Tempest under a teacup

City unearths contamination at teahouse site

This undated photo of the plant shows one of the holding tanks in the background.
Photo courtesy of Carnegie Branch Library for Local History/Boulder Historical Society

Read a history of the teahouse site, 1770 13th St., here.

Editor’s note: There is no evidence that any of the contamination discussed in this story poses any health threats to patrons of the Dushanbe Teahouse, Farmers’ Market or any other attraction in the area.

Something unsightly has gotten a bit too close to one of Boulder’s crown jewels.

An environmental contractor hired to deal with possibly hazardous materials from an old gasification plant near the Dushanbe Teahouse downtown has confirmed the need to clean up contamination at the site.

And if an extensive remediation project is required, it will likely be city of Boulder taxpayers and Xcel ratepayers left holding the tab.

Most of the health risks seem to be buried underground — there appear to be no immediate threats to those visiting the teahouse or adjacent properties. The question is, how far have contaminants traveled through Boulder’s groundwater and even into local waterways over the 110 years since the plant was built?

The City of Boulder hired USA Environment to excavate areas of the parking lot on the east side of the teahouse in late 2012, in an effort to learn more about why elevated levels of contaminants showed up in six monitoring wells installed in 2010. The company dug up sections of old gas lines and put in two additional monitoring wells, uncovering high levels of chemicals like benzene and naphthalene.

According to the Environmental Protection Agency (EPA), benzene is a carcinogen that has been linked to increased rates of leukemia, chromosomal aberrations and disorders of the blood, especially in bone marrow, as well as excessive bleeding and damage to the immune system. Acute exposure to naphthalene has been linked to hemolytic anemia as well as neurological and liver damage, while chronic effects include cataracts and retinal damage.

The property, known as the 13th Street Plaza, is the site of a coal gasification plant operated by the Federal Gas Company from 1902 to 1952. The plant generated fuel used by Boulder residents for heating, cooking and gas lamps.

The contamination at the property is nothing new to the city. The EPA investigated the site in 1994, exposing many of its flaws, and in 1996, a prospective restaurant proprietor for the teahouse reportedly got cold feet over the contamination issues and backed out, prompting the city to procure the necessary public financing to make the project happen.

But air-quality tests conducted by the city in January 2012 in the teahouse and Atrium Building at 1300 Canyon showed that levels of benzene and naphthalene were well below government contamination thresholds.

“We just wanted to double-check that everything was fine, and it is,” city spokesperson Jody Jacobson told BW last fall.

The current hubbub over the property was prompted by complaints in 2009 about contamination along 15th Street, some 300 feet away, at the former location of a dry cleaner where elevated levels of certain chemicals associated with coal gasification plants were detected. Some substances appeared to be residues left by chemicals formerly used by the dry cleaner; others seem to have spread from the teahouse site — although Jacobson says it’s unlikely that groundwater is flowing in that direction.

The latter question is still an open one, but two contaminants detected downstream at the dry cleaner are substances commonly found at gasification plants and were detected at high levels at 13th Street Plaza, suggesting that the contamination has wandered to adjacent areas.

This electromagnetic survey shows where metal underground elements like pipes and oil tanks are in relation to the teahouse.

Xcel, which chipped in up to $50,000 for this round of consultant work, bought the company that previously owned the plant and has secured permission from the Public Utilities Commission to pass clean-up expenses along to its ratepayers. Does the November 2011 agreement with the PUC mean that the company is bracing itself for the possibility of being on the hook for at least part of a costly cleanup? Xcel officials did not respond to questions about the PUC filing.

But it seems the public has a vested interest in keeping the cost of remediation down, since it’s their pocketbook that could suffer, whether through city tax dollars, their Xcel bill, or both.

* * * *

USA Environment, the city’s contractor, was charged with identifying some of the gasification plant’s leftover underground pipes and tanks, cleaning up what was encountered, and determining whether those features were responsible for previously detected contamination in the area.

