BOONE COUNTY, Mo. - Fifteen water towers sprout from the ground south of Columbia, like the corn growing next to them. While wind rustles the corn stalks, the towers give a slight hum to break the quiet near Eagle Bluffs Conservation Area. Across Route K is a louder hum, from the eight stone basins, each holding 985,000 gallonsr, Columbia Water & Light uses to treat the water those towers collect.
Every day, those towers pump 14 million gallons of water from the ground to the treatment plant to be sent to the city's customers. Hardly a dent, according to Water & Light spokeswoman Connie Kacprowicz, since the groundwater in the area holds 44 billion gallons.
"We're very fortunate here that our water requires just a little bit of finesse to get it safe to drink," Kacprowicz said.
The city uses the McBaine Aquifer for its drinking water, a reservoir of groundwater replenished by streams and storm water. The water runs 100 feet below the surface, a benefit Kacprowicz says keeps the city's treatment process low.
"Ground water is more protected, and our aquifer has the added benefit that it's filled with sand and gravel, which is a natural filtration device," Kacprowicz said.
The groundwater also makes it less likely water is severely contaminated. In Toledo, Ohio, water treatment workers noticed a toxic algae forming in Lake Erie, where the city gets its drinking water. Workers blamed abnormal amounts of nitrogen and phosphorous in the lake for the presence of the algae, caused by runoff from chemical fertilizer and leaking sewage lines.
"If you're getting your water from a lake or a river, there's a lot of other things that can influence it," Kacprowicz said. "Anything that's being dumped into the river or into the lake can end up in your drinking water."
The sand, clay and gravel in the McBaine Aquifer filters larger, organic material caught in the streams, Kacprowicz said. When it makes it to the treatment plant, the water is oxidized to remove gases like carbon dioxide. The city then adds lime to the water to "soften" it, or remove some of the metals like calcium. Before heading to customers in Columbia, the city adds chlorine and fluoride to treat it.
In 2013, a citizen group examined potential threats to the McBaine Aquifer, including herbicides, waste water pipes and infiltration from the Missouri River.