KCCI Investigates: Central Iowa Water Works running nitrate removal facility, rare in January
DES MOINES, Iowa (KCRG) — High nitrates levels are back in the Des Moines and Raccoon Rivers, KCCI reports.
That means Central Iowa Water Works nitrate removal facility is running again.
The facility turned on three of these eight vessels on Tuesday. But this is a rarity for January.
“It’s been on for a couple of days now,” said Tami Madsen. “All water produced by Central Iowa Water Works is below the safe drinking water standard.”
The Environmental Protection Agency set that at 10 milligrams per liter. Public water systems are required to meet that.
Former University of Iowa researcher Chris Jones says it’s odd to run the nitrate removal facility in the winter.
The recent weather is worth considering.
“What we have right now, in my estimation, is this warm weather is keeping the ground from freezing. And so, if the frost doesn’t descend to about four feet, below the Earth’s surface, then it remains thawed down where the field tiles, the agricultural field tiles are,” Jones said.
Nitrate from fertilizer runoff or manure can sit in those tiles. When rain comes, it washes out.
“Now this high-nitrate water is coming out of the tiles. And that’s what’s dominating the stream,” Jones said.
In spring and summer 2025, the nitrate removal facility ran in part of fully for 112 days.
“It has been quite a year,” Madsen said.
A wet July drove nitrates out of farm field drainage tiles and into lakes and rivers. That all led to an unprecedented lawn watering ban in central Iowa this summer.
Jones says the high numbers aren’t just hitting central Iowa. He noted the Cedar River on Thursday was almost 10 milligrams per liter.
“This is something that’s happening statewide,” he said.
The nitrate removal facility, located in Des Moines but operated by Central Iowa Water Works, has been in used since the 1990s.
This is the fourth time in the facility that it has run in the winter. Most times have been in 2015, including:
- 2014: December, 28 days
- 2015: All January
- 2015: March, 10 days
- 2026: January, 3 days
Water sample tests today show nitrates in the Raccoon are 11.66 milligrams per liter. The Des Moines is a little under that at 9.62 milligrams per liter.
Jones says he hopes for lawmakers returning next week to notice.
“When you have a city of the size of Des Moines, where their drinking water supply is continuously imperiled, that is a bad issue. That’s a bad thing,” Jones said, “and so we need some urgency here.”
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