Pretty much RV that’s built some sort of self-contained standard has a tank for fresh water. You fill that tank and can use it for drinking water, showers, and cleaning food. But there can be a hidden danger in your RV’s water tank. If you never clean this tank out, it can be a vessel for serious diseases, possibly even one that could cause your death. Here’s how you can help protect yourself.
Concern about the cleanliness of RV freshwater tanks has been raised recently following a May 29 report by the Disease Control and Prevention. The report documents the case of an RV owner who used tap water from their RV for nasal irrigation. This person ended up catching a brain infection, which sadly turned fatal. What the CDC concluded in its investigation is chilling.
The self-contained RV has existed throughout much of camper history. In essence, a self-contained unit is one that is capable of operating away from a source of power, sewer, and water. So, you’ll have a battery or generator for power, holding tanks for your wastes, and a tank for potable water. Some of the earliest motorhomes had self-contained features, and the 1958 Airstream International is often credited as being one of the first truly self-contained travel trailers.
These features are critical if you want to use your camper somewhere that’s not an improved campground. Every year, I spend a week with over 40,000 campers at EAA AirVenture Oshkosh, depending on my family’s travel trailer’s water stores, battery, and a generator to be comfortable.
Sheryl and I have a hard rule to never use the RV’s water tank for internal use. This is because when we first started using the trailer for boondocking at AirVenture in 2023, we learned that there was something horribly wrong with the trailer’s water tank. The tank emitted a foul odor when we filled it, replacing the air inside with water. Then, when we used said water, we found little black particles in the water.
My family has owned this trailer since 2016, and I asked my parents about the last time they had the tank cleaned. They didn’t even know that was a thing, so it’s safe to assume that it hasn’t been cleaned in at least a decade. If my parents didn’t know that you’re supposed to clean the water tank, how many other Americans are the same?
A Tragic Report
The CDC report is something of nightmares. Here’s a snippet from it:
Primary amebic meningoencephalitis (PAM) is a rare, often fatal brain infection caused by the free-living ameba, Naegleria fowleri (1). Infection is typically associated with recreational water activities; however, using tap water when performing nasal irrigation is also a risk factor for PAM (2–4). Improperly maintained municipal water and recreational vehicle (RV) water systems can be a source of waterborne disease; CDC recommends the use of distilled, sterile, or boiled and cooled tap water for nasal irrigation.* Household safe water practices can help prevent waterborne illness associated with RV water systems. This report describes a fatal case of N. fowleri infection associated with improper use of a nasal irrigation device with suspected contaminated tap water from an RV.
A previously healthy woman aged 71 years developed severe neurologic symptoms, including fever, headache, and altered mental status within 4 days of using a nasal irrigation device filled with tap water from an RV’s water system at a campground in Texas. Despite medical treatment for a suspected PAM infection, the patient developed seizures and subsequently died 8 days after symptom onset. Laboratory testing at CDC confirmed the presence of N. fowleri in the patient’s cerebrospinal fluid.
An epidemiologic investigation conducted by the Texas Department of State Health Services included a review of the patient’s medical and exposure history. The patient had no recreational exposure to fresh water; however, she had reportedly performed nasal irrigation on several occasions using nonboiled water from the RV potable water faucet during the 4 days before illness onset. This practice suggested two water sources of concern. The first was the RV’s potable water tank, which flowed directly to the faucets and shower when a municipal water connection was unavailable. The tank had been filled with water collected on an unknown date before the patient’s purchase of the RV 3 months earlier. The second potential source of contamination was the municipal water system, which was connected by a hose and water filter to the RV potable water system, bypassing the tank, at the time the patient used it for nasal irrigation.
The CDC then tested water from the campground and water from the RV’s tanks. No N. fowleri was found in these samples, but the CDC did find that the total chlorine and monochloramine disinfectant levels in the campground’s tap water were below the Texas Commission on Environmental Quality’s recommended levels. Combined with a low pH level, the presence of free ammonia, and unequal concentrations of active disinfectant, the CDC concluded that it was possible for pathogens to thrive in the water.
Samples from the RV proved to be even worse, with water quality that was lower quality than than recommended for drinking water, let alone water you’re going to shoot up your nose.
Ultimately, the CDC couldn’t figure out if the source of the brain infection came from the RV’s tank or the campground’s tap water, and some of the blame might be because the samples were taken 23 days after the patient shot the water up her nose. However, the conclusion was pretty serious, with Texas public health officials and the CDC calling for, among other things, the maintenance of RV water systems and ensuring that municipal water systems are clean.
