant. Gas storage tanks on the property were being dismantled and decades-old sludge — a mixture of captured rainwater and a chemical concoction — inside the tanks was being removed.

She called the state Department of Environmental Management (DEM) to inquire about the work and the stink. She was passed along to National Grid, which has owned 20 of the site’s 23 acres since 2006. Dygert said the pungent odor — which she later learned, after making numerous phone calls, pouring through mounds of air-quality data and “begging” DEM to investigate — was from toxic chemicals in the sludge that had been released into the air, with little warning to the public, during tank dismantling.

The former gasification plant, between Taft Street, an extension of Tidewater and Thornton streets to the west and the Seekonk River to the east, is bordered by residential properties, including four houses that abut the property, and three schools — the International Charter School, the Blackstone Academy, the Francis Varieur Elementary School, whose Max Read Athletic Field was once part of the gasification plant property.

Dygert said she was told by National Grid that air quality during the tank-dismantling/sludge-removal work was being monitored and no odor problems had been detected. A senior project manager at GZA GeoEnvironmental Inc., a Providence consulting firm hired by National Grid, told Dygert that she was perhaps smelling a fire or the local coffee roaster.

“She said, ‘Some of us have sensitive noses,’” recalled Dygert, a Mount Pleasant resident and an assistant anthropology professor at Rhode Island College. “The work was being done right across the street from where my daughter goes to school. The way they handled the removal was ridiculous. There’s something not right when the property owner gets to tell people the site is safe.”

A total of 443,340 gallons of liquid sludge was removed from the gas-holding tanks and 295 tons of solid sludge was disposed off-site, according to National Grid.

After the tank/sludge-removal work was mostly complete, DEM requested the project’s air-quality data. Officials found that hazardous substances had, indeed, been released into the air during the fall 2010 work at levels that exceeded health thresholds.

“The data collected indicate that levels at the down-wind perimeters of the site during the period that the sludge was being removed from the tanks and processed at times substantially exceeded the chronic exposure health benchmarks,” according to a DEM analyst of the data.

National Grid was notified of the findings and no further investigation was conducted.

Dirty site
From the late-1880s through the mid-1970s, a manufactured-gas plant and electric generation facility operated at the end of Merry and Tidewater streets. The 23-acre facility used industrial processes to produce gas from coal and oil. The gas was used primarily for the same purposes that natural gas is used today — for heating, cooking and lighting.

Such plants were common before the region’s natural gas pipelines were built, and often produced nasty byproducts such as tars, sludges and oils. Few, if any, rules and regulations existed then for dealing properly with such waste byproducts. In fact, residuals from such operations often remain in the environment long after a facility is shut down. Gas manufacturing and electric generating operations at the Tidewater plant were terminated in 1968 and 1975, respectively, according to a public-information website operated by National Grid.

National Grid currently operates a natural gas regulating and interchange station and an electrical substation and switch house on the brownfield site. The rest of the property is vacant, and gas manufacturing is no longer part of the facility’s operation.

With its prime location along the Seekonk River, Pawtucket and Greater Providence would benefit from the remediation of the former industrial site. But, local resident Lon Plynton, like Dygert, doesn’t believe the neighborhood, schoolchildren and the environment should be saddled with health costs to make it happen.

“This place is definitely bad news,” said Plynton, who has owned a home on Pleasant Street for the past seven years. His family no longer lives there, having moved to another neighborhood a few years ago. But he has been unable to sell his Pleasant Street house. “I’d like to see more testing done, especially around the schools. There’s all kinds of poisons in that soil.”

In May 2011, International Charter School director Julie Nora wrote a letter to National Grid and GZA GeoEnvironmental to politely make the school’s frustrations and concerns known.

“We are particularly concerned about protecting the children, whose size and stage in the human development process make make them especially vulnerable to toxic substances. With this goal in mind, we observed shortcomings in the Gas Holder Dismantling work that was conducted at the site last Fall. We note these concerns here and suggest solutions to improve the process as the full remediation goes forward,” Nora wrote. “At the conclusion of the Gas Holder Dismantling Project, we learned that additional mechanisms have been successfully employed at similar sites to keep emissions from contaminating the air in the surrounding community. For example, we understand that caps and tents are often erected around sites to migrate migration of VOCs.”

Filthy process
Manufactured gas was one of the great industrial enterprises of the 19th century. It was made primarily from coal, and during its production, tars were created and leaked, spilled or dumped into the environment. These tars aren’t susceptible to natural degradation, according to Allen Hatheway, Ph.D., a geological engineer and author with nearly five decades of professional experience.

Hatheway, a noted scholar on manufactured gas who is often sited by those concerned about the Tidewater Street property, has written that operators of gas manufacturing plants routinely dumped toxic byproducts wherever they could find a place. Tars associated with the process are made up of 500 to 3,000 different compounds, typically toxic to humans. Sometimes carcinogenic, these tars are more dense than water and tend to sink into the soil, where they remain for a long time.

These tars are complex mixtures of organic chemicals, and two major classes of chemical compounds can be found in coal tar: volatile organics such as benzene, toluene, ethylbenzene and xylene — known as BTEX compounds; and semi-volatile organic compounds known as polycyclic aromatic hydrocarbons (PAHs).

BTEX compounds often represent only a small percentage of the mass of manufactured-gas tar, but they are the most soluble and thus the most likely to be dissolved in groundwater and migrate off site. They also are the most volatile and the most likely to migrate through subsurface soils as vapors or soil gas.

