Boise to test new technologies that could remove PFAS from wastewater before it’s reused

By Angela Kerndl; Idaho News

BOISE, Idaho (CBS2) — The city of Boise will be testing new technologies for treating industrial wastewater, which could remove PFAS before it’s reused. It’s part of the city’s proposed recycled water program.

The city’s conducting a pilot project in January. The basis for its recycled water program is – pulling water from existing or future industries, sending it to a separate dedicated facility, then using advanced water treatment. The city has discussed using that water for groundwater recharge or returning it to industry.

The city has been working on its plans for a recycled water program for almost two years.

“Our best day is that the community is proud of this – they understand the climate offset and the support for kind of climate resilience around creating a water supply,” said Haley Falconer, environmental senior manager for the city of Boise.

A major piece of the plan includes treatment and research.

A pilot project starting this January will test a number of new cutting-edge technologies to produce the best water quality, which would include the removal of PFAS – toxic chemicals that otherwise would stay in the environment forever.

“One of the things that we’re trying to do is learn as much as we can, that’s why we’re doing so much sampling and so much research. It’s really the first step in being able to address some of these issues,” said Natalie Monro, a spokesperson for the city’s public works department.

“We are testing multiple technologies in the pilot specifically that should be able to remove PFAS and other emerging constituents,” Falconer said.

One of the pieces of technology they’ll be testing is an air scrubber. Monro describes it this way, “Essentially there’s things in the water- chemicals, constituents that like to evaporate, and so we run a lot of air through the water to help those evaporate out.”

Another piece of technology is membrane filtration. “We use membranes to filter the water. It’s a low-pressure filtration, and we’re using membranes that like each little tube is like the width of a human hair, and it’s either going in and coming out the sides, or out in the sides and out the top depending on which technology we end up with,” Monro said.

Granular activated carbon is another one. Monro says, “that is essentially we run the water over a bunch of solids like carbon, and a lot of the constituents in the water will stick to it, and will be just filtered out by that carbon.”

Then there’s reverse osmosis. Monro says it’s another type of membrane filter, but a more high-pressure filter. “Osmosis is where everything in water wants to reach equilibrium on both sides, and we’re going to force the water to do exactly the opposite. It’s going to take all of the salts, dissolve everything in the water and essentially push it out,” Monro said.

The last one is UV advanced oxidation process. “UV is just like the disinfection that we have at our current facilities, so we’re disrupting the virus and bacteria cells, but then when we add in the advanced oxidation, which is like adding in that peroxide that Natalie mentioned, then we’re getting further disruption of those, and then paired in with the GAC or other treatment then we get that absorbed and removed that way,” Falconer said.

The pilot program will help the city determine in which order they’ll use the technology to get the best results.

PFAS are all around us – in non-stick cookware, water-resistant clothing, food packaging, and even firefighting foam.

There’s a long list of potential negative health effects of exposure to PFAS, including increased risk of kidney and testicular cancer, increased cholesterol levels, and increased risk of high blood pressure or pre-eclampsia in pregnant women.

The city has already sampled the Boise river for PFAS. There weren’t measurable amounts, but PFAS was found in the city’s wastewater.

“We’ve completed a sampling program looking at the influent and effluent, the Boise River upstream and downstream, as well as other watershed areas to really see where it is in our community,” Falconer said.

While there are no current national standards for PFAS levels in wastewater, city leaders say they’re committed to a proactive approach – getting ahead and not waiting until the EPA sets its standards.

“We are engaged in understanding what’s happening with the wastewater rulemaking,” Falconer said. “We’re also trying to contribute to the science because that should really lead.”

The city also wants to reduce the amount of PFAS going into wastewater, to begin with.

“If we have industries that are using products that have PFAS, we want to have them do best management practices to reduce those before we ever get them,” Falconer said.

The city has made changes to previous plans because of pushback from the community. Falconer says community input has been and is hugely important in its planning process.

“We’ve heard from them, and I hope that our, you know I guess I expect we’re reflecting their concerns in the work that we’re doing,” Falconer said.

Richard Llewellyn was critical of Boise’s previous plan to dump treated wastewater into the Farmers Union Canal and has pushed back against Nampa’s current wastewater recycling plan. He said in a statement, “This is the right way of going about water recycling — start with a small but cutting edge pilot project(s), deal up front with the modern realities of chemical contaminants such as PFAS and antibiotic resistance DNA, and produce water that I (with a PhD in biochemistry) would be fine drinking. I expect much will change on the technology front as regulations and the public demand that we come to terms with the pollutants that we’ve ignored for far too long, so flexibility is critical at this point — there may be big improvements on the horizon.”

Shelley Brock, the president of the local organization Citizens Allied for Integrity and Accountability, says she thinks Boise’s plan is a very positive step in the right direction.

“In the big picture, I think it’s important that Micron – or whatever private industry ends up using the recycled water in the future – pay their fair share for it rather than have Boise ratepayers have to carry the full burden,” said Brock.

The community will get to see some of the new technology being tested early next year.

Falconer says the National Water Research Institute has experts that will also work with the city once this pilot is underway and make recommendations for potential changes moving forward.

The water recycling project isn’t expected to come online until 2029. There will be more opportunities for public input.