An open house held Friday hopes to grow interest in job opportunities at the Columbia Wastewater Treatment Plant. 

Like many career fields, there are multiple openings under seven different job titles at the facility. 

This includes five openings under the Wastewater Treatment Plant Operator listing, said Jeanne Locklear, City of Columbia human resources coordinator. 

There are positions where some previous skill is needed, but then there are plenty of others that are entry-level and have on-the-job training, she added. 

The open house offered rotating 30-minute tours of the facility to not only give the public a peek into one of the myriad of city services, but also to give potential employees a look at operations as well, Locklear said. 

"I believe people don't always understand the critical, essential service that is provided here," she said. "... (The open house) gives the community an opportunity to see our awesome facility." 

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Each tour had about a handful of participants, Locklear said. For those looking for a job, they had opportunities to apply and even go through a job interview onsite, she said touting City of Columbia benefits and stability.

The open house was a way to think of "other ways on engagement on worthwhile work," Locklear said.  

The city's wastewater treatment facility is part of a separate system from the McBaine Water Treatment Plant, where upgrades have been part of recent Columbia City Council discussion.

While the treated water is at a drinking standard, said Lee White, Columbia city sewer utility engineer, it is not put directly back into the city's water system. 

Water treated at the wastewater plant is anything that comes out of a residence or business. It eventually will end up in Missouri waterways.

It has to be treated to standards set by a permit with the Missouri Department of Natural Resources. The Missouri Department of Conservation also uses treated water in the Eagle Bluffs Conservation area adjacent to the treatment plant. 

Water treated at the McBaine facility comes from ground source wells and the Missouri River, and is what goes into a residence or business with which to use to bathe, wash clothes and dishes, drink or cook.

The wastewater plant treats upward of 16 million gallons of wastewater per day, White said.

"We get all the gray water," he said. 

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This can increase to nearly 40 million gallons, he said, if there has been heavy rain. This will happen when stormwater gets into sewer lines due to any damaged lines or from people who have connected stormwater systems, such as sump pumps, into a sewer line. 

The facility also is home to sewer and stormwater line maintenance and a lab keeps track of water conditions coming in and what eventually will leave the facility to make sure it is keeping in line with DNR permit, White said. 

Treating wastewater is a multi-step filtering process. 

Most of the city's sewers are gravity-based, though there are 26 pump stations, said Erin Keys, engineering and operations manager at the wastewater treatment plant.

"We're at a low spot," she said. 

Depending on the business, some wastewater may be pretreated to standards set by the city for those businesses, said Tami Hansen, lab supervisor. This is for industrial businesses. 

The first filtering gets out the largest particles, which often are items that are flushed that should not be, such as "flushable" wipes or small toys, for example. The second filtering process gets out a majority of grit material: sand, some dirt, and, yes, even corn kernels. 

The water then goes into settling basins. So any further particulate matter drops to the bottom of the basins, while the water flows out through weirs. This water goes into both little to no oxygen and aeration basins, where microorganisms eat the particulate matter. 

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This water then goes into another settling basin. What settles out goes back into the aeration basins. The water also goes into constructed wetlands for further treatment, including UV treatment by the sun. 

"They really are a great feature. They do a considerable amount of additional treatment," Keys said.

Anything that cannot be filtered out goes into centrifuges to get a majority of the water out so the sludge can be further digested in a higher-temperature closed environment. The final product from the digesters and other treatment is a fertilizer the plant can provide for free to farmers. 

The plant collects methane gas from the digesters for use in a boiler, which keeps the digesters at the right temperature and provides heat in the winter for facilities. 

Sewer maintenance crews also are on site, which are among the open positions. They are the ones seen by the public when working to repair sewer lines or find why there was a backup as well as to try and get ahead of potential back-ups.

They can put cameras down manholes, which are fed into sewer lines. The distance traveled is tracked, so crews can note how far any issues is down the line. 

"We try to keep wastewater in the system. We don't want it coming out because that is what causes health problems," Key said, adding she got into this job as a means of helping the environment. 

Charles Dunlap covers local government, community stories and other general subjects for the Tribune. You can reach him at cdunlap@columbiatribune.com or @CD_CDT on Twitter. Please consider subscribing to support vital local journalism.