Black Tank Chemicals - Liquid or Dry?

[sandsys]

3 hours ago, Five Wood said:

Just hold the foot pedal at 50% to allow fresh water to enter the toilet and then quickly push the foot pedal down to drain it.  

So that's how I do it.

That's how we taught visitors to do it. They were impressed with how efficient a system it is.

Linda Sand

[Zulu]

.....

[Zulu]

OP, as you can see from the replies, water, water, and more water is the chemical of choice in black tanks.

Most of the water-water-water people usually say they've been using it for umpteen years. Sometimes, but not very often, they'll link to an article to back up their opinion. But, typically, folks just say that since it's been working for them, you should do it too.

I, too, typically just plain old water to flush my black tank, but at times I use bleach (for any number of reasons).

However, using anything besides water (Happy Camper, Geo Method, bleach, etc) can subject you to criticism like . . .

• You're just wasting your money on chemicals
• You're going to harm your RV
• You're going to harm septic systems, environment, etc.

You're just wasting your money on chemicals
No, not if I think it's worth it.

You're going to harm your RV
My favorite. While I'm certain there are chemicals that can harm an RV's plumbing system, bleach isn't one of them. An RV water/waste system is made from ABS, PEX, polyethylene, and Santoprene (the "seals") . . . all of which is bleach tolerant.

You're going to harm septic systems, environment, etc
This is a hard one. Too much bleach will kill a septic system. So I did some research and found a couple of sources from universities:

• Household Chemicals and Your Septic System (Cornell Cooperative Extension)
• Why Do Septic Systems Fail? (NC State Extension)

The upshot from these and other articles I read is that non-excessive use of bleach is ok. What's "non-excessive"? From the first article above, 2 gallons of bleach will kill most of the bacteria in a 1,000 gallon septic tank. For a 40 gallon RV black tank, that's about 20 ounces (2 1/2 cups). Even doing that, it only takes about 45-60 hours for the bacteria to regenerate.

On the other hand, the most common cause of septic system failure was too much water. Sound familiar?

 

[FL-JOE]

5 hours ago, Zulu said:

OP, as you can see from the replies, water, water, and more water is the chemical of choice in black tanks.

Most of the water-water-water people usually say they've been using it for umpteen years. Sometimes, but not very often, they'll link to an article to back up their opinion. But, typically, folks just say that since it's been working for them, you should do it too.

I, too, typically just plain old water to flush my black tank, but at times I use bleach (for any number of reasons).

However, using anything besides water (Happy Camper, Geo Method, bleach, etc) can subject you to criticism like . . .

• You're just wasting your money on chemicals
• You're going to harm your RV
• You're going to harm septic systems, environment, etc.

You're just wasting your money on chemicals
No, not if I think it's worth it.

You're going to harm your RV
My favorite. While I'm certain there are chemicals that can harm an RV's plumbing system, bleach isn't one of them. An RV water/waste system is made from ABS, PEX, polyethylene, and Santoprene (the "seals") . . . all of which is bleach tolerant.

You're going to harm septic systems, environment, etc
This is a hard one. Too much bleach will kill a septic system. So I did some research and found a couple of sources from universities:

• Household Chemicals and Your Septic System (Cornell Cooperative Extension)
• Why Do Septic Systems Fail? (NC State Extension)

The upshot from these and other articles I read is that non-excessive use of bleach is ok. What's "non-excessive"? From the first article above, 2 gallons of bleach will kill most of the bacteria in a 1,000 gallon septic tank. For a 40 gallon RV black tank, that's about 20 ounces (2 1/2 cups). Even doing that, it only takes about 45-60 hours for the bacteria to regenerate.

On the other hand, the most common cause of septic system failure was too much water. Sound familiar?

 

Some of your information makes sense.  However, is your RV tank made of concrete and buried 5 to 8 feet underground with no vents?  RV blacks tanks ARE NOT RESIDENTIAL SEPTIC SYSTEMS!

[GlennWest]

We don't get black tank odors. Only time I ever get a smell is outside dumping. The air passing over the top of our unit picks it up as the wind blows by. We use water only. 

[Kirk W]

1 hour ago, FL-JOE said:

However, is your RV tank made of concrete and buried 5 to 8 feet underground with no vents?  RV blacks tanks ARE NOT RESIDENTIAL SEPTIC SYSTEMS!

