First, a quick poll: how much water/etc do you really drink daily?
If you haven't monitored this, please do so for at least a week.
There's a lot of wrong "data" floating about the net, including government prep sites. Some even claim you need a gallon (3.8 L) per day just for drinking purposes. I suspect they're confusing the gallon per day rule of thumb, and don't grasp that's for all uses (which you folks do understand!).
If you're working outside in hot weather, and/or physically very active, then yes, a gallon or more is possible.
For the sedentary majority, that's way off.
Personally, I drink about 0.5 to 1.0 L per day, including soda, milk, juice, and water. I tracked that over a one month period, and found that I averaged one 355 mL soda per day, plus one gallon of water and milk per eight days.
Those are the numbers I use to target my actual needs vs goals.
How much do you actually drink?
Back to "general" water issues...
I agree completely with the water storage tips and recommendations you folks made in the original thread, including the importance of a water filter.
I do have three: a "Pur" filter on the kitchen faucet (which will be of no use if the water supply cuts out), a low-end Aquamira Frontier filter (the "straw" style) in my car, and a new cheap "100 gallon" filter that came with the Augason Farms bucket.
I definitely need to do some detailed research into the pros vs cons of each of those, particularly the new one.
My main (water) concern is contamination at the water treatment plant.
My current mitigation is to "quarantine" tap water (filtered by the Pur) for at least one week before using it. That way, most of the rest of my city acts as "my" canaries-in-a-coal-mine. If nobody gets sick in the week plus since I filled a jug, it's almost certainly safe.
Currently, I have three 1-gallon (3.8 L) jugs designated for rotating drinking water, with one in the fridge. When the fridge one is empty, I refill it, move the oldest jug into the fridge, move the middle-aged one forward, and put the freshly filled one behind it.
That's both simple and frugal/cheap.
I do not bother quarantining water that I'll be boiling as part of food prep.
I also have several gallon jugs of distilled water, and several 2L soda bottles refilled with filtered tap water. Plus, of course, about 18 gallons of soda in convenient cans.
There's also a nearby pond and a wetland area, so there's plenty of non-potable water suitable for flushing the toilet.
Right now, I have enough bottled water for a 'routine" natural disaster, but not enough for a comfortable prolonged (3-6 months) societal disruption such as a pandemic or persistent regular+cyber terrorism. I do have enough to "get by", but hygiene would, um, "suffer". Hmmm... I suspect Mountain Dew would be suboptimal for sponge baths.
Realistically, I am satisfied with what I have, since it's extremely unlikely that the water supply would be disrupted for multiple months. Not impossible, just very unlikely. Food and electricity are more likely to be issues. I'm now ok food wise (6+ months), but I need to look into small scale solar and more cooking fuel/devices.
Short term water purity issues are far more likely, hence my simple quarantine habit.
Ruleryak:
Thanks for bringing up the bath tub liners! Those definitely appeal to me as an easy way to bulk up.
Has anyone tried one?
I first read about them last year, and have one in my CTD shopping cart, but they're currently out of stock. Again, I'm basically ok with where I am, water wise, but it's such an essential that $20 to $40 for a backup is attractive.
Back in 98' hurricane Georges slammed Puerto Rico and sent us back to the beginning of thw 1900's for several months. 