Using an electromagnetic geophysical survey conducted in 1997, before the teahouse was constructed, the contractor identified the location of the plant’s old gas lines, tanks and holders and dug up a section of them in the parking lot east of the teahouse. The excavation confirmed the survey’s findings, indicating that the two remaining 12-inch pipes run under the teahouse and connect to other possibly submerged plant structures to the west and northwest of the teahouse, along 13th Street.

In its report, posted to the city’s website on April 8, USA Environment
writes that between Nov. 27 and Dec. 18, it dug up 177 feet of pipe
and 1,750 square feet of soil, hauling off 340 yards of contaminated
earth to a waste management facility in Aurora after discovering a
three- to six-inch layer of odorous, discolored dirt around pipes,
discoloration that was thicker around joints. The pipes led to a submerged structure of a “main holder” tank northeast of the teahouse, where they joined with two “pipe chase structures” connected to the tank. Workers attempted to get to the bottom of what was believed to be the foundation of the above-ground tank, digging down eight and a half feet, but they never found the bottom. It was common for gasification plants to have above-surface tanks above underground tanks, but Joe Castro, the city’s facilities and fleet manager, says there is no sign of a submerged holding area.

It was in this area where testing showed that the levels of substances like benzene and naphthalene were highest.

According to the report, at these pipe connections to the holding tank, the city directed its contractor to refrain from pumping out toxic liquid, but Xcel disagreed. The company, sometimes referred to in the report by the name of its subsidiary that previously owned the property, Public Service Company of Colorado (PSCo), hired its own firm, Tetra Tech, to extract the contaminated fluid.

“Given the unknowns about the size of the pipe chase, the source and quality of the pipe chase contents, and the effect of its removal on static conditions, the City elected not to pump out the pipe chase contents until next steps had been determined for the Site,” the report states. “However, PSCo wanted to pump out the pipe chase, and the City allowed Xcel and its consultants access to do so. … These residual [manufactured gas plant] generated process fluids (combined water, oil, and sludge) were subject to sampling, characterization, and removal by PSCo.”

“The company thought it was prudent to remove the liquid wastes before closing the site back up, to avoid any potential for releases of the liquids into the environment,” Xcel spokesperson Michelle Aguayo told Boulder Weekly via email. “This was outside the scope of work that the city originally intended, but the city was willing to let the company step in to perform this task upon its request.”

When asked why the city didn’t want to pump out the toxic fluid, Castro says the Colorado Department of Public Health and Environment advised city officials that it was not an immediate threat to the environment and could be left in place until the actual clean-up begins, and there was some concern about disturbing the stability of the structure.

Colorado’s basic standards for groundwater call for no more than 5 micrograms of benzene per liter. According to the report, the benzene level at one pipe was 3,170 micrograms per liter, and 4,000 micrograms per liter at the other. At the main holder tank, benzene measured 2.4 million micrograms per liter.

Similarly, while the state’s allowable standard for naphthalene in groundwater is 140 micrograms per liter, the report states that the level measured at the tank was 60 million micrograms of naphthalene per liter.

Joe Ryan, a professor of civil, environmental and architectural engineering at CU-Boulder, says those levels are off the charts because they represent amounts that are far more than can be absorbed in water, indicating that some solids must have been tested with the liquids, even though they are labeled as “aqueous samples.”

“I’ve never seen a sample that’s exactly what they pulled out at that site,” he says. “I have never seen a comparable sample.”

But the city’s website stresses that there is no immediate health risk.

“Most of the area where the gas manufacturing equipment was located is now covered in pavement, which prevents exposure to the public from any materials that remain,” according to the website. “Tap water at the Teahouse and neighboring facilities comes from the City of Boulder’s water system, not from area groundwater sources.”

According to Ryan, assessing how far the chemicals might have traveled since the plant was built in 1902 depends on the rate of the flow of groundwater in the area, and he says that is a guessing game that depends in part on the type of soil in the area. He says the site should undergo extensive remediation if it can be shown that substances like benzene and naphthalene have entered nearby surface waters.

