Plastic water bottles for fermenting

I have a surplus of 15 L plastic bottles from buying distilled water for brewing.  I was considering using one to brew in.  Has anyone used these? Is there any worry about the alcohol leaching compounds out of the plastic?  Not sure what sort of plastic it is.
I want to try a sour-mash beer and I thought one of these would be perfect because I could just recycle it after brewing without worry of passing on bacteria to subsequent batches and I also wouldn’t tie up a good carboy for a long time.
Thanks.

as long as they are pet or hdpe there is not a problem.  most returnable bottles are number 7 which i don’t trust. i have found 4g pet bottles at menards and i have used 1gal pet and hdpe with success

can’t you refill those at a culligan machine or similar? I have 3 5 gallon water bottles that I just refill when I am brewing or it is time to refile the soda water keg.

I admit, I’m suspect of what comes out of those machines.  I’m buying distilled water to blend with my tap water.  I know I wouldn’t buy it from my local store because I don’t trust that it isn’t just tap water run through a hose.

Are those machines distilled, mineral, RO (does that have any minerals?) or filtered tap?

The machine I get mine from (a health food store!!! well co-op actually but I know how much you like healthfood stores ;)) gives a choice of RO or DI. I get the RO. The machine will say what it is