People chose the RV lifestyle for a reason. They love the freedom to travel around the country and essentially drive their house to the next destination. RVs are simple to set up and can sleep quite a few people.
What’s nice is that they have their own bathroom and septic system, so you get the feeling that you are staying in a tiny home and not camping. However, at some point in time, you need to empty the septic tank.
Many people who have permanent home bases want to know if they can dump their camper tank into their home septic system.
Emptying the septic system is one of the most unpleasant parts of RVing, but you can dump your RV tank into your septic tank. However, this task comes with the need to understand how your home septic system and the RV wastewater system works.
Your Home Septic System
Every time you flush your toilet or turn on the faucet, the water and waste move through the pipes in your house. They travel through these pipes into your septic tank. In the middle of the tank, there is a baffle that keeps oil, sludge, and grease from obstructing the outlet; preventing blockages.
Halfway down the baffle, there is an opening for wastewater to pass through. The water ensures that solids don’t sit on the bottom of the tank and that oil doesn’t rise to the top and exit the outlet into the drainage field.
As additional waste enters the tank, the same amount of water pushes out of the container into the drain field. The drain field consists of three pipes or laterals with holes in them. They gradually decline into the ground at approximately ¼ inch every foot. A rapid decline wouldn’t help push the solids through the pipe. It would just rush right past them.
Additionally, rocks surround the pipes to assist the drainage process. It would be best if you pumped septic tanks on a regular basis, or the lines can clog as sludge may creep over the baffle in the tank.
The most critical part of dumping your RV waste into your septic tank is making sure that you know exactly where your tank is underground. You must make sure that you don’t empty your RV wastewater on the wrong side of the baffle. The solids and sludge could get pushed into the outlet and obstruct the drainage field.
About the RV Septic System
While people call the wastewater and plumbing system in RVs a sewer system, this system actually doesn’t have much in common with a traditional system. The only time it resembles a home sewer system is when it’s hooked up to a sewer system to empty the waste.
Think of the RVs system as a septic system. So, what is the difference between a septic system and a sewer system? Homeowners have septic systems if they aren’t in range of large, centralized wastewater systems that cities and towns maintain. People in rural areas usually have septic systems.
Essentially, septic systems are structures built underground that naturally break down the waste from your home and disperse the wastewater. RV septic systems work similarly. These systems can be complicated or exceedingly simple. Here are the different components of the septic system in an RV.
Gray Water Tank
Not all RVs come with a gray water tank, but they are popular now. This tank holds all of the liquids that range in quality between black water and freshwater tanks. Gray water tanks receive water from the shower or sink; the water not comprised of garbage or toilet waste.
Today, people use their gray water for chores such as washing the RV or their dishes.
Wastewater or Black Water Tank
This tank does the dirty work on the RV. It’s the chief component of the septic system in your unit. Black water tanks gather all of the wastewater from your shower, sink, and toilet.
Dumping systems differ depending on the RV. It’s the same general concept, however. When dumping your waste, you attach the sewer hose to the waste tank on the RV to empty them into a dump station or sewer connection. Most RVs use gravity to push wastewater out, but some include pumps to force it out.
Its only in theory that your RV septic system is similar to your home system. These two septic systems don’t operate the same way.
Typical toilets on RVs flush directly down into the black tank. It’s a straight drop versus in houses where the toilet flushes wash waste through curving pipes. This system effectively creates a seal after the toilet flushes and thus prevents odors.
The RV toilet is more like the old-fashioned outhouse where you saw the cone of feces if you looked down the hole. It just naturally forms with that vertical drop. Without enough liquid in your RV holding tank, the same thing happens. It’s not easy to get rid of and a costly repair.
Without the seal that the home plumbing system creates, you must combat odors in your RV differently.
Dumping Your RV’s Septic System
There is a reason that people suggest you only empty your black water tank when it’s at least half full. The greater amount of sewage in your tank the more considerable the “head pressure.” That pressure assists the dumping process by forcing the sewage out of the hose. With a little help from gravity, the waste forces itself out. So, the more sewage in the RV the more “head pressure” there is.
Allowing the septic tank to fill more naturally changes the liquid-to solid-ratios. As your tanks fills with normal usage, you increase the amount of the liquids compared to solids just by flushing. Additional liquid works with the required chemicals to break down the solid waste.
How often you empty your tank depends on how many people are traveling with you. If it’s a large RV with several people, you may need to drain it every other day. Once a week could be enough if it’s just two of you.
There are a couple of ways to gauge how full your RV septic tank is. Some RVs have systems that show how much waste is in your tanks. However, over time the sensors start to malfunction providing incorrect information.