Alright, so there can be danger in your RV’s water supply. What can you do about it?
The first thing you should do is consider where your RV’s water is coming from. Countless campgrounds, especially remote ones, are pulling their water out of a well. As the CDC suggests up there, water straight from a campground’s taps could be dangerous, as the typical person will not know what’s in that water.
Some campgrounds bring city water into their taps. This water is generally safer and, so long as the delivery system from the campground’s pipes to your RV’s plumbing are clean, then there is less risk here. But even that requires you to assume everything is up to spec. As Joshua Baker of RV dealer Texas RV Guys noted in an interview with NBC DFW, campground water systems aren’t well-regulated, either, so you can’t even trust that the government will keep you safe.
Water Filtration
Your first line of defense is a water filtration system. There are tons of these things commercially available and the simplest of these systems is an inline filter. These filters screw right into the line going from your RV to the spigot at the campground. Some folks who infrequently use their RV might use a cheaper filter like a unit from Clear2O. People who are more serious about clean RV water invest in more expensive systems from the likes of Clearsource or Blu Technology, which can either be used externally or mounted permanently to the RV.
Some people also combine more than one system into one, such as an inline filter outside and another filter mounted to their coach, or two different types of filters outside.
The general idea I’ve seen around RV communities is that multiple filters is better and you want to get a filter that drills down to two microns as much as possible. Some folks will employ other measures, including installing a filter directly onto a faucet by tying it onto the feed line in the cabinet.
Installation of an external filter is about as easy as you would expect, and you connect the filter to your water source and then connect the filter to your motorhome. If you have 36 minutes to spare, RV Youtube channel Our Journey In Myles explains one way to set this up while also reviewing a popular RV filtration system.
Even the types of filters get properly nutty. There are sediment filters, which remove larger suspended matter like sand, scale, and clay from the water supply. Then you have carbon filters, which use activated carbon to absorb and remove impurities, including chemicals and organic contaminants. There are also UV-based water filters, which use UV-C to destroy bacteria and viruses.
Another kind of filter that you’ll find is a gravity filter. These are pretty simple filters that use gravity to pull water through a filter, leaving behind contaminants and cleaner water. A very popular gravity filter among RVers is a Berkey; however, it’s notable that you wouldn’t be using one of these to take a shower. Instead, they’re more for getting cleaner drinking water. Some people will use a Berkey for drinking water and an inline filter system for everything else.
Some folks will even buy a reverse osmosis-based water filtration system and plant it on their countertop.
It seems that there is no single answer for what kind of filtration system to use. I would recommend joining a forum for your particular model of RV and seeing what others are using with their rigs. Some people swear by Clearsource equipment, influencers seem to like Blu Technology rigs, and a lot of people are just creating their own budget filtration systems using parts from the hardware store meant for residential filtration systems.
For sure, I’ll be trying out a water filtration system for myself. I’ve been RVing for over two decades, and yet even I’ve made the mistake of not using any real filtration system. That’s how much water quality gets ignored in the RV world.
Tank Cleaning
As I said before, a water filtration system is really your first line of defense. You also want to make sure that your RV is as clean as possible. Clean water is of little help if it’s getting contaminated by a camper that’s never been cleaned.
You’ll want to clean both your tank and your lines. A commonly cited method for this would be to fill your RV’s tank with a water and bleach solution. A standard guideline is a quarter cup of bleach per 15 gallons of water.
Start by draining any water that’s in your RV. Your fresh tank likely has a drain valve on its bottom, and your hot water tank likely has a similar valve. Be sure that your hot water heater is turned off during this process.
Once you’ve drained your camper, fill up your fresh tank with the bleach and water mix. One easy way to do this would be similar to putting an additive into your car’s gas tank. Put bleach in first using a funnel, then hit it with your water to mix it up.
Once you’re all filled up with bleachy water, turn on every faucet and shower in the trailer, ensuring to turn on the taps for both the cold and hot water. Turn off these faucets and the shower once you smell bleachy water coming out of all of them. Now, let the solution sit and marinate for between five to 10 hours.
Now, you basically want to run the process in reverse. Run your faucets to fill up your waste tanks with the used bleachy water mix. Then, dump your tanks. Now, refill your fresh tank and run the faucets again until you don’t smell bleach anymore. Drain and refill your tank until the bleach has been eliminated. You can probably expect to spend about a day doing this whole process.