Not all septic systems meet your description either. Septic tanks come made of a wide range of materials and concrete is getting less common. I can't recall ever seeing one that was 5' below the surface. I could tell you much more about septic systems due to my involvement in care and maintenance of the 10 systems in our home community, but that has nothing to do with the discussion here and isn't likely to change your mind. It also has nothing to do with the original question, so let's not waste time or forum space arguing over something that we aren't likely to agree about anyway?☺️

[Zulu]

2 hours ago, FL-JOE said:

However, is your RV tank made of concrete and buried 5 to 8 feet underground with no vents?  RV blacks tanks ARE NOT RESIDENTIAL SEPTIC SYSTEMS!

FL-JOE, two things:

1. Yes, you are correct, an RV black tank is not a septic system. The black tank is just a holding tank. However, the contents of an RV black tank ends up in a septic system. Get it?
2. There's no need to quote an ENTIRE post -- just the cogent points. Unless, of course, you're posting on IRV2 where continuously re-quoting complete posts is the norm.

[Pat & Pete]

10 hours ago, Zulu said:

 

You're just wasting your money on chemicals
No, not if I think it's worth it.

 

How ridiculous .

Just because you think something , doesn't make it anything other than a thought . 

If it did , we'd all be in Shangri-La and have no need for 'worth' .

[Zulu]

44 minutes ago, Pat & Pete said:

Just because you think something , doesn't make it anything other than a thought . 

Very Zen-like post, P&P, but it also applies to you.

 

[Pat & Pete]

2 hours ago, Zulu said:

Very Zen-like post, P&P, but it also applies to you.

 

Of course it does . Same for everyone .

[RV_]

Zulu,

None of your links addressed an RV park with 100 or 1000 RVs dumping into one system. They do apply to an RVr who also owns a home and has hookups for their one RV and maybe even a guest RV in addition.

But one toilet flushing a gallon and 200 dumping from 20-100 gallons of black water at a time, each, are entirely different animals.

I linked earlier in this thread to the University of Arizona article dealing with RV dumping into RV park septic systems specifically.

Here it is again:

https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1233.pdf

Excerpt from that Arizona State University article:

"RV Holding-tank Treatments & Deodorizers in Septic Systems

If you spend any time in a recreational vehicle (RV), you probably have experienced the problem of unpleasant odors from the graywater and blackwater holding tanks. There are a number of commercial products available to treat and control those odors while traveling or camping in your RV. Some of the products contain chemicals which may also adversely impact the septic systems that receive your holding-tank contents and, as a result, may pollute water resources. These chemicals and their by-products can kill the good bacteria in septic systems and may contribute to the discharge of dangerous, contaminated, health-threatening effluent to the soil surface or into groundwater or nearby surface waters.

Many RV facilities, throughout the country, rely on onsite wastewater treatment systems (septic systems) to treat sewage, and septic systems are particularly vulnerable to chemical contamination. The purpose of this fact sheet is to explain how a septic system works and how RV holding-tank treatments and deodorizers may harm them.

How A Septic System Works

Septic systems are individual (onsite) wastewater treatment systems where wastewater is collected, treated, and disposed (as 0pposed to offsite treatment at a municipal wastewater treatment plant). A typical septic system contains two major components: a septic tank and a soil treatment area, also known as a drainfield or leachfield. The purpose of the septic tank is to allow for separation of solids from liquids and to provide time for naturally-occurring microorganisms to partially breakdown organic matter in the wastewater. The soil treatment area disperses the septic tank effluent and provides the final treatment of the wastewater through physical, biological, and chemical processes in the soil.

