OTHELLO — There’s at least one more test, but when it’s completed, the city of Othello should be ready to build the first phase of a facility that will treat water from irrigation canals to municipal use standards. 

“In the next two weeks the test plot is going to be set up and built,” said Othello Mayor Ken Johnson.  

City officials have been working on an “aquifer storage and recovery” project for more than a decade. The goal is to replace some of the water pumped from the underground aquifer that supplies the city’s water with treated water pumped from irrigation canals near town.  

Othello shares its aquifer with cities, towns and farms across the region, and over time, all the water use has depleted the aquifer. Under agreements with the East Columbia Irrigation District, the city could pump out irrigation water in the spring and fall when the canal is in use, but there’s less demand from farmers.  

Earlier tests proved the system does work; they were conducted with components that used membranes to filter out particles. City officials are looking to test a different method, using sand. That, Johnson said, would be cheaper than the membrane components. 

The city received about $887,500 from the state capital budget for the water system. Othello City Council members approved contracts with the Department of Commerce for the funding Monday. Johnson said that money will pay for planning and engineering if the tests are successful. 

Water will be pumped into the test plot from mid-September until the end of the irrigation season in October. Johnson said Washington Department of Ecology officials are interested in how the facility survives the winter. 

“After it sits for six months, what does it look like?” Johnson said.  

Since most sand filtration systems are in use year-round, Johnson said DOE officials also want to know how periodic shutdowns affect its operation.  

The information obtained through the test will determine what happens next, he said. 

“The engineering and design will be built off the test results,” he said. The money from the capital budget request will pay for that part of the project.  

The test site is on city-owned property at the intersection of Lee Road and North 14th Avenue. The city purchased 77.12 acres along North 14th Avenue in March 2025, part of a deal with the Othello School District and local property owners AJ and Jodi Ochoa. 

When it’s completed, the water treatment facility will take up about 24 acres.  

Johnson said he hopes to start construction of the first phase of the permanent facility next year.  

“We’re ready to go,” he said.