Septic tank additives (C) Daniel FriedmanSeptic Tank & Drainfield Treatments & Chemicals vs Septic Tank Pumping - expert advice

  • SEPTIC TREATMENTS & CHEMICALS - CONTENTS: Septic System Treatments are NOT recommended and may be illegeal; Septic tank additives, septic drainfield restorers, Septic system chemicals, septic tank treatments, septic tank bacteria, yeast in septic tanks. Authoritative citations explain that septic tank pumping is what's needed to maintain & preserve the working septic tank and drainfield or soakaway bed, not Septic tank additives: position of septic experts, Canadian & US Government Agencies
  • POST a QUESTION or READ FAQs about the need for and use of septic system treatments, chemicals, additives, restorers
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Septic tank maintenance:

This article discusses the need, choices, and use of septic chemicals or bacterial or other septic tank additives, septic system restorers, and septic tank treatments for septic systems. We cite expert sources all of whom advise against the use of septic treatments, additives, restorers and the like.

Should you add septic treatment chemicals, nutrients, cleaners, bacteria, yeast, root killers, septic drainfield dec loggers to septic systems? Generally, no. Why not? What causes septic system failures?

Green links show where you are. © Copyright 2017, All Rights Reserved.

SEPTIC PRODUCTS FOR SALE - Alternative Onsite Waste Disposal (Septic System) Materials & Products

Septic treatment chemicals (C) Daniel FriedmanWhat do experts say about septic chemicals and septic treatments? Why do people use them?

Bottom line on septic treatments

Septic tank treatments and additives are not necessary for conventional septic tanks & absorption fields, some can contaminate the environment, others can destroy a septic drainfield or soakbed, none will repair a failed drainfield, and such products are at best usless and at worst harmful. This is the view of all of the septic system authorities we've found and are the views of most engineers and sanitation professionals. Those expert sources are cited here.

Types of septic system treatments and restorers, their use and effects are addressed here. Our page top photograph shows a collection of septic system additives, chemicals, cleaners, root killers, etc. for sale at a building supply store.

An exception: as we detail at the end of this article, some septic designs such as some aerobic and BAT systems may require occasional addition of beneficial bacteria to the septic tank.

InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information provided free to the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.

Article Series Contents

Despite that compelling evidence people still buy and use septic treatments or restorers. So did I - previously. Why? Because repairing a failing or failed septic system drainfield or soakaway bed is expensive the temptation to try a magic bullet is nearly overwhelming. Those bullets, generally, are going to shoot us in the foot.

Are Septic Tank Additives or Treatments Useful or Not? - Septic System Additives and Chemicals - are they needed?

Roebic septic tank treatment for sale at a building supply store (C) InspectApedia.comSeptic Additive Companies are Asked for Independent Supporting Research

Many septic treatment producers and distributors contact us with suggested products. We ask for independent, peer-reviewed, professional research supporting each suggested product. Such support is particularly needed for two reasons:

  1. Magic Septic System Cure Industry: The high cost of replacing a failed septic absorption field or seepage pit system naturally breeds an industry of "magic bullets" that are questionable (see the citations which follow) and sometimes actually harmful to the septic system and/or the environment.
  2. Illegal Septic System Treatments: Because of the lack of demonstrated effectiveness, and perhaps more important, because some septic additives or cleaners are dangerous or can cause serious ground water contamination they are illegal in many jurisdictions.

Septic tank additives or "rejuvenators" are not needed in your septic tank, whether the additives are chemically-based (organic or inorganic compounds that claim to break up sludge or scum or to unclog drainfields), or biologically-based septic additives (septic tank yeast cultures, septic tank bacteria, starter bacteria, or septic tank enzymes).

Watch out: While many septic and drainfield or soakaway bed treatments are relatively harmless combinations of bacteria and enzymes, some septic tank or septic drainfield additives such as yeast or harsh chemicals can actually damage the septic system and may also be environmental contaminants.

