Cover Stories: Behind the Scenes

Behind Closed Doors: Waste Water Treatment Plant

Knoxville Museum of Art
New Knoxville Brewing Company
Tennessee Theater
The Orangery

Charging, boiling waves of murky reddish-brown water. Pools of blue so still that the water is indistinguishable from the sky it reflects. Huge tanks threateningly labeled "Poison Gas." Welcome to the Waste Water Treatment Plant, where Knoxville's sewage becomes fit to dump into the river.

Until 1954, the mucky water you see in this picture was sent straight into the Tennessee River. Now the cleaning process is so exact that the waste is clear and cloudless before it leaves the plant. Surprisingly enough, that squalid river is about 99.97 percent water, and only 300 parts per million are waste. The process goes in stages: The primary stage is physical treatment, where screens and grids block out the solid stuff, which amounts to 50 percent of the waste. Secondary treatment is organic; waste-munching organisms (flagellates, amoebas, ciliates, etc.) are released into the water to feed. They reduce the waste content to about 150 parts per million.

Advanced treatment is often chemical, to get rid of anything the little critters missed. This is where the poison gas comes in. It's chlorine, and it's pumped into these cobalt pools to remove the creatures that removed the waste. It is indeed toxic to humans, although they've never had a leak.

Charging, boiling waves of murky reddish-brown water. Pools of blue so still that the water is indistinguishable from the sky it reflects. Huge tanks threateningly labeled "Poison Gas." Welcome to the Waste Water Treatment Plant, where Knoxville's sewage becomes fit to dump into the river.		Until 1954, the mucky water you see in this picture was sent straight into the Tennessee River. Now the cleaning process is so exact that the waste is clear and cloudless before it leaves the plant. Surprisingly enough, that squalid river is about 99.97 percent water, and only 300 parts per million are waste. The process goes in stages: The primary stage is physical treatment, where screens and grids block out the solid stuff, which amounts to 50 percent of the waste. Secondary treatment is organic; waste-munching organisms (flagellates, amoebas, ciliates, etc.) are released into the water to feed. They reduce the waste content to about 150 parts per million.

	Advanced treatment is often chemical, to get rid of anything the little critters missed. This is where the poison gas comes in. It's chlorine, and it's pumped into these cobalt pools to remove the creatures that removed the waste. It is indeed toxic to humans, although they've never had a leak.