Is it appropriate for a company to not bring a water buffalo to a week long field exercise?

So no HIPPO? No 5gal cans? No orange igloo water jugs? Just expected to go cactus mode? If your M149 trailer aka water buffalo was NMC or not certified by PM, you can still get other sources. Tisa likely won’t issue bottled water without special circumstances. What did your first line say? First Sergeant?

Are you on a small remote site? Like a retrans....then you need 5gal cans that get swapped at your logpac.
Are you in the field, but close to a potable source (like range control etc?).....5 gal cans that someone takes a cargo vehicle to go fill every day.

Sounds like bottled water purchased at your expense is shitty first line leadership. PS, the answer is Army issue 5 gal plastic water cans as part of your team's basic load. Recommend your first line grabs the Supply Sergeant by the ankles and shakes them until water cans come out. Your profile doesn't show unit data. There should be these cans at at the SSA. Google the NSN. Else the commercial igloo or gott blasting jugs locally purchased will do the same thing....again through unit supply.

Your TACsOP doesn't have 5 gallon cans on the vehicles clue as a load Plan item? Every unit I've ever been in specifies minimum one per vehicle in case you are marooned somewhere. Sorry, just having a hard time believing there is no water. Is there an MKT on your site? Then there has to be bulk water for,field san, somewhere.

Good subjective question. Water in bottles is better than chlorinated water from a water buffalo.

Spent three months in the desert with no buffalo. Bottled water, baby, all the way. Truckloads of it.