Even yeast, which one might think is harmless, can cause frothing and excessive activity in the septic tank, preventing normal settling of solids and coagulation of greases. This agitation forces solid waste into the drainfield and by clogging the soil, shortens its life. Other septic chemicals intended to kill tree roots or unclog clogged leachfield soils can contaminate the environment.

Exceptions to the generally-true "use no septic treatments" can arise however for some advanced-design septic systems such as some aerobic or biologically-accelerated treatment (BAT) septic system designs.
See SEPTIC TANK BACTERIA BOOST at the end of this article.

Can Some Conditions Kill Off Needed Septic Tank Bacteria? Do we need a septic tank "starter bacteria"?

If other conditions at a property have resulted in killing-off the (needed) septic tank bacteria (such as adding unusually large amounts of bleach, disinfectants, or antibiotics to a septic tank) some folks sell bacterial "starters" to "rejuvenate" the septic tank. This makes little sense for the following reasons:

  1. Calculations of "septic tank die-off" which demonstrate that about 2 gallons of bleach is likely to harm septic tank bacteria have been based on a "static septic system", a fixed septic tank volume into which no new wastewater, sewage, and their diluting and re inoculating effect have been considered.

    You will see in the Ontario ministry statement 3(f)(ii)[below] that small amounts of bleach, drain cleaners, lye, etc. such as the quantities expected in normal household use will not harm a functioning septic system.
  2. If you don't correct the conditions that have caused a bacterial die-off in the septic tank, no amount of starter or booster is going to make any difference. For example, large quantities of antibiotics entering a septic system at a nursing home will continue to risk harm to the septic tank ecology.
  3. Adding to a septic tank products such as enzymes which claim to break down grease risk destroying the floating scum layer in the septic tank, forcing unwanted oils and debris into the leach field. in the Ontario ministry statement 3(f)(iii) [below] you will note that enzyme treatments have not been found effective nor useful in septic systems.
  4. As soon as you stop putting inappropriate bleach, disinfectant, or antibiotics into the septic system and after the first time someone uses a toilet, the septic tank has been re inoculated with what it needs.

    However the release of chemicals from a septic system to the environment can be a serious problem in some locations, especially if larger volume industrial processes or larger facilities such as nursing homes are the chemical source, or if a well-meaning property owner pours large quantities of some treatments, chemicals, yeast, bleach, some root killers, or other "additives" into the septic system.
  5. Forcing hydrogen peroxide or other chemicals into drainfield or leach field soils can damage the soil and contaminate the environment.

Septic Tank PUMPING PREVENTS FAILURES - Authoritative Citations on Septic Tank Pumping, Failure Prevention, Additives

Pumping the septic tank regularly is the main thing that can and should be done to extend the life of your septic system.

See SEPTIC TANK PUMPING SCHEDULE for details on deciding how often the septic tank should be cleaned.

Details of a thorough septic tank pumpout, cleaning, and inspection are found beginning

In general, septic system chemicals are not needed and are not recommended: Chemicals and other additives promoted to keep a septic system "healthy" or "free-flowing" or "nourished" are generally not required nor recommended by expert sources. The following references support this statement:

The view that chemical and other additives are not necessary, and in some jurisdictions are illegal, was held by information we collected from every U.S. state as well as Canadian sources.

CANADA PROHIBITS Septic Tank ADDITIVES - Canadian citations on Septic Tank Additives - prohibited

Roebic root killer treatment for sale at a building supply store (C) InspectAPediaOur Canadian sources have offered the most detailed explanation of these issues. (Thanks to Alan Carson, Carson Dunlop, Associates, Toronto, Ontario, for providing this information.)

See "Manual of Policy, Procedures, and Guidelines for Onsite Sewage Systems," Referring to Ontario Regulation 374/81 under part VII of the Environmental Protection Act, ISBN 0-7743-7303-2.

ONTARIO MINISTRY - Ontario, Canada, Ministry of the Environment, "9.4.1 Class 4 Sewage Systems, Construction, Operation, and Maintenance," May 1982.

