Septic tank pumpout SNAFUS:
This article describes common mistakes and misunderstandings about cleaning or pumping the septic tank. We explain why pumping too infrequently (or never) is a bad idea but we add that pumping more often than necessary is more or less tossing money down the toilet.
We also explain why a septic tank is normally always "full" and that after pumping the septic fills up pretty quickly in normal use. The article also describes effective vs. ineffective septic tank pumping and how you can improve the septic tank cleaning procedure so that pumping the tank is actually useful.
Finally we note immediate & serious safety hazards that should be addressed when cleaning septic systems.
Green links show where you are. © Copyright 2017 InspectApedia.com, All Rights Reserved.
[Click to enlarge any image]
A septic tank in normal use is always full, right up to the bottom of the outlet pipe (near the top of the tank). After pumping it out completely, an empty septic tank fills up again under normal usage in just a few days, after which it is again discharging liquid effluent to the absorption field, soakaway bed or leach field - names vary by country.
In a normally-working conventional septic tank we find wastewater, or "blackwater": a combination of watery sewage effluent, a floating scum layer at the tank top (in Austraila the "scum blanket", and settled sludge in the bottom of the tank.
If as in the sketch above we could see a cross section of the septic tank contents (if we wanted to) we would know when pumping the septic tank is actually necessary based on its sludge and scum layers - that is, based on data instead of either theory or wild arm-waving.
A septic pump-out is needed when the thickness of the floating scum layer and settled sludge layer occupy so much of the tank volume that the free liquid area is "too small" - the "net free area" has become so small that
the EFFLUENT RETENTION TIME, the time that wastewater has in the tank to allow for solids and floating scum to separate from effluent being discharged to the drainfield (soakaway in the U.K.) is too short. This gives new meaning to time is short, right?
Short septic tank effluent retention time means we're pushing solids into the drainfield, clogging it up & shortening its remaining life.
Two valid septic tank cleaning approaches involve either using
the SEPTIC TANK PUMPING SCHEDULE or using objective data obtained by actually inspecting the septic system, diagnosing any problems or failures, and inspecting conditions inside the septic tank.
In part II of this discussion SEPTIC TANK OBJECTIVE DATA we explain how a septic contractor can measure the scum and sludge layers - a step that's sometimes worth the trouble and that might be taken the next time you have the septic tank pumped. You can't see into the septic tank, but a contractor, by opening the tank
can MEASURE SCUM & SLUDGE.
Pump the septic tank when ANY of the following is TRUE:
- Total depth of scum plus sludge layers equals 1/3 of the depth of the tank
- Bottom of the septic tank outlet baffle has less than 3 inches of clearance from the bottom of the floating scum layer
- Bottom of the outlet baffle is less than 6 inches from the top of the sludge layer on the septic tank bottom
If you're are among the two percenters who want to become expert on this see or
see SEWAGE LEVELS in SEPTIC TANKS.
Finally, sometimes extra septic tank pump-outs are useful - something that we will discuss below.
In a conventional and most other septic system designs not only do additives, chemicals and treatments do little or no good, some can damage the system, causing frothing, causing solids to be discharged to the drainfield.
No expert recommends the use of septic treatments or additives, and these substances are illegal to use in many jurisdictions in the U.S. and Canada, at least in part because some of them are also toxic and are environmental contaminants.
Details are at CHEMICALS & TREATMENTS for SEPTICS.
Nope. As my Mom used to day, in your dreams, buster.
The septic tank shown at left was totally packed with solids and was collapsing - it had not been pumped in decades. The home, occupied by a single elderly person, limped along until new owners bought the property and tried taking a couple of showers.
The morning after the new family moved in sewage was coming up in the yard. This case is discussed
at SEPTIC FAILURE LAWSUIT.
It is true that the required septic cleanout frequency varies not only by tank size, wastewater volume being produced, and system design, and some systems require less frequent cleaning for the same usage level compared to other designs, but all septic systems need periodic maintenance.
Failure to properly maintain the septic system is the No. 1 cause of early septic system failures.
Unfortunately, a drainfield or soakaway bed that is in failure would require an estimated 5-10 years of total rest to "recover" enough to be restored to normal use.
