Water works

City officials said the 1958 Hutchinson Waste Water Treatment Facility on Halstead Street needs millions of dollars of upgrades to keep up with the flushing demand. The facility pumps 5 million gallons of the treated effluent water each day into the Arkansas River. It takes about 30 hours from when a liquid first enters the facility to when it leaves. Here’s the process from start to finish:

1) Headworks: Wastewater flows into the headworks building where screens catch rags, flushable wipes, plastics and even bones before moving onto the next stage. About five tons of non-biodegradable material is hauled from the treatment facility each month.

2) Primary Clarifiers: The influent or inflow building diverts the water to the primary clarifiers. The two primary clarifiers are the main ones in use at the facility. Each holds roughly 250,000 gallons. The others on each side are used as backup during massive rainfalls. The solids fall to the bottom of the clarifier tanks.

3a) Anaerobic digesters: The solids go through another pump station and onto the anaerobic digesters. Four of the six 58 gallon anaerobic (free of oxygen) digesters are heated to between 95 to 100 degrees where the bacteria is the most efficient at breaking down the solids. The process creates carbon dioxide and methane gas; the latter is used to run the boilers that keep the digesters warm.

3b) Aertian basins: Liquid (and inevitably some solids) are moved through the 28-foot high screw pumps, then gravity pulls them into the four aertian (air) basins. Blowers keep air moving to allow the bacteria to keep working more efficiently.

4a) Centrifuge: The “biosolids” are taken from the digester after about 30 days and brought to the centrifuge for some water to be removed from the solids. Approximately 2.2 million pounds of solid are removed from the facility each year and spread around roughly 800 surrounding acres to fertilize nearby farmland. The solid removed are still 80 percent water.

4b) Final clarifier: The liquid moves into the final clarifier. The remaining solids from the final clarifier are moved into digesters or back into the basins to keep the bacteria “healthy, hungry, happy.”

5b) UV Station: Liquid is moved through the UV station before heading out to the Arkansas River. The UV lights remove some of the ammonia.

Water/Wastewater superintendent Joel Davenport said: “I like it, but we don’t get a lot of visitors.”