Q: Hey Jason, just a quick question about the upcoming pool season. I have two little girls and they love to swim! At my neighborhood pool, I have reason to believe that there are some guests, whom I believe may be *ahem* urinating in the pool during their swim. This is ATROCIOUS! I can't believe any person in their right mind would even CONSIDER urinating in a public pool! Someone needs to teach these people a lesson! Can you tell me something to ease my mind?
A: Uhhhhh, hi Ashley…I mean, you're right (I guess)…wow….I mean, personally I never….I mean…let's just get to your question….
So, you want to keep the "P" out of your pool ("ool…"?)
I get it. No one wants to go swimming in a dirty pool, and we've all heard the rumors about how if you smell a strong chlorine smell there must be a lot of urine in the pool (*SPOILER ALERT*-it's not just a rumor…). But that’s a different article. Today, let's just talk about the actual amount of urine in a pool, and what that means for us.
Take a good look around any pool during the summer and you're going to see all kinds of people. From week old babies to 99 year old lap swimmers, the pool is one of the most popular spots on nice, warm, sunny days. And, let's be real, sometimes Mother Nature strikes when we feel that cool water on our bare skin. It’s natural. In fact, I did some research for you guys to see just how much we need to be worried about swimming in other people’s pee-pee.
Alright, let's take a look at an average sized swimming pool. Let's say a 15' X 30', that’s pretty average, right? Ok, just for arguments sake, we'll say its 8' deep on the deep end, and 3' deep on the shallow side. That’s going to give us a total of 18,513 gallons of water. Ok, you're with me so far, right? According to the NC swimming pool rules, the maximum bather load for a pool this size is 24 people. That’s not too bad. Stay with me… Now, according to different sources, the average person urinates a total of 5 to 6 times a day, for a total of between 800 and 2000 milliliters per day of urine. That’s kind of a big range, so let's agree to split the difference and say 1400 milliliters. 1400 milliliters is 47 ounces. That gives us 47 ounces of urine per day, per person. Heck, that's just a little over 2 pints! You probably drink more than that at lunch (not that you're drinking urine for lunch, but you know what I mean…) SO, let's assume our 24 people are all in the pool at the same time, and spontaneously decide to release their total amount of urine for the day. (We don’t really need to know why they would decide, or even be able, to do this… maybe they are just really in tune with their bodies, that’s something we should all aspire to… doesn’t matter for the purposes of this article though) That’s still only 1,128 ounces of urine! That’s about 141 cups, which is roughly 8.8 gallons of urine that just got released. Sounds pretty gross, right? Well, let's look at this way…8.8 gallons out of 18,513 gallons is only 0.047%!! That’s not so bad, right?
Now, let's talk about what's going on down there at the bottom of the pool with those drains. Take a look at the bottom of the pool and you are either going to see one, or two drain covers. Now, if you don’t see any drain covers down there, and it just looks like a big hole…Get. Out. Of. The. Pool! Those drain covers do more than just look pretty (and let's be honest, none of them are really that great looking). So here's what you need to know. A single drain pool is exactly what it sounds like… one main drain at the bottom of the pool. So what difference does that make? Well it means that the pump is only pulling water out of that one hole, and therefore has an incredible suction. These are the kind of drains where kids (and grown-ups!) get stuck. Not to overstate the obvious here, but GETTING STUCK ON A DRAIN IS VERY VERY BAD!! Now, a pool with 2 drains (more than 3' apart) is a little safer in that in the event that someone does get close enough to get stuck, the presence of the additional drain allows for less suction per drain. Pools are safer now than they were even 10 years ago, with advancements in drain cover design and the inclusion of safety vacuum release systems that sense when a single drain cover is blocked and will automatically shut off the pump, but suction hazards can be present in all pools and parents should NEVER let children play in or around swimming pools without adult supervision. So what should you look for before cannon-balling in? First and foremost, the water itself. Swimming pool water should be clear enough that you can easily see the drains. If you jump in the pool and notice that you can't see your Spiderman aqua socks, you should get out of the pool. Next, the drains and drain covers. Make sure the drains have covers that aren't broken or cracked, and are securely attached to the pool floor. If you see a single drain, ask someone in charge if there is a safety vacuum release system in place that is checked regularly. Make sure there are no uncovered holes in the sides of the pool. Some holes are return inlets, where the water is placed back in the pool after going through a filter and usually a chlorine treatment, and maybe a heater, but no holes should ever be uncovered. Even a small hole can present a suction hazard to hands, hair, or anything else. Make sure you are familiar with the location of the life-saving equipment and the emergency phone. They should all be accessible and in good repair. Don’t bring glass bottles into the pool enclosure, and leave your sweet little Jack Russel terrier at home. Lastly, follow the pool rules. They're right there on the sign! Read them!
Do yourself a favor…Right after you get to the pool and put your Gremlins (Don’t feed them after midnight!) beach towel down on that chair with the plastic strands that have been baking in the hot sun all day (you know the kind I'm talking about), and while Toad the Wet Sprocket's "Walk on the Ocean" is playing on the teenagers radio, do a quick walk around the pool and take note of a few things. Better safe than sorry.
Have a great summer everyone!
Jason Masters, REHS
Environmental Health Program Specialist