You’re just wrong lol. You should get your money back for that fancy degree of yours because you’re still dumb and talking out the booty. Per Wikipedia the human body produces about 0.5 grams of methanol per day endogenously and the exhaled breath has about 5ppm on a casual basis.

Unless you’d like to posit that eliminating this methanol entirely from the body could grant eternal youth or something, it seems fair to say that methanol does not possess any noteworthy toxicity “at any level.” Only high levels.

The Ohio river has a flow of about 16 kilotons of water per second. The spill was 1.4 kT. There’s just so much water in that river that the concentration will rapidly drop down to ppm levels. And then it gets to the ocean where it becomes even lower. And of course, even if you drink a whole liter of the water, it’ll then be divided by 60-100 if it’s much stronger than your body. The odds of this spill introducing even milligrams of methanol into the system of anybody who wasn’t on the barge are roughly zero in my estimation. In any case, it will definitely be a lower amount than our endogenous production.

Methanol is certainly not a notable health hazard at the milligram or microgram scale. If it gives you like a +0.0001% chance of cancer, that has yet to be demonstrated. I’d drink 50 mg right now if you give me a beer to drip it in.

As to whether or not some or all commercial breweries strive to cut methanol down to nil:

Maybe. Goals and regulations don’t have to be based on actual medical consequences though.