2,4-D 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 kidney, liver, or adrenal gland problems. 2,4-D is one of the most widely used herbicides in the US and is currently under review by the EPA for potential cancer risk.
📍 Sources in Water
Applied to lawns, crops, and rights-of-way. One of the most widely used herbicides globally. Enters water through agricultural and residential runoff. An active ingredient in many common lawn weedkillers.
✅ What To Do
Activated carbon filtration and reverse osmosis can reduce 2,4-D. Violations in community water systems are uncommon but can occur in agricultural regions during spring runoff.
📜 Regulation History
The EPA set the 2,4-D MCL at 0.07 mg/L (70 ppb) in 1991 under the Phase II rule. 2,4-D has been in continuous use since the 1940s and was a component of Agent Orange (in combination with 2,4,5-T). The WHO guideline is 0.03 mg/L, stricter than the US standard. IARC currently classifies 2,4-D as a possible human carcinogen (Group 2B).
🔬 How To Test Your Water
Certified lab tests for 2,4-D cost $50-$100 using EPA Method 515.3 or 515.4. Home test kits are not widely available. Testing is most relevant for private wells near agricultural areas or golf courses where 2,4-D is commonly applied.
💧 Which Filters Remove 2,4-D?
Granular activated carbon (GAC) filters are effective at removing 2,4-D (NSF/ANSI 53 certified). Reverse osmosis also works well. Standard sediment filters do not remove 2,4-D. Look for NSF/ANSI 53 certification specifically for pesticide or herbicide reduction.
🔗 Related Contaminants
Check your tap water for 2,4-D
Search your ZIP code to see if your water system has had 2,4-D 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.