Nitrate In Drinking Water In Indiana
What residents of Indiana 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, Indiana Department of Environmental Management (IDEM), CDC · Last reviewed: 2025-01-01
Quick Answer
Is nitrate in drinking water a real concern in Indiana?
Yes — Indiana is a major corn and soybean producing state, and extensive tile drainage systems channel nitrate from agricultural fields directly into streams and rivers used for drinking water.
Is this mostly a public-water issue, a private-well issue, or both?
Both public water systems drawing from affected rivers and private well users in agricultural counties; Indiana's tile-drained landscape accelerates nitrate delivery to surface water used by public utilities.
What is the main reason residents should care?
Indiana's intensive row-crop agriculture combined with pervasive subsurface tile drainage creates a fast pathway for fertilizer nitrate to reach streams and rivers. Public water utilities drawing from the Wabash River, White River, and other agricultural waterways can experience seasonal nitrate spikes.
Key Facts
| EPA Nitrate MCL | 10 mg/L as N |
| Tile drainage | Pervasive subsurface drainage channels nitrate directly from fields to waterways — fast pathway |
| Affected rivers | Wabash, White, and Tippecanoe Rivers — public utilities in these basins monitor nitrate |
| Private well risk | North and central Indiana agricultural counties — annual testing recommended |
| State oversight | Indiana Department of Environmental Management (IDEM) |
Why This Matters in Indiana
Indiana is one of the top corn and soybean producing states in the nation. The state's flat agricultural landscape is extensively tile-drained — subsurface pipes that remove excess water from fields and channel it directly to ditches and streams. These tile drainage systems bypass the natural filtration that would otherwise slow nitrate movement from fields to waterways. Public water utilities in Indiana that draw from agricultural rivers — the Wabash, White, and Tippecanoe Rivers and their tributaries — can see seasonal nitrate increases following spring fertilizer application and heavy rain events. Private well users in agricultural counties are also at risk. IDEM monitors public water systems for nitrate compliance statewide.
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.
Indiana 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.
Fort Wayne - 3 Rivers Filtration Plant
Fort Wayne · 269,994 served
Evansville Water Utility
Evansville · 182,444 served
Carmel Water Department
Carmel · 99,927 served
Citizens Water of Westfield, Llc
Carmel · 61,493 served
Anderson Water Department
Anderson · 55,212 served
Purdue Univ. Water Works
West Lafayette · 50,000 served
Mishawaka Utilities
Mishawaka · 49,675 served
Elkhart Public Works and Utilities
Elkhart · 46,455 served
Valparaiso Department of Water Works
Valparaiso · 36,000 served
Plainfield Water Works
Plainfield · 34,477 served
How Nitrate Gets Into Drinking Water
Agricultural fertilizer and manure runoff
Nitrogen-based fertilizers and animal waste applied to Indiana 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 in Indiana's heavily agricultural counties — particularly in north and central Indiana — should test for nitrate annually. Communities served by public utilities that draw from agricultural rivers should review recent Consumer Confidence Reports for 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 Indiana
- 1
Identify your water utility. Use the ZIP lookup below or browse the Indiana 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 Indiana Department of Environmental Management (IDEM)-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
Indiana 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
Indiana Department of Environmental Management (IDEM) ↗