Nitrate In Drinking Water In Iowa
What residents of Iowa need to know about nitrate in drinking water — including how it enters water, which utilities have documented violations, and what steps to take.
Source: EPA SDWIS, Iowa Department of Natural Resources (IDNR), CDC · Last reviewed: 2025-01-01
Quick Answer
Is nitrate in drinking water a real concern in Iowa?
Yes — Iowa has among the most documented and severe agricultural nitrate problems of any state in the nation. Des Moines Water Works has publicly highlighted the challenge of agricultural nitrate loading in the Raccoon River, which serves more than 500,000 people.
Is this mostly a public-water issue, a private-well issue, or both?
Both public water systems drawing from Iowa's agricultural rivers and private well users across the state's farming landscape; Iowa's tile-drained corn and soybean fields create intense nitrate loading.
What is the main reason residents should care?
Iowa is the nation's largest corn and pork producer. Its landscape is almost entirely agricultural and extensively tile-drained. This combination creates among the most intense agricultural nitrate loading pathways in any state, affecting both river-sourced public water systems and private wells.
Key Facts
| EPA Nitrate MCL | 10 mg/L as N |
| Des Moines Water Works | Publicly highlighted Raccoon River nitrate challenge — serves 500,000+ from agricultural rivers |
| Iowa agriculture | #1 corn and pork producer — extensive tile drainage accelerates nitrate loading |
| 2015 lawsuit | DMWW sued upstream drainage districts over nitrate — drew national attention |
| State oversight | Iowa Department of Natural Resources (IDNR) |
Why This Matters in Iowa
Iowa's nitrate problem is among the most thoroughly documented in the United States. Des Moines Water Works, which serves the Des Moines metro area from the Raccoon and Des Moines Rivers, famously sued three upstream drainage districts in 2015 over nitrate loading — a case that drew national attention to agricultural nitrogen pollution and its effect on public drinking water. Iowa's nearly continuous corn-soybean rotation combined with pervasive tile drainage creates intense seasonal nitrate spikes in virtually every river in the state. IDNR monitors public systems; private well users are responsible for their own testing. Iowa State University Extension and the Iowa Department of Agriculture and Land Stewardship have resources on private well nitrate testing.
Historical Context
Des Moines Water Works sued three upstream Iowa drainage districts in 2015 over nitrate pollution in the Raccoon River, arguing that the tile drainage systems function as point-source pollution. The case was ultimately dismissed on jurisdictional grounds, but it focused national attention on Iowa's agricultural nitrate challenge and the limits of the Clean Water Act in addressing nonpoint source pollution.
Critical — Infants Under 6 Months
Do not use tap water that exceeds 10 mg/L nitrate-nitrogen to prepare infant formula or feed infants under six months. Boiling will concentrate nitrate — do not boil. Use bottled water or a certified reverse osmosis system (NSF/ANSI 58) until the issue is resolved.
Iowa Utilities With Nitrate Violation Records
The utilities listed below have at least one nitrate violation on record in EPA's SDWIS database. Violations may be open or resolved — see individual utility pages for current status and risk level.
How Nitrate Gets Into Drinking Water
Agricultural fertilizer and manure runoff
Nitrogen-based fertilizers and animal waste applied to Iowa cropland can leach into groundwater or run off into surface water supplies. This is the dominant nitrate pathway in most agricultural regions.
Septic system effluent
Failing or poorly sited septic systems release nitrogen-rich wastewater near drinking water wells. Rural areas with high well density and aging septic infrastructure face elevated risk.
Concentrated animal feeding operations (CAFOs)
Large livestock facilities generate significant waste. Lagoon leaks and overapplication of manure to nearby fields can create localized nitrate hotspots in groundwater.
Natural geological deposits
In some regions, naturally occurring nitrogen compounds in soil and bedrock contribute background nitrate levels to groundwater independent of agricultural activity.
Who Should Pay Closest Attention
Private well users across Iowa should test for nitrate annually — the state's intensive agriculture affects groundwater broadly. Households with infants should test before using well water for formula preparation. Public water utility customers should review their CCR for annual nitrate monitoring results.
Households with infants under six months
Pregnant residents
Private well owners in agricultural areas
Households near livestock operations or CAFOs
Rural residents on shallow groundwater wells
Households with older or failing septic systems nearby
How to Check Your Situation in Iowa
- 1
Identify your water utility. Use the ZIP lookup below or browse the Iowa utility directory on this site.
- 2
Read your utility's page on this site to see its current risk level and any open nitrate violations.
- 3
Review your utility's most recent Consumer Confidence Report (CCR) — mailed annually or available on the utility's website. It must disclose any MCL exceedances.
- 4
If you are on a private well, arrange testing at a Iowa Department of Natural Resources (IDNR)-certified lab. Your state health department maintains a list of certified labs. Annual testing is recommended in agricultural areas.
- 5
If you have an infant under six months, use bottled water or a certified RO system (NSF/ANSI 58) immediately as a precautionary measure — do not wait for test results if you are in a high-risk area.
- 6
If your utility issues a nitrate exceedance notice, follow their guidance and do not use tap water for infants until the issue is resolved.
Treatment Options
Carbon filters and boiling do not remove nitrate. Only the options below are effective.
NSF/ANSI Standard 58 — Reverse Osmosis
RO systems certified to NSF/ANSI 58 reduce nitrate by 85–95% at the point of use. Under-sink installation required. The most practical residential option for nitrate concerns.
Distillation
Distillation units effectively remove nitrate along with most other dissolved contaminants. Suitable for drinking and cooking water — not whole-house use.
Anion Exchange
Ion exchange systems designed for nitrate removal exchange nitrate ions for chloride on a resin bed. Effective as a point-of-entry system; requires periodic regeneration and monitoring.
Carbon filters do NOT remove nitrate
Standard pitcher filters, faucet filters, and under-sink carbon units — including those certified NSF/ANSI 42 or 53 — do not remove nitrate. Do not use these for nitrate reduction.
Frequently Asked Questions
Related Pages
Nitrate — National Overview
All U.S. utilities with nitrate records
Iowa State Overview
All utilities and water quality data
Lead in Drinking Water
A separate but common concern
Reverse Osmosis Guide
Removes 85–95% of nitrate
Well Water Guide
Private well testing and safety
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
Find Your Utility
State Regulator
Iowa Department of Natural Resources (IDNR) ↗