potable water

Here are some guidelines, but note the MANY disclaimers (where you measure, when you measure, how you measure, etc) and this presumes a sanitation facility.

For home use long term storage try here.

Also note chlorine is a bacteriacide - so chlorine kills and prevents bacteria. If you have other problems you need other solutions.

The dissolved free chlorine content should not exceed 0.5ppm. There should also not be any dissolved heavy metals or pathogens, and the turbidity should not exceed 20NTU in general.

Wow, 20 NTUs seems pretty turbid for drinking water.

Turbidity is a measure for solids that can degrade chlorine disinfectant and harbor infectious agents (it can also be colonies of such agents, such that chlroine is less effective at destroying them).

You should setle large solids out in presedimentation, then add a flocculating agent to remove the finer solids, then disinfect at a reasonably high rate upwards of 1 to 3 percent, then polish and supply a residual chlorine equivalent of at least 0.5 percent (chloramine is preferred currently because of chlorine taste and odor issues and longer effectiveness in distribution system). Many Cities with modern systems supply drinking water with turbidities below 1 NTU, and 3 NTUs is a regulatory limit for most modern municipal systems in the Western US (in part due to cryptosporidium and such)

Further, if the conductivity of the water is below 1500μS/cm @20degC, then it is on the right side for human consumption. However it will taste 'king horrible at those conductivities.

Also it should be largely free of particulates and entirely free of things like e-coli, staphylococcus and cryptosporidia.

The water will taste insipid at such low total dissolved solids content .

Seawater reverse osmosis plants do a similar thing. Having RO'd the living daylights out of seawater to produce it, the permeate water is usually too clean to drink and, indeed, its purity threatens the downstream pipework. Usually it is passed through a re-hardening filter that adds a dash of calcium carbonate to the water to improve taste and to raise the pH a little.

The water will taste salty above about 1000-1100μS/cm. Although it will still be safe enough to drink, it won't taste very pleasant while doing so.

Above 1500μS/cm, the water falls outside the World Health Organisation's guidelines for potable water. Above this point, the nature of the dissolved substances start to beome important; one could call it something else, like cream soda, or lemonade or something, depending upon what the conductivity consists of, but not 'potable water'.