Even then the field won't work if it's flooded or if the field has been damaged by vehicle traffic, tree roots or similar troubles.
What you actually get by extra septic tank pump outs in an area of failed drainfield is a few days (less than a month) of toilet flushing and wastewater disposal into the septic tank until it fills up again and is again trying desperately to push septic wastewater effluent out into the soakaway bed.
How quickly does the septic tank fill up again? Experts estimate as much as 200 gallons of wastewater is generated per occupant per day. Even using a fantastically small number of 50 gallons per person per day in a home where extreme water conservation measures are in effect or where there is a single elderly occupant using very little water, the septic tank still fills up quickly - typically in as few as 1-2 days, or at most in about 20 days of use.
Resting a failing or failed drainfield for 20 days doesn't fix anything.
Wow what a mistake this is.
At left I show sewage effluent running down a hill over rock. That straw-covered pile in the top of the photo was covering the septic tank that the property seller had asked her septic contractor to pump out just a few days before my inspection.
That the system was in total failure was evident after just two days of household use of the septic system. The tank had re-filled in that time, then sent effluent to the property surface.
To be of any use at all, when pumping the septic tank we need to remove the settled sludge and floating scum from the septic tank, not just the liquid effluent.
If the septic contractor just pokes that septic tank pumping hose down into the middle of the tank and just pumps like mad all she's doing is removing the effluent.
What is our septic tank pumping contractor doing with that pole in his right hand while he manuipulates the pumper truck hose with his left?
He's using long-handle hoe-like tool to scrape and stir up the dense sludge on the septic tank bottom, mixing in a bit of liqui so that the vacuum hose can pull the sludge out of the septic tank.
Your guy doesn't do this? Interesting.
Watch out: If your septic tank pumping company tells you it's a good idea to leave solids in the septic tank - we know of a company that actually returns solids to the septic tank after separating out the effluent in their special pumper truck - Just Say NO! Tell 'em not to let the door hit their backside while they're on the way out. You need to find a different septic pumping service.
The We Pump it & then We Put it Back septic pumping company is simply saving themselves the cost of disposing of sewage from their truck, they're not doing anything to help your septic tank nor system and they're speeding the demise of the absorption field.
The object of tank pumping is to remove the solids (sludge and scum) from the septic tank and thus to increase
EFFLUENT RETENTION TIME.
An effective septic tank cleanout removes the scum and sludge by moving the pumping hose around and by using the liquid effluent to help break up and pump out the solids. If the pumper just tackles the easy task of pumping out the liquid effluent itself he's not performing a useful job.
Just pumping out liquid effluent doesn't benefit the system. In fact, just pumping out effluent and leaving the solids means that after every such unfortunate "mis-service" of the tank the actual remaining tank volume available for wastewater treatment is less and less.
Not easily, but it might be possible. In traditional septic tank cleaning operations the operator needs room to manipulate the septic pumper truck hose to remove the floating scum layer and settled sludge layer. Without manipulation space and room to stir sludge and scum with a hoe, rake or other tool, removal of solids is difficult and might be limited.
At left we show small-diameter septic tank riser that has been used for years to "pump out" the septic tank at this Minnesota home. I'm using this mini-septic-tank-riser to empty a small chemical toilet - which is OK as long as we respect the guidelines
at RV HOLDING TANK DUMP INTO SEPTIC TANK?.
But how thoroughly do you think the septic tank pumper can clean the septic tank working through just this small-diameter opening to reach a tank located several feet below?
Using a Manual Tool to Break Up Septic Tank Sludge & Scum for Pumping
Unless we do something extra (see below) it is just about impossible to remove most of these key constituents if all we can do is poke a pumper hose straight down into the septic tank. Jimmy Herring (Herring Sanitation, Poughkeepsie, NY) demonstrated the right way to clean out a septic tank in the photos below. You'll see that Mr. Herring is working through a much larger opening - the septic tank access cover gives enough room to manipulate the pumping hose.
Crust Busters provides a motor-driven auger that stirs up the septic tank floating scum and settled scum layers, permitting the septic tank pumper to successfully remove these constituents along with septic effluent.
The Crust Buster is a 33-pound motor driven mixing device that combines an 80-inch shaft with folding, hinged mixing bladesthat open out when spinning to break up and make septic tank solids pump-able through a small access port.
