Water for me is not a problem, many streams and lakes plus rainwater. I have filtration equipment.
I have an extensive first aid kit including surgical supplies and antibiotics.
As far as hygiene, I buy extra soap, shampoo, and toothpaste when I run low on the ‘house’ supply.
I train and plan weekly with a couple of like minded neighbors.
That’s very impressive!
If you need any excuse to buy just a small amount of precious metals to go with your excellent domestic preparations: remember that a silver dollar immersed in a container (say 4 pints) of lake/river water will disinfect it overnight.
The water will contain a (tiny) 20 parts per billion of silver ions afterward, and the coin can be re-used indefinitely.
This trick was used by the settlers who conquered the Wild West, and may come in useful if you guys ever have to do that again :0)
How did you broach the subject to your neighbors?