Although hundreds of PAH compounds have been identified in coal tar, there are 17, including

2-methylnaphthalene, naphthalene and acenaphthylene, that the Environmental Protection Agency (EPA) recognizes as priority pollutants.

Captured impurities such as ammonia, cyanide, sulfur and heavy metals, particularly arsenic, also are generated during gas manufacturing.

Much of the soil on the Tidewater site likely contains toxic byproducts from almost a century of gas manufacturing. Dygert, Plynton and others believe keeping local residents and schoolchildren safe during any remediation efforts, no matter how small, should be a bigger priority and a more-pressing concern.

“It’s a pretty contaminated site and they shouldn’t be doing things that disturb soil unless the public has had a chance to comment on the work and the proper precautions have been taken,” Dygert said. “What is the exposure risk to the contaminants that are in the ground there? Any remediation should be conducted without exposing the neighborhood to possible dangers.”

She points to two albeit “little projects” conducted last year that kicked up dirt and the three-month-long tank removal project in 2010 that drew her into the Tidewater site issue.

“Exposure to the community during the removal of those tanks is still unclear,” said Amelia Rose, director of the Providence-based Environmental Justice League of Rhode Island. “The tanks were dismantled before any public comment period was held. The odors could have been kept down to at least to keep people from getting nauseous and scared for kids’ safety.”

Mercury rising
The underpublicized removal of the gas tanks and the toxic sludge inside them hasn’t been the only Tidewater issue to anger and frustrate the neighborhood. In October 2008, two years before National Grid bought most of the property, a jury found Southern Union guilty of illegally storing mercury on the site. The Houston-based company had owned New England Gas for several years.

During the trial, the government presented evidence that, in 2001, Southern Union began removing from customers’ homes gas regulators that contained mercury. Southern Union employees brought the regulators to the Tidewater Street site, where the regulators, and later liquid mercury, were stored in a shed. The liquid mercury was stored in glass jars and plastic jugs.

In September 2004, three youths broke into the shed — the site was much-less secure back then — and took several containers of liquid mercury. They broke some of them, spilling mercury around the facility’s grounds, and took some of the mercury to a nearby apartment complex, Lawn Terrace, where it was also spilled.

After the contamination was discovered, the apartment complex was evacuated, and its 150 tenants were displaced for two months while the mercury was cleaned up. Southern Union was fined $18 million for illegally storing mercury.

Today, despite a hole-less chain-linked fence that now surrounds the property, warning signs in both English and Spanish, no more jelly jars filled with mercury and the tanks filled with nastiness gone, neighbors and parents of children who attend the three nearby schools have been pushing for greater public involvement in the site’s remediation plans.

They say they are still very much worried about the soil’s toxicity. They are concerned about dust and other airborne particles floating around the neighborhood anytime Tidewater site ground is disturbed. They get anxious when they see workers in white hazmat suits and wonder if they and their children are adequately protected.

Before the site was properly secured, when liquid mercury was carelessly stored in plastic jugs, neighbors want to have an idea about how much of the former industrial site’s dirt was tracked around the neighborhood by curious teenagers, dog walkers, urban hikers and the less fortunate who often slept there.

“Before the break-in, no one paid any attention to the site,” said Plynton, who created a website as a place to store information about the former gasification plant. “There was gross negligence regarding that site for many years. … It was all hush-hush, and there was little public information. Trucks not covered driving off with dirt flying all over. The owner before (National Grid) should be held more accountable.”

Public involvement
Prompted by a spring 2012 petition from the Environmental Justice League of Rhode Island and signed by about 30 concerned parents of local schoolchildren, National Grid agreed to draft a Public Involvement Plan (pdf) in preparation for future remediation work at the Tidewater site.

In late January, National Grid held a public meeting at the Varieur Elementary School to review the PIP plan. At that meeting, representatives for DEM, National Grid and GZA GeoEnvironmental discussed the plan and solicited public comment. Some 20 people attended, including city officials and Fire Department personnel, and many left with unanswered questions and lingering concerns, according to Dygert.

Since the lines of communication between National Grid and the community have improved, the energy company has met with neighborhood residents, concerned parents and members of the Environmental Justice League. It has installed a benzene monitoring device on the site and erected an air-monitoring station near the row of four houses. National Grid also held a public information meeting March 27 at Varieur Elementary School.

DEM is currently reviewing National Grid’s remediation plans for the site. “The site itself doesn’t really pose a risk as it is,” said Joe Martella, DEM’s project manager for the Tidewater Street site. “There are environmental concerns with the property which will require some type of cleanup. The intent is to have a remedy that cleans up the site but also maintains a factor of satisfaction with the nearby community.”

The site’s remediation plans include capping, removal and containment, according to Michele Leone, a manger for National Grid. Along the Seekonk River, where soil contamination runs deep, an in-ground containment wall will be built to keep contaminants from migrating to the water, she said.

Leone said the site’s cleanup will likely require thousands of truckloads during a two-year period and cost about $20 million. “We want to clean the site up and let the public make use of it,” she said. “We’re moving the site forward and we want the public involved.”

Since the early 1990s, National Grid has been investigating and remediating gasification plants. The Tidewater Street property is one of a dozen such sites National Grid owns in Rhode Island. It owns 60 such sites in Massachusetts and 300 across the country, according to National Grid officials.