The Water Store is conveniently located right off the main street leading into Boulder City. I've been going to this place for several years now and never ran into any issue. It's a small store with tight parking because they share space with a couple other businesses around it but nothing too crazy. The customer service they provide is top notch from when you enter the store you're happily greeted from someone on the staff. Inside you will see a lot of items from small - big bottles of all different shapes you can purchase from the store to all sorts of water coolers to one of my favorite things to see is their 12-stage purification system.
If you decide to bring your own bottles in to get them filled the staff will assist in taking your bottles, rinsing them out, and fill them up using their purification system. It take no time for them to fill up your bottles and place them on a store cart so you don't have to carry them out to your vehicle. They also have a vending type system that use the same purification system outside just in case you don't make it in time for store hours, you can always use this to fill up your bottles with their great clean and good water. They have purified water and ozone water which are great options for a nice and refreshing thirst quencher.