* * * *

Of course, much depends on the direction of groundwater flow.

USA Environment, just like a previous city-contracted firm in May 2012, determined that groundwater flows from the site to the northeast, seemingly away from Boulder Creek and the manmade ditch that runs along the teahouse’s south flank.

But in January 2009, Terracon, the engineering consultant hired to install monitoring wells and investigate the contamination found at the nearby dry cleaner property, determined that groundwater was flowing to the southeast, toward Boulder Creek.

Other contaminants that Terracon found at Art Cleaners, which has since relocated to north Boulder, included excessive levels of benzene and naphthalene, the primary gasification plant contaminants found at the nearby 13th Street Plaza just 300 feet away.

In addition, trichloroethene, a substance not typically found at gasification plants but historically used as a degreaser for metal machinery, was found at both Art Cleaners and 13th Street Plaza. Trichloroethene, which was also used in the dry cleaning process, was measured by USA Environment at 38,000 micrograms per liter at the underground vault structure below the main holder foundation at the 13th Street Plaza, many times higher than the state groundwater threshold of 5 micrograms per liter. It may prove to be another connection between contamination at 13th Street Plaza and the property that once housed Art Cleaners, and it is unlikely it would have spread from the dry cleaners, uphill, into the base of the vault.

“Based on previous investigations and the results from the recent investigation, Terracon reiterates our contention that petroleum hydrocarbon impact at the Site likely originates from an upgradient source, namely the former Federal Gas Company facility,” Terracon wrote in its report.

But city officials Castro and Jacobson disagree. Castro points to the fact that the city has had four separate studies reach the conclusion that the groundwater heads northeast.

While the water may, indeed, be moving northeast on the plaza property, this doen’t mean it doesn’t change direction to the southeast towards Boulder Creek and the dry cleaning monitoring wells only a few feet beyond the property line.

Such natural groundwater behavior was recently demonstrated at the site of the Parachute Creek benzene spill in Western Colorado. CDPHE officials and oil company execs claimed that the creek was in no danger from the spill because monitoring wells showed that the creek was recharging the groundwater and therefore the groundwater was moving away from the creek.

But the officials failed to consider that the natural path of the groundwater would eventually turn it back towards the creek, which it did, reversing its direction just a few feet farther west, contaminating the creek and now threatening the Colorado River.

It is likely that the ditch next to the plaza property, which is several feet above the level of the groundwater, is recharging the groundwater. This would likely result in a northeast movement immediately adjacent to the ditch on the property’s southern edge. But like at Parachute, the water should turn back towards the area’s natural drainage of Boulder Creek to the southeast very quickly. This would explain why the water at the dry cleaner property just a block away is moving southeast towards Boulder Creek.

Groundwater from the plaza site could show a northeast movement in the property’s monitoring wells and still turn quickly to find its way into the dry cleaning wells to the southeast.

When asked how benzene and naphthalene could have ended up at the Art Cleaners site, Jacobson initially told BW that the two substances are used in the dry cleaning process, but she later backed off that assertion.

“We think it’s two separate contaminations, we feel like it’s not coming from here,” she says. “I could be wrong about those being related to the dry cleaning process itself, you’d want to confirm that, but we do feel pretty confident it’s not from this site.”

“We don’t think they’re related at all, with the dry cleaners,” Castro says.

They add that benzene and naphthalene are water-averse and don’t migrate quickly underground.

“So the fortunate piece of any of it is that they don’t move very far,” Jacobson says.

“Because of the nature of these chemicals, they aren’t transported in the environment, so we think the chances of migration off site are very low,” Castro says, adding that the city has determined that there are no drinking water wells within a mile of the property.

But information provided by the EPA and other environmental regulatory agencies contradicts the city’s assessments of these contaminants’ mobility. According to the New York Department of Environmental Conservation, of all the contaminants found in coal tar, benzene is “the most soluable and thus the most likely to be dissolved in groundwater and migrate off site.”

