Central Iowa Water Works is running its nitrate removal system due to high nitrate levels in the utility’s source water. We want to make sure our farmer and partner readers have all the information they need to understand this issue.
So, at the risk of breaking our brevity rule… let’s get into it.
What’s normal?
The last (and only) time Des Moines had to run the pumps in January was in 2015.
If you like numbers, a quick look at current nitrate levels:
EPA drinking water standard: 10 ppm
Finished water: 8.42 ppm as of Monday (Fleur)
Des Moines River: 11 ppm as of Tuesday
Raccoon River: 15 ppm as of Tuesday
Okay, what’s going on? (science geeks unite!)
Here’s what trends tells us:
Higher flow rates are correlated with higher nitrate levels. This January we have seen higher than average flow.
Why higher flow rates? The ground isn’t frozen as it usually is in January so rain and snow has penetrated the soil.
What’s this we’ve heard about drought? Iowa had a wet 2024 and 2025 springs following years of drought, which could be continuing to have effects. Nitrate can be flushed into groundwater during drought. It is released when the water table rises and reaches tile lines. In major drought periods like 2012, we’ve seen high nitrate release last longer than just one spring season.
Why it matters
While large fluctuations in nitrate levels can be associated with weather, we know that on-farm conservation practices do work at a field and watershed level.
For example, on average:
A rye cover crop reduces nitrate loss by 31%
Nitrogen management by 4-9%
Saturated buffers by 50%
With increasing acres of these practices, farmers are making a difference statewide. And we have more work to do.
A note of inspiration
The Black Hawk Lake Watershed Project in Sac County started in 2012. It’s led to thousands of new acres of conservation, and that’s translating to sampling results.
Areas with the most conservation practices had 64% less nitrate loading than areas with lower implementation, according to an ISU study.
--Proof that collaboration of urban and rural folks works.
Water monitoring changes just around the riverbend?
Iowa DNR is considering updates to its 27-year-old water monitoring program that could improve statewide coverage and expand testing. The program is called the Ambient Stream Monitoring Program.
What it is
Tests 60 locations
Monthly samples
Compares samples to nearby USGS samples
Tests for 24 parameters including nutrients, dissolved oxygen, temp, and pH
It’s funded by the Iowa legislature out of a $3 million pot for water monitoring.
Why it matters
This program is best at tracking long term trends and for reporting required data for the Clean Water Act. It does not test for other contaminants like pharmaceuticals, pesticides, and metal.
A proposal is in the works that would:
Allow the program to test for pharmaceuticals, pesticides, and metal on a rotating annual basis.
Scrutinize how many sites are tested and where, with the goal of creating broader and better coverage statewide.
Is this related to the monitoring program whose funding was reallocated?
Sends data back to the lab every 15 minutes for real time data.
The main difference? The ambient program is monthly, so it’s best for trends. The IWQIS program has more frequent data which is better for tracking how, why, and when water quality changes (a major rain event, for example).
Up next: DNR could propose the ambient monitoring changes to the Environmental Protection Commission this fall.
What do Miley Cyrus, Thin Lizzy, Michael Jordan, Donald Trump, Simone Biles, and Trumpeter Swans have in common?
A comeback story.
The update:
Trumpeter swans attempted a modern-day record of 158 nests in 2025 in Iowa – an increase of 17% over 2022.
Get your baby shower gifts ready! Active nests average around 4.4 cygnets, or young swans. About 60 percent of the nests were successful in hatching. (Cue the collective “Awwww”)
Why it matters
Trumpeter swans are emblematic of healthy wetlands systems (a key conservation practice for clean water).
Surveys in 1935 found fewer than 100 trumpeter swans across the US.
Thanks to restoration efforts, more than 4,700 swans were recorded in Iowa alone!
The Natural Resources Committee centered their remarks Monday on water quality. As the session begins, a few water quality topics we're watching are water monitoring funding and continued funding for the Iowa Nutrient Reduction Strategy. Read more from Successful Farming.
*Editor's note - IAWA is not a policy organization; it does not participate in legislative work or influence policy.
New resource helps farmers and landowners test nitrate levels
The new resource outlines the importance of nitrate monitoring, provides basic instructions for testing water using nitrate test strips or kits, teaches how to interpret results, and explains the difference between nitrate and nitrate-nitrogen. Download the resource from ISU.
Saturated buffers cut farm drainage nitrate by half
A review of research finds that saturated buffers can reduce annual nitrate losses by about 46% on average and remove over 80% of nitrate from the water that flows through them, Read the summary on conservationdrainage.net.
Iowa Agriculture Water Alliance, 1255 SW Prairie Trail Pkwy, Ankeny, Iowa 50023, United States
