Wednesday, April 9, 2008

Let's all dump...our RV holding tanks!

If you’re new to the RV lifestyle, there are usually 3 tanks installed on most RVs: the fresh water tank (we'll discuss that topic in a different blog), the black water holding tank, and the gray water holding tank.

Today we’re going to tackle the sometimes messy, always gross, but very necessary dumping of gray and black water tanks. I know…yuk. I’m reminded of the movie “RV” starring Robin Williams…well, although sensationalized, his ordeal wasn’t really too far off the mark. In this case, crappy things can happen to nice people. Let’s not leave anything to chance. This blog will be your step by step guide to dumping your tanks efficiently and with minimal effort.

To accomplish this task successfully, you’ll need the following:

· A box of rubber or vinyl gloves

· A garden hose at least 25 ft. in length

· An RV sewer drain hose, usually comes in 10 ft. sections and you’ll need a clear sewer pipe adapter to twist the hose onto the drain valve coming out of the storage tanks and you’ll need a elbow fitting that you insert into the sewer hook-up in the ground.

· A “rinsing wand” – found at Wal*Mart or any RV store such as Camping World. This contraption is a long narrow PVC pipe that has an on/off valve and a threaded fitting for attaching the garden hose to one end…and at the other end there are tiny holes where the water jets out.

· Liquid sewer chemicals

· Paper towels

· Disinfectant cleaner such as Clorox Bleach Cleaner

Let’s chat about hold tank chemicals for just a moment: There are special chemicals you should use, especially in the black tank, to reduce odors and the buildup of solids in the tank, which could cause problems down the road. There are many brands and types on the market, from powder to liquid. Regardless of the type, it is usually recommended (or required by most campgrounds) not to use chemicals that contain formaldehyde, which is a chemical that is harmful to some septic systems. There’s a big debate going on about the use of formaldehyde in holding tank products…I use Thetford Campa-Chem Holding Tank Deodorant. I’ve used both non- formaldehyde and with formaldehyde and as far as I can tell they both work equally well.

Please note that use caution when using holding tank chemicals. They are used for breaking down waste…they can be hazardous if you don’t follow the directions.

Now that you’ve had your warning…generally speaking holding tank chemicals are very easy to use. Just follow the directions.

One more thing…toilet paper. I recommend you use one-ply Scott toilet paper…labeled “septic-safe” on the package. You can buy the special RV brand of toilet paper and use it, but it’s expensive and it doesn’t last very long. The Scott brand works just as well, for less money.

A couple of other pointers you should know: RVs come with “tank level indicators” so you can just press a button to find out how full your tanks are. These lights are usually mounted in the kitchen area, but are sometimes found in the bathroom.

However, if the sensors in your tank are covered with muck, the indicator lights can be deceiving…they will lie to you! That’s why it’s crucial to keep your tanks clean, especially if you’ll be RVing for more than 3 – 4 days. I can go up to 2 weeks before dumping my tanks. I’m a fanatic when it comes to clean tanks!

Keep your black and grey tanks closed and dump them when they are at least ¾ full or completely full…which is best.

Dumping a full tank provides a sufficient quantity of water to flush solids from the tank. Leaving the drain valves open allows the water to drain off without flushing out solid waste. That solid waste will collect in the tank(s) and cause problems over time. Trust me on this!

The #1 problem with the black holding tank is clogging! Do not put facial tissue, paper, sanitary napkins, ethylene glycol based products, automotive antifreeze or household toilet cleaners in the holding tanks. Do not put anything solid in any tank that could scratch or puncture the tank.

If the drain system does get clogged:

Use a hand-operated probe to loosen stubborn accumulations. Seriously clogged P-traps may require disassembly. Be careful not to over tighten when putting everything back together. Do not use harsh household drain cleaners. Do not use motorized drain augers.

It might even be best to call a pro when if you’re not feeling comfy about tacking a clog. It’s up to you!

DUMP TANKS IN ORDER FROM DIRTIEST TO CLEANEST! In other words, dump the black toilet water tank first, then dump the grey tank which is the shower, bathroom sink and kitchen sink tank. This way you’ll be flushing out the dirtiest water with cleaner water.

And now…


Never, never, never dump grey or black water on the ground….especially black water! Black water is raw sewage is a bio-hazard. I’m reminded of the time I was staying in a park and someone dumped their black tank water on the ground. When management “caught wind” of this…they called 911 because they are required to do so by law. Well, about 5 snappy minutes later a HAZMAT team arrived on the scene, all dressed up in their HAZMAT gear, they cordoned off the area and evacuated part of the park so they could clean up the “bio-spill”.

Now you see why you should NEVER dump your black water on the ground. In some places it’s against the law and sometimes result in a hefty fine and a possible stay in the local jail. Think about it for a moment…that is some vile, disgusting stuff coming out of that black tank.

