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For decades, Nebraska has faced elevated nitrate levels in its groundwater, sometimes approaching or exceeding federal safety standards.
This fall, Fairbury became the first Nebraska city to host a pilot project that could change how nitrate-contaminated drinking water is treated.
High nitrate levels in drinking water have been linked to health and safety concerns, including some cancers, as well as elevated risks for pregnant women and infants. While nitrogen is a naturally occurring compound in soil, agricultural states such as Nebraska tend to have higher concentrations of contaminants in their groundwater.
Scott Nelson manages the Little Blue Natural Resources District, which sees its share of water contaminants, which are accelerated mostly from a variety of agricultural practices.
“Main sources would be fertilizer runoff from row crops, the leaching of nitrogen into the aquifer, either from over-irrigation or applying too much fertilizer, and animal waste from livestock operations that can contribute,” Nelson said. “And then, too, in the urban situation, just homeowners fertilizing their lawns. They can contribute, and then fertilizer from golf courses.”
Tucked inside the Little Blue NRD is the southeastern Nebraska town of Fairbury. Like other communities surrounded by agriculture, Fairbury’s nitrate levels hover near the Environmental Protection Agency’s (EPA) maximum contaminant level of 10 parts per million.
“It’s kind of been a little bit of a roller coaster,” Brian Schmidt of the Fairbury Water Council said. “Our east-side wells are right around 8 parts per million, and one of them is just over 10. By the time we blend the three together, we stay under the maximum, but we’re pretty close.”
Eight years ago, Fairbury recorded nitrate levels above federal standards, prompting the city to look for new solutions. A well at Crystal Springs, a public park southwest of town, was eventually reactivated in 2019 but was turned off two years later because of a non-toxic biofilm buildup which clogged the filtration system.
The city also tried to develop a third well field north of town with help from the Little Blue NRD, but the project stalled. The city council voted 6-2 against the estimated $20 million project in November 2022. A month later, the city created the Fairbury Water Source Committee to investigate the biofilm problem at Crystal Springs.
Despite the challenges, residents have largely supported the city’s efforts to secure safe water, Schmidt said.
“Yeah, I think if it gets more severe, certainly we’ll have people probably up in arms at us, but for right now, I think as long as we’re on the path to a good solution, which I feel like we are, then I think we’re OK there as far as a public perception goes," Schmidt said.
As the focus shifted to Crystal Springs, Fairbury hired Olsson, an engineering and design firm headquartered in Lincoln that has worked with the city before. While looking at solutions for the biofilm, Olsson lead engineer Craig Reinsch suggested piloting a new nitrate-removal technology he learned about from a California company at a water conference in Arizona.
“They’ve basically created a whole biocatalyst which is a polymeric composite. And so, it contains microorganisms. And then those microorganisms are circulated within a reactor — a bioreactor — and then raw water is mixed, and nitrate is removed as part of that process, as well as chemical feed,” Reinsch said.
Fairbury decided to move forward with the project with Olsson overseeing tests at two well locations.
“While we were piloting to take care of Crystal Springs, we also piloted this BNR nitrate removal process that utilizes the nitrogen cycle to see how it would react, both at the wellfield with its increasing nitrate concentrations, and also at Crystal Springs,” said Reinsch.
Microvi’s system, according to its creators, converts nitrates in water into harmless nitrogen gas, removing contaminants without producing hazardous waste. Ali Dorri, vice president of business development at Microvi, said the system is more efficient than other water treatment methods.
“In the world of contaminant removal or water treatment, you can pretty much classify all the treatment methods into two categories: contaminant removal options and contaminant reduction options,” Dorri said. “Most of the physical and chemical processes that we use to clean water. So, whether that's reverse osmosis or ion exchange, these technologies are actually very good at removing the contaminant from a body of water, but they don't actually destroy it.”
Dorri said processes like ion exchange or reverse osmosis create a concentrated waste stream that is hazardous and costly to dispose of.
“The disposal of this concentrated stream, whether it's with ion exchange or reverse osmosis, has become more difficult. It's become more expensive,” Dorri said. “The beauty of a kind of biological system, which is what Microvi deploys, is the fact that it reduces contaminants. It converts nitrate to nitrogen gas; you're not ending up with a hazardous waste stream that you then have to dispose of.”
Microvi claims that its MicroNiche Engineered (MNE) technology standard modular system costs 60% less than other water treatment systems, while providing a 92% reduction in non-hazardous waste compared to a regular biological system.
While Microvi’s technology may be more affordable for better-funded larger cities, Dorri said smaller areas would need outside funding.
“I think for towns like Fairbury, to be able to take on these types of projects, they are going to need help from a funding perspective, whether it's from a state level or federal level,” he said.
According to Olsson’s testing of a small-scale model of the Microvi’s technology, the pilot projects at Fairbury’s wells have shown promising results.
“For the East Well, it was 78% removal over 30 days. And then at Crystal Springs, around 90% removal over 23 days and counting,” said Reinsch. “That was towards the end of October.”
Craig Reinsch said the city would consider full-scale use if nitrate levels exceeded federal limits, marking the first pilot of its kind in Nebraska and a potential step forward in cleaner water treatment for small agricultural communities.
Olsson is coordinating with the Nebraska Department of Water, Environment and Energy (NWEE) to explore the options of permitting and cost for full scale use in the state.
“We have met with the state, provided a technical presentation and tour, and are awaiting final data to continue the discussion," Reinsch said. “Then the State will need to determine regulatory applicability for the technology as part of the construction permit review process if and when the project is selected by the city to move forward.”
Even with a low likelihood of full-scale implementation in Fairbury anytime soon, Dorri said smaller places like this act as an introduction to the technology to a state.
“It's towns like Fairbury who don't have another water source or kind of on an island with their water that - they have some demand that they have to meet. And so that's where innovation really shines,” said Dorri.