The science of sewage: Students tour wastewater treatment plant

Eight Columbia Falls High School students got the chance to learn about the town deals with its wastewater Friday as Erin Quintia and her sustainable systems class toured the town’s treatment facility with Chief Operator Grady Jenkins.

Originally built in 1969, the Columbia Falls wastewater treatment plant was modified and expanded in 1983, 1987, 2000 and most recently in 2010. The facility treats approximately 400,000 gallons of wastewater per day, releasing the treated water directly into the Flathead River at a rate of 278 gallons per minute.

Jenkins, who has worked at the facility for 23 years, says a lot has changed over the years, but the goal stays the same.

“We are constantly striving to meet the water quality standards that DEQ has set for us and the water we are putting into the Flathead River. That is our number one priority. That, and always being able to meet the needs of the town,” Jenkins told the students Friday. “We are a small town, but we are watched pretty closely by the DEQ because we discharge directly into the Flathead River.”

According to Jenkins, water is fed into the facility from nine lift stations around the city, which deliver the water to the pretreatment, or headworks, station first. There, a filter separates and removes solid waste from the liquid before it moves into the equalization basin, which helps maintain a constant flow throughout the plant.

From there, the water goes through a nutrient removal process, which takes out the nitrogen and phosphorous to help stem algae growth caused by the discharge into the river. The plant is allowed to release one milliliter of phosphorous per liter and 37 pounds of nitrogen into the water per day.

Despite efforts by several companies to remove phosphates from their products in recent years, Jenkins says the chemicals will always be a concern.

“No matter how much you restrict the amount of phosphorous in household chemicals, you are still going to have to deal with it in wastewater. It is just a naturally occurring chemical that we are always going to have to deal with,” he said.

After the remaining sludge is separated from the liquid through a settling process, the effluent is treated with ultraviolet light to kill E. Coli bacteria before it is released into the river. In all, it takes about a day for water to move through the plant and into the river.

According the Jenkins, the process usually goes pretty smoothly, but there are a few things that can be kept out of wastewater to help the process along.

“Our biggest item to deal with here, maintenance wise, are baby wipes,” he said. “They just get in the system and cause all kinds of problems. My father-in-law told me a long time ago, ‘Whatever you can’t put through the human body, don’t put down the sewer.’ That’s still true today. It makes good sense.”