Back in the old days, people would toss their sewage out of the window and onto the street…well, this is what you are doing when you dump black water on the ground. Also, don’t dump your grey water on the ground….that stuff is also gross. Don’t be a lazy “Terd”…please either dump at your site (if you have full hookup) or at a dump station!

Before we get started, look for the FHU (full hook up) at your campsite…both the water spigot and sewer hook up are usually located very close together. Remove the cap from the sewage drain (if it’s capped).

Here are your step by step instructions…let’s dump your tanks:

Step 1: put on your rubber or vinyl gloves

Step 2: find the compartment where the dump valves are located, open the compartment. You’ll see a 3 inch black “Y” pipe coming down out of the bowels of the RV with two T shaped pull handles…or if you have a really long 5th wheel, you’ll see two separate 3 inch black pipes sticking out from the bottom of your trailer…these should be connected to drain pipes and Y-ed at the sewer hook up…at any rate…(do not pull the T handles, not yet!)…you’ll see a termination cap fastened to the end of the 3 inch pipe.

Step 3: While the T handles are still CLOSED, unscrew the termination cap slowly from the end of the pipe.

Step 4: Attach the clear sewer pipe adapter to the end of the pipe.

Step 5: Attach the sewer hose to the end of the clear adapter.

Step 6: Insert the other end of the sewer hose with the elbow fitting into the sewer hook-up in the ground.

Pat yourself on the back…so far, so good!

Remember black first, gray last! This means, always dump your black tank first and save the gray tank for last. This way the grey water will flush the black water residuals down the hose and into the drain.

Step 7: slowly and carefully open the black water T handle. The liquid and waste will start to flow down and out.

Step 8: attach the “rinsing wand” to the garden hose. With the wand securely attached to the garden hose, insert the wand into your toilet…far enough down so the water will not blast out of the toilet and all over the bathroom or you. Make sure the on/off valve is set to “off”.

Step 9: slowly turn on the garden hose until flow is at 100%.

Step 10: slowly turn on the rinsing wand. Gently move the wand around to hit the walls of the holding tank and loosen material (toilet paper, solid waste, etc.) from the holding tank. Continue to do this for about 5 minutes, turn off the rinsing wand.

Step 11: turn off the water to the garden hose.

Step 12: disconnect the rinsing wand from the garden hose and insert the garden hose into your toilet…far enough down so the water will not blast out of the toilet and all over the bathroom or you.

Step 13: shut the lid to the toilet, so it closes over the hose, but does not restrict water flow.

Step 14: slowly turn on the garden hose until flow is at 100%. Check on your hose to make sure water is not flooding your bathroom. (By the way…it’s good to have a “helper” when doing this.)

Step 15: go outside and watch the water flow through the clear sewer pipe adapter. When the water flows clear and you no longer see waste debris washing through the adapter, turn off the water and close the black water T handle.

Congratulations! You have successfully drained your black water holding tank…now let’s do the gray water tank!

Step 1: slowly and carefully open the gray water T handle. The liquid and food waste will start to flow down and out.

Step 2: remove the garden hose from your toilet…drain excess water into the bowl.

Step 3: spray a paper towel with Clorox cleaner, wipe and clean the rinse wand…wipe and clean the garden hose…remove both from the bathroom. Stow the rinse wand, keep the hose handy…you’ll be using it again shortly!

Step 4: look at the clear sewer pipe adapter…when the grey water flow is at a trickle, close the grey water T handle. Let any water in the sewer hose finish draining.

Step 5: gently disconnect the clear sewer pipe adapter from the end of the 3 inch pipe.

Step 6: turn on the garden hose to a gentle flow of water…50% flow…and thoroughly rinse out the sewer pipe, the rinsing wand, and the garden hose.

Step 7: stow everything for next time.

Step 8: following the directions on the label, pour the suggested amount of blue holding tank chemical directly into your toilet and flush into the holding tank….run the water for a few minutes.

Voila! You are finished…remove your gloves, toss them in the garbage, wash up and have a great day!

You did good!

…and remember, practice, makes perfect!!

To find out more information about this subject just google “dump RV tanks” and you’ll see several links to online articles with photos, opinions and how to tips. Also, go to and click on the link “RV sanitation and sewer” where you’ll see many of the hoses and fittings we’ve discussed during the show.

And of course, everything we’ve discussed here in this blog can be downloaded via podcast so you can take your ipod with you and follow my step by step instructions. Just go to and click on the “podcast” link.

Until next time!


1 comment:

Anonymous said...

Great post but I have one comment to make.
I always check for leaks and the security of the waste connection by slowly opening the grey water valve first. Just for a few seconds then closing it before dumping as described above. If there is a leak or worse, the waste hose isn't securely fastened you're are only dealing with spilled grey water.
A campsite owner once told me how she watched the owner of a big rig get a good hosing down of the brown and smelly when he failed to secure the waste hose correctly.