Can Your House Kill You?

I squeezed past Maya and closed my office door behind her, shutting out the last rays of natural light. Under the cool fluorescents, she was already at work, reaching past her rounded belly to sort documents on the table, preparing to brief me, her new manager, on the results of the recently finalized 1996 Palermo Wellfield site investigation. When her dark hair cascaded forward and she brusquely tossed it back, I hid a smile. We were rarities, Asian American women engineers infiltrating a white-male-dominated field, constantly challenged to prove that we belonged. To fight back, we assumed gestures of no-nonsense professionalism. She reminded me of my younger self.

I’d worked at the US Environmental Protection Agency for eleven years, mostly in water programs, and was thrilled with my new management role in the Superfund cleanup program. Over the past month I’d been poring through the underlying law and enabling regulations while acquainting myself with my staff and their responsibilities. The Superfund law, the 1980 Comprehensive Environmental Response, Compensation, and Liability Act, was complex and powerful. Enacted in response to the disastrous public health crisis at Love Canal, it gave the Superfund program a clear mandate: discover, and clean up, the worst of the worst hazardous waste sites in America. Polluters would pay for cleanup. One sledgehammer provision – and one of the most controversial – was that where there were multiple polluters of a site, even small contributors could be liable for the entire cleanup. Finally, if no viable responsible parties could be found, the government would pay.

Maya was a site assessment manager, part of a gatekeeping team working to identify sites bad enough to be put on the National Priorities List, known colloquially as the Superfund list. She’d already overseen the sampling work, already roughed out a hazard score using EPA’s national formula. After this meeting, she and I would make a recommendation to our top management about whether the site warranted a Superfund designation. Most sites didn’t make it this far. But when a site hit the high bar of “imminent threat to public health and the environment,” EPA would solicit public comment prior to Superfund listing. Once listed, those high priority sites were turned over to remedial project managers for cleanup. In the past, hard data and good science drove listing decisions, but in the supercharged political environment of 1996, the site assessment program had hit an inflection point. States could now block Superfund listing. Claiming that Superfund put an unnecessary stigma on property, most states refused listing of any new site. Maya was here to brief me on the gravity of the environmental problem and the severity of the political pushback.

She slid the Palermo Wellfield Site Inspection report across my office table and scooted her chair next to me. “Ready?” she asked, her dark eyes alert for my reaction. Although I might have been projecting, I sensed a bit of her unease. How well did I understand the site assessment program? How much detail did I need? She probably knew that, like her, I was a civil engineer. She might have heard that I’d had six years of engineering experience in private industry prior to my eleven at EPA, and that I was known in the agency for my technical chops.

Maya opened the site inspection report and flipped to the summary page. “Our contractors did a good job, they chose the right sample locations,” she began. “The data clearly show there’s a real problem.” Thick with sampling data and maps, the site inspection report laid out the dry facts of our case.

Like every great detective, because every site investigation is a detective story, Maya worked backwards from “dead body” to “possible suspects.” First, the metaphorical body. Routine sampling by the City of Tumwater had caught dangerous concentrations of trichloroethylene (TCE) and perchloroethylene (PCE), known carcinogens, in the City’s tap water. Levels exceeded safe drinking water standards. In addition to health risks from ingestion, tap water sprayed from household faucets and shower heads could vaporize. Tumwater residents were at risk both from drinking the water and inhaling the solvents.

To their credit, the City took quick action, switching to a clean water supply while they searched for the cause. Samples taken at the wellfield – the source water – also showed high TCE, indicating that the aquifer was contaminated too. Where were the solvents coming from? The aquifer, like a slow underground river, had to be carrying the contaminants from an upstream, or upgradient source. Searching for possible users of TCE or PCE in the area, the investigation turned up two possible sources: a Department of Transportation site which could use TCE to clean equipment, and a dry cleaning shop which could use PCE in its cleaning process. No smoking gun had been found, but all we needed to move forward was probable cause.

