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SEPTIC SYSTEM INSPECT DIAGNOSE REPAIR
SEPTIC CARE INSTRUCTIONS
SEPTIC D-BOX INSPECTION
SEPTIC DRAINFIELD FAILURE DIAGNOSIS
SEPTIC DYE TEST PROCEDURE
SEPTIC FAILURE SIGNS
SEPTIC INSPECTION & TEST GUIDE
SEPTIC LIFE EXPECTANCY
SEPTIC SUPPLIES & PARTS
SEPTIC SYSTEM DESIGN ALTERNATIVES
SEPTIC SYSTEM DESIGN BASICS
SEPTIC SYSTEMS, HOME BUYERS GUIDE to
SEPTIC SYSTEM SAFETY WARNINGS
SEPTIC TREATMENTS & CHEMICALS
SEWAGE BACKUP PREVENTION
SEWAGE EJECTOR / GRINDER PUMPS
SEWER GAS ODORS
SEWER LINE REPLACEMENT
SINKHOLES, WARNING SIGNS
SOAKAWAY BED FAILURE DIAGNOSIS
SULPHUR & SEWER GAS SMELL SOURCES
TOILETS, INSPECT, INSTALL, REPAIR
TRAPS on PLUMBING FIXTURES
TREATMENTS & CHEMICALS, SEPTIC
VIDEO GUIDES: Septic Videos
WATER CONSERVATION MEASURES
WATER SOFTENERS & CONDITIONERS
WATER SUPPLY & DRAIN PIPING
WATER, WELLS, WATER TANKS: TESTING GUIDE
WASHING MACHINES & SEPTIC SYSTEMS
WASTEWATER TREATMENT BASICS
WINTERIZE A BUILDING
Septic tank interior inspection: here we explain the importance of (and procedures for) inspecting the septic tank baffles and tank interior after septic tank pumping/cleaning. Cleaning the septic tank during tank pump-out can expose damage to the septic tank sides and bottom that cannot otherwise be found. This septic tank pumpout article series provides a step by step, photo-illustrated guide to opening, pumping, and inspecting septic tanks, how a conventional septic tank is located, opened, pumped out, cleaned, and inspected. This guideline is intended for septic pumping tank truck operators and as general information for homeowners or septic service companies concerned with septic system care.
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A Photographic Guide to Pumping a Septic Tank
Inspect the Cleaned-Out Septic Tank for These Problems
Next step be sure to read CLOSE the SEPTIC TANK.
Frequently Asked Questions (FAQs)
Question: Is it acceptable practice to return sewage from a septic pumper truck back into the septic tank after a pumpout?
The septic contractors convinced our municipalities that after a septic tank has been emptied it should be immediately refilled (to its original level) with effluent from the pumper truck - claiming that a) gravity in the pumper truck's tank separates the solids from the liquids (during the 5 to 10 minutes the effluent is in the truck) so that mostly only liquid is returned to the septic tank; and b) that this return of effluent improves septic performance. I can see the financial advantage for the contractors (fewer trips to the water treatment center; lower disposal costs; charge homeowners extra $$$ for 'complete' emptying) but I cannot find any independent evidence from a reputable source that supports these claims. Does anyone know of any sources that actually support these claims? - Bob 5/3/12
Reply: Pumping out and then restoring sewage to a septic tank is a Churn-and-Return Septic Tank Agitation that is likely to cause costly damage to the septic system
Thank you for this question about what appears from your description to be a seriously problematic septic tank "service procedure". This process you describe will absolutely not improve septic tank performance, in fact it will harm it and will destroy the septic drainfield. In fact no septic tank additives nor improvers are necessary nor recommended for conventional septic tank operation and using them is not only harmful, but is illegal in many jurisdictions in the U.S. and Canada.
In our opinion the process you describe fails to respect the most fundamental principles of septic tank and drainfield operation, as we explain below.
In addition to the financial issue that you point out surrounds the apparent delivery of a service that is then "un-done" afterwards, below we list the concerns in order from least harmful and costly to most harmful and costly.
We recommend the use of effluent filters at the septic tank outlet to extend the life of drainfields, precisely in order to reduce the passage of suspended solids into the fields. If, however, the septic is simply agitated by the process you describe rather than being properly pumped, cleaned, and inspected, even if a septic filter were installed at every septic tank serviced by the pumpers you describe, the filter life would be drastically reduced, septic system operating costs will be increased, and the other problems we listed above will still be present.
