Glyphosate in Drinking Water
EPA limits, health effects, and what to do if your water is affected.
🩨 Health Effects
Long-term exposure above the MCL may cause kidney problems and reproductive difficulties. The MCL has a significant safety margin above levels that cause effects in animal studies. The carcinogenic classification of glyphosate is debated among regulatory agencies.
📍 Sources in Water
Glyphosate (the active ingredient in Roundup) is the most widely used herbicide in the world. It enters water from agricultural runoff. Residues are found in some surface water, especially in agricultural areas.
✅ What To Do
MCL exceedances are uncommon in community water systems. Activated carbon and reverse osmosis can reduce glyphosate levels if concerned.
📜 Regulation History
The EPA set the glyphosate MCL at 0.7 mg/L (700 ppb) in 1991. In 2015, IARC classified glyphosate as "probably carcinogenic to humans" (Group 2A), while the EPA concluded it is "not likely to be carcinogenic." The WHO guideline for glyphosate is 0.9 mg/L, similar to the US standard. The EU has repeatedly debated banning glyphosate but has extended its authorization.
🔬 How To Test Your Water
Certified lab tests for glyphosate cost $75-$150 using EPA Method 547 (HPLC with post-column derivatization). Home test kits for glyphosate have become available for $15-$30. Standard VOC panels do not include glyphosate; it must be specifically requested.
💧 Which Filters Remove Glyphosate?
Reverse osmosis (NSF/ANSI 58 certified) is effective at reducing glyphosate. Activated carbon provides some reduction but is less effective than for other pesticides since glyphosate is highly water-soluble. Oxidation with chlorine or ozone can also break down glyphosate at the municipal level.
Check your tap water for Glyphosate
Search your ZIP code to see if your water system has had Glyphosate 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.