Septic tank flooding or back flooding questions & answers:

Questions & answers on the causes and cures for flooded or back-flooded septic tanks.

Backflooding means that water or wastewater is flowing backwards into the septic tank from a soakbed or drainfield or from surface runoff.

Septic Tank Flooding & Back-Flooding: Why it is important to diagnose & fix water leaking into the septic tank

[Click to enlarge any image]

These questions & answers about flooded or back-flooded septic tanks were posted originally at SEPTIC TANK BACK FLOODING - be sure to see that article.

On 2019-12-23 by Yolanda

my 81 year old mother left the kitchen sink running, now septic tank backing up. Plumber says wait a few days as septic tank may be overloaded with water.

My biggest problem is I found out the septic tank has a slab pored over it so no access to pump out. if it is built into the side of a hill, can you drill into it to create another access to the septic tank?

I am stumpted.

On 2019-05-30 - by (mod) -

Ella,

My guess is that the tape down the vent opening finding no water could be a useful diagnostic if we were sure that the vet were actually near the end of one of the lines in the drain field.

I don't think that just pumping the tank again is going to fix anything, and it's not appropriate if the type of recently pumped anyway. I also don't think digging up the entire drain field is appropriate without more diagnosis.

Er need a plumber on site who has a sewer camera and who can run that through the lines to find the distribution box and through the distribution box the drainfield lines that can then be examined directly.

Ella - following up:

About proper septic tank pumping, Yes I've written about the details of a thorough septic tank cleaning, as demonstrated to me by a Jimmy Herring, a Poughkeepsie septic pumping contractor.

And yes I agree that most pumpers are rushing the job.

There is no statute regulating what the pumping company must do - not in any jurisdiction I know-of.

In my OPINION the worst offense is not being thorough by failing to stir up the sludge on the tank bottom, it's those people who get paid for "pumping" the septic tank, then empty most of the pumped volume BACK into the septic tank, claiming that "the water is needed" which is

1. not true at all - the water is not needed. The septic tank fills up and begins treating sewage within a few days of normal use.

2. misrepresents what they're doing: Unless the return-effluent is very thoroughly-filtered to remove small fine floating solids, the septic pump chops up the sewage and disperses solids into the truck during pumping - putting that back into the tank clogs up the drainfield.

I'm indeed happy that you found our (as in editorial "we") information useful - we work hard on it and are grateful when a reader finds the effort useful.

I too am a photojournalist - card carrying member of the US Press Association - ok so I don't usually carry my card. I didn't know I was a journalist until a lawyer representing an electrical manufacturer told me so during a meeting with the US CPSC on aluminum wiring connectors.

The lawyer told some of the meeting attendees that he and his client would not continue the meeting with "that journalist" in the room.

I looked all around wondering if the NY Times had somebody hiding under the table.

Then he pointed at me.

I should have been upset, or insulated that he'd impugn my integrity but hell, the truth was I was really excited. Geez I told my friend as we took a break: After all these years, writing and scribbling since the 1950s, finally oh finally I'm a real journalist - I had no idea.

On 2019-05-29 by ella seneres - I had not clue I was being robbed and not only that, but oh the thought I have 40 years of sludge that should have been sucked out,

I just spend the last hour reading your site. First I am a photojournalist; and you write so well. I was laughing most the time, as you are funny. Second I had no clue all these decades, and its worth repeating this for others as they may not be as diligent as myself in exploring your site.

The Septic tank service has to use a pole to stir up the sludge so it can be pumped up.

That has NEVER happened, they just stick it in and look around. I had not clue I was being robbed and not only that, but oh the thought I have 40 years of sludge that should have been sucked out, my last septic sucker cost me 650 for 2000 gallons. He used a hose a little, but on one else ever did anything but suck.

I want to re re thank you for your site; its very informative and funny. From now on I almost feel I know more then these crooks because of your depth sharing and educating us.

Thanks for the learning curb on nothing I choose to learn about but had to. Bravo, oh and that you used s/he. Lord that almost made me weep. Hardly no one does that. Brava.

I am so sorry to bother you again. I am so relieved you are here. So I wrote before about the overflowing septic tank. It was backing up into my studio, the stench blablabla.

Had it pump, then snake thru the outdrain, and then did not cover manholes good enough, rained, flooded.

So no one could help me 4 months later! Finally one guy came up who put a measuring tape into a pipe that vents? the drain field, and said it was bone dry, and said if the septic tank is overflowing from the manholes but the leach fields are bone dry, possibly a clog.

