Did you ever wonder about the chemistry of the currently available holding tank treatments?
Here is some information for you to ponder over…..
What we RVers put into the holding tank in solid form (yes, human waste) contains friendly bacteria known as coli forms. This is the same bacteria that digests the food we eat and is necessary to breakdown the solid waste in the holding tanks.
The black holding tank in RVs can be thought of as a small septic tank where the breakdown process begins and here, the proper use of chemicals is important. Using improper chemicals can kill the beneficial bacteria and cause improper waste breakdown that leads to odors. Makes sense!
A septic tank system consists of two major parts: a tank and a drain field or leach field. The septic tank or holding tank allows the solids to settle to the bottom. This settling process gives the bacteria time to break down and liquefy the waste. During the breakdown process in the holding tanks, it is important to keep the bacteria supplied with oxygen (in an aerobic condition) so the bacteria can liquefy the waste without producing the odor nobody likes.
This gas, hydrogen sulfide, is corrosive to both steel and cement which is the reason waste treatment plants will aerate the sludge or add oxygen-releasing chemicals to the sludge to keep the bacteria working properly. So . . . it is important to use a product that supplies oxygen to the bacteria and not use a harsh chemical that will kill the bacteria. Still make sense!?
Waste treatment plants monitor the oxygen content and the goal is to maintain the oxygen content between three and five parts per million. Above five parts per million, the bacteria begin to die and below three parts per million there is not enough oxygen and the bacterium goes into an anaerobic (without oxygen) condition. This anaerobic condition produces the odor nobody likes to smell.
The use of harsh chemicals that kill the bacteria will slow or stop the liquefying process in dump station systems and lead to costly repairs or replacement of the system. Also malfunctioning systems can contaminate underground water sources, surface water sources or even the soil.
There are many products on the market for use in holding tanks – but you do have to be careful and do your research. Here is a brief overview of what you will see in some of the products available:
- Enzymes – The labels on these products usually are not specific about the active ingredients. The word “enzyme” is usually associated with compounds that are needed for a chemical reaction to occur. The function of supplying oxygen to the friendly bacteria is difficult to determine. Most products carrying enzymes to not specify the type or what kind of enzymes the consumer is buying.
- Nitrates – Nitrates are useful to the RV holding tank because the chemical compound breaks down to release oxygen to the friendly bacteria resulting in an aerobic condition as the bacteria process the sewage.
- Formaldehyde – This most widely used chemical is mixed with methyl alcohol and is marketed as a blue-colored, perfumed liquid. The EPA states “formaldehyde kills or retards bacterial growth; is recognized as a probable cancer-causing agent and is moderately toxic to humans. It does not supply oxygen to keep the bacteria in an aerobic condition.
- Benzaldehyde – The label on this package states it is formaldehyde-free. Here is a deception in marketing – sure, it does not contact formaldehyde, it contains benzaldehyde, which is in the same chemical family as formaldehyde. Most chemicals in the same chemical family act the same way.
- Paraformaldehyde – EPA states this is a variation of formaldehyde. When heated, paraformaldehyde releases formaldehyde. According to the EPA, it is also a bacterial pesticide and very toxic to humans.
- Glutaraldehyde – This chemical is better known as embalming fluid. For many years, it was used as gray water treatment product. In 2003 or so, the gray water treatment package was redesigned and the glutaraldehyde was removed. The label now states the product contains surfactants. Surfactants are chemicals that make water “wetter”. Surfactants reduce surface tension; the water loses its suction, and falls off the surface walls. These products are usually lemon-scented.
- Bronopol – The EPA states that Bronopol is a bacteria pesticide (kills bacteria). It also states that Bronopol breaks down into formaldehyde. It is a common ingredient in products marketed in tablets and green liquids.
These products are labeled as formaldehyde-free which is correct, however, what is little known to the average RVer or campground owner is that in the presence of sewage, bronopol breaks down into formaldehyde. This information should be included on the label so the environmentally conscious RV consumer can make an informed choice in the use of chemicals.
- Dowicil – The EPA states this chemical is a bacterial pesticide (A bacterial pesticide kills bacteria). EPA states “Do not discharge effluent containing this product to sewer systems withouth previously notifying the local sewer treatment plant authority.”
- Ammonium Compounds – These are bacterial pesticides that kill bacteria. They are often found in sprays for surface bacteria. This chemical and most of the chemicals discussed in this article do not provide a source of oxygen to the friendly bacteria to conform to normally practiced and recognized sewage treatment methods.
WHY SHOULD RVers BE CONCERNED WITH WHAT PRODUCTS THEY USE? – As RVers we must be concerned about the chemicals we use in our holding tanks. Most of the products are harsh chemicals designated by the EPA as bacterial pesticides that either kill or slow down the growth of the bacteria. Unpleasant odors are still present so perfumes or deodorizers are added to these products to hide the smell making these products nothing more than glorified tank deodorants.
Of concern to us RVers is the closing of dumpsites. Every year another state or city will close their usually “free” dumpsite because of overuse of these “harsh chemicals”. Local tax dollars are used to put the system back in use and with government bodies being squeezed by higher demands from voters and resistance to tax increases, these “free” privileges for us may very well vanish in the future. So it is to the benefit of all RVer’s to become familiar with the sewage treatment process and chemicals they buy. It may take a little effort to remember the chemical names but the effort is worth it.
What do we recommend? Pure Power Waste Digester will do all of this for your holding tank to keep it clean, free flowing and smelling good.