A Friday with a band on the stage moves more liquid through a bar than any other night of the week, and almost none of it is the part anybody notices. Between doors and last call the staff fill and dump ice bins, run the glasswasher through cycles, purge draught lines, empty drip trays, and rinse shakers between rounds. All of that water leaves the bar the same way, through one floor sink set into the concrete behind the well. The soda gun, the ice machine, the glasswasher, the drainboard and the beer trough all drain to it. On a slow Tuesday nobody thinks about it. On a Friday with a headliner it is the narrowest part of the whole operation.
The first sign of trouble is never dramatic. Water stands an inch deep in the well and a bartender spends the rest of the set standing in it. A strainer basket belongs in that sink, pulled before doors, because one night of citrus wheels, straws and bar napkins will close a two-inch line faster than grease ever does. It also pays to keep the glasswasher off its fill cycle during a set, because the pressure drop shows up at the soda gun and the first person to notice is a guest who ordered a well drink with a mixer. None of that appears on a sound checklist. It probably should.
The part of a bar that turns out to be an actual code matter is the soda system. Carbonated water is acidic, and if it sits back against copper it will pull copper into the drink. That is why a carbonated beverage dispenser is supposed to have a backflow preventer between the water supply and the carbonator, and why that device is not something you install and then stop thinking about. It is a tested device. Somebody with the right certification puts a gauge on it, runs the test, and signs for the result, on a schedule.
The next question is who actually performs that test in Clark County, which is a narrower list than the number of plumbing companies in the valley suggests. A.A. Cassaro Plumbing, a Nevada plumbing contractor operating under licence 0022036, lists backflow certification and testing among its plumbing services, alongside leak detection, line locations, and medical and gas line installations. Its own site says the company has been serving Clark County since 1982. That is a listing, not a review of anybody's work. What we can say is that the certification is a specific thing to ask for by name, and that plenty of plumbing companies do not list it at all.
The fixes worth making are small and mostly clerical. The test date belongs on a laminated card inside the dry goods closet door instead of in somebody's inbox. The ice machine's supply valve should be labelled, because at eleven at night nobody should be guessing which valve feeds it. The glasswasher cycle can move into the gap between sets. And when a line does back up mid-show, the response is a wet vac and a bucket rather than a phone call, which is the right order of operations at that hour and a poor substitute for the call the following morning.
Anyone booking a bar for a private night should tell the venue two things: the headcount and whether they want a bar tab or drink tickets. It sounds like a billing question. It is really an ice question, and an ice question is a drain question. With the number a week out, a venue can have the bins prepped, a second machine running, and somebody assigned to the floor sink for the night, which is the unremarkable reason the last hour of an event ends up looking the same as the first.