Two experts on manufactured gas plants like the one that operated at the Dushanbe Teahouse site in Boulder for half a century say it’s likely that contamination found at a nearby dry cleaner site came from the plant.
And it seems there are some features of the historic gas plant that have been unaccounted for. One expert has suggested that the teahouse be moved, at least temporarily, so that the site can be properly cleaned up.
The City of Boulder, which now owns the property, and its consultants have argued that a toxin called naphthalene found about a block southeast did not come from the gas plant, partly because groundwater at the site flows northeast.
But scientists say naphthalene in groundwater is considered a “fingerprint” for gas plants.
Allen Hatheway, who wrote a 1,400-page book titled Remediation of Former Manufactured Gas Plants and Other Coal-Tar Sites and is considered one of the nation’s top authorities on the topic, says that while dry-cleaning operations have their own set of contamination threats, naphthalene isn’t typically one of them.
“If there is naphthalene at the dry cleaner or anywhere else, it’s most likely associated with the gasworks,” he says, adding that it doesn’t make sense for groundwater to be flowing away from Boulder Creek, at least not for any great distance. “Why would the groundwater be flowing to the northeast?”
Similarly, Bob Lewis, who is principal hydrogeologist at Aqui-Ver and who has investigated more than 50 gasification plants around the country in his 24 years in the field, says the solid crystal form of naphthalene that is used for mothballs and might be found at dry cleaners is different from the liquid form of the substance that one would find emanating from gas plants and turning up in monitoring wells like those dug at the dry cleaner site a block from the teahouse.
“I’m not an expert on the dry cleaning process, but I’ve worked on a number of dry cleaning sites, and typically you find that the chlorinated solvents they used tend to be the problem at those sites, not naphthalene,” he says. “I’ve not seen that at those types of facilities. It’s much more likely to come from a gas plant, and I wouldn’t necessarily even talk about the mothballs, because I’m not sure how they would end up in the groundwater. Basically, when you look at a facility and the materials that they use, you might come across mothballs and naphthalene and say, oh, well, that’s why it could have come from the dry cleaner site, and that’s not very likely.”
Lewis adds that the city should be able to provide some additional scientific evidence to back up the claim that its property was not responsible for contamination at the dry cleaner.
“If they’re just saying that without any data, then I don’t know why they’d assume it didn’t come from the gas site,” he says. “My first inclination would be that it came from the gas plant.”
Lewis also agreed that while the nearby ditch may cause groundwater at the 13th Street Plaza to move to the northeast, it’s bound to change direction.
“At some point down-gradient of the site, you’re going to expect to see water beginning to move more southerly, toward the creek,” he says.
Lewis and Hatheway, both of whom examined the 378-page report issued April 8 by city consultant USA Environment regarding contamination discovered at the property, agree that the contaminants would travel very slowly through groundwater. Hatheway says the substances stay where they were dumped, for the most part, but as groundwater moves through the area, it travels along the edges of the waste because the soil is more porous there, and picks up the contaminants, carrying them away. He describes the water as being eager to absorb the substances in question, and even though the density of the waste-soaked soil is high, “it’s still hungry and looking for its meal.”
But Lewis says by the time the chemicals migrate a significant distance, they are probably too diluted to pose much of a health threat. Hatheway agrees that the contaminants’ rate of travel “will be a lot slower than you think.”
Of course, in the case of a plant built in 1902, some of the contamination has had 11 decades to make its journey.
There are also unanswered questions about where the Federal Gas Company dumped the massive amount of waste it generated while it was operational.
Lewis says it was common for gasification plants to be built next to creeks or other bodies of water — and not just because they used water in their processes.
“It was not unusual for them to discharge their wastewater to the streams,” he says. “At the time, it was just considered a normal way of disposing of wastewater.”
Lewis says the older the plant, the more likely it also had a dumping site on solid ground.
Hatheway goes so far as to declare, “For every gasworks, there is a gasworks dump.”
The location of this particular plant’s disposal site is not identified on maps prepared by the city and its consultants, but Hatheway says it was typically located on, or adjacent to, the property, within a half-mile, often along a river bank where spring floods could sweep the waste downstream. An examination of historic Sanborn Fire Insurance Maps is inconclusive, although there are several areas around the property where no structures were built until after the plant’s holders were torn down in the early 1950s.
