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Early water tests show low levels of emerging contaminants in and around Boise River


Early water test results conducted after residents raised safety concerns about potential plans for water recycling in Boise show levels of emerging constituents on par with other utility systems, officials say. 

Employees from Boise’s Public Works Department conducted three different rounds of water sampling at six different locations in and around the Lander Street Water Renewal. The testing this summer aimed to determine if the water contained harmful chemicals. This city ordered the testing in preparation for the city council’s Tuesday vote on a water renewal utility plan, which includes the possibility of recycling water. 

“The early analysis and early results we’ve seen is we haven’t seen anything that raises those yellow flags,” Boise’s Senior Environmental Manager Haley Falconer told City Council on Tuesday. 

[Deep Dive: A look at Boise’s proposal for the future of waste water]

Emerging constituents are a wide range of chemicals including hormones, endocrine disruptors, and “forever chemicals” in the PFAS family found in common household items like Teflon, waterproof jackets and other products. They enter the wastewater system and the overall environment through human ingestion, water runoff and other sources. 

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Residents in Northwest Boise raised strong objections to one water recycling project proposed by the city, and in some cases the entire water renewal utility plan itself. Their main objection is to a proposal first explored under the administration of former Mayor Dave Bieter to pipe highly treated wastewater down the Farmer’s Union Canal. Some canal users expressed concern the canal could contain emerging constituents from wastewater. They say any chemicals then harm them when they use the water to flood irrigate yards, grow food in their gardens or if it enters wells used for drinking water. 

As part of the promises the city made to the concerned residents, it paused all progress on the Farmer’s Union Canal project. It also said would approve any project in the water renewal plan individually. The city also agreed to test the water in the current system to see what the levels of emerging constituents are before starting any water recycling projects.

Low levels found in all testing locations

The city tested for 308 different constituents, which all came back “far less” than the health screening level, according to Falconer. The levels were roughly equivalent to seven comparable utility systems, with the exception of one chemical, which Falconer said the city will continue to monitor. 

To complete the testing for the emerging constituents, city employees went without showering for multiple days or drinking caffeine in order to make sure any chemicals on their own bodies would not taint the testing. 

Tests did find emerging constituents found in groundwater, upstream of the treatment facility, downstream of the treatment facility, and in a nearby irrigation drain. Falconer said although there are chemicals found in the river after treated wastewater goes through the water renewal process, she said even the city’s basic cleaning process in place now is lowering levels of many contaminants. She expects that number to decline even further when the city upgrades the facility to treat water to the higher standard required for water recycling. 

“We are seeing some removal of constituents in our process and as we shift to recycled water we would see further removal as we added steps, but there’s further analysis required,” she said.”

Falconer also said the city has implemented numerous programs to limit what enters the wastewater system in the first place with programs for safe disposal of prescription medicine, regulations on mercury from dentists offices and hazardous waste drop-off sites. She also pointed to how the city blocked a request in 2019 from the Ada County landfill to dump liquid that had soaked through the landfill into the water renewal system due to high levels of heavy metals in the material. 

A letter from the Farmer’s Union Canal Stakeholders, a group advocating against the city piping recycled water into the canal, praised the city’s decision to test, but said they were still concerned about the constituents found and the emerging science around their harmful effects. They said until regulations catch up to the science around the topic, Boise should proceed with caution.

“Across the country, old techniques for water reuse are being confronted with new information on the dangers of common contaminants and, in some states, new standards that address these dangers,” the group’s letter said. “Boise may still adjust to this new climate by finding a strong footing informed by current research, and become a true pioneer in sustainable water conservation, water use, and as appropriate, water reuse.”

‘Not ignoring it’

The analysis searched for 18 types of PFAS chemicals, with 11 types coming back undetectable. Falconer said the seven types found in the water were also well below the EPA advisory level of 70 nanograms per liter. There are currently no EPA regulations for PFAS in wastewater, which means Idaho is unable to set limits on the chemical in wastewater at this time. Criteria for human health levels in wastewater is expected in 2021, Falconer said. 

Some residents have also criticized the city’s choice to hire water recycling consultant Carollo Engineers to advice the city on emerging contaminants. They say the company has relied on studies making recycled water look safe, instead of studies conducted by scientists at universities outside of the private sector. 

In response to these criticisms, Boise Public Works Director Steve Burgos said the claims city officials are looking at biased information from consultants who only want to present information favorable to recycled water is “unfortunate.” He said questions about emerging contaminants have arisen quickly, and the scientific community is still studying the topic. Burgos also posited if consultants were gaming their research to land more costly contracts they would most likely encourage cities to build and implement high-cost treatment systems, instead of saying recycled water is safe. 

“The industry is not ignoring it,” he said in an interview Wednesday. “There are any number of studies happening as we speak to figure out what are the implications of emerging constituents.”

Margaret Carmel - BoiseDev Sr. Reporter
Margaret Carmel - BoiseDev Sr. Reporter
Margaret Carmel is a BoiseDev reporter focused on the City of Boise, housing, homelessness and growth. Contact her at [email protected] or by phone at (757)705-8066.

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