RV Black in a septic tank

[plongson]

I own a large piece of property, and use my travel trailer as a cabin retreat. I have installed a septic system to accommodate JUST the trailer waste, gray and black. Can I safely dump my treated trailer black waste in the septic? I am afraid that with no untreated black waste to offset the treated waste, it will kill all bacteria action. Does anyone have any information or thoughts about this... .

 

[LesStallings]

I live in an area that relies on septic systems and know the value of maintaining the health of the bacteria that "digest" household effluent.



I'm not sure how toxic your treated waste will be, but if I was in your situation, I would add Rid-X to the system a few days after I dumped treated waste. It will replenish your "bugs" and keep the system happy.



Properly operated septic systems work surprisingly well. I've seen septic tanks go over well over ten years without needing to be pumped.

 

[WestTN]

The formaldehyde in standard toilet chemicals will kill the septic system. Use one of the biodegradable formulas instead. Clean and flush the tanks thoroughly before beginning to use that septic system.

 

[DaveHess]

I have always wondered about that. I have a 1500 gallon septic system that services my home and I have wondered what the effect would be to pipe in a line from my RV parking spot and empty the tank into my septic. My fear is shocking the system or overloading it. I carry 74 gallons of gray and 40 of black. Let me rephrase that, I have the capability to carry these quantities. Has anyone out there ever done this before and what was the results. I know it is off the topic here but do we have any resident septic system specialists that could answer some questions off-line? Thanks in advance.

 

[plongson]

I went to the Thetford site and posted the same question. I got pretty much the same answer. Bottom line, this stuff is not good for septic systems, although they downplay it.



I have dumped once and will need to again before too long, and both batches have chemical in them. Well... Too late now to worry about what is "Down the Tube" as they say... Who makes the bio formula?? I don't remember seeing it. As a last resort, I will just not add ANY chemical but will just dump the black ALOT more often. After all, it is just a pull of the handle now...



Here was Thetford's reply:



Good Morning,



Attached is the information concerning your question provided by the Thetford Chemist:



Empty in Septic System

In response to your inquiry about emptying holding tank waste containing Thetford's Aqua-Kem form your RV into your home septic system.



The active ingredient of Aqua-Kem is formaldehyde. Formaldehyde is readily biodegradable and completely treatable in both aerobic and anaerobic (septic) treatment systems. Several tests performed by many independent scientists shows formaldehyde can be successfully treated with no adverse effects at 100 ppm. Many studies show higher levels of formaldehyde can be treated if the systems always treats formaldehyde , but as a conservative guideline, Thetford accepts the 100 ppm upper limit.



Calculations using an eight-ounce dose of Aqua-Kem directly into a 1000-gallon septic tank result in formaldehyde concentration of 23 ppm. This assumes the deodorant is dosed directly into the system. In actual practice, the level will be much lower as the formaldehyde is consumed by the waste in the holding tank prior to emptying. Formaldehyde is inactivated by contact with certain naturally occurring material such as feces and blood. The more waste in the tank, the higher the temperature, and the longer the waste is held in the tank before emptying, the lower the formaldehyde levels will be. The formaldehyde concentration in your septic system will be much less than the allowable upper limit. The important aspect of treating holding tank waste in a septic system is to maintain the system properly. The solids level must be monitored and pumped out when needed.



In order to be certain the formaldehyde concentration does not exceed the 100 ppm level, you should only use the recommended dose of eight ounces to a forty gallon tank. You should never overdose the tank with deodorant. As a conservative guideline, Thetford recommends you empty your holding tank in your home septic system only once per week. If a new home, must use one year before start emptying RV waste in it regularly. If more than two people in household may be able to start using sooner.

 

[GAmes]

FWIW, I quit using additives in my black water tank years ago. I "full timed" in my back yard for almost two years while doing extensive remodeling on the house and flushed my tank about once a week (50 gal). Part of that time was septic, now am hooked to city sewer. We never had a problem with fumes or dumping the tank. I'd say quit using any additive in the tank (except maybe Rid-X) and dump away!

