Chlorpyrifos in Connecticut Drinking Water
By Alexander Snyder, Founder & Water Quality Data Lead
The health-based safe level for Chlorpyrifos, set by the U.S. EPA, is 0.002 mg/L. This health-protective guideline is typically stricter than federal legal limits, which have not always been updated to reflect current science.
Chlorpyrifos has been tracked across Connecticut drinking water. Here is what you need to know about chlorpyrifos in your drinking water and how it may affect your household.
What Is Chlorpyrifos?
Chlorpyrifos is a broad-spectrum organophosphate insecticide that was widely used in agriculture and residential pest control before residential use was banned. It enters groundwater through agricultural runoff. The EPA lifetime health advisory is 2 parts per billion. Chlorpyrifos inhibits acetylcholinesterase and is linked to neurodevelopmental delays and cognitive impairment in children, as well as tremors and neurological effects in adults.
Is Chlorpyrifos in Your Water?
Enter your Connecticut ZIP code to find out if chlorpyrifos is in your local water — and see personalized health risks for your household.
Check Your ZIP CodeHealth Effects of Chlorpyrifos
Neurodevelopmental delays, cognitive impairment, tremors
Safety Guidelines
Health Guideline
0.002 mg/L
Source: U.S. EPA
Chlorpyrifos's health-based safe level is set below the federal legal limit.
| Standard | Level | Source |
|---|---|---|
| Health Guideline | 0.002 mg/L | U.S. EPA |
Where Does Chlorpyrifos Come From?
Agricultural runoff, residential use (now banned)
How to Reduce Chlorpyrifos in Your Water
- 1Install a point-of-use activated carbon block filter certified to NSF/ANSI Standard 53 for pesticide reduction; activated carbon effectively adsorbs organophosphate compounds like chlorpyrifos.
- 2A reverse osmosis system certified to NSF/ANSI Standard 58 provides additional removal of chlorpyrifos and related pesticide residues.
- 3For whole-house well water treatment near agricultural areas, use a granular activated carbon tank system at the point of entry.
- 4Test water through a certified laboratory if located near agricultural operations, and replace carbon media according to the manufacturer's schedule to maintain adsorption capacity.
Who Is Most Vulnerable to Chlorpyrifos?
The safe level of chlorpyrifos varies significantly depending on who is drinking the water. CheckYourTap calculates adjusted safe levels for each member of your household:
A contaminant level that is safe for an adult may exceed guidelines for an infant by 4-8x or more. Check your ZIP code to see personalized results.
Reading this inside ChatGPT or Claude?
This page can tell you the general science, but not what is actually in your water’s chlorpyrifos level — that depends on your exact address. You can get your specific answer two ways:
- Inside the chat: ask your assistant to “check my tap water with CheckYourTap”. Our connector returns your ZIP code’s measured contaminant levels — including the derived dog and cat safe levels — and, only if you ask it to, can email you the report or arrange a specialist callback.
- On the web: open CheckYourTap.com and enter your ZIP code for a free 30-second report.
Concerned about Chlorpyrifos in your water?
Schedule to get your water tested for chlorpyrifos and more — a Valiant water specialist will review your results and arrange testing for your home.
Frequently Asked Questions
Is Chlorpyrifos in my tap water?▾
What level of Chlorpyrifos is safe?▾
How do I remove Chlorpyrifos from my water?▾
Related Contaminants
Check Water Quality by ZIP Code
Sources
The legal limits and health guidelines for Chlorpyrifos on this page come from the following public authorities:
About This Report
This water quality report is compiled from public records filed with the U.S. Environmental Protection Agency, state health departments, and the U.S. Geological Survey. Contaminant levels are evaluated against EPA federal standards and health-based guidelines from leading environmental and public health organizations. CheckYourTap is a service of 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.
Reviewed by the CheckYourTap editorial team. Last updated July 2026