If you’re not comfortable with bleach or don’t have somewhere to dispose of it (some campgrounds use septic systems), you can also use vinegar or hydrogen peroxide. There are also commercially available tank cleaning products that do a similar job to bleach.
Most shops recommend sanitizing your RV tank once every three to six months. Doing it with frequency is important because you don’t want mold, bacteria, parasites, algae, and other nasty stuff growing in your tank. Likewise, if you’ll be storing your camper after completing this process, you’ll want to store it with the tank emptied out rather than sitting for months with water just sitting around.
Even then, many people, myself included, just buy jugs of water to drink out of and use the camper’s water supply only for cleaning and showers. However, admittedly, carrying around gallons of water is annoying. So, a lot of folks will go through the work to create a pretty comprehensive filtration system so that they can drink water from a campground.
No matter what you choose with filtration, I highly recommend that, at the very least, you clean out your RV’s water tank regularly. It’s easy to ignore something like this because your tank is out of sight and sometimes out of mind, but for the safety of yourself and your family, take a day out of your busy schedule to make sure your RV is as clean as it can be. Good luck!
Once a year I fill up the aluminium 30litre tank of my VW T3 camper with 5litres of vinegar and drive around for half a day and then flush out a few times with the hose and that seems to do it. I leave the drain open for the rest of the time not using it but have some gauze that I put over the tap. seems to work fine but I have a britta jug that I use for drinking from when camping that I fill up out of this tank. I’ve always thought of as bleach as poisonous even in small amounts.
Chemist here! When we refer to “chlorine” in water, it is actually bleach or Sodium Hypochlorite. Sodium hypochlorite naturally breaks down over time into chlorine gas and sodium hydroxide. At low levels, bleach is perfectly safe, and if you clean something with bleach and then drain, the bleach will be gone in a few days. The decomposition of sodium hypochlorite in water is slowish but it is much faster when it is dry.
As the great Paracelsus said “The dose makes the poison”. This means that everything is poisonous at a certain level (like people dying from drinking too much water).
Thanks Thomas for that great explanation. i’ll give it a shot next time I flush the water tank.
This is me slinking off to our 25-year-old 3rd-owner truck camper that we fill with well water from a hose, to see if I can find an inspection hatch for the tank that we definitely use for drinking water when camping.
Thank you for this article, Mercedes. I’m going to clean my Keystone’s tank now.
We always put a little bleach in the tanks of our rv and boat every time we fill
up. We drink and cook with bottled water. I don’t like using the campsite fresh water where your hose is always attached to the RV; I prefer just filling up the tank. Most of the time, we’re dry camping anyway. I rarely use that spigot next to the dump station unless there’s no other alternative.
Same reason you never drink the water on an airplane.
As you mentioned, the bleach/water solution needs contact time in order to kill everything and even then, the results are mediocre. The best way to kill everything quickly is with ozonated water.
RVing is such a hastle it might make sense to just keep the RV money in the bank and go to an interesting hotel/resort with the returns
Don’t f’in snort tap water, no matter where it comes from! Stomach acids are really quite good at getting rid of some of this stuff. No amount of tank cleaning is going to get it hygienic enough to inhale.
Yea you gotta boil it and let it cool before snorting it, no matter where the water comes from.
What a minute! Do we have a Floridian telling us NOT to snort something!?
Hahaha! Well played!
Having always gone the used route with RV’s, I’ve stuck to the rule of never trust the freshwater tank and plumbing to be clean, no matter how well-maintained it appears. Heck, I’d still clean and flush the water system on a brand-new RV. There are more products than ever on the market that will work just fine if you follow the directions, Good old-fashioned chlorine is always available, and it only takes a little bit of math to figure out the right concentration.
And don’t forget to replace hoses used to fill the tank or connect to potable water supplies periodically, no matter how well they’re cared for.
Maybe it’s because I grew up in a place that was primarily rural/agricultural — but you learn to just assume that any water holding tank system of any kind will get nasty stuff growing in it and has to be cleaned and rinsed/flushed periodically, full stop.