Likewise, the NYDEC states that most polycyclic aromatic hydrocarbons (PAHs) do not readily dissolve in water, so they “are not easily transported in groundwater … with the exception of naphthalene,” which can move quickly and easily with groundwater. NYDEC further warns that “despite low solubility, PAHs may still migrate significant distances because mobile tars or emulsions may move through the subsurface.”

In addition, the EPA report on the Federal Gas Plant site states that there are 63 groundwater wells within one mile of the site and 222 wells within two miles.

* * * *

Considering the taxpayer dollars that have gone into cleaning up the city’s Valmont Butte dumping ground, the decision to build the teahouse at its current location may prove to be a decision that Boulder officials regret. While the problems at Valmont dwarf the contamination at the 13th Street Plaza, there are parallels. As they did at the Valmont site, city officials plan to pursue a Voluntary Cleanup Plan (VCUP) with the CDPHE. The VCUP process is an arrangement between the CDPHE and the EPA that allows parties to do their own remediation of toxic sites when they aren’t serious enough to qualify for the Superfund National Priorities List.

This aerial photo from the 1940s shows the above-ground holding tank on the northeast side of the Federal Gas Company Property. 13th Street appears in the bottom half of the image.

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, city and Xcel deny 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 future cleanup.

“If there were ongoing releases, that’s intolerable,” Warren Smith, CDPHE community involvement manager, told BW. “It’s not a get-out-of-jail-free card.”

Doug Jamison, the CDPHE’s Superfund/Brownfields unit leader, described the VCUP as being a way to “avoid liability for buying a contaminated site,” but he said underground storage sites do not qualify for the program.

Castro says the VCUP involves “getting ahead of any regulatory acts, required regulatory actions, and having a formal, approved plan to clean up that takes you outside of any EPA or regulatory … structure.”

He adds that the VCUP is “a less regulatory-driven process. It’s more us driving the train than the regulatory agencies.”

Jerome Davis, regional vice president for Xcel, said in an interview that the VCUP won’t just be an effort to “throw some dirt on it,” and he stressed that the cleanup would be “a very transparent process, and the number one goal is the safety of the public.”

He acknowledged that the amount Xcel contributes to the cleanup could increase.

“It could be more for both sides,” he says. “It’s not just a one-way street. … We’re not trying to skirt our responsibilities.”

But he stopped short of admitting that the company is liable for the actions of the Public Service Co., which acquired majority ownership of the plant in 1926 and operated it until it closed in the early 1950s. Davis says Xcel is still researching whether, or to what extent, Xcel is responsible for what happened at the site between 1926 and its closure.

“That’s one of the things that is still being scoped out,” Davis says. “There’s no finger-pointing going on right now.”

An Xcel spokesperson gave a similar answer in a September 2010 Camera article, saying that the company’s legal ties to the gasification plant were being researched.

“Xcel Energy was the result of a merger with Northwest Power in August 2000 — so in essence, Xcel Energy never owned the property,” Xcel’s Aguayo told BW via email. “Public Service Company of Colorado sold it in 1963. It sounds like the assumption is that any issue with the site comes solely from the manufactured gas plant. Due to the number of different businesses that have been located at the site (and nearby), there are a number of possible sources. … Because the City of Boulder currently owns the property, Boulder is in charge of any site investigation and/or cleanup work. As a former property owner, we are cooperating and supporting Boulder’s efforts. We have a shared goal to ensure the site is responsibly managed to protect public health and the environment.”

In actuality, the town gas plant was the only business ever located on the site until the teahouse was built. And an EPA report states that there is no other known business in the area that could have produced the contaminants in question.

Aguayo did acknowledge in a subsequent email that, just as Honeywell was on the hook for a portion of the Valmont cleanup after buying a company that contributed to the contamination, “under environmental laws and regulations, current and past owners and operators of a site where hazardous substances have been released may be potentially responsible for certain types of investigation and cleanup costs. No such determination has been made at this site. It is our understanding that the City intends to undertake a voluntary cleanup of the site under the State’s oversight.”

