Here is a link to an article on atrazine.

Atrazine is not glyphosate. Glyphosate (commonly sold as RoundUp) will kill everything. Atrazine will kill much of what it touches but in small amounts, St Augustine will survive it. St Aug may yellow some but will not die.

If you are not near a water table, and you only mist the leaves of the plants (do not drench the soil), then you will likely have good success killing weeds in St Aug with atrazine. If you apply a good organic fertilizer (like plain alfalfa pellets (rabbit chow)), then the atrazine will decompose in your soil in a few weeks. If you have no good organic life in your soil, then the atrazine will take all season to decompose. The longer it takes to decompose the more likely it is to wash down into the water table.

Where do you live? Please be specific.

Bad. Look at some of the lawsuits on the subject. Nasty stuff.

every weed & feed fertilizer has it in Florida, a lot of people use it onnlawn

Atrazine is the most widely used herbicide in the world. You would starve to death without it as there would not be enough food to feed the population.

Atrazine is the only effective herbicide to use on SA, and as mentioned in is every herbicide product made for SA. Use it as prescribed and you will have no problems.

I understand, it is widely used, but how it affects living organisms in soil besides leaching into water? Our sink water not comming from around areas.

****** Use it as prescribed and you will have no problems.******

Please reread the above.

Any material can be used safely if used as directed. If miss used one of the most deadly poisons that could be applied to a yard is salt, It will kill every thing. BUT who considers salt NaCl a poison.

I believe Water causes more deaths in the US that any other chemical but we use it safely daily.

I understand, it is widely used, but how it affects living organisms in soil besides leaching into water?

Look at the map at the end of this post. Atrazine is used by just about every farmer in the Midwest bread basket and and nationwide where food crops are grown. Farmers including myself make their life of the soil. Do you think they would really do anything to hurt their livelihood?

http://en.wikipedia.org/wiki/File:AtrazineUSAMap.png

If you use it right, it should not get into your soil. It is a foliar spray, not a soil drench.