Worst in my book are underground holding cisterns. Even for non-potable water, those things are nasty unless they’re maintained properly. And there are old campgrounds which may still have those — for “potable” water. Then there are “dug” wells, which often aren’t much better; anytime water is allowed to stand, underground, for much time at all before use is a perfect place for contaminants to get in. Drilled wells are safer since they have no real reservoir of any size; the water is pumped on-demand into a small pressure tank and then distributed; it rarely sits for very long. Even so, since campgrounds are seasonal, the system should be started off every year with a dose of chlorine and a flush. But can you rely on every campground you stop at to have done that?
I’ve always used filters for incoming campground water, even on well-maintained systems because you never know if previous campers managed to back-flush into the pipes. Drinking water is from bottled water containers, unless the (cleaned) freshwater tank was filled at home or from a known safe source. If any other water gets put in it, it’s not used for drinking at all until it’s been cleaned again. A little common sense and a healthy sense of self-preservation goes a long way.
So if Top Gear accurately portrayed the perils of caravanning:
Cue theme music….
“Tonight: Richard gets brain amoebas, I’ve been shitting myself for a week, and James died from dysentery yesterday”.
I drain the entire water system completely after every use and store it with the taps on the inside open so water can evaporated out. I always close the outside drains though to prevent bugs and dust from getting up there. No smelly water or particulates. I didn’t do this with my first trailer and the water smelled absolutely foul after sitting a few months. It was brand new too.
I run a simple carbon filter between the water hookup and the hose and like you, drinking and brushing teeth is done with bottled water. Trailer water is only for hand washing, dishes and showering.
I think I’m going to do the bleach treatment before our next trip though. We bought it new 4 years ago and have never done it so it’s probably smart.
I’m curious what percentage of people who own RV’s actually do the proper maintenance on their tanks. I can imagine somebody buying a used one that has never been properly serviced. Heck, I looked at one of the water bottles that I use for cycling yesterday that had been sitting around half filled for a while and it was filled with all sorts of new life forms. I can’t imagine what the average RV tank looks like.
Yeah, it’s scary. All my water bottles get stored fully dried out, and hydration bladders and tubes (what a PITA) always go into the freezer because those lines never fully dry out.
At one point, I also used a brewers’ cleaning product called B-brite if I knew I’d have any standing water. Much less offensive than bleach, but I’ve never heard it used outside of homebrewing. Flavorless white powder, seems to do a good job. Not sure how long you’d want to let it sit around, though.
My easiest water solution is just those 18.9L (5 gallon) water jugs you can pick up cheap at the grocery store. Add in one of those cheap hand pumps or a gravity mount, and you’re done.
Most places around me charge $10 or less for one of those jugs. So load up with a couple before leaving and you have your fresh water supply, properly filtered and sealed. Then use the RV tank for washing as you said earlier.
Indeed Mercedes!
In addition, I add a teaspoon of unscented bleach to our thirty gallon tank when we fill it for use. That little chlorine won’t hurt you to drink, but will nicely inhibit growth.
Furthermore, every single water container should be stored either bone dry or with a bleach solution in it. Period. Because once a fungal biofilm forms you ain’t removing it with anything but mechanical force. I’ve saved five gallon water jugs by cleaning them with bleach, soap, unpopped popcorn, and a shit ton of exhaustive shaking, but that won’t work for your RV tank. Again, not kidding about the biofilm shit. You don’t want to ever let it start.
“You’ll want to clean both your tank and your lines. A commonly cited method for this would be to fill your RV’s tank with a water and bleach solution. A standard guideline is a quarter cup of bleach per 15 gallons of water”
I will add this: Use FRESH bleach. Bleach will degrade into saltwater if it sits around too long.
I’ve used Five star PBW for potable water tanks followed by star San. If it’s good enough to kill off bacteria for a clean fermentation and still be drinkable it’s good enough for potable water. Plus brewerys run into though all their stuff and it’s safe for gaskets rubber plastic and various metals. They are really dirt cheap too for how concentrated it is.
I was going to say exactly this. Don’t fear the foam!
Few things:
1. Bleach does not clean, it sanitizes. Cleaning generally requires mechanical action. A water system that has been kept appropriately sanitized from new may not ever need cleaning. If it has sat with questionable water in it, it probably needs a true cleaning. I would guess there are companies that do this service, similar to duct cleaning.
2. It’s not a great idea to pour undiluted bleach into anything other than a receptacle specifically designed for it. It is extremely aggressive against many metals and some elastomers. You want to calculate the appropriate amount as well and not just pour in randomly. Then fill your tank 1/2 to 3/4, add the calculated bleach and then fill the rest of the way. Then you can follow the rest of the protocol.