Depending on the diameter of the septic tank pumping opening the operator selects a 2-blade attachment that can slip thorugh a 4-inch diameter opening, or a 3-blade attachment that is not collapsible and fits through a 12" or larger diameter opening. Crust Buster shaft extensions permit operating the device in deeper septic tanks. - Thanks to septic cleaning contractor Daniel Zeimet, Two Harbors MN, for this tip.
You could also fabricate your own septic tank sludge/scum break-up tool or scum and sludge measuring tool.
See TOOLS for MEASURING SCUM & SLUDGE.
Still Septic Tank Inspection Limitations May Remain
Still, working through a tall, narrow 6" diameter vertical riser, it is difficult if not impossible to inspect the septic tank condition and that of its baffles through such a narrow vertical access opening, even using a traditional flashligt and mirror.
See(INSPECT the SEPTIC TANK DURING PUMPING
If we can't gain visual access to the septic tank interior or visual access by removing covers at the inlet and outlet ports, we won't know the condition of the tank, it baffles, its sludge and scum layers. We also may not know if there are leaks into the septic tank or leaks out of it through damage or poor seals at any of its openings.
Without using a larger septic tank access opening we probably won't know if a flooded drainfield is back-flowing into the tank during pumping, and we won't know how much sludge and scum were left in the tank. The photos above show important conditions that you cannot see through an 8" diameter septic tank riser.
Technical note: it's possible to to add a large-diameter septic tank riser capped by a vehicle and child-safe cover to make future septic tank servicing more effective. But don't spend on this improvement before knowing that the septic tank itself will continue in use. For example, a rusted-out steel septic tank is going to need complete replacement.
It may also be possible to gain improved visual access to an otherwise difficult-to-access septic tank interior using electronic gear including flexible borescopes, lights, and similar remote inspection camera-equipment: all added sophistication, complexity, and costs that may mean these tools are not in the hands of most septic tank pumping companies.
Are you kidding me?
In a conventional septic system (tank and soil absorption bed or drainfield) no more than 40% of the wastewater treatment is handled by bacteria in the septic tank. The rest of the wastewater treatment occurs thanks to bacteria in the soil.
Discharging such wastewater anywhere out of the treatment system is unsanitary, contaminates the environment, makes your neighbor mad, and is illegal virtually everywhere. You are not even allowed to discharge graywater (washers and sinks) to the surface.
An exception is clarified highly-treated wastewater effluent produced by a properly working aerobic septic system and highly-treated wastewater from advanced septic system designs that treat effluent to a level equal to or exceeding the sanitary nature of ordinary ground water or surface water.
In these instances discharge of wastewater may be allowed by permit though for some installations a final wastewater disinfection step may still be required. In some jurisdictions such as areas of the U.K., sewage treatment plants are required and traditional septic tanks and soakaways are no longer permitted. - Crystal Tanks, U.K. (2014)
Our photo at left shows heavy algae growth along the shore of a waterway abutting an older home whose septic system was installed in the 1970's.
No sewage effluent appears at the surface of the property, toilets flush (though slowly and badly) and drains drain (though sometimes slowly). There are no sewage odors at the property. Even a septic loading and dye test may fail to show a system failure at this home.
Because the algae grows only close to this property we suspect that high nitrate discharge from a failed septic system is producing heavy algal growth in this spot. The combination of age, algae, and slow burbling drains is an indicator of the condition of the system though there is no evidence of sewage effluent at the ground surface.
This septic system is in technical failure in that it is not properly treating the wastewater it receives.
Watch out: A system in this condition is also at high risk of sewage backup into the building.
Pumping the septic tank won't alleviate this trouble: days after the tank is pumped effluent will again be discharged into soils that ultimately drain into this waterway. Improvement in the treatment level within the septic tank might help (a conversion to aerobic?) or drainfield reconstruction may be needed.
Pumping the septic tank may give temporary toilet flush improvements but it's not going to repair a clogged drain nor a failing drainfield.
Technical note: if an older grandfathered septic drainfield is closer to a body of water than current codes allow, its replacement may need to be relocated to a more distant location. In that event we usually can leave the septic tank in place, adding an effluent pump to move the tank output to the new absorption bed.