I had someone finally come up today and I scrambled to come back and ask you, HELP. He ignored or did not want to hear about the dry fields and said pump the tank again and dig the leach fields. I have no business owing a house, I inherited it, and I am on severe limited income, and to fork out 12,000 plus may put me under.

Now if I need it, I am gladly willing to bite my lip and pay up as I will pay for work rendered. But once again we come to those dry fields. And yes the system is 40 years old, but I never use nasty chemicals, I do not abuse water.

Thank you again for, us lost souls who do not know what is up and can easily be fooled and ripped off.

On 2019-05-29 by ella seneres

I just spend the last hour reading your site. First I am a photojournalist; and you write so well. I was laughing most the time, as you are funny. Second I had no clue all these decades, and its worth repeating this for others as they may not be as diligent as myself in exploring your site. The Septic tank service has to use a pole to stir up the sludge so it can be pumped up. That has NEVER happened, they just stick it in and look around. I had not clue I was being robbed and not only that, but oh the thought I have 40 years of sludge that should have been sucked out, my last septic sucker cost me 650 for 2000 gallons.

He used a hose a little, but on one else ever did anything but suck. I want to re re thank you for your site; its very informative and funny. From now on I almost feel I know more then these crooks because of your depth sharing and educating us. Thanks for the learning curb on nothing I choose to learn about but had to. Bravo, oh and that you used s/he. Lord that almost made me weep. Hardly no one does that. Brava.

On 2019-05-29 by ella seneres

I am so sorry to bother you again. I am so relieved you are here. So I wrote before about the overflowing septic tank. It was backing up into my studio, the stench blablabla. Had it pump, then snake thru the outdrain, and then did not cover manholes good enough, rained, flooded. So no one could help me 4 months later! Finally one guy came up who put a measuring tape into a pipe that vents? the drain field, and said it was bone dry, and said if the septic tank is overflowing from the manholes but the leach fields are bone dry, possibly a clog.

I had someone finally come up today and I scrambled to come back and ask you, HELP. He ignored or did not want to hear about the dry fields and said pump the tank again and dig the leach fields. I have no business owing a house, I inherited it, and I am on severe limited income, and to fork out 12,000 plus may put me under. Now if I need it, I am gladly willing to bite my lip and pay up as I will pay for work rendered. But once again we come to those dry fields. And yes the system is 40 years old, but I never use nasty chemicals, I do not abuse water. Thank you again for, us lost souls who do not know what is up and can easily be fooled and ripped off.

On 2018-09-14 - by (mod) -

This link is a place to start

https://inspectapedia.com/septic/NYS75-A.8_Absorption_Bed_Design_Specs.php

On 2018-09-13 by Rhonda

How large of a drain field do we need for our 1500 gallon tank. There is a backyard area of about 350 Sq ft that is our drainfield.

On 2018-08-15 - by (mod) -

You probably have a failing septic field. Possibly rain floods the field and also back flows into the septic tank

On 2018-08-09 by terry

I had a lot of people to my cottage over the last month, toilet was bubbling up after a flush, exposed septic was full, within a couple days of reduced usage, toilet returned to normal operation and septic level dropped to intake / outtake pipes. Do I have a clog or just a slow draining field.

We also had 1 full day of heavy rain after discovery of full tank. Pls advise, thx

On 2019-04-11 by (mod) -

Elua

I think someone has given you confusing information. Pumping a conventional septic tank does not ruin it nor cause damage except by accident such as breaking a lid or cover or driving over the septic tank.

And when a tank is pumped out it should not need to be pumped over and over again right away.

The pumping frequency is given in the septic tank pumping schedule article in this series and depends on the size of the tank and the Wastewater volume or number of bedrooms or number of building occupants.

However if surface water is leaking into your septic tank it will flood the tank and flood the drain fields and possibly ruin them. That's a question to have answered by your septic contractor.

If that is happening see

SEPTIC TANK BACK FLOODING

Otherwise see

FLOODED SEPTIC SYSTEMS, REPAIR to read suggestions for repairing a flooding septic tank or soakbed system that floats full of water when it rains

On 2019-04-11 by ella seneres

Sorry forgot to mention; it rained cats and dogs, and that is how it filled up with California rain. Thanks again.

Hi, I just had my septic tank pumped, and I failed to properly seal the lid, with a tarp then dirt. So I noticed a pool of water, and I saw more dollar signs in my future.

But when I googled it, it said you must not pump out water from the tank as it will damage it. I cannot ask my tenants to stop using water, as they are to used to wasting water with lots of laundry.

So I may be forced to pump it out if it will not damage the tank.

I myself cut back severely no dish washing for a month, a rare shower twice a month, beginning to feel real ripe, and not much toilet flushing. And lastly if I do not pump it out how long on average would it take to drain into the leach fields, its 2500 gallons. Thank you.