2. If you’re regularly sanitizing your tank, doing all your filtration upstream might make sense. Otherwise, it’s probably best to do a moderate level of filtration when filling or on shore water, and then install a point of use RO system for drinking water.
I have a big evaporative (swamp) cooler in my garage. It’s hooked to a hose, but a float valve keeps the water tank about half full all the time. Even if it’s used daily, so the water circulates/used/replaced, it still only takes a few weeks for it to start getting funky in there and a noticeable odor in the breeze. Being only water evaporates, not all the other crap/scale/minerals in it, so those start building up in the tank over time. Throwing a little bleach in the tank….makes the air smell bleachy, but yep, does nothing to clean it, and the funk smell quickly returns.
What I found much more effective is dumping the water, adding about 1 cup of citric acid crystals (to about 10 gallons water), turning the pump on but not the fan so it just circulates the water around and over the mats, leaving that overnight, then draining it. The water that comes out is always really gross, and looking in the tank it looks brand new afterwards. All the slime and scale and that is gone (as there’s really no good way to mechanically brush/scrub the inside of the tank, at least not without taking the entire thing apart since the tank is sort of built in to the whole housing). Give it a quick rinse down with the hose, then back into service.
I typically do that every month or two. So far it hasn’t hurt any of the plastics, hoses, pump, or anything like that in the past couple years. In the winter months I always do a citric acid “rinse” first, then completely drain it.
Also found citric acid crystals work really well for cleaning dishwashers and washing machines (particularly front loaders) too. Again, been doing that occasionally for years to no ill effects to the machines. Commercial products for that same purpose are usually mostly citric acid anyway, just with some fragrance added.
The worst one of all is Affluenza, it’s highly contagious, especially in low-density suburbs.
I’ve been lucky and our popup tank is always fresh and clean tasting. I winterize it with bleach water and then drain it and blow out all the lines with compressed air, and then in the spring I do the bleach water again. So far so good. I have no reservations about drinking that water. Not sure if I would put it up my nose…but there you go.
Also – don’t drink the tap water on public transportation. And I would not even drink coffee or tea brewed with water from those tanks.
Yep, heard the coffee on airliners is toxic. Just get a bottle or can.
It definitely can be, and part of the problem is that at altitude (typical cabin altitude is ~8000ft) the boiling point of water is quite a bit lower, so the brewing is a lot less effective at killing the nasties, if they even get it that hot to begin with. Given the litigiousness of the populace, and the probability of spills due to turbulence, they probably don’t.
I highly doubt that coffee on planes is brewed with water from the plane. The faucets on the plane are all marked non-potable and they serve water either in small sealed bottles or from big sealed bottles. They almost certainly fill up a special reservoir for the coffee and it gets cleaned regularly.
I’ve definitely seen flight attendants fill the coffee makers with bottled water. Can’t say that’s what happens every time, but I’ve had plenty of airline coffee with no known side effects.
Maybe we should disinfect the NYC taxi first…
Doing nasal lavage with tap water is idiotic to start with (I’m a big fan, but I would never ever do that). There are a number of critters that can be in there that are perfectly fine to have go through the hellscape that is your stomach that should NOT be going up your nose and into your sinuses.
Yeah, I wasn’t even aware that people shoot regular tap water into their noses! Definitely don’t do that, either.
It’s a thing, likely best to boil it first.
As one with savage pollen allergies and chronic sinus issues, nasal lavage is a Godsend. But you HAVE to use distilled water, or at least well and truly boil the literal shit out of water to do it safely. And sterilize the lavage bottle properly too.
I have an Aquasana filter system installed at the house with a seperate spigot for drinking water in the the kitchen.
Yep, I sanitize the tank every spring before I take it out. I buy gallons of water to drink. I don’t even rinse my toothbrush with the tank water or even campground water if I’m hooked directly up to water.
Great article, thank you.
My go-to for disinfecting and antifreezing my freshwater tank and lines is inexpensive, potable alcohol. My somewhat scientific reasoning is alcohol kills bacteria and viruses, and if I do not rinse the tank or lines completely the alcohol is not toxic in small amounts. Diluted chlorine is safe to consume in small concentrations, sure, but its taste lingers when left in contact with some plastics.
So – vodka kills everything. College rings true.
Oh, so that’s why I failed advanced Algebra 2…