The Hidden Danger in Your RV Water Tank, and How to Fix It

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If you haven’t cleaned your RV’s water system in a while, you could be putting yourself at serious risk.

According to the CDC, a 71-year-old woman died after using water from her RV’s tap for a sinus rinse (more on this later). The infection attacked her brain, and health officials found that both the RV’s tank and campground water supply had serious safety issues.

This isn’t just a rare case. Bacteria, mold, and parasites can grow inside any RV tank that hasn’t been properly maintained. And many RV owners don’t realize how often these systems need to be cleaned.

If you use your camper’s water for cooking, brushing your teeth, or even showering, you need to know how to keep the system clean and safe.

Understanding the Risk

How Contamination Happens

RV water tanks can pick up a range of unwanted stuff over time:

• Algae and mold can grow in standing water, especially in warm environments.
• Bacteria and parasites can enter from unfiltered campground water or hoses.
• Biofilm can develop inside plumbing if the system hasn’t been cleaned for a while.
• Old hoses can leach chemicals or grow mildew, especially if they’ve been stored wet.

The tank isn’t the only issue. Water connections, hoses, and filters can also carry contaminants into your system. And depending on how often you camp or where you get your water, the risk can go up. Seasonal campgrounds and older parks may use well water. If those systems aren’t maintained properly, they can introduce even more bacteria into your tank.

A Look at the CDC Report

According to the CDC, a 71-year-old woman died after using water from her RV’s tap for nasal irrigation while camping in Texas. The water had come from both the RV’s freshwater tank and a direct hose connection at the campground. Testing didn’t confirm the source of the contamination, but the campground water was found to have low disinfectant levels. The RV’s water system also showed poor water quality.

This case didn’t involve drinking the water; it involved inhaling it through the nose. That matters because the body has different defenses in the digestive system than it does in the sinuses. The stomach can kill off many microorganisms, but the sinuses and brain don’t have that same protection.

While most people won’t get seriously ill from occasional exposure to questionable water, there have been confirmed cases of Giardia, Legionella, and other bacteria causing outbreaks in campgrounds and RV parks. In rare situations, infections like Legionnaires’ disease have been linked to water systems inside RVs or their supply hoses.

These cases serve as a clear warning that routine maintenance and smart habits are needed if you’re using your RV’s water system for anything more than washing your hands or rinsing dishes.

RV Water Safety Best Practices

General Guidelines for Staying Safe

RV freshwater systems are not maintenance-free. Tanks, lines, and hoses can all become breeding grounds for bacteria, algae, and other contaminants if they’re not cleaned regularly. Even if the water looks clear, that doesn’t mean it’s safe.

Here are some basic practices to follow:

• Clean your freshwater tank and plumbing system regularly, especially before the first trip of the season or after long periods of storage.
• Use only drinking water-safe hoses marked for potable water. Store them dry and keep the ends covered to avoid dirt and insects getting inside.
• Install a water filter at the point of entry to help remove sediment and reduce contaminants before water enters your system.
• Avoid using your RV water system for nasal rinses or any activity that involves inhaling water through the nose. This is how the woman in the CDC case became infected.
• When in doubt, use bottled water for drinking and brushing your teeth. Many RVers do this even after sanitizing their system.

How Often to Sanitize Your RV Water Tank

There’s no single rule that applies to everyone, but most RV manufacturers and experts recommend sanitizing your freshwater system at least every 3 to 6 months.

You should also clean the tank anytime:

• You buy a used (or even new) RV
• The water smells or tastes off
• The tank has been sitting unused for several weeks or more
• You notice visible debris or particles coming through the taps

Even if the RV is brand new, the water system could have been sitting unsealed or untested for months. It’s a good idea to sanitize it before your first trip. Regular cleaning is the only way to help reduce the risk of contamination from mold, bacteria, or biofilm buildup.

How to Sanitize Your RV’s Water Tank

The Standard Bleach Method

Bleach is one of the most common and effective ways to sanitize an RV freshwater tank. When used in the right concentration, it’s safe for this purpose and breaks down over time.

I’ve already covered this in-depth in my sanitizing a freshwater system guide, but here’s a quick rundown:

What You’ll Need

• Unscented household bleach (fresh, not expired)
• Clean water hose rated for potable water
• Funnel (if needed to pour bleach)
• Measuring cup

Steps to Sanitize

1. Drain the System
   Empty the freshwater tank completely. If you have a water heater, turn it off and drain that too.
2. Mix the Bleach Solution
   Use 1/4 cup of bleach per 15 gallons of tank capacity. For example, a 30-gallon tank would need 1/2 cup of bleach. Dilute it in at least a gallon of clean water before adding it to the tank.
3. Fill the Tank
   Pour the bleach solution into the freshwater tank using a funnel or through your gravity fill port. Then fill the tank with fresh water.
4. Run the Solution Through All Lines
   Turn on every faucet, including hot and cold, until you smell bleach at each outlet. This pulls the solution through the plumbing lines and water heater.
5. Let It Sit
   Leave the solution in the system for 5 to 10 hours. Do not use the water during this time.
6. Drain the System Again
   Empty the freshwater tank and water heater completely. This removes the bleach solution.
7. Flush the System
   Refill the tank with clean water. Run all faucets again to rinse out the system. Repeat this step until the bleach smell is gone.

This process can take most of a day, especially if you’re flushing multiple times. If you’re connected to a sewer system, you can drain directly into it. If not, you’ll need to follow local rules for safe disposal.