It seems contradictory that at the same time Xcel is deflecting its potential responsibility for the Federal Gas plant site clean up, it has already gone through the PUC process and gotten permission to pass along any expenses associated with the clean-up or subsequent lawsuits to its ratepayers.

Jacobson, the city spokesperson, says there is no agreement yet with Xcel on how the cost of future work will be covered, but those discussions are expected to start this summer. When asked whether the city believes Xcel has some liability for the contamination, she told BW, “That is a question for their legal counsel and our legal counsel, but the city has maintained its cost recovery rights. … But we hope to be working collaboratively with them.”

* * * *

City and Xcel officials were upbeat about USA Environment’s findings.

“The investigation confirmed the presence of underground pipes which were in good condition, with no signs of degradation, and the investigation confirmed that the main holder is no longer present at the site, however a concrete foundation of the holder was discovered,” Aguayo said via email. “Groundwater data shows declining contamination as compared to previous testing. Some isolated soil contamination was noted. There is no direct contact by the public with any impacted soils or groundwater, as the soils are at depth and below asphalt, and given that groundwater in the area is not used for drinking water purposes.”

“It was positive in that we confirmed some things we suspected, like were the structures at the site still there,” Castro says. “That was confirmed, it was important to have that confirmed.”

He adds that USA Environment completed another round of work at the site in March, adding another monitoring well in the middle of the plaza and investigating the relief holder tank west of the main holder.

Castro declined to say what excavation was done at that tank or what was found, saying the consultant’s report will be included in the VCUP application when it is submitted in the late summer or fall.

When asked whether the city plans to test for heavy metals like lead, which have been common contaminants associated with gasification plants nationally, he says he isn’t aware of that concern and is unsure whether such tests will be conducted.

The city and various regulatory agencies failed to test for lead for several decades at the Valmont Butte site, and it was later found to be the most serious contaminant at the property.

According to Castro, the plan is to begin the clean-up after the conclusion of the Boulder Farmers’ Market season and complete it before the market reopens in spring 2014.

And as for the gas pipes under the teahouse?

Castro says USA Environment recommends leaving them in place, since the ends were sealed with concrete and they don’t pose a threat.

“What we saw was that there wasn’t a whole lot of contamination in the piping itself,” he says. “The teahouse really hasn’t been impacted by this, it’s all outside the teahouse. We don’t anticipate any impacts to the teahouse.”

Teahouse proprietors Lenny and Sara Martinelli did not respond to requests for comment by press time.

When asked whether it was a good idea to put the teahouse at that site, Jacobson replies in the affirmative, adding, “based on what we knew at the time.”

But it’s clear the city was aware of the contamination at the property, to at least some degree, before the teahouse was built.

One question BW plans to explore in a future installment is why city officials persisted in choosing this site over other possible locations that didn’t have the same environmental problems.

The other lingering question, one that may not be answered for a long time, is whether the decision will end up coming back to haunt taxpayers and Xcel ratepayers alike.

The state of town gas sites in the United States

The EPA has identified 1,502 former town gas sites in the United States.
Other sources state that as many as 25,000 such sites may exist in the
U.S., with most still unreported.

are 350 former town gas sites under review in the Superfund system, and
nine are listed or proposed for listing on the National Priorities
List, which would qualify them as Superfund sites that could receive
federal funds for clean-up.

study that examined 30 of the nation’s primary U.S. utility companies’
financial information found that the companies had set aside $1.5
billion for the purpose of remediating town gas sites. It appears that
the companies estimate an average cost of $3 million per site, which the
study notes is enough money to initiate, if not complete, a cleanup.

average town gas site covers approximately 2.5 acres, and the price of
remediation tends to increase based primarily on the extent of treatment
of subsurface soils and groundwater.

In 2001, it was estimated that the total cleanup cost for town gas sites ranged from $2.8 million to $17.7 million.

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