“If a house post-dates the gasworks, it may be in trouble,” Hatheway says, explaining that these dumping sites “would be graded and leveled, and they’d build a house on it for some poor bastard.”
Similarly, historic aerial photos don’t definitively show evidence of a disposal area on or next to the property. But after examining them carefully, Hatheway, who was an aerial observer in the U.S. Army and who has been interpreting aerial photos for more than 50 years, identified several strong candidates, including the mounds that have been piled up around the sides of the relief holder, the large, circular tank closest to the plant building. A monitoring well on the edge of that holder has recorded the highest levels of contamination of all monitoring wells on the property, exceeded only by levels recorded at the other tank, the main holder, when it was excavated in late 2012.
Hatheway says that, based on aerial photos from the 1930s, 1940s and 1950s, other possible candidates for the dump site include the property directly east of the gas plant and an open area on the same block as the gasworks, directly north of the two holders.
The photos also show that a rail line ran next to the property, raising the possibility that waste materials could have been hauled by train to any of a number of known dumping sites, from the kids fishing pond at Ninth Street and Canyon Boulevard to Valmont Butte — near where Public Service Co. built a coal-fired generation plant in the 1920s, the same time it took over majority ownership of the Federal Gas Company.
Hatheway says the location of the disposal site would be documented in the archives of the Public Service Co., which has surely preserved all of its historic maps and files.
“Gas companies do not destroy their archives,” he told Boulder Weekly. “The drawings and documents held there in are essential to the safe and economical planning and conduct of gas distribution to the public.”
According to Hatheway, a former Public Service employee told him that the company maintains a huge historical archive.
“If they tell you they don’t have any, it’s a bald-faced public relations lie,” he says.
Michelle Aguayo, a spokesperson for Xcel, the company that now owns Public Service, was still looking into the matter as of press time.
Evidence of a gas plant’s dump site can linger for decades. Hatheway cites a case in Champagne, Ill., in which a low-income neighborhood located at a former gasworks property experienced high cancer rates and had a 150-square-foot patch of land where no vegetation would grow.
Hatheway says Boulder’s gas plant would have dumped a variety of hazardous materials at its disposal site. Residuals included wastewater, or “gas liquor,” light tar oils and broken ceramic bricks that fractured regularly when subjected to the high temperatures employed in the gasification process, he explains. The dump would have likely also received waste material from the purifying process, such as cyanide, sulfur and tiny tar particles. In addition, Hatheway says, the gasification process produced “lampblack,” a powdered black carbon.
When asked for his impressions about how the City of Boulder is handling the cleanup, he expressed concerns about the quality of the USA Environment report, and he was critical of the voluntary clean-up (VCUP) process that the city plans to use to remediate the site.
The VCUP process, which the city also employed at the controversial Valmont Butte site, is an arrangement between the Colorado Department of Public Health and Environment and the Environmental Protection Agency that permits parties to perform their own remediation of contaminated sites when they aren’t serious enough to qualify for the Superfund National Priorities List.
According to a memorandum of agreement between the CDPHE and EPA, the VCUP is encouraged “due to limited resources, the need to prioritize sites and the need to expedite cleanup action” in cases where facilities are being transferred, redeveloped or reused. The VCUP “is tasked to operate quickly and with a minimum of administrative processes and cost,” the agreement states.
Officials from the CDPHE, the city and Xcel have denied that the VCUP is a way to fast-track cleanups on the cheap, to avoid cumbersome and expensive EPA procedures as well as limit the EPA’s ability to require additional cleanup in the future.
But Hatheway says VCUPs around the country have repeatedly been proven to be ineffective.
“You put the fox in charge of the chicken coop, and if the fox doesn’t eat the chicken, it will take as long as possible to do anything,” he says. “The world’s largest environmental parking lot is the VCUP. It’s shameful. … What they always want is that the public accepts all responsibility.”
And just because the EPA granted the site a “no further remedial action planned” ruling in 1997 doesn’t mean the property poses no health threats, it just means it did not meet the high threshold of being eligible for the National Priorities List.
“It does not mean it’s safe,” he says.
According to Hatheway, it would be “a really draconian escape from the reality of social responsibility” to just clean around the teahouse, because it will be impossible to properly remediate the site unless the building is relocated, at least temporarily.
“The teahouse should be carefully disassembled and moved to safe ground,” he concludes.
In a future installment, BW will explore how the site was chosen for the teahouse, even after news of the contamination came to light.