Alternatives to Bleach

Some RVers prefer other sanitizing options, especially in areas where bleach disposal is a concern:

• White vinegar: Use about a gallon per 15 gallons of tank capacity. It’s less harsh but not as effective against certain bacteria.
• Hydrogen peroxide (food grade): Can sanitize without leaving an odor, but concentrations and amounts vary.
• Potable alcohol: Used by some for winterizing and light sanitizing. It evaporates quickly but may leave a taste in some plastic lines.
• Star San or PBW: Popular in homebrewing. Safe for potable systems when used properly and rinsed thoroughly.

Always read labels and instructions before using any cleaner, and never mix chemicals unless directions explicitly say to do so. And remember, some options may not be very effective, so I’d recommend checking out this article on sanitizing your freshwater system without bleach to find a good alternative.

Water Filtration Options for RVs

Not all campground water is the same. Some sites use city water, others rely on wells or older delivery systems that may not meet modern standards. Even if the source is clean, contaminants can still enter through hoses, fittings, or storage tanks. That’s where water filters come in.

Types of RV Water Filters

There are several ways to filter water in your RV, depending on your setup and how you use your water system.

Inline Filters

These are the most basic and common type. They connect directly between your hose and the RV’s water intake. They’re easy to install and remove and are a decent first layer of defense. Do NOT rely on these alone, though!

• Example brands: Clear2O, Camco TastePURE
• Helps remove sediment, chlorine, and some bacteria

Multi-Stage External Filters

These units often have two or more filtration stages and are mounted outside the RV. They offer better filtration than single-stage inline units.

• Example brands: Clearsource, Blu Technology
• May include sediment, carbon, and UV stages
• Useful for full-timers or those who use campground water frequently

Under-Sink or Point-of-Use Filters

These systems are installed inside the RV, typically under the kitchen sink, and filter only the water coming out of a single faucet.

• Common for drinking and cooking water
• Can include reverse osmosis (RO) or carbon block filters

Gravity Filters

Gravity filters, like Berkey systems, sit on the counter and rely on gravity to push water through multiple filter elements. They’re popular for drinking water but don’t connect to the RV plumbing.

• Not used for showers or dishwashing
• Portable and don’t require installation

UV Sterilizers

Some advanced systems include UV light to kill bacteria and viruses. These are often part of a multi-stage setup and require power to operate.

• Effective for microbial contamination
• Typically combined with other filters

What Most RVers Use

There’s no one-size-fits-all approach. Some RVers use a single inline filter. Others combine an inline filter at the hose with a Berkey inside for drinking. Full-time RVers or those who stay at a wide range of campgrounds often invest in multi-stage systems.

Maintenance Tips Beyond the Tank

Keeping your RV water tank clean is only part of the job. The rest of your water system – hoses, connectors, filters, and plumbing – can all impact water quality if not maintained properly. Even a freshly sanitized tank won’t help much if bacteria are introduced through a dirty hose or a neglected filter.

Hose Maintenance

Using the right hose matters. Regular garden hoses are not safe for drinking water and may leach chemicals into your water system.

• Use only potable water hoses labeled safe for drinking, like the Camco TastePure Hose
• Store hoses dry and out of direct sunlight to prevent bacteria and algae growth.
• Replace hoses when they become discolored, cracked, or develop a smell.

Water Filter Upkeep

Filters don’t last forever. How often you replace them depends on the type of filter and how much water you use.

• Inline filters typically last one season or a few thousand gallons.
• Multi-stage filters often have separate replacement schedules for sediment, carbon, and UV elements.
• Always follow the manufacturer’s instructions on when and how to change filters.

Letting filters go too long without replacement can cause bacteria to grow inside them or allow contaminants to bypass the filter entirely.

Plumbing and Fixture Tips

• Run water after storage: Flush your entire system before using it again if the RV has been stored for more than a few weeks.
• Seal exterior drains: After draining, keep external drain ports sealed to prevent insects or debris from getting into the system.

When to Inspect

It’s a good idea to inspect your water system:

• At the start of each season
• After long periods of non-use
• If you notice smells, discoloration, or reduced flow

Staying ahead of maintenance reduces the chance of needing to do deep cleans later. A clean hose and a fresh filter can make just as much of a difference as a clean tank.

What Experienced RVers Actually Do

If you talk to long-time RVers, you’ll find that most have settled into a routine that works for their setup and comfort level. While some rely fully on their RV’s water system, many use a mix of methods to reduce risk and keep things simple.

Common Practices in the RV Community

• Sanitize the tank regularly, but still use bottled water for drinking.
  This is one of the most common approaches. Even with a clean tank, many prefer the extra peace of mind that comes with using sealed drinking water.
• Use the RV tank for washing, showering, and dishes only.
  This allows people to use their onboard system without worrying about ingestion risks.
• Filter all water going into the tank, not just the water at the faucet.
  Some install filters right at the source to reduce sediment and chlorine before it enters the RV. This helps keep the tank and lines clean.
• Don’t rely on campground water to be safe.
  Not all campgrounds are on regulated municipal water systems. Seasonal sites, rural parks, and older setups may use wells or cisterns that aren’t maintained as strictly.
• Replace hoses and sanitize lines just like the tank.
  Letting a hose sit in the sun or leaving water standing in it can cause mold and bacterial growth. Many treat hoses and plumbing as part of the routine cleaning process.