City Explores Options in Accepting Toxic Compounds in Wastewater from Landfills
The city’s wastewater treatment plant will continue to accept contaminated landfill leachate while officials work to find better solutions to a growing environmental problem.
The City Council recently received a 90-minute briefing from city employees and state officials on a report that quantified the level of a class of toxic compounds found in treated wastewater leaving the plant and flowing into the Winooski River. The report, done for Coventry landfill owner Casella by the firm Weston & Sampson, showed a level of 69.5 parts per trillion (ppt) of per- and polyfluoroalkyl substances (PFAS) in treated wastewater being discharged into the river. The leachate is a byproduct of trash decomposing in the lined landfill and sinking to the bottom where it is trucked to wastewater treatment plants such as Montpelier’s.
To put that level in perspective, the federal Environmental Protection Agency has set a drinking water maximum allowance of 70 ppt for these compounds and the state has set a lower 20 ppt standard for drinking water. Water from the Winooski is not used as drinking water for Montpelier or any other community, and the testing did not detect the compounds about one mile downriver from the plant. Neither the state nor the EPA has established PFAS standards for surface water, such as the river or Lake Champlain. The 70 ppt limit for drinking water is the equivalent of about a teaspoon of sugar in an Olympic swimming pool.
But even small amounts of these compounds can be a concern as they accumulate in the body from many sources and can interfere with the body’s natural hormones; increase cholesterol levels; affect the immune system; and increase the risk of some cancers, according to the Centers for Disease Control and Prevention. PFAS are a class of some 7,000 compounds that resist grease and water and are found in firefighting foam, food packaging such as pizza boxes and microwave popcorn bags, carpeting, furniture, non-stick cookware, and waterproof clothing. They are referred to as forever chemicals because they do not break down in water and are not removed by standard wastewater treatment protocols.
These compounds are in the bloodstream of most humans and are much more likely to be ingested in everyday life than from surface water contact. For example, household dust can contain as much as 2,000 ppt of these chemicals, studies show.
City, State Response
Rather than seeking an outright ban on accepting leachate at municipal treatment plants, city, state, environmental, and landfill officials are focusing on efforts to halt the use of these chemicals in manufacturing and on monitoring and pretreating the landfill seepage at the site.
“It would be better that we were not bringing this into Montpelier,” District 1 City Councilor Laure Hierl said. “If I could snap my fingers it would be that Casella treats it onsite and not send PFAS-contaminated leachate into any community, but that’s not what’s happening. Until that happens I don’t know if there’s a good alternative in the meantime.”
Hierl, who is also executive director of Vermont Conservation Voters, said the city should ask the state or Casella to pay to monitor the levels of PFAS coming out of the wastewater plant and urge the landfill to invest in pretreatment options.
Casella’s state permit allows it to send leachate to five municipal treatment plants—Montpelier, Newport, Barre, Essex, and Burlington—and requires the company to test the leachate at the landfill twice a year, said Chuck Schwer, director of the state’s waste management and prevention division. Newport no longer accepts Coventry leachate under an agreement that allowed for expansion of the landfill over concerns about effluent being discharged into Lake Memphremagog, which is a drinking water source.
State officials are also concerned about the impact of PFAS on aquatic life and have submitted a proposal to monitor the effects of PFAS on fish and fish consumption, among other things, but the Department of Environmental Conservation recommends against having the state establish its own limit for PFAS in surface water, saying that EPA should take the lead. That view is not shared by many environmental groups.
Montpelier processed 6.1 million gallons of leachate from Casella’s New England Waste Services of Vermont landfill in Coventry last year and 1.8 million gallons from the closed Moretown landfill, for total revenue of about $300,000. The leachate is combined with other wastewater to further dilute the substance as it enters the treatment plant, city officials said. Sludge containing PFAS that filters out of the treatment process is returned to the landfill, said Kurt Motyka, deputy director of public works and chief engineer for the city.
“We’re keeping a close eye on it,” he said. “We are continuing our partnership with the state and helping them gather samples to learn more about it. At this point I don’t see that it would make sense for the city to stop taking it because there’s not a good alternative.”
Motyka and Chris Cox, chief operator of the city Wastewater Resource Recovery Facility, said the levels are low and that if Montpelier stopped accepting the leachate it would merely kick the can down the road to another facility.
They said current pretreatment options are ineffective because even if some of the compounds from the leachate were filtered out at the landfill, the media used for filtration, such as granulated carbon, is still contaminated and remains at the landfill.
Efforts in the Statehouse have turned toward the makers of products containing PFAS. Lawmakers last year adopted Act 21, which requires testing for PFAS in community water systems. This year a bill is being considered that would restrict the manufacture, sale, and use of per- and polyfluoroalkyl substances in firefighting foam, food packaging, and carpeting.
The legislation, S.295, which is still sitting in the Senate Health and Welfare Committee as the legislative session passes its halfway point, targets the producer end of the wastestream and is supported by Casella and the Vermont environmental organization Conservation Law Foundation. It is unclear whether it will emerge for action this session.
Elena Mihaly, a senior attorney with the Conservation Law Foundation, said that the group’s priority is attacking the problem before it reaches the landfill, as well as advocating for statewide surface water standards.
“The wastewater problem highlights the need to turn off the tap of products that contain PFAS,” she said. “That’s the root of the problem and why we are even faced with the question of what should the municipal wastewater plants be doing. So, we are really working to advance this bill that would ban PFAS in three common consumer products that are disposed of and then leach into the landfill and then that leachate is being sent to Montpelier.”
The Conservation Law Foundation also would like to see continued monitoring at treatment plants as well as pretreatment options at the landfill site. Mihaly disagrees with the state, however, on waiting for the EPA to establish surface water standards for PFAS.
“The state needs to continue working toward establishing a surface water quality standard for PFAS so that it can be incorporated into wastewater permits and pretreatment discharge permits,” she said. “There is no kind of regulatory way to set wastewater treatment limits for PFAS.”
In written testimony on S.295, Sam Nicolai, vice president of engineering and compliance for Casella, said the company agrees with efforts to regulate PFAS at the source.
“Restricting the use of PFAS by the upstream manufacturers, and encouraging the development of safe, effective alternatives to these compounds should be among our highest priorities and most effective solutions,” he wrote.
City Councilors will continue to encourage solutions to the problem and did not rule out halting the flow of what some call “garbage juice” to the wastewater facility.
Mayor Anne Watson said it wasn’t yet time to turn off the spigot but that income the city derives from accepting the leachate would not be a factor.
“For me it’s not based on the revenue because we could learn to live without that revenue over time,” Watson said. “If this was objectionable to the point where we want to get rid of it, we can make a plan to get rid of it over time. It doesn’t seem that the problem is with our wastewater treatment plant but further up the wastestream.”
Negotiating with Casella over pretreatment and monitoring appears to be the first step.
“In the immediate term the Council should take the issue back up and probably sit down with Casella and the state and see what are our options for pursuing pretreatment for the leachate before it comes to us,” Councilor Hierl said. “And if that is not an option then I think we need to discuss whether we want to continue bringing the leachate into Montpelier.”