Exceeds EPA Limit Nitrate EXCEEDS EPA LIMIT

Nitrate in Waukesha, WI Drinking Water

Nitrate data for Waukesha, Wisconsin · 72,248 residents · 4 ZIP codes

If you rely on a public water system in Waukesha, Wisconsin, Nitrate is a contaminant your utility has been required to test for — and EPA records show it has been detected at measurable levels, making it worth understanding as part of your tap water's detection record.

10 mg/L (as nitrogen)
EPA MCL
24
EPA Violations
High
Health Risk
Reverse Osmosis or Ion Exchange
Best Filter Method

Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14

Nitrate in Waukesha Tap Water

Waukesha, Wisconsin has 24 EPA violations related to nitrate in drinking water.

This analysis covers 72,248 residents across 4 ZIP codes in Waukesha.

Waukesha's overall water quality grade is C (55/100).

Is Nitrate in Waukesha Water Safe?

Nitrate levels in parts of Waukesha exceed the EPA MCL of 10 mg/L (as nitrogen). The EPA requires water systems to take corrective action when this limit is exceeded.

If you live in an affected ZIP code, consider installing a reverse osmosis or ion exchange filter certified under NSF 53 / NSF 58 and testing your water independently.

EPA Violations for Nitrate in Waukesha

Date Violation Type Status ZIP Code
2023-04-01 Nitrate (Resolved) Resolved 53186
2023-04-01 Nitrate (Resolved) Resolved 53187
2023-04-01 Nitrate (Resolved) Resolved 53188
2023-04-01 Nitrate (Resolved) Resolved 53189
2023-01-01 Nitrate (Resolved) Resolved 53186
2023-01-01 Nitrate (Resolved) Resolved 53187
2023-01-01 Nitrate (Resolved) Resolved 53188
2023-01-01 Nitrate (Resolved) Resolved 53189
2022-10-01 Nitrate (Known) Known 53186
2022-10-01 Nitrate (Known) Known 53187
2022-10-01 Nitrate (Known) Known 53188
2022-10-01 Nitrate (Known) Known 53189
2022-07-01 Nitrate (Known) Known 53186
2022-07-01 Nitrate (Known) Known 53187
2022-07-01 Nitrate (Known) Known 53188
2022-07-01 Nitrate (Known) Known 53189
2022-04-01 Nitrate (Known) Known 53186
2022-04-01 Nitrate (Known) Known 53187
2022-04-01 Nitrate (Known) Known 53188
2022-04-01 Nitrate (Known) Known 53189
... 4 more violations

Health Effects of Nitrate

  • Methemoglobinemia ("blue baby syndrome") in infants under 6 months
  • Increased risk of colorectal and bladder cancer (long-term)
  • Thyroid disease from chronic exposure
  • Possible reproductive effects

Health risk severity: High. Governed by the National Primary Drinking Water Regulations.

How Nitrate Gets Into Drinking Water

  • Agricultural fertilizer runoff
  • Animal feedlot operations and manure
  • Septic system leachate
  • Urban stormwater and wastewater discharge

What to Do About Nitrate in Waukesha Water

  1. Reverse osmosis is the most effective method for nitrate removal
  2. Ion exchange systems designed for nitrate can also work
  3. Standard carbon filters do NOT remove nitrate
  4. Boiling water increases nitrate concentration — never boil for nitrate

Look for filters certified under NSF 53 / NSF 58 for nitrate removal.

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