Maya smoothed out a well-worn location map in front of me. “Let’s look at the direction of groundwater flow,” she said. As I gave the map a quick once-over, I almost gasped as my finger underscored a telling detail: the map title.

I turned to Maya with a wry smile. “So, wait a minute, this Palermo wellfield is in Tumwater, Washington?” She nodded briskly, and I warily shook my head. Still smiling, I asked, “So just for reference, where’s the Olympia brewery?”

Olympia beer commercials, then pervasive in the Pacific Northwest, touted the natural artesian water of Tumwater, Washington as their secret ingredient. One jingle even ended with the slogan, “It’s the water, and a lot more.” With damning data about the Palermo aquifer right in front of us, and the sure knowledge that pollutants can spread, the catchphrase felt badly misplaced, if not a bit sinister.

Maya’s brows shot up as she stood to scan the map. She knew exactly what I was thinking: Does the brewery pull from that aquifer? At last she pointed to the edge of the map and rubbed her forehead in relief.

“No, no, the brewery’s upgradient. Not affected at all. Oh, and besides, they don’t brew with well water anymore, they’re hooked up to the City water supply now.” When my eyes widened in alarm, she quickly clarified, “The City of Olympia, not Tumwater!”

We laughed together, in mutual respect. An EPA public relations disaster had been averted, although the Olympia brewery and their advertising agency had some explaining to do.

She swept back her dark hair and leaned over the table. Tapping first on the dry cleaner site and then the Department of Transportation site, she drew her finger toward a web of roads that marked a residential neighborhood. “There’s the Southgate Dry Cleaner, the big source of the PCE, and the DOT site, the source of the TCE. Here at the bottom of a steep bluff is the Palermo neighborhood. The site scores because the Palermo Wellfields over here – the target,” she met my eyes, checking for understanding, “provide drinking water for the City of Tumwater. There’s a direct human health risk. Just being over drinking water MCLs – maximum contaminant levels – is enough to score.”

I lapsed into engineering shorthand. “So we need to air-strip the wells?” Air stripping, a common treatment, was part of my graduate school curriculum and private sector experience.

She looked impressed but apologetic. I’d identified the likely technical solution, but we weren’t there yet. “No, not us,” she patiently explained, waving her hand between us. “The site assessment program determines if the site qualifies as a Superfund site, and later, after it’s listed, the remedial program figures out the remedy. We need to list it first. Here’s what we know. We know the site scores because drinking water is affected.” She turned back to the map. “But there’s another big problem.” From pictures on my desk, she must have known I was a single mom, and in her frown I saw the deep concern of the young mother she was soon to be. She pointed to the bottom of the bluff, and her voice rose with new urgency. “See these backyards? Water pools up there when it rains! Is it groundwater or storm water? Is it contaminated? When we were out there drilling sampling wells, we saw lots of kids playing in their yards!” I grimaced and started to respond but caught myself as her voice dropped ominously. “And that’s not all.”

My chest tightened. Not all? People were drinking carcinogens, kids might be splashing in carcinogens. The danger wasn’t just hypothetical. How could it be worse?

She waved her hand over the map of the whole neighborhood. “Look, that groundwater flows under their houses. If some TCE or PCE vaporizes, it can seep up through the soil into their crawl spaces and into their homes. So there’s the potential for vapor intrusion, like with radon gas. While they’re at home, they could be breathing it too.”

Oof. I sat stunned, virtually gut punched. Pollution could stalk you, creep into your house, get that personal. Vapor intrusion is such an insidious threat. Everybody breathes. Unlike dealing with tainted drinking water, you can’t just buy bottled air.