A brand-new system can give an inaccurate reading if waste or paper is sticking to the sensor. You can also put a stick into the tank to judge the level of waste in your containers. Stay aware of the amount of waste and water that you’re collecting.
Using Toilet Chemicals in Your RV and How They Affect Your Home Septic System
RVs require certain chemicals to help break down the waste and reduce odor. It’s a different environment than that of your septic system at home that uses a natural process to disintegrate and disperse waste.
Toilet chemicals do two things in RVs. They break down waste and help with odors. These chemicals are enzymes and bacteria that decompose or digest the solids in your wastewater tank. Many of these chemicals begin the decomposition process within three to four hours and keep working. This process is similar to the same one that occurs in your home septic tank except:
• Home septic tanks aren’t dumped therefore the chemicals continue to work for several months.
• The RV septic system is miniscule compared to the home system that can hold 1,500 gallons of waste.
Next, chemicals used in RVs control the odors in the wastewater system. Many people mix there own toilet chemicals to save money using ingredients such as pine oil, water softener chemicals, bleach, cleaning liquids, cooking yeast, caustic soaps and more. There are simpler ways to save your money.
Rid-X is a common chemical used by RVers for their septic system. Its more known for its use in home septic tanks, but can also be used in an RV. Two capfuls in a 56-gallon tank with four to five toilet flushes starts the process. It’s a good idea to add a capful to your grey tank too after every other dump to help eliminate sewer odors as well.
After you add it just run plenty of water to flush the chemical out of the P-trap in the drain.
Make sure if you use Rid-X that you don’t use the crystals because they are harder to measure for dispersion. Some RVers have used Rid-X for many years, and say it worked well.
The most significant problem with emptying your RV’s contents into your home septic tank is the chemicals. These chemicals may harm the natural biome within the septic tank.
Wastewater treatment systems for homes have anaerobic and aerobic organisms that help decompose and digest organic matter. Aerobic organisms require oxygen to work while anaerobic organisms require less. It is necessary to monitor and keep both organisms in your septic system because they both consume different pathogens.
Chemicals that help dissolve waste also kill any good bacteria. It could completely unbalance the organisms and environment in the tank and even cause the natural break down process to stop. If the bacterial action halts, there could be blockages, flooding of the drainage field, and more severe problems. Other words, chemicals can wreak havoc on your home septic system.
You may have noticed that most dump sites for RVs don’t have restrictions for dumping waste with chemicals in it. Just remember, you’re not in charge of maintenance of the dump sites, but you are responsible for maintaining your home septic system. So, if you plan on dumping your RV tank at home into your septic tank, we’d advise you to use chemicals cautiously.
Perhaps using a product such as Rid-X or something similar approved for use in home waste treatment systems is advisable.
Rid-X even has a product specifically for RVs, and there are many other similar products on the market. Research the product you choose to see what effect it could have on the natural break down process.
Also, beware of the size of your septic system and the number of bedrooms that its rated for. The extra dumping will likely mean that you need to pump your septic tank more frequently. The average septic tank should be emptied every two to three years. Regular pumping and maintenance are vital for a healthy home septic system.
How to Dump Your RV Waste into Your Septic Tank
It’s easiest to dump your RV wastewater tank into your septic tank using the system’s cleanout. The cleanout is a PVC pipe that sticks up above ground and has a screw cap. You can find this pipe between the tank and your house.
It’s a simple process. Just remove the cap on the cleanout and attach your RV’s sewer hose to the cleanout and the RV. Make sure you secure the line or place a heavy object on top of the hose to safeguard against it lifting from the “head pressure.” Otherwise, it may fly off of the cleanout flinging a horrible mess everywhere that no one wants to clean off!
Some septic tanks don’t have a clean-out, and if this is the case, you can remove the access port lid. You must be careful because the gases inside have the potential to be fatal. It’s best if you must empty your tank this way that you have someone with you to help you take off the lid safely. Never leave your RV connected to the septic tank like this because its dangerous and too much oxygen may kill all of the anaerobic organisms inside.
Emptying your RV tank into your home septic tank is one solution for dumping your waste and also the most convenient. As long as you know the location of your home septic tank and use chemicals carefully, it’s okay to do this.
Understanding how both wastewater systems work helps the emptying process. It prevents you from emptying your tank on the wrong side of the baffle. If you follow the advice that we’ve provided, you can safely dump your RV tank at home.
I am a well traveled Marine Corps veteran that enjoys the outdoor and nomadic lifestyle that RV living provides. I am also a member of the National RV Inspectors Association (NRVIA.org). As the founder of Camperguide.org my goal is to provide you with well researched information so that you can enjoy the best of the RV lifestyle.