Bioremediation of Dodgy IBC Totes?

There are a lot of IBC totes out there, for cheap or free -- previously filled with ?? crazy stuff like resin (undefined) or some other mystery material.

Polyethelene is rather porous, so stuff soaks in --and given enough time it soaks out.

Water catchment is pretty damn crucial for a lot of us. How would you define the point where when the evil crud is no longer a big concern? Are there biological agents you would introduce, or biological markers you would watch for, that tell you it's probably okay?

I did this in a small way with 5 gal. pails from the recycling centre next to a pool. 10% sodium hypochlorite, high-alk-break, all sorts of crazy chem. But great pails! When I took the lids off, soaked them well, and saw algae growing on the walls, I knew I had turned the corner.

What do you folks think?

For me, much depends upon the intended use.  I have two IBC totes that were filled with a commercial herbicide.  I feel comfortable after rinsing them out several times to use them for methane production.  Using them for drinking or garden water leaves me with serious concerns.

To me, it takes a lot of work to try to clean something that had other than food-grade products in them.

Plus, the expense of what to use to clean something like that.

My go-to cleaner is usually vinegar because it is a lot cheaper than the other cleaners on the market.

So I will have to say no to "Bioremediation of Dodgy IBC Totes".

Maybe I might use that kind of tote to grow mushrooms or mealy worms.

Something that actually might bioremediation the IBC Totes.

I agree that algae growing on them is a good sign that biocides have dissipated a good amount. I might also look into how biochar filtration for heavy metals (one study mentioned in the podcast below was with zinc from galvanized fence and roof runoff). This research seems to indicate that combined with algae on the walls, biochar can remove the vast majority of heavy metals in water filtering through it for years without reduced efficacy. For organic contaminants I’d look into IBC worm bin septic tanks with a substrate of woodchips (I’d also add 5% biochar).

I would still not drink water from a toxic and/or chemical biocide IBC, and would do chemical testing of the water running out, as well as try small test plots before irrigating with it. I try to find food grade IBCs, with breweries and wineries being the best bet in my experience. They have to use a lot of food grade acidic (citric acid usually), and alkaline (potassium and oxygen based usually) cleaners for their equipment, and this comes in IBCs. I suppose these fermentation equipment cleaners are techniquely biocides as they kill the problem microbes on brewing/fermenting equipment, but they are meant to wash off easily in water and any residue is much safer than herbicides or “resins”. If it doesn’t kill yeasts needed for fermentation, it probably won’t be too hard on soil microbes.

Here’s the podcast by Diego Footer on biochar:
https://podcasts.apple.com/us/podcast/in-search-of-soil/id1535285404?i=1000527342641