 

[Gene Arnold]

I am also someone who doesn't use anything in my blackwater tank. I never notice any odor.



Gene

 

[JStraw]

No additives for me either. I live / work out of state in my RV and dump / flush once a week. Been that way for three years with no problems. Save your money for beer

 

[richardcoxid]

I am definitely not an “expert” in the septic tank field. I also don’t know of anyone who has gone “diving” in one lately (at least on purpose). This is our first hand experience though in the subject matter.



18 ½ years ago we built our house with a septic system and a 1000? Gal septic tank. I had the plumber install a 4 inch clean out plug in our driveway next to where we park our 5th wheel.



We use ONLY the enzyme/Rid-X/biodegradable type of chemical (not perticular on any brand) or sometimes no chemical at all and dump at home on our return from every outing. For convience when out for only a few days we will not dump at the Rv park but will haul the “stuff” home (it is mixed up that way) and dump while un-loading the RV.



This summer we had our septic system pumped for the first time. The pumping service “dipped” the tank and said that it was only about ¾ full of “solids”. Maybe the enzyme type of chemical “adds” to the “action” in the septic tank?



When questioned, a personal friend (a Nuclear Chemistry Analyst not an Organic Chemist though) feels that due to the dilution and other “unknown” factors an OCCASIONAL dumping of a black tank containing formaldehyde will do no harm. If you were to dump a black tank containing formaldehyde 2/ 3 or more times/day all summer long it would probably then slow down or stop the action. This is similar to what Thetford said above.



BTW do you know what an “expert” is?



Ans. - In mathematics “X” is the unknown factor and a spurt is a “drip” under pressure! LOL



May you have fair winds and following seas.

 

[richardcoxid]

I should of added that we dump our "black" and "gray" tanks in our septic system

 

[abdiver]

"pumping service “dipped” the tank and said that it was only about ¾ full of “solids”. "



Much more than you wanted to know about septic tanks



I don't know what was meant by your pumper service by only ¾ full of “solids



Septic tanks protect your leachlines lots better to pump your tank out every 2 - 5 years (depending on usage and what all you put in it size of family, garbage disposer, etc. ) than pay thousands to replace leachlines not to mention digging up your yard.



Make sure pumper removes all liquid and solids from both sides of tank

Most modern tanks are 1200 gallons in size this depends on local and state codes



Septic tank operation is based on detention time, the amount of time it takes for a flush to pass thru the tank if it passes to fast solids will end up in your leachlines



If there a tank is 3/4 full of solids that only leaves 1/3 of tank for liquids, 1/3 tank is aprox 300 gallons if you place 100 gallons a day into your tank every three days this will get into your leachlines



For almost 30 years I installed and pumped septic tanks A septic tank should be pumped out when the floating mat is over 9 inches thick and or if the sludge (solids that settle on the bottom of your tank) are more than a foot thick. Only way to tell how thick bottom sludge is. Use a mortar hoe or take a 6" x 9" 1x board and screw it to a 7' to 8' 2x2 and place the 6" x 9" on top of the floating mat and slowly push down on the 2x2 handle and the 6" x 9" will break pass through the mat once it breaks through the 6" x 9" in the liquid and will go down with very little pressure BE CAREFUL DON'T FALL IN ! Once you break through the upper mat Not the thickness. Now continue to slowly press the 6" x 9" through the liquid till you feel a slight resistance this will be the top of the sludge near the bottom of tank Make a reference mark on the 2x2 handle and continue to push down till you feel the bottom of tank Make another reference mark on the handle remove tool and wash of handle and measure the difference between the reference marks, this will be the aprox depth of the sludge

 

[cwsoules]

I do not use chemicals in my tank and dump it on occasion into a septic system. We have had no complaints. I use my sewer solution system to dewater my tanks, then back flush the tank and drain again. No odors and no problem.