How would you clean that up? The air, the water, the soil? Although Maya had gently reminded me that we weren’t at that stage yet, my engineering brain was already racing ahead, sorting facts, spotting data gaps, and riffling through options. This site hit the jackpot, the trifecta of Superfund exposure pathways: direct contact, ingestion, and inhalation, or more simply, touching, drinking, and breathing. Direct contact and ingestion were complicated, but the Superfund program had done this many times. We knew the science, knew how to calculate the risk, knew how to clean it up. But how do you even begin to evaluate the risk of the inhalation pathway to Palermo residents? You’d need to know how much TCE and PCE is inhaled, and how dangerous it was. Like a Rubik’s cube, there were so many interlocking variables. Adults have larger lung capacities than children, but children might be more vulnerable. Other sources of solvents in the home – off-gassing from formaldehyde insulation or household cleaning chemicals – might add to, or even overwhelm, the groundwater contribution. Cracks in a floor slab could increase the amount of vapor intrusion, but people who left their windows open would have less. Levels of TCE and PCE in each home could vary depending on the house’s location in the neighborhood and individual family habits. Were they close to the bluff? Did the residents leave their windows open in the winter? In the summer? What household cleaners did they store under the sink? As regulators, our challenge was huge. We needed to answer any resident’s bottom line question: Is my home safe?

“So what do you think?” Maya’s measured voice brought me back to the decision at hand, step one in a well-defined process. “The site automatically scores because the risk to drinking water affects the people of Tumwater.” She sat down beside me, notebook open, pen poised.

It seemed like a slam dunk, but had I missed something? Earlier I’d been warned that not every site that scored should be put on the Superfund list. I tried to read her face and buy some time. “And the air problem?”

“We don’t need air to score the site. Drinking water’s enough.”

In that moment I thought of my elementary-school-aged sons, how they drank from our tap and ran in our yard. How they sat in their rooms to study or to play with their friends. Like any other kid, they were oblivious to any environmental danger and simply assumed that home was safe. And that I, their mom, would keep them safe.

I focused on Maya’s eyes. “What’s your recommendation?”

She settled back into her seat and absently folded her hands over her swollen belly. Her dark eyes held an intense look of absolute certainty. “If the remedial program does it right and puts in the air strippers, they’ll fix the water and air problems at the same time. If the state of Washington agrees, I recommend we move the site forward for listing.”

Much to our surprise, citing the imminent threat to Tumwater’s drinking water supply, the state agreed to make Palermo a Superfund site. The site was listed in 1997. Within a year – in one of the fastest cleanups on record – a soil/vapor extractor was pulling PCE out of the soil at the dry-cleaner site. A year later, two air stripping towers were actively purging the drinking water wellfield of solvents. A subdrain was installed at the bottom of the bluff to intercept contaminated groundwater before it surfaced in neighborhood yards. These quick actions were aimed at breaking both the ingestion and direct contact pathways.

The inhalation pathway proved more difficult. EPA promised to investigate the groundwater table throughout the entire neighborhood and recommend fixes if needed.

Construction was complete on January 30, 2001. All that was left was to monitor the site to ensure the remedy was working properly. We applauded a major milestone, and I left the Superfund program in May 2002.


Close to 20 years later, I’ve since retired from the EPA, Maya’s son is out of college, and the Palermo Wellfield project is still active. Is the site safe? Is the remedy protective? Not according to a terse statement in the latest Five-Year-Review, completed in 2018, which cites unsafe levels of TCE vapors from groundwater in at least one house, and determines that the subdrain at the bottom of the bluff isn’t intercepting groundwater as well as expected. Superfund’s Five-Year-Review exists for exactly this purpose – to check whether the remedy’s protective and beef it up if it’s not.

The review process also allows EPA to update the remedy to include advances in toxicological research. In 2011, when TCE exposure in pregnant women was found to increase the risk for fetal heart defects, EPA’s quest to find, measure, and remediate vapor intrusion in the neighborhood reached a fever pitch.

“I knocked on every door in the neighborhood, pleading with them to let us sample their air,” says EPA’s current remedial project manager, a friend of mine – and a mom – when I reach her over the phone. “Everyone, especially prospective parents, needed to know the dangers were real. I brought our hydrologists and toxicologists, and we answered their questions until late at night. We tried so hard to win their trust. Finally, about 30 of the 47 households at one point said yes.” She pauses, then lightly adds, “Meanwhile, our technical staff was scrambling to determine the best way to sample those homes.”

