Shallow well root problem

[canecutter]

I have a shallow well, only 16 ft with an average of 5 to 6 ft of water. The water is good enough to drink but I use it for irrigation only and leave it idle for much of the year.
I found roots coming in near the bottom last summer. It's Sassafras roots. No trees within about 50 ft of the well and I've tried to cut every Sassafras possible since they are so invasive.

Any ideas to kill the roots or the tree without contaminating the well permanently? I can take it out of use for awhile and flush it if needed..
My well is more important than any few trees, I have more than enough.. I need the well to keep my garden and orchard alive.

I'm thinking maybe a large dose of chlorine over a few days..

Would be thankful for any advice or ideas..

[uncle Will in In.]

I agree with putting bleach down the well and leaving it there a few days when you don't need the well. Before using the water, run the pump until the water coming out of the well no longer smells like bleach. I'd pour a gallon down the pipe.

We shock our 100 foot well this way if the water gets an odor. We pump it out right away however and use the water when the bleach odor is gone.

[Wanda]

Use copper sulfate for the roots. You will still be able to water your plants with the water.