Well this fantasy has merit: sort-of.
We never want to call a contractor in a panic asking for an emergency repair: the price of the job doubles or worse, not only out of gouging or greed but because the contractor has to shuffle work, put off other customers, and maybe ultimately even lose that deferred business.
But considering the cost of having to clean up a major sewage spill in a building it makes sense to fix septic problems before the last possible occasion: when the system has suffered a catastrophic failure. Meanwhile here are some limp-along steps that can help defer the inevitable:
No, that's not true.
People really do fall into septic tanks, cesspools, drywells, usually with fatal results. The requirement to assure safe covers on septic tanks and similar equipment are important. See this list of septic tank fatalities and other accidents SEPTIC TANK ACCIDENT REPORTS.
Continue reading at SEPTIC TANK OBJECTIVE DATA for more about alternatives to using the septic tank pumping schedule table.
If you don't know where the septic tank is located, see SEPTIC TANK, HOW TO FIND.
At TANK INSPECTION PROCEDURE we describe how to inspect the septic tank before, during, and after tank cleaning operations.
Or see SEPTIC TANK PUMPING PROCEDURE - home
Green link shows where you are in this article series.
OR use the Search Box found below at Ask a Question or Search InspectApedia
Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
(June 18, 2014) steve f said:
im using a septic tank just as a holding tank (no outlet to drain field) tank will be pumped out when full. i was told to pump out tank once a year even if not full is this true.
Not in my opinion, Steve. Pump the tank when it is nearly full. Watch out.mfor the case you describe if you don't monitor the sewage level in the tank toilets may back up.
To be smart: install a septic tank alarm system to give you warning enough in advance of a full tank that you can schedule a pump-out. Otherwise you're asking for a sewage backup into the building.
6 March 2015 Anonymous said:
Comment:8:07 pm 3/5/2015landlord case,
2/8/2015 do to no maintence or pumpng septic sludge flooded the bottom floor units #1 and #2.Because its hazardous i took family to hotel.
Plumber coming in morning and i assumed a cleaning crew would disinfect carpet/pad and check if the sub flooring was contaminated ,dispose and replace anything that the spill touched.
2/9/2015 after asking what the toilet was doing unattached and laying in middle of floor,thought the place would have been cleaned instead it was the dumping ground for the upstairs tenants waste because donna did’nt tell anyone it was a septic backup,or even to stop using plumbing till its fixed.Also removed toys from tub and trashed them(got mad when janelle told her return the property),the when returning property,she also put a notice of disturbance on door;inoperable car could be towed at our expense,and charging 25$ per month for extra car.Stating in notice “only 2 cars per tenant.So i sent called and ask where in rules or contract that says this…..And our cars are all running with all insured and registered.
2/17/2015 the eviction notice without cause came the day before my appointment with lawyer,whom says we have proof of retalitory action and in a notice to the landlord dated 2/18/2015.Our health hazard and loss of essential services,is a threat to our health and want the certified cleaning company send the findings and what action taken in mail to me. Also informed her of no inoperable cars and nothing in the rental agreement saying anything about 25$ for extra cars. In 48 hrs if the problems are not corrected we can terminate the rental agreement.
2/19/2015 i talk to bill,saying that the lawsuit against donna is a go if she dos’nt
Stop trying to throw us out and that if i find out that you did not give donna the moneys to get the cleaning company responding and hindered her in her responsibilities, its gonna be your liability and all i ask is that my home is not a health hazard.
2/19/2015 donna sends note written on plain paper”the request you are asking for is not giving me a resonable amount of time to get a repatable company out here to do the testing.I will honer your request but it will take longer than 2 days to get a company out there. I hope to have it done by the end of the next week.”still nothing as of 3/2/2015
Employee civil rights violation
2/22/2015 went to job site told bill that my stones have passed and ready to return to work,he told me to get with mike mon morning.
2/23/2015 mike informs me that i can not return until i drop lawsuit its gonna cost bill lots of money.
2/24/2015 county sanatation inspector called to come and do an onsite inspection of septic system and inform donna the protocol for dealing with septic spill inside home.
