Arsenic in Connecticut Drinking Water
By Alexander Snyder, Founder & Water Quality Data Lead
The EPA legal limit (MCL) for Arsenic is 10 ppb, but the health-protective reference published by California OEHHA is 0.004 ppb. That health reference is roughly 2,500x stricter than the legal value.
Arsenic is listed in preserved public-system records associated with 142 Connecticut ZIP codes. This page summarizes record coverage and governed reference values. It does not establish that arsenic is present at a property, identify its serving utility, or determine exposure, safety, or health risk.
What Is Arsenic?
Arsenic is a naturally occurring element that can enter drinking water through erosion of mineral deposits and, in some settings, through contamination from human activity. Long-term drinking-water exposure is associated with cancer risk.
Review Arsenic 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 CodeHealth Effects of Arsenic
- Lung And Bladder Cancer
- Skin, Liver, And Kidney Cancer
These are source-classified outcomes in the exact OEHHA release, not a diagnosis, exposure determination, or finding about a property. See the cited reference below.
Safety Guidelines
Health Guideline
0.004 ppb
Source: California OEHHA
Legal Limit (MCL)
10 ppb
EPA Maximum Contaminant Level
Arsenic's health-protective reference is roughly 2,500x stricter than the legal limit (MCL).
| Standard | Level | Source |
|---|---|---|
| EPA legal limit (MCL) | 10 ppb | EPA — legal/regulatory context |
| Health-protective reference | 0.004 ppb | California OEHHA |
| Gap | ~2,500x stricter than legal | |
Where Does Arsenic Come From?
Erosion of natural deposits; runoff from orchards; runoff from glass and electronics production wastes
This preserved EPA table describes common ways arsenic 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 Arsenic in Your Water
The reviewed certification sources include an exact Arsenic (pentavalent) reduction for incoming levels at or below 50 ppb claim under NSF/ANSI 58. Certification is product- and claim-specific; the standard number alone does not prove that a product reduces arsenic.
- 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.
- 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.
- 3Follow the certified product's inlet conditions, installation, service-life, and replacement instructions, then retest treated water to verify performance at the property.
The listed claim is valence- and incoming-concentration-specific; it does not establish performance for arsenite or water above the certified inlet condition.
Certification verifies a named reduction claim under defined test conditions; it does not certify that every installation reaches CheckYourTap's EWG/OEHHA health reference.
Reading this inside ChatGPT or Claude?
This page can explain the general science about Arsenic 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 Arsenic at a property?
A certified sample from the relevant tap or well can establish whether arsenic 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 Arsenic. 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 Arsenic in my tap water?▾
What treatment guidance is released for Arsenic?▾
What reference values are shown for Arsenic?▾
Related Contaminants
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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.
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.