WC142 MayJune 2025 - Magazine - Page 18
INNOVATION
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1. Aquagga treats concentrated PFAS streams using Hydrothermal Alkaline
Treatment (HALT).
2. Aquagga installed a ‘Steed’ series unit at the Tacoma Central Wastewater
Treatment Plant in a demo project.
3. In 2024, the 昀椀rst-ever industrial pilot of HALT was completed with 3M.
4. Aquagga has also run projects at an airport in Alaska and two U.S. military
sites, for example. It has now secured EPA funding to explore HALT in treating
municipal wastewater.
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WATER C AN ADA • M AY/JUNE 2025
First municipal project
From January to February 2025, Aquagga installed a ‘Steed’
series unit at the Tacoma Central Wastewater Treatment Plant in
a demo project, in partnership with the University of Washington-Tacoma and the Washington State Department of Ecology.
Foam fractionation by another firm was used to concentrate the
PFAS.
This builds on other Aquagga projects. In 2024, the first-ever
industrial pilot of HALT was completed with 3M. (3M holds
the distinction of inventing the first PFAS almost a hundred
years ago and recently agreed to settle a PFAS lawsuit for $10.5
billion USD. In 2022, the firm committed to stop making
PFAS by the end of this year.) Aquagga has also run projects at
an airport in Alaska and two U.S. military sites, for example.
It has now secured EPA funding to explore HALT in treating
municipal wastewater.
“The insights gained [at the Tacoma plant] will be invaluable
as we explore broader applications in municipal systems,” says
Woodruff. “Our next steps include scaling up HALT’s deployment through additional pilot projects and securing a permanent installation at an industrial site. Alongside those efforts, we
have several Department of Defense-funded pilot demonstrations taking place later this year. We expect to have about 100
HALT systems operational at industrial sites within the next five
years.”
WAT E R C A N A D A . N E T
Aquagga Inc.
PFAS into a concentrated stream, but these streams must be
treated. ALTRA of Quebec uses foam fractionation and absorbent media to treat PFAS; the company remediated the Lac-Mégantic site after the train disaster in 2013, and also did a project
in Canada’s Arctic over a decade ago. Regenerable ion exchange
resins can also effectively capture most PFAS from wastewater,
and while these resins can be regenerated for long-term re-use,
the regenerative brine requires treatment.
Tacoma, Washington-based Aquagga treats concentrated
PFAS streams using Hydrothermal Alkaline Treatment (HALT).
It completely destroys PFAS in a continuous flow treatment
protocol using common chemicals such as lye. There are no
byproducts or emissions, and it treats both high-salinity water
and freshwater. HALT does employ extremely high temperatures
and pressure, but energy requirements are low with a heat recovery system in place. Aquagga COO Chris Woodruff explains
that HALT can also destroy PFAS in low concentrations, but
“pre-concentrating the waste stream significantly allows for
larger-scale treatment systems and optimizes unit economics,
reducing both treatment time and energy consumption.”
HALT was developed through research at several institutions,
including the Colorado School of Mines. So far, there are nine
peer-reviewed papers published on the technology.