On 2019-04-10 by (mod) - our pump went out. The tank full alarm did not go off The alarm warning light is almost always on

Eric

I think you're on a reasonable diagnostic track by looking into the drainfield condition.

Yes a septic tank failure can damage a drainfield, in particular if a baffle is broken or overflowed such that solids are pushed out into the drainfield piping and leach lines.

Take a look in the D-box to see if there is flooding there.

Then you may need to have someone with a sewer camera check your leach lines for obvious damage, flooding, or sewage solids - as a step that might be worth doing before exploratory digging.

On 2019-04-09 by erics

We have a 2 tank septic system. About 2 months ago, our pump went out. The tank full alarm did not go off and we called somebody as soon as we saw standing water above the tank. They came out the next day, pumped the tank, replaced the broken pump w/ a more powerful pump, & fixed the alarm.

Ever since then, it seems like the system is struggling to keep up with our usage (which has not changed). The pump is always running. I can hear & feel it when standing above the tank. Maybe the old pump was always running too and I just couldn't hear the less powerful pump.

The alarm warning light is almost always on too. We even had the audible alarm go off when we happened to be using a lot of water at once. This was never an issue before.

When I called the same guy that installed the pump, he said it sounded like an issue in the septic field. It sounded like the next step in solving our problem, at least according to him, would be expensive. He said something about hydrostatic testing that could cost several thousand dollars depending on how many branches and how deep they are. Before agreeing, I wanted to do a little research (which is why I am here).

I've done some reading on this site and others and from what I can gather, it does sound likely that it is a drainfield issue. It just seems odd that we did not have any problems before the new pump; however, after the new (more powerful) pump, our system suddenly has problems keeping up. It seems unlikely that our septic field would suddenly get clogged.

This especially seems true since it has two sides and it seems to me like any issue caused from the overflow would have only affected the one side, but we are now having problems regardless of side.

I'd like to think that I can trust the technician, but I am a bad judge of that sort of thing and I hate the idea of wrongly doubting an honest guy.

Questions:

1. Could the initial tank overflow issue cause issues in the septic field? In case it matters, the tank had been emptied a year prior.

2. Could anything the technician have done when replacing the pump cause this kind of issue?

3. What is the proper next step to diagnose the root issue and how much should I expect to pay?

4. I'm reasonably handy and not afraid to get dirty. Is there anything I can do to diagnose/fix/etc?

5. If I need to call somebody, should I call the same guy or have a new guy that could also verify his previous work?

6. What should I be asking but I'm not?

On 2019-02-11 by (mod) - bathroom & garden tub is overflowing onto the floor.

SK

When the septic system has failed - from flooding combined with perhaps inadequate original design or soil clogging - waiting for the soil to dry out will, sadly, not fix the problem - it's going to recur until the field is re-built above the high water table.

But I agree that it makes sense to stop the water softener regen cycle - that adds more water to the septic tank and increases the chance of sewage backup into the buiding.

There is of course also the risk of scale clogged hot water pipes, tankless coil, water heater, etc. when the water softener is out of service for much time.

On 2019-02-10 by skashon

Will bypassing water conditioner help or do we just have to wait for things to dry up?

The past 2 nights our master bathroom & garden tub is overflowing onto the floor. The only thing that is different @ night is our water softener runs. The stool flushes normally during the day. We've had like 2.5" of rain the past week which is way above normal. Anybody know why this has started all of a sudden?

On 2018-11-25 by (mod) - pumping the septic tank will never ever fix anything.

April,

Unfortunately pumping the septic tank will never ever fix anything. Pump in the tank protects the field and extends the drainfield life but it won't fix a blocked sewage or septic line or will they fix a clogged drain field.

So what you need is some on-site diagnosis. That might involve looking at the sewers levels in the septic tank and looking at the waste water level in the distribution box or D box.

On 2018-11-23 by April Roberts

How can I fix septic issues all the sudden it’s backing up in my basement I had it pumped 13 months ago what do I do

On 2018-09-14 by (mod) -

I can't really say for sure because I don't understand the situation, but it doesn't seem likely.

On 2018-09-13 by Anonymous

Will a hole in the pipe that is directly under my kitchen sink (under the house,a rotorooter accident) cause my draim field to flood? It is about 40 feet from the septic tank

On 2018-04-12 by (mod) -

See SEPTIC TANK DEPTH

On 2018-04-12 by scott

Approx how far down would i have to dig

On 2018-04-12 by (mod) - What would cause my drain field to leak into my yard

Yes, Scott, a blocked or broken line, or a backup leaking at an inspection port, or (worst news) a clogged, failed drainfield.