Turns out, it wasn’t easy to get meaningful data. It was hard to nail down the ghoul in the room, the unseen, odorless, airborne toxin that might or might not exist. Other cleaning supplies in their homes, like Lysol and bleach, interfered with TCE measurements. Dry-cleaned clothing was a problem; a wedding dress that had been preserved 20 years prior was still off-gassing. Heavy rain even affected vapor intrusion levels.

But they did it. Now, armed with a working sampling protocol – and a science-based not-to-exceed action level – EPA can keep Palermo residents better informed of the risks.

“If you measure concentrations above the 2 microgram-per-cubic-meter action level, what can you do?” I brace myself for a multi-million-dollar treatment solution – the kind that the Superfund program is always vilified for.

Her high-pitched laugh throws me for a loop. “The fix is easy! It’s the same as for radon. Google ‘radon mitigation.’ Lots of radon companies can install a home venting system for under a couple thousand dollars.” I’m astonished that the technical solution’s so simple, but my hopes are dashed when she continues, “But the house with the acutely high concentration? The DOT offered to install a venting system for free, but the residents refused. We keep trying to reach them, but they won’t respond.”

Why are they in denial? Like residents at other Superfund sites I’ve dealt with, not everyone wants to know they have a problem. Why would you still live in a house that can kill you?

Her voice grows louder, and I sense her frustration. “Vapor intrusion’s such a crazy pathway. The science, the sampling protocol, the action level – nationally, Palermo’s on the cutting edge, and we’re confident about what we can do when we pinpoint a problem. More data could help us find those houses, but…”

As she lapses into silence, a verbal shrug, I feel for her. It’s the scourged blessing of Superfund: the power and urgency to act, pitted against the time needed to gather conclusive evidence to justify that act. On one hand, our project managers must select cleanup remedies that protect people and the environment. On the other, those remedies can’t be too expensive or place an undue economic burden on the community. At Palermo there’s even another hurdle. Because the remedy must be placed in residents’ homes, we need to secure their permission. Contrast that to Love Canal, the famed “first of the worst” site, where the health danger was so obvious and extreme that shortcuts were justified. Residents were simply evacuated. But most sites don’t warrant such quick and costly – not to mention disruptive – solutions.

She sighs, muted now. “It really comes back down to the personal. Does the community trust us? They’re scared. We’re dealing with real people here.” I’m just about to say it, but she beats me to it when she blurts, “Their health is all that matters.”


Image: “day 020” by Holly Lay, licensed under CC 2.0.

Amber Wong
Latest posts by Amber Wong (see all)


  1. Wow. The author can make, what others might consider a dry topic into an edge of your seat read. What’s next? A poem about anaerobic digestion?

  2. EPA should use this to train new employees, both Superfund and non-Superfund, for the clear discussion of the trade-offs EPA staff regularly face. As a former EPA employee, I know I would have found this helpful and inspiring when I first started work.

  3. Thanks for your comments and reactions! Hidden dangers have no easy solutions.

    As others have pointed out, the Palermo residents’ response to this Superfund site echoes the current controversy around the pandemic response. Mistrust also has no easy solutions.

    Re: EPA training, thanks for that comment. I’m looking into that.

    Re: anaerobic digestion, been there, done that.

  4. I’m thrilled to report that this essay has withstood public scrutiny as well as the scrutiny of many environmental professionals, several of whom have appended charts and diagrams in notes back to me about their experiences in remediating TCE plumes. (!) Among my responders are my water chemistry TA/grader (now professor emeritus in Civil and Environmental Engineering at the University of Washington), a current professor of Engineering at Stanford University, and a cohort of readers who are familiar with the workings of Superfund.

    Also among my responders: people who enjoyed Olympia beer.

    A big thanks to Pangyrus, who brought this complex story to light.

  5. Thank you for showing this insider’s view of the process of defining and remedying a superfund site. An engrossing read!


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