Biological and chemical additives are not needed to aid or accelerate decomposition in conventional residential septic systems. In some jurisdictions such septic tank products, cleaners, root killers, grease dissolvers, etc. are prohibited by building codes, as the municipality is concerned for chemical pollution of groundwater and aquifers.

Other products may actually harm the septic system. Some of my clients who added yeast to their septic tank regularly discovered that the yeast caused so much frothing in their septic tank that solids were forced into the leach field rather than settling to the tank bottom.

Opinions about what ought to be added to septic tanks to keep them "healthy" range from obscure possibility to ridiculous. At a class on this topic in Ontario an inspector insisted that a bacterial inoculation was needed in the septic tank whenever it was pumped. Nonsense.

There is plenty of bacteria left in the tank and entering it when it's used. Another inspector said he tossed a cat into the septic tank after cleaning.

Although it was difficult to take such a comment seriously, he insisted that he was not kidding. Popular delusions and the madness of crowds has infected the onsite waste disposal topic as badly as the Dutch tulip craze affected gardeners.

National Environmental Services Center (NESC) Statement on Septic Tank Treatments

Additives/System Cleaners

While many products on the market claim to help septic systems work better, the truth is there is no magic potion to cure an ailing system. In fact, most engineers and sanitation professionals believe that commercial septic system additives are, at best, useless, and at worst, harmful to a system.

There are two types of septic system additives: biological (like bacteria, enzymes, and yeast) and chemical. The biological additives are harmless but some chemical additives can potentially harm the soil in the drainfield and contaminate the groundwater.

While there hasn’t been extensive study on the effectiveness of these products, the general consensus among septic system experts is that septic system additives are an unnecessary evil.

Be aware that the extended use of strong pharmaceuticals and personal care products may harm the working bacteria population in the tank. The total effects are unknown at this time. - NESC Pipeline - Fall 2004, Vol. 15 No. 4.

US EPA Statement on Septic Tank Additives

Onsite Wastewater Treatment Systems Special Issues Fact Sheet 1 EPA 625/R-00/008

Description of Septic Tank Additive Products

Because of the presence of significant numbers and types of bacteria, enzymes, yeasts, and other fungi and microorganisms in typical residential and commercial wastewaters, the use of septic system additives containing these or any other ingredients is not recommended.

The benefits of consumer products sold as septic system cleaners, degraders, decomposers, deodorizers, organic digesters, or enhancers are not significant or have not been demonstrated conclusively, depending on the product.

Some of these products can actually interfere with treatment processes, affect biological decomposition of wastes, contribute to system clogging, and contaminate ground water. The septic tank/soil absorption field system is the most commonly used onsite wastewater treatment system in the United States. It is relatively low in cost, has no moving parts, and requires little maintenance.

Septic tanks have a number of important functions, including:

Types of septic tank or septic system additives and effects on treatment processes

This topic has moved to SEPTIC ADDITIVE TYPES

There are three general types of commonly marketed septic system additives:

Baking Soda in the Septic Tank?

This discussion has moved to BAKING SODA

Odor Control For Septic Systems

This topic is now at ODOR CONTROL


Phosphorous Removal For Septic

Please see the new page for this topic at PHOSPHOROUS REMOVERS 

Yeast Treatments for Septic Tanks

Yeast in septic systems and tanks is now discussed at YEAST in the SEPTIC TANK

Porosity Restorers for Septic Fields

This discussion is now at POROSITY RESTORERS

So What Should I Put into the Septic Tank?

  1. Normal human waste and wastewater
  2. Toilet Paper

Reader opinions on toilet paper and septic filters or lint traps

Do not put toilet paper or any other material except human waste in the toilet. Place garbage can in bathroom and place paper in the can. Dispose of paper with other household garbage. Will extend life between pumpings by years. Randy Green, 10/30/12

You can extend the life of your septic system by removing enough non-biodegradeable clothing fibers to carpet your living room each year by adding highly-technical lint traps that filter all the fibers from the washing machine discharge line.