I would dig at the wet spot, with care, to find the conditions there in the actual drain field piping - that'll be diagnostic.

Use the picture frame icon next to the Comment button to attach photos of what you find and we can comment further.

On 2018-04-12 by scott

What would cause my drain field to leak into my yard the leak is located about 20 ft from tank, I was thinking a broken line

On 2018-04-12 by (mod) - investigate a wet spot in the drainfield

Yes, Scott, a blocked or broken line, or a backup leaking at an inspection port, or (worst news) a clogged, failed drainfield.

I would dig at the wet spot, with care, to find the conditions there in the actual drain field piping - that'll be diagnostic.

Use the "Add Image" button next to the Comment button to attach photos of what you find and we can comment further.

On 2018-04-12 by scott

What would cause my drain field to leak into my yard the leak is located about 20 ft from tank, I was thinking a broken line

On 2018-02-28 by (mod) - When it rains water from the septic lines runs back into the tank

Buddy

I am genuinely sorry to be the bearer of bad and expensive news, but a septic drainfield that floods from ground-water in a level area is probably improperly designed and needs significant revision.

The bottom of the drainfield trenches needs to be at least 24 inches above the seasonal high water table - that can mean a raised bed septic or mound septic design (search InspectApedia.com for those phrases to read details).

Sometimes an intercept drain around the fields can carry off ground-water and leave fields working but that works best where there is some slope and some hope.

I'm doubtful that it'd work in an entirely level area as water may just come up under the intercept drain and into the septic area.

On 2018-02-28 by Buddy Cromer

I have flat ground. When it rains for days the ground get socked and the water from the lines runs back into the tank. Is there anything that can be done?
Bud4auburn@yahoo.com

On 2018-02-24 by (mod) -

No, Terry septic tanks don't use a backflow valve.

You need some on-site help to see if the fields are saturated or blocked - start by checking in the D-box.

Also look for surface or ground water leaking into the septic tank

On 2018-02-24 by Terry

Does the tank have s back flow valve?

High waters recently septic tank keeps filling with water?

On 2018-02-12 by (mod) -

TBV

Back-flowing into the septic tank, if it stops quickly - minutes or less - could be a simple blocked line.

But if it continues longer the fields are most-likely saturated - which your description suggests is the case.

Given that the curtain drain hasn't fixed the trouble I suspect

1. the curtain drain doesn't go deep enough or lacks capacity to keep extraneous groundwater out of the septic fields
or
2. the fields are basically in failure regardless (or both)

You may need to go to a raised bed or mound septic. That does not mean just adding soil over the existing fields. That won't work and will block oxygen. Instead it'd be a new elevated pipe network in a mound.

On 2018-02-12 by tbv

we have a two concrete box septic system for a very large house. last spring and recently our drain field (back yard) has been back flowing into the tank which holds the gray water. This tank subsequently backs into the primary tank causing it to become full.

During pumping of these tanks we can witness water flowing back into the outlet hole. Our backyard during heavy rains in the spring becomes wet and soggy. To remediate the problem we put in a curtain drain last spring. It helps and we can see water flowing out of curtain drain but hasn't solved the problem.

What to do next? Any suggestions would be appreciated.

Back yard is flat and I'm told adding soil to it puts your leach field lower than ideal and makes it harder to incorporate evaporation, wind sun to dry leach field.

On 2017-09-19 by Peggy

My septic tank is not completely in the ground. Should it be

On 2017-05-07 by (mod) - water running out of the top of my septic tank?

Nancy:

1. Give a call to your septic pumping company to have the tank pumped: that will stop the immediate risk of a costly sewage backup into your home3 and will give you 1-3 days to find out what is the real problem. (After that the tank will be full again).

During pumping there is more information to be learned - the condition of the tank, tank baffles (bad baffles = clogged incoming lines or clogged drainfield), backflow into the tank from its outlet means the soakaway bed is flooded, failed.

Read with care the article above on this page about septic tank flooding: causes, implications.

2. Diagnose the cause of backup in the septic tank; a broken or clogged pipe can be repaired.

Flooded or failed septic drain field will require replacement, or at the least, direction of surface runoff or groundwater away from the fields.

On 2017-05-06 by Nancy

What do I do when the water starts running out of the top of my septic tank? septic tank

On 2017-03-28 by (mod) - septic backup soon after tank pumped

Sharon

Watch out: warning that leaning over an open septic tank inspection cover can expose the observer to methane gas, fainting, falling into the septic tank, or other hazards

with that arm-