Simazine in Drinking Water
EPA limits, health effects, and what to do if your water is affected.
🩨 Health Effects
Simazine is a triazine herbicide similar to atrazine. Long-term exposure above the MCL may cause problems with blood, liver, kidney, and adrenal glands.
📍 Sources in Water
Used to control broadleaf weeds in corn crops, orchards, and on residential lawns. Enters water through agricultural and residential runoff. Detected in surface and groundwater in agricultural areas.
✅ What To Do
Activated carbon and reverse osmosis can reduce simazine. Violations are most common in agricultural surface water systems in the spring.
📜 Regulation History
The EPA set the simazine MCL at 0.004 mg/L (4 ppb) in 1991 under the Phase II rule. Simazine is a triazine herbicide closely related to atrazine. The EU banned simazine in 2004 along with atrazine. The WHO guideline is 0.002 mg/L, stricter than the US standard.
🔬 How To Test Your Water
Certified lab tests for simazine cost $50-$100 using EPA Method 525.2 (GC/MS). Home test kits are not widely available. Simazine is often tested alongside atrazine as part of a triazine herbicide panel. Test in spring when agricultural runoff peaks.
💧 Which Filters Remove Simazine?
Granular activated carbon (GAC) filters are effective at removing simazine (NSF/ANSI 53 certified). Reverse osmosis also works. Carbon filtration is the most practical home treatment option. Replace filters regularly during agricultural season.
Check your tap water for Simazine
Search your ZIP code to see if your water system has had Simazine 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.