My friend LA asked in my comments:

I’ve always wanted to know how water towers work. How do they get full? Does the top open to catch rain? Why are they so tall? I assume gravity is involved somehow. Do animals get inside and drown? What keeps the water from freezing solid? I’m embarrassed I know so little about something so ubiquitous, but you’re my go-to girl on this subject and I know you won’t mock me for my ignorance.

Well, I’ll do my best to answer you, but remember, I’ve led a really, really sheltered life as an operator, running one small system of the easiest type, and in a state where we don’t do freezing much. The last hard freeze was in the nineties, and we don’t even bother to wrap our pipes many years. In fact, most of the wrapping is probably left over from the ‘99 freeze and is disintigrating and waiting to bite us in the asses as we speak.

Mine is a simple system. We have two groundwater pumps that pump from a very deep aquifer (very nice and ancient water, and below any contamination, which my day job addresses.) The pressure from the pumps sends the water up into the tower, which tops out at 140 feet at the very top, plus those little rotating airplane lights (we are an airport too) and some antennas that probably bring it all to 150 feet or so. I have not and will not ever go up there. No way, no how. Oh, and it holds 525,000 gallons. We’re about the size of a largish industrial park; in the summer, when we’re watering the grass, the pumnps come on about every day. In the winter, every few days is fine. I should be good for the long weekend, as there’s hardly anyone there flushing.

My main pump is pretty far away from the tower, so we chlorinate that water at the wellhead. Groundwater’s the cleanest water source, since you don’t have all of that fish poo and other fun things to deal with. The chlorine is to keep it that way inside the piping. Since the well is so far away, the connections between it are hooked right up to the piping between the pump and the water tower. The pump gives plenty of pressure, and the water to a building just comes from the other direction when it’s off. The other, secondary pump, only goes up into the tower and chlorinates right before it goes in.

Both of them send the water straight up into the stem of the tower, and it’s released to storage up near the top. You guessed right about the height of the tower being for pressure. We’re lucky enough to have a pretty flat system; at sites with hills, they have to put the tower at the highest point or use booster pumps to get it up to the ends of the lines, or both. We have a State-mandated minimum pressure that we have to meet, both for everyday operation convenience and for fire use. I was just talking to one of my inspectors, and suggested that we refill an old 700,000 gallon storage tank that was used only for fire suppression in the big hangars to have a cushion if our treated water gets low again. (I know it’s empty because I’m the one who emptied it, for my day job. So circular, no? They should hire me.)

Since ours is so high and completely enclosed, critters aren’t an issue, but they can be for storage tanks that sit right on or even somewhat below the ground. They try to screen these out as much as possible, but those tanks are also usually full of pre-treated water, so it still has to get the full filtration and disinfection process anyway. I gather that the old fashioned storage tanks that sat on the ground weren’t always covered, which makes sense, as the original reservoirs (lakes!) sure aren’t either. Those are more of a convenience though, to have water sitting right there ready for treatment. I do not have a treatment plant, only a distribution plant, and as far as I know, all tower-types like mine are enclosed.

The cover broke on that one episode of My Name is Earl though. “Ricolaaaaaa”

Sorry, where was I?

I’m embarrassed to say that I don’t really know what’s done in very cold climates. I’m sure it was covered in my classes, but probably only minimally, as that was a California-oriented license exam, and we only have freezing weather like that in the very north state, and those are pretty small water systems. Even if we get a hard freeze, I’m only going to be worried about my smaller pipes and valves.

And while I was gearing up to write this, it called me three times! We have some new automated software, and a little power failure seemed to give it the hiccups. It started all on its own when it really shouldn’t have, but the cool part is that I dialed in to the computer from here, clicked a button, waited a couple of minutes, and it shut itself off. Without overflowing this time; I’m sure twice in one weekend would be some sort of a record.

This all makes me sound like I know more than I do. When things go to shit, there are times when I really want to run around like a chicken with my head cut off. Since it’s an old Air Force system, not everything makes a lot of sense, and I dread the day when the last Air Force water guy retires and I have to figure out what kludges these guys used twenty years ago. I’ll either learn fast or quit in despair, I predict. I should go work for a nice shiny system to learn the right way first.