Pool person here.

For container sanitation they usually recommend 100-200 PPM, which is 1/2 to 1 tablespoon chlorine bleach per gallon. This is supposed to "soak" for at least 2 minutes, and preferably longer (time is an important element of chlorine sanitation).

For drinking water most municipalities seem to target that same concentration as pool water - 1-3 PPM, which is 2-4 drops per gallon, but most seem to recommend higher concerntrations for sanitizing drinking water - 5-8 drops per gallon. This is probably because all the PPM calculations assume the water is pure to begin with - and it might not be. Unclean water will end up with lower PPM levels as the Chlorine does its work.

Liquid bleach will dissipate in water VERY fast if stirred. Even in my pool the motion of the pump dissipates it quite fast.

Chlorine sanitation works best at room temperature 70-80 degrees. Sun spontaneously causes chlorine to convert to a gaseous form and "dechlorinates" water fairly quickly - a good sunny day with clear of pool of chlorine in just one day unless stabilizer is used.

Pool owners have use cyanuric acid to "stabilize" chlorine in a pool. The cyanuric acid essentially acts like a sunscreen for the chlorine. Without it, chlorine would disappear all to rapidly on a sunny day.

Heat also causes chlorine to escape from a solution. Boiling would certainly drive out the chlorine, but you wouldn't really need to get it that hot.

An easy way to check your water is to go to a local pool store and purchase some pool testing strips. They are a simple pieces of paper that you dip in the water and within 30 seconds tells you how much chlorine (free and total - "unfree" chlorine is that which has done its work and latched onto and sanitized organic matter - it is called chloramine) in the water with pretty decent precision.

I think drinking water up to 20 PPM or so is considered OK to drink, but I would't let my kids drink it. I'd rather it came down to 5 PPM or so.