I am so depressed and feel like there is nothing i can do to shelter my family getting an eviction is making it hard to find a new place,losing my income too has put me in a place where the inability to shelter and feed my family is making me think about taking my own life,that is what all these actions that my boss/landlord have forced on me. I want justice and reparations so that i can get a job without fear of my last employer giving me a bad refferal,and the next landlord an eviction.My promised 2 years of lost work or the income plus all the cost to fight. Diminished value of unit for the month of feb.And anytime up until we are assured safe place.
Mike chesser (tell ing me cant work till lawsuit is dropped and that im a desireble employee willing to work.
Tom mcgilvra (maintanince,who informed donna about septic tank needing serviced two weeks previous to backup. And did the repairs.And witnessed donna in our apt. Without a legitamit goul,but to allow more waste from upstairs tenants)
A&s septic system (clearly explains sit.As of the 2/8/2015 and how donna lied to him about the system magically start working again.)
Erin oconnel evironmental serv.Specialist for columbia county land development .(stating that the spill in the hom
6 March Raymond Rackley said:
I Didnt mean to be anonymous I need some one to help me.
see HEALTH DEPARTMENT HELP for RENTERS at inspectapedia.com/sickhouse/Rental_Unit_Mold_9.htm
(June 1, 2015) SW said:
We bought a house 5 years ago & had the tank inspected & pumped at closing. We had it pumped again two weeks ago. At the time of pumping, the guy said that the tank appeared to be in good shape but the line running to the D. box is clogging. He said that he purposely did not pump it dry to keep moisture in the line so that it wont harden & clog. Yesterday, while doing laundry, we had sewage bubbling up out of the septic tank. The service guys are saying that the line between the tank & the D box has hardened & clogged. Needs to be replaced. Have you ever hear of this? our house was build in 1969 and still has original system.
(Aug 12, 2015) paul said:
after pump out does a tank need to be resealed? Ours had a seal of concrete originally but none was put back. Thank you
Great question, Paul.
Maybe yes. If the septic tank is located where surface runoff or ground water can enter it, the best approach is to direct that water away from the tank. Sometimes that's too difficult or expensive. Certainly in that case we'd want the tank lid, access covers, and sewer piping connections sealed to keep ground water out of the tank lest we otherwise flood the septic tank, flood the drainfield, and destroy it. Flooded septic systems also can lead to a costly sewage backup into the building served.
24 August 2015 Brad said:
Great site, all the info is appreciated. I have a tank, installed over ten years ago but as of yet unused, on a steep hillside roughly 200 horizontal feet away from where a vac truck could park. To make issues worse, there is probably close to 20 feet of vertical lift as well. I know this is a very long run, so I am considering laying a dedicated pipe for pumping next to the sewer line running up grade, I'm thinking 1 1/4"
100 PSI poly pipe. My thought is that the truck to hook onto the top end of the line and pull, and we could put a trash pump at the tank to push. What are your thoughts? There is not really a better location for the tank available, or we would have used it. Local DEQ selected the site and approved the installation, but its tough for sure. I have installed 3' of 24" riser over the effluent filter access hole to bring it to grade, so there should be room to manipulate a hose or even lower in a submersible pump. Thanks for any advice you can offer.
Good question, Brad. Septic pumpers, at least some of them, use a rotary vane vacuum pump and have a good lift capacity. Check with your local pumping company to ask what they can lift.
http://natvac.com/ is a a producer / vendor of vacuum pumps whom we are consulting in this matter. When I can get some vertical lift specifics I'll add them here.
Most septic pumpers with smaller trucks will be close to their pump lift limit but may be able to do the septic tank pumping job, though it will take longer with a typical rotary vane pump used on many pumping trucks. Newer high-lift pumps are available that can lift 30 or even 50 feet using a different technology and the assistance of air in the procedure.
I will expand on the topic of septic pumper truck pump types, pumping rates, lift capacities and sources in a related article and will post a link to it here.
In sum, yes your septic tank can be pumped from 20 feet below the truck parking area. Actually it's probably more like 30 feet of lift when you add the height from ground to pumper truck tank and the depth of the septic tank from top to bottom. Older 200-300 CFM rotary vane pups may not be up to the job. A newer type higher vacuum air velocity hybrid pump and larger capacity septic pumping truck may be needed for higher lifts.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website