In sum, the procedure you describe is not one we can recommend for your community nor any other. 
Watch out: Pushing grease, scum, and small solid debris out of the septic tank and into the leach field reduces the future life of that expensive component of a septic system. In fact if a septic tank has become blocked or even nearly-blocked by solids, the system has already had a history of pushing solids into the drainfield and even if the system appears to still be working properly, the future life of the drainfield has been substantially reduced.
Reader Follow-Up 5/15/12 - will I find an authority that prohibits churn-and-return septic tank pumping?
Mr Friedman: Thank you for the very comprehensive response that confirms my suspicions that homeowners in our (rural) municipalities have long been paying $175 every 2 years for a mandatory service using a questionable procedure (empty & refill) that is damaging septic systems (using the “it removes the solids & maintains a bacterial population” rational sold to them by the service contractors). To date they have not been able to provide me with valid, independent documentation supporting ‘empty & refill’.
Reply: No, probably not. The number of bad ideas always exceeds the details in codes & legislation
Seeking Authority vs. Understanding A System
You are welcome to refer your authorities to the identitiy of many of our principal technical reviewers and contributors found in these pages and to my own CV and bio linked-to from the About Us page link at the bottom of each of our web pages and to . However, in my OPINION the approach of seeking an authority that the parties (with conflicts of interest) will accept and who will provide a simple statement that the septic tank stirring-up churn-and-return practice you described is "prohibited" or "illegal" is a dangerous simplification.
The number of crackpot or profit-motive bad ideas and the rate of their appearance in most fields easily exceeds the specific prohibitions one will find in model building codes. You won't find a specific law stating that it is "illegal" to use M1 firecrackers instead of a conventional buckle to un-fasten your car's seatbelt, a goofy example I just "invented", so you won't find explicit prohibition for every crazy septic scheme that comes along.
A second approach, and one that I prefer, requires some mental effort on the part of those involved, to become familiar with how a system works, its principles and with its established maintenance and care procedures, sufficiently to form an educated and defensible opinion about the advisibility of the proposed septic tank "churn and return" policy your pumpers and municipality like.
Two Technical Approaches to Evaluating the Sewage Churn-and-Return Pumping Procedure
While the time, cost and trouble may preclude a scholarly study of the matter, I can describe how you might produce two additional compelling data points to add to the explanation I've already offered.
1. Septic Tank Effluent discharge sample analysis: Collect 5 samples of clarified effluent flowing into the D-box from a conventional septic tank in good condition, with a reasonable net-free area, that has not been churned-and-returned by the process you describe.
Collect 5 samples of effluent flowing into the D-box of a septic system out of septic tanks that have just been "serviced" by the churn-and-return procedure.
Compare these. You will almost certainly observe a very much higher level of floating solids and debris in the second group than the first. Those solids are what are being sent into and damaging the drainfields of homes in your community. In addition to what will be visually obvious you could have the BOD and total suspended solids in the samples examined by an independent testing laboratory.
2. Aerobic septic system comparison: compare the design of aerobic septic systems to conventional non-aerobic designs. In an aerobic system we deliberately agitate the contents of the septic tank and add oxygen via an air bubbler at the same time. This approach significantly increases the treatment level of the sewage and produces effluent with a lower level of both solids and pathogens.
However, you will observe that in aerobic systems provision is made, usually in the form of additional chambers or a separate tank, to provide additional settling time for effluent before it is discharged to the drainfield. I am very doubtful that your officials can produce a single independent government or exert source that supports the claims of your pumpers. No one except those profiting by the procedure would be expected to support such a worrisome approach.
The churn-return procedure you described lacks the continuous oxygenation of the churned effluent, settling chambers, filters, and any other step to protect the septic drainfields. I expect that if you send our discussion to nationally recognized septic system design and maintenance experts such as Jantrania, Loomis, or Minnis, they will be as worried as I am about the process you described.
Watch out: It will take some time for homeowners in your area to figure out that the average life of their septic system drainfields has been significantly cut by the new churn/return practice (soil conditions, maintenance, usage levels, tank sizes, site variations add complexity to septic field life). There are numerous citations to this effect,such as Laak (1970) who observed that "Investigators found that the initial soil clogging rate was directly related to the TSS load.". I worry that both your municipalities and your septic pumpers are inviting class action litigation.
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Technical Reviewers & References
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