​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​If you’re camping or using a recreational outdoor area during a boil water advisory, it’s important to know what to do.

The following is general information about how to safely disinfect and flush out RV water tanks and systems during a boil water advisory.

If you’re in the backcountry or you can’t boil your water, learn other ways to make your drinking water safe:

• Drinking Water in the Backcountry
• How to make your drinking water safe when you can’t boil it

Disinfecting and flushing RV water tanks and systems

If your recreational vehicle (RV) is filled with water that’s unsafe, you need to disinfect and flush the water system. You may also want to do this for other reasons:

• The water from the RV water system smells stale.
• The RV has been sitting for a month or more and the water system has not been used.

It’s important to follow the owner’s manual for disinfecting RV water storage tanks and for flushing the RV water system. If you don’t have the owner’s manual, then follow the steps below.

Disinfecting RV water storage tanks

1. Remove any internal or external water filters.
2. Drain all the water out of the water storage tank, water lines, and the water heater, then close all of the drain valves.
   Caution: Never drain the water heater when it’s hot or under pressure.
3. Find out the size of your water storage tank (in litres).
4. Figure out how much unscented liquid bleach (5.25%) you’ll need. For every 250 litres of water your storage tank can hold, use 250 millilitres of bleach.
5. Mix the amount of bleach you need into 5 to 10 litres of water first. Then use a clean funnel to pour this solution into the RV water storage tank.
6. If there’s a bypass for the water heater, set it to normal use so the water heater will be disinfected.
7. Fill the RV water storage tank as full as you can with fresh water that’s safe to drink.
8. Turn on the pump. Run all hot and cold water taps one at a time for a few minutes until you smell the bleach, then close the tap.
9. Top up the RV water storage tank with water that’s safe to drink.
10. Let the bleach water sit in the water storage tank and plumbing system for at least 6 hours (overnight is better).
11. After 6 hours (or in the morning), drain the bleach water using the taps into the grey and black wastewater tanks.
    Caution: Highly bleached water is not safe for drinking and is not good for pets. It will cause problems if drained directly into septic fields or into surface water. Always drain this water into grey and black wastewater tanks.
12. Fill the water storage tank again with fresh water that is safe to drink, and drain the tank using the taps to flush out any leftover bleach.
13. Install new internal or external water filters.

Flushing RV water systems

Some RVs don’t have a water storage tank, but they have a direct connection hookup to a water supply. Here’s how to flush this type of RV water system:

1. Remove any internal or external water filters.
2. Drain the water heater.
   Caution: Never drain the water heater when it’s hot or under pressure.
3. Connect the RV directly to a chlorinated town-water supply that’s not under a boil water advisory.
4. Run the hot and cold water taps that are the furthest away from the direct connection hookup. Let the water run for 5 minutes.
5. Flush all other taps for 5 minutes.
6. Install new internal or external water filters.

More information​​

Learn more about safety during a boil water advisory from Alberta Health Services Environmental Public Health​.​