I gave up drinking water as a part of my shift to a more minimalist lifestyle.... : )
Firstly, I installed an Apec ROES-UV75 Reverse Osmosis 6-stage water filtration system that I bought from Amazon for around $300. You can find that HERE.
I have a city water inlet that I can connect any garden hose to to fill up my large water tank.
I also have a filler / breather vinyl hose attached directly to my water tank with a garden hose barb adapter on it that I can use in tandem with my in-line pump power drill bit to suck water in from any body of water.
That vinyl breathing / filler hose is attached to a right angle elbow adapter with a shutoff valve that is a key component in a rainwater collection system I installed which you can learn more about here:
I occasionally buy big jugs of water for emergencies.
You can fill up jugs of water at a lot of climbing / camping / outdoors shops or from water fountains all around town.
Feel free to share how you manage securing, filtering, storing your drinking water!