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Inorganics

Nitrate in Connecticut Drinking Water

By Alexander Snyder, Founder & Water Quality Data Lead

The EPA legal limit (MCL) for Nitrate is 10 mg/L, but the health-protective reference published by EWG is 0.14 ppm. That health reference is roughly 71x stricter than the legal value.

Nitrate is listed in preserved public-system records associated with 107 Connecticut ZIP codes. This page summarizes record coverage and governed reference values. It does not establish that nitrate is present at a property, identify its serving utility, or determine exposure, safety, or health risk.

What Is Nitrate?

Nitrate is a common drinking-water contaminant that can enter water from fertilizer runoff, manure, wastewater discharge, leaking septic systems, and stormwater. Health review must distinguish the stricter chronic health benchmark from the higher regulatory level designed around acute infant methemoglobinemia.

Review Nitrate Records Near You

Enter a Connecticut ZIP code to review associated public-system or regional monitoring records. The lookup does not identify the serving utility or measure a property.

Check Your ZIP Code

Health Effects of Nitrate

  • Cancer
  • Fetal-development Effects
  • Child-development Effects

These are source-classified outcomes in the exact EWG release, not a diagnosis, exposure determination, or finding about a property. See the cited reference below.

Safety Guidelines

Health Guideline

0.14 ppm

Source: EWG

Legal Limit (MCL)

10 mg/L

EPA Maximum Contaminant Level

Nitrate's health-protective reference is roughly 71x stricter than the legal limit (MCL).

Legal limit versus health-protective reference for Nitrate in drinking water
StandardLevelSource
EPA legal limit (MCL)10 mg/LEPA — legal/regulatory context
Health-protective reference0.14 ppmEWG
Gap~71x stricter than legal
EWG Nitrate and Nitrite

Where Does Nitrate Come From?

Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits

This preserved EPA table describes common ways nitrate can enter drinking water. It is source context, not a finding that any source applies to a ZIP, utility, property, or tap, and not a health-standard or treatment claim.

How to Reduce Nitrate in Your Water

The reviewed certification sources include an exact Nitrate/nitrite reduction claim under NSF/ANSI 58. Certification is product- and claim-specific; the standard number alone does not prove that a product reduces nitrate.

  1. 1Confirm the analyte and concentration at the relevant tap or well with a certified laboratory before choosing treatment; a ZIP-associated record is not a property result.
  2. 2Choose a specific current product whose independent certification listing and performance data sheet explicitly name the exact reduction claim. A standard number by itself is not an analyte claim.
  3. 3Follow the certified product's inlet conditions, installation, service-life, and replacement instructions, then retest treated water to verify performance at the property.

Certification verifies a named reduction claim under defined test conditions; it does not certify that every installation reaches CheckYourTap's EWG/OEHHA health reference.

Who May Need Closer Review?

The governed EWG release classifies the following household groups as priorities for nitrate context. This classification does not lower or multiply the cited reference and does not determine anyone's exposure.

Pregnant
Newborns (<3mo)
Infants (<1yr)
Breastfeeding
Toddlers (1-2)
Children (2-6)
Children (6-11)

Confirm the serving utility and use a certified property sample before making a health, exposure, or treatment decision.

Reading this inside ChatGPT or Claude?

This page can explain the general science about Nitrate records associated with a ZIP, but it cannot identify what is at a specific tap or property. You can get ZIP-level context two ways:

  • Inside the chat: ask your assistant to “check my tap water with CheckYourTap”. Our connector returns available public-system or regional monitoring records associated with your ZIP. It does not identify your serving utility or test your tap, well, or property. The current connector is read-only and does not email reports or submit contact information.
  • On the web: open CheckYourTap.com and enter your ZIP code for a free ZIP-level report.

Need to confirm Nitrate at a property?

A certified sample from the relevant tap or well can establish whether nitrate is present before any health, filtration, or treatment decision.

CheckYourTap is an independent water-quality service, not your town or utility. We connect you with a vetted local partner. Your online report is free. Testing and treatment are paid services, and there's no cost to talk.

Have a dog or cat?

Read the source-linked veterinary context for Nitrate. These pages do not turn a human guideline into a pet-safe number or claim that a ZIP record describes your pet's water.

Frequently Asked Questions

Is Nitrate in my tap water?
Nitrate has been listed in preserved public-system records associated with 107 Connecticut ZIP codes. Whether it is present at a property requires confirmation of the serving utility and, when needed, a tap sample. CheckYourTap provides free records associated with a CT ZIP.
What treatment guidance is released for Nitrate?
Confirm the analyte and concentration at the relevant tap or well with a certified laboratory before choosing treatment; a ZIP-associated record is not a property result. Choose a specific current product whose independent certification listing and performance data sheet explicitly name the exact reduction claim. A standard number by itself is not an analyte claim. Certification is product- and exact reduction claim-specific and does not guarantee the EWG/OEHHA health reference at a property.
What reference values are shown for Nitrate?
The displayed EWG health reference is 0.14 ppm. It is not an EPA compliance conclusion or a property-specific safe level.

Related Contaminants

Check Water Quality by ZIP Code

View all contaminants in Connecticut water

Sources

The exact released health reference and the reviewed sources for this definition are listed below:

About This Report

This page restores the preserved Connecticut route and historical public-record catalog. It does not publish the catalog’s old percentages or promote its stored threshold fields. Exact released health references come from EWG or California OEHHA; EPA material is legal, regulatory, and source context. CheckYourTap is an independent water-quality service funded by Valiant Energy Solutions, a Connecticut water quality and energy services company established in 1930.

EPA SDWISEWG Tap Water DatabaseCA OEHHA Public Health Goals

This report is general information, not medical advice or a substitute for certified laboratory testing. Talk to your pediatrician or physician about specific health concerns.

Unmatched analytes remain visible without a numeric health verdict. Last reviewed August 2026.