RV Treatments & Deodorizers

The two major functions of RV treatments and deodorizers are to facilitate the liquefying of solid wastes and reduce odors in the holding tanks. These RV products may contain enzymes or very toxic chemicals, such as formaldehyde. Most products either mask the odor or kill the bacteria causing the odors. When such treated RV wastewater is dumped into a septic system (or municipal wastewater treatment facility), it can kill the bacteria in the system and ultimately cause the treatment system to fail. Without bacteria, the treatment system cannot adequately treat the waste. There is no (or very limited) breakdown (“digestion”) of organic matter, and the primary treatment process (settling of the waste) may be hindered. Inadequately treated wastewater allows solids to pass from the septic tank to the absorption field and clog the soil. Clogged systems will allow inadequately treated sewage to surface or percolate to groundwater. Surfacing effluent can affect the health of people or pets who come in contact with it. Percolated chemicals and untreated wastewater may contaminate nearby drinking water wells, rivers, and streams. Please read the labels carefully to identify any hazardous ingredients. Table 1 has a list of active ingredients to avoid because of their potential threat to onsite wastewater treatment systems.

What You Can Do to Help

Sewage treatment problems make RV living less comfortable and increase the cost of operating a RV park. You can help keep your fees reasonable and protect the environment by taking these basic steps:

- Minimize your use of holding-tank treatments and deodorizers by dumping your holding tanks frequently.

- Leave graywater valves open whenever you are connected to a RV park sewer service line. Leave blackwater tank valves closed and dump when half or more full. NOTE: Dumping with less than a half tank will seldom be an adequate volume to properly “flush” solids, and you could experience a persistent paper/fecal build-up in the tank. Holding tank gauges/monitors are seldom accurate.

Therefore, use a flashlight and look down from above the stool to judge the fullness of your tank. Don’t dump holding tank contents on the ground. Use a tank flushing device after dumping a RV holding tank each time. These in-tank devices can be self-installed or by a RV service center. In-line back-flushing or “wand” type devices are also available. NOTE: don’t use potable drinking water hoses for such activities.

- When using a holding-tank treatment or deodorizer, read the label and follow the directions carefully.

REMEMBER, excessive amounts of RV holding tank treatments or deodorizers and those not recommended by the manufacturer can and will disrupt the wastewater treatment system you dump into. Consider using only enzyme-based or bacterial-based products. Please note that the term biodegradable does not necessarily mean that the product is safe for humans or the environment.

Never use bleach to treat or “sweeten” a tank. Bleach can severely and quickly damage valves, seals, and gaskets.

- Ask questions of your park manager about drinking (potable) water and wastewater management. Sanitation costs can be minimal, but are not free.

- Educate other RVers. Don’t be shy about your health or the health of the environment.

The restoration of failed RV-park septic systems ultimately costs you money. The costs to renovate a system will be added to your space fee, and the restoration of contaminated groundwater can be extremely time consuming and costly.

Further information is available on household septic systems at the University of Arizona Extension publications

web page ( http://ag.arizona.edu/pubs).

That whole page with the tables of black water additives and more hotlinks can be found here:

https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1233.pdf

Safe smell-free travels!

 

 

 

[noteven]

This first world problem could be a script for a reality TV series: $hit Tank Wars

[Zulu]

 

2 hours ago, RV_ said:

I linked earlier in this thread to the University of Arizona article dealing with RV dumping into RV park septic systems specifically.

 

Yes, I read the article . . . and then some . . .

The 2010 Arizona Extension Article you linked to is based on an earlier 2001 Arizona Extension Article which are both based on an even earlier 1999 EPA Article.

All three articles say basically the same thing -- some RV chemicals (like formaldehyde and insecticides) are bad for RV septic systems. However, both AZ Extension articles went on to claim that using bleach will essentially destroy your RV plumbing . . . which was true at one time.

The original AZ Extension article was written in 2001 during the time of the Spencer Class Action Lawsuit over polybutylene (PB) plumbing failures. You see, even small levels of bleach could damage PB plumbing in homes and in RVs.

Apparently, the AZ Extension authors never updated their article to match current RV plumbing which is bleach tolerant.

[2gypsies]

..... just wondering, what exactly does bleach do?

[Barbaraok]

And Zulu, do you have a degree in Chemistry or Chemical Engineering, Microbiology, Molecular Biology, etc.?   Do you know the age of all RVs that are currently on the road?    Since there is absolutely no need for bleach in either waste tank, why use it?   Seriously, why do you think you need to use bleach?    If it is for killing mold, there are also other oxidizers that will work just as well.  Same for washing clothes in an on board washing machine.     

[Five Wood]

9 hours ago, Zulu said:

The original AZ Extension article was written in 2001 during the time of the Spencer Class Action Lawsuit over polybutylene (PB) plumbing failures. You see, even small levels of bleach could damage PB plumbing in homes and in RVs.