It is these non-settleable, drain field plugging fibers that you find adorning the landscape with spider web like features whenever you run into someone who has recycled his gray water for lawn and garden watering. - Sweetfilter 11/1/11

Reply: What's the difference in effect between toilet paper and fabric fibers in the septic system?

Randy, indeed in some countries it is common practice to keep a small, plastic lined waste container next to the toilet, into which used toilet paper and other wastes other than urine or excrement are deposited. I expect that keeping paper out of the septic system gives some added relief in areas where the system is of very limited capacity and perhaps where the water volume is lower than common in North America too.

Toilet paper settlement test (C) Daniel FriedmanBut in normal use with a conventional septic system such as designs commonly used in the North America that does not appear to be necessary and I have not found an authoritative source that recommends it. If you or other readers come across such a reference be sure to let us know so that we can post it for others.

On the other hand, I agree completely with Sweetfilter that a septic filter that keeps cloth fibers and similar debris out of the septic system or even out of a drywell used to dispose of laundry wastewater and similar graywater is a great idea and will reduce soil clogging and extend the system life.


What's the difference in effect between toilet paper and fabric fibers in the septic system?

Toilet tissue is claimed to break down into small enough biodegradable fragments that it does not add significantly to soil clogging in the drainfield. Illustrated in our photo (above left), we are running an ongoing test of RV toilet tissue and other tissues to see how they dissolve or break down in plain water and ultimately in water that contains the appropriate septic tank bacteria.


Use of Recycled Paper - Based Toilet Paper, US EPA Recommendation, vs. Septic Tank Enzymes

See TOILET TISSUE CHOICES where we address the EPA recommendation for recycled-paper content in toilet tissue. The EPA also provides a search engine to find suppliers.

To Maximize the Life of Your Septic Tank and Drainfield You May

Watch out: adding a septic tank aerator with incomplete design can push solids into and destroy the drainfield. Aerobic septic tanks use multiple chambers to avoid this problem; a retrofit design would typically include an outlet tee filter or separate filtering chamber that, if omitted or not properly maintained is likely to lead to sewage backups or septic system failure.

We make no specific representation about the efficacy of any of the particular products shown in the page top photo, but expert sources quoted in this article should be read carefully by any property owner considering adding a chemical, enzyme, or other product claimed to treat their septic tank or drainfield.

Comments and suggestions for content and citations of unbiased expert authority are welcome. Citation of this article by reference to this website and brief quotation for the sole purpose of review are permitted. Use of this information at other websites, in books or pamphlets for sale is reserved to the author. Technical review by industry experts has been performed and is ongoing - reviewers are listed at "References."

Need for Bacterial Boost in Some Septic Systems

Really?: OK so there are some exceptions to the "no septic tank additives or treatments are needed" rule.

While septic tank chemicals, treatments, additives are both unnecessary and often prohibited for conventional septic tank & soakbed or leachfield systems, there are exceptions: occasional treatments with a dry-pack (or wet pack) of beneficial bacteria may be recommended by the manufacturer / designer of BAT or biologically accelerated treatment septic systems and for some aerobic septic treatment systems that are left un-used for six months or longer.

That's because some septic designs continue to treat and remove bacteria during periods of dis-use. But in an ordinary septic system the tank and its wastewater are not normally sanitized.

In addition, flushing continuous or high levels of chemicals or drugs into any septic system can seriously damage the systems' biological process and equipment. Paints, high-phosphate detergents, salty water softener discharge, heavy use of drain cleaners, concentrated detergents, antibiotics, and even high usage of antibacterial soaps can be a problem for more-delicate septic systems such as the BAT septic design cited above.

See BAT MEDIA SEPTIC PLANTS for an example of cases in which a septic design or manufacturer recommends the replenishment of septic tank bacteria formulated for use with aerobic or BAT (Biologically Accelerated Treatment) septic systems.

See TOILETS, DON'T FLUSH LIST for complete details about stuff to keep out of the septic system.

InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information provided free to the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.


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