Atrazine in Drinking Water
EPA limits, health effects, and what to do if your water is affected.
🩨 Health Effects
Long-term exposure above the MCL can cause cardiovascular problems and reproductive system issues. Animal studies suggest possible cancer risk. Atrazine is one of the most commonly detected herbicides in US drinking water.
📍 Sources in Water
One of the most widely applied herbicides in the US, used primarily on corn. Enters water through agricultural runoff and is highly persistent. Levels are highest in spring after application and in Midwestern agricultural watersheds.
✅ What To Do
Activated carbon and reverse osmosis effectively remove atrazine. Levels tend to spike seasonally after application. Check your utility's Consumer Confidence Report for average annual levels versus seasonal peaks.
📜 Regulation History
The EPA set the atrazine MCL at 0.003 mg/L (3 ppb) in 1991 under the Phase II rule. The EU banned atrazine entirely in 2004 due to persistent groundwater contamination. The WHO guideline is 0.1 mg/L, far less strict than the US standard. Despite restrictions, atrazine remains widely used in the US with about 70 million pounds applied annually.
🔬 How To Test Your Water
Certified lab tests for atrazine cost $30-$75 using immunoassay or GC/MS methods. Home test kits for atrazine are available for $20-$40, particularly marketed to rural well owners. Test in late spring or early summer when levels peak after application season.
💧 Which Filters Remove Atrazine?
Granular activated carbon (GAC) filters are very effective at removing atrazine (NSF/ANSI 53 certified for atrazine or VOC reduction). Reverse osmosis also works well. Standard sediment filters do not remove atrazine since it is dissolved. Replace carbon filters regularly during peak agricultural season.
Check your tap water for Atrazine
Search your ZIP code to see if your water system has had Atrazine violations, plus lead testing results and an overall safety grade.
Search your ZIP code →Data from the EPA's Safe Drinking Water Information System (SDWIS). MCLs reflect minimum federal standards; some contaminants may pose health risks below these thresholds.