Apparently, the AZ Extension authors never updated their article to match current RV plumbing which is bleach tolerant.

I have a 98 Carriage so I guess I don't have "current RV plumbing"☺️.  As I stated above, one of my reasons for not using it is because many of them slow the natural process of decomposition.  Many people use and love these products and that's just fine.  But if I can sit in my RV and smell my black tank, I know I have a mechanical problem.  Rather than mask the odor with perfume, I will correct the mechanical problem causing the odor.

Jim

[FL-JOE]

22 hours ago, Zulu said:

FL-JOE, two things:

1. Yes, you are correct, an RV black tank is not a septic system. The black tank is just a holding tank. However, the contents of an RV black tank ends up in a septic system. Get it?
2. There's no need to quote an ENTIRE post -- just the cogent points. Unless, of course, you're posting on IRV2 where continuously re-quoting complete posts is the norm.

Yes, I GOT IT.....but apparently you don't.  The OP asked about adding chemicals in his holding tank/black tank.  What does that have to do with it ending up in a septic system.  Besides that, not all CG's sewer system set ups are septic systems, some are municipal sewer systems, which are different.

Sorry for quoting an entire post.  didn't mean to take up valuable space on your I-phone screen or whatever device you are using where space is some type of major "get your panties in a wad" issue.  I'll try to do better next time.

[FL-JOE]

23 hours ago, Kirk Wood said:

Not all septic systems meet your description either. Septic tanks come made of a wide range of materials and concrete is getting less common. I can't recall ever seeing one that was 5' below the surface. I could tell you much more about septic systems due to my involvement in care and maintenance of the 10 systems in our home community, but that has nothing to do with the discussion here and isn't likely to change your mind. It also has nothing to do with the original question, so let's not waste time or forum space arguing over something that we aren't likely to agree about anyway?☺️

Kirk, I grew up working for a residential builder.  Owned homes both in a northern state and recently in Florida that had septic systems instead of being on municipal sewer systems.  I realize there are dozens of types/sizes of systems, but they are all basically the same.  My point was that a black holding tank in an RV is not a septic system and should not be treated like one.  

If folks don't want to put chemicals in their black tanks and that works for them then more power to them.  If others feel better about adding something to their tanks, then so be it.   I'm certainly done giving my opinion here and will let the "real experts" finish battling it out.

[Zulu]

12 hours ago, Barbaraok said:

And Zulu, do you have a degree in Chemistry or Chemical Engineering, Microbiology, Molecular Biology, etc.? 

The Queen of Leading Questions . . .

No, my degree is not on that area. However, you're really asking -- Since you probably don't have a degree in chemistry, etc, then how can you recommend using bleach?

Lots of reading. Doesn't make me an expert, but I think I can make intelligent decisions.

Let me ask you:

• Do you think bleach will destroy the plumbing currently used in RVs?
• What do think is more likely to cause problems in RV septic systems: (1) occasional use of bleach by RVers or (2) Inadequate septic system maintenance by the park owner?

12 hours ago, Barbaraok said:

Do you know the age of all RVs that are currently on the road? 

No, but I think you're really asking -- How can you recommend using bleach in RVs since there are a lot of old RVs that may have PB plumbing on the road?

I'll leave it to the RV owners to know how their RV is built.

12 hours ago, Barbaraok said:

 Since there is absolutely no need for bleach in either waste tank, why use it? 

 

Says you.

[Zulu]

4 hours ago, FL-JOE said:

Yes, I GOT IT.....but apparently you don't. 

What's funny is that we're essentially on the same side.

[RV_]

I agree that RV black tanks are holding tanks. Then they are dumped into septic systems.

Jim said it exactly best. If we smell the black tank there is a mechanical problem.

Fifteen years ago the guy from Cabo had a persistent odor issue that seemed worse when the A/C was turned on. We trouble shot it and on a hunch I suggested he take the A/C shroud off and check the sheet metal ofr holes and sure enough there were several big screw holes and some tape missing. His A/C was sucking the air from the nearby black water tank vent.

