Simazine
Simazine·Affects reproductive, liver
A triazine herbicide closely related to atrazine, used on corn, sugarcane, and orchards. Frequently detected in groundwater across the corn belt.
Simazine
EPA limit
0.004 mg/L (MCL)
Most at risk
Rural well-water households in corn, sugarcane, and orchard regions
Found in
City water · Well water
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
Simazine is a triazine herbicide chemically and biologically similar to atrazine. Both are endocrine disruptors. Animal studies show effects on the reproductive and hormonal system, including disruption of the hypothalamic-pituitary-gonadal axis, altered estrus cycles, and developmental effects.
The liver is also a documented target organ, with chronic exposure producing increased liver weight and enzyme changes. The EPA sets the MCL at 4 ppb to protect against these chronic reproductive and hepatic effects over a lifetime of exposure.
Simazine is classified as not likely to be carcinogenic to humans at relevant exposure levels, but the endocrine concern alone justifies the low MCL.
Where it comes from
How it gets into your water
Simazine is applied as a pre-emergent herbicide on corn, sugarcane, citrus, orchards, vineyards, and turf. It is moderately water-soluble and moderately persistent, with a soil half-life of two to four months, so a meaningful fraction reaches surface water and shallow groundwater through runoff and leaching.
Detections are most common in the corn belt (Iowa, Illinois, Indiana, Nebraska), in California's Central Valley orchards and vineyards, and in Florida and Louisiana sugarcane regions. Concentrations peak in late spring and early summer following application.
Corn, sugarcane, and orchards
Pre-emergent herbicide application
Agricultural runoff
Storm water carries it into waterways
Shallow groundwater
Routinely detected in farming regions
Source-water rivers
Seasonal peaks in late spring and summer
Find out for yourself
Is it in your water?
Public utilities in agricultural regions test for simazine and report results in the annual Consumer Confidence Report. USGS monitoring data shows simazine in a substantial fraction of streams and shallow wells in farming regions, often alongside atrazine.
Private well owners in farming regions should test for triazine herbicides annually, ideally in late spring after the application season. State environmental quality offices and county extension services often offer subsidized testing.
The fix
How AquaOx filters it
Simazine is filtered efficiently by activated carbon. The coconut shell carbon stage in The AquaOx adsorbs triazine herbicides as water passes through the bed, with independent testing showing reductions well above 90%.
For well-water households in agricultural regions, we recommend pairing The AquaOx with our FE or RE Edition if iron or hydrogen sulfide is also present, and adding the under-sink RO for additional drinking-water polish.