With the consequences of per- and polyfluoroalkyl substances (PFAS) contamination continuing to make headlines, the solid waste industry has found itself having a prominent role in the management of the notorious “forever chemicals.”
During an Environmental Research & Education Foundation (EREF) Science Session on PFAS, industry leaders discussed how the man-made compounds have become intertwined with societal infrastructure, including the solid waste stream, and discussed what waste management companies are doing to find solutions.
“I think all of us—and myself certainly—have been charged with assisting our field teams with implementation, construction, compliance and any other issues that the company might run into across the footprint of our facilities. Most of the challenges we face in a day are well-defined … and we follow a pretty prescriptive set of regulations,” says Joe Benco, director of engineering for Republic Services. “If you compare that to what we’re seeing on the PFAS challenge, we’re seeing regulations and technical issues are evolving real time and at different speeds throughout the country as a lot of the efforts have been driven at a state level. It’s unique from a lot of other issues Republic deals with on a daily basis.”
Samuel Nicolai, vice president of engineering and compliance for Casella Waste, has experienced a similar phenomenon, saying the speed at which PFAS research has moved has made it one of the biggest challenges in dealing with the compound.
“PFAS are certainly not the first emerging contaminant in my career to come out, nor is it the first time we’ve seen changes that have been impactful,” he says. “But the speed at which everything has rippled on the technical and operational side has been one of the biggest challenges, and probably will be for some time in the future.”
According to EREF, PFAS have been detected nearly everywhere on the globe and can be found in consumer products—including carpet, furniture, food packaging, clothing, protective coating—as well as in firefighting foam. Due to the various sources of PFAS, a spotlight has been cast on landfills, where many of these products are eventually discarded.
“These compounds are pretty ambiguous in that their presence is in … all the things we work with in our daily lives. It’s not a solid waste problem right now, it’s an industry problem, and it starts up at the manufacturer level and goes down through consumers. [The landfill industry] is in the unfortunate place of being at the end of the line here trying to help manage these waste materials and dealing with the impacts,” says Nicolai.
In order to start evaluating potential sources of PFAS, many landfill operators have begun to look at waste streams where the chemicals may be more prominent.
“[There are] different sources. It’s all over the place in consumer products that are coming into landfills right now. So, to just chase it solely because of the fact it’s in the stream probably is not [going to be] a real good return on investment (ROI),” says Benco. “We try to be mindful and look at the potential waste streams that might be a large source. [This includes] having more discussions around identifying well-documented streams [where there is contamination] versus looking across the whole inbound portfolio of the landfill because it’s going to be very prevalent.”
The concentration of PFAS found in these waste streams is tracked through landfill leachate, which the panelists agreed has become “the easiest full-scale laboratory” to go out and look for components in the environment for PFAS.
“I think landfills have been really successful at taking in inbound waste and putting it where it stays,” says Benco. “They are well-monitored, and to some degree, we know we’ve got the pathways pretty well mapped out in terms of we know where the mass comes into the landfill and we know that the leachate coming out can be all collected through a sump and sampled. If [PFAS are found] it’s easy to detect and locate.”
However, Benco says that just because these compounds are found in landfill leachate, the leachate may not be the main source of the compounds in the particular environment in which the landfill is located. David Pepper, vice president of post collections for U.S. solid waste operations at GFL Environmental Inc. can attest to this, with a recent study conducted in North Carolina showing that leachate only accounts for 3 percent of total mass coming into treatment plants.
Currently, only 15 to 30 percent of PFAS exposure in humans is caused through indirect sources, according to a 2020 study from Harvard. Meanwhile, roughly 75 to 85 percent of exposure is through ingestion.
"PFAS are certainly not the first emerging contaminant in my career to come out, nor is it the first time we’ve seen changes that have been impactful. But the speed at which everything has rippled on the technical and operational side has been one of the biggest challenges on our side, and probably will be for some time in the future.” –Samuel Nicolai, vice president of engineering and compliance, Casella Waste
“The leap from a concentration in leachate to a discussion about exposure in drinking water really ignores the path that a compound needs to follow,” says Nicolai. “To our knowledge, there’s nothing unique about these compounds compared to the other compounds that we deal with and that are present in landfill leachate. So, [to contain them], they have to have a path, they have to flow in a certain direction and concentration, and all the things we’ve talked about, such as liner systems, monitoring networks, the siting of our facilities, must be done in way to be protective and ensure the leachate is properly managed.”
In general, Benco says leachate can be a challenging liquid to treat, as it’s a mix of everything leaching out of the waste.
“It’s not a single contaminant and it’s not a single issue, and it can vary depending on what’s coming into the landfill. So, it’s been a higher strength industrial wastewater for some time, and certainly we’re working on methods to treat it, but I think the challenge has been that there’s an awful lot going on in the matrix,” he says. “Finding ways to treat [PFAS is challenging because] you can’t focus on that one constituent [of the leachate], especially at the one part per trillion level and ignore everything else that’s already in there that can easily impact any sort of treatment technology.”
Because of this, Nicolai says there have been a lot more problems than solutions when addressing PFAS contamination. To better tackle this issue, he suggests that the management of the compounds needs to begin at the manufacturer level.
“Today, we have a voluntary ban of a couple of the compounds found in PFAS, but not all of them, and the ban is not implemented widely or relevant to overseas [manufacturing]. So, there’s more work to [be done to] stop it at the source,” he says. “A lot of states are looking at solutions that also involve trying to divert waste [from landfill] or identify certain types of waste materials and figure out if there are better solutions. I think those are good things to look at.”
“It’s a process,” Pepper adds. “We may be decades away from even developing technology that destroys the compounds, [but we also] may be two weeks away—who knows. We need to understand that we’re all not where we would like to be [in terms of research], but that there’s a process involved that includes science, engineering, legislative activities and the regulatory community all working together to try to make sure that we’re [moving] in the same direction, not against each other or pointing fingers.”
According to Benco, these solutions can be expedited by prioritizing different management strategies, such as looking into exposure pathways that present the most risk to health and human welfare.
“It’s not just about solid waste and it’s not just about landfills anymore, it’s about policymakers, it’s about regulators, it’s about wastewater treatment plants, it’s about the municipalities that are having to figure out how to manage providing utilities to their citizens, and managing clean drinking water and taking care of their wastewater, and how they’re going to do that with budgets and revenues and [those other considerations],” he says.
Nicolai adds, “We certainly want to make sure that we move forward with urgency. Our goal is not to say that we have to wait for years and years of data before we’re going to do anything, but that we move forward in a way that is supported by the science of the compounds and the exposures.”