The most often seen culprit are owners who replace a rooftop vent sealing flange and push the vent tube down into the black or gray tank further than it was. When odors only appear when the tank is 1/4, 1/2, or 3/4s full the pipe may have been pushed into the bottom or the tank and not pulled back up at the factory. If the tank end of the vent is under water (liquid) in the tank it is the same as if it were blocked up top in that the gases have nowhere to go and a positive pressure will cause them to exit at any possible opening or loose place in the toilet floor seal, the down pipe, or around the black tank seal/flange around the tank end of the vent pipe.

The tank valve rubber seals are subject to deterioration by bleach as well as the rubber flange around the vent pipe.

Bleach (Sodium Hypochlorite still eats away at PEX or cross linked polyethylene, but much more slowly than PBX. Here is a chart with the resistance of PEX to chemicals:

The full chart and article is here: https://mrpexsystems.com/wp-content/uploads/2016/04/MrPEX-Chemical-Resistance-Chart.pdf

The chemicals you put in your black tank still get dumped into septic systems and sewers. If they are harmful once outside of your rig are you saying that is OK as long as your stuff is OK?

Like all folks new to the PB issues many haven't really checked into the one chemical at less than 15% concentrations that eats away at it slowly. It is only 50% resistant at 73 degrees f to Sodium Hypochlorite - bleach.

But you know what? Many folks will use a quick fix and not find the mechanical problem causing the odor. Most caused by an obstructed vent at the top or bottom, and having the exhaust fan on when flushing. just use it after flushing. Flushing in an RV exposes one to the full odor briefly and a spritz of air freshener takes care of it.

Folks will do what they will. Most of us use only water.

My black tanks and holding tank, down pipes, valve seals and gasket are all PVC or other materials, only my freshwater supply pipes to the toilet are PEX. Where does your rig run chlorinated/additive full sewage through freshwater pipes?

Dihydrogen monoxide is better than all of them. The universal solvent.

Zulu you have a great day!

 

[Barbaraok]

Zulu, again why do you think you need to use bleach besides sanitizing the fresh water tank?   No need what so ever for either waste tank. You have stated that bleach is needed, I’m asking for the reason.  Do you understand that bacteria working in the tanks need to be allowed to work, however briefly they are there.  That bleach laden discharge from hundreds of RVs could ruin a septic system if adequate dilution water is not available?  

If you have odor in your rig, get the problem fixed.  Hook up to certified municiple water systems every once in a while and run water through your system.  At most, a pint bottle of bleach for the sanitizing of fresh water tank is all you need.

[Zulu]

34 minutes ago, RV_ said:

My black tanks and holding tank, down pipes, valve seals and gasket are all PVC or other materials, only my freshwater supply pipes to the toilet are PEX.

Your black water and gray water tanks are probably ABS which is bleach tolerant. Bleach enters via the toilet.

PEX is for the fresh water system (+ polyethylene water tank). Typically the only time bleach runs through these is during water tank sanitation.

[Zulu]

7 minutes ago, Barbaraok said:

Zulu, again why do you think you need to use bleach besides sanitizing the fresh water tank?

Even when odors are not present, I'll use bleach occasionally to "freshen" my black tank because it's fast, cheap, effective, and readily available.

Now you're turn. Please answer my questions:

• Do you think bleach will destroy the plumbing currently used in RVs?
• What do think is more likely to cause problems in RV septic systems: (1) *use of bleach by RVers or (2) Inadequate septic system maintenance by the park owner?

* I mean the levels of bleach currently dumped into holding tanks, not if all of a sudden every RVer decided to use bleach.

[Zulu]

1 hour ago, RV_ said:

The chemicals you put in your black tank still get dumped into septic systems and sewers. If they are harmful once outside of your rig are you saying that is OK as long as your stuff is OK?

I'm saying that occasion use of bleach (not all chemicals, RV) in your black or gray tanks will probably not hurt your RV or septic systems. 

1 hour ago, RV_ said:

Like all folks new to the PB issues many haven't really checked into the one chemical at less than 15% concentrations that eats away at it slowly. It is only 50% resistant at 73 degrees f to Sodium Hypochlorite - bleach.

PB plumbing was not used in waste or drain plumbing (see International Association of Home Inspectors article which also explains how to identify PB plumbing).

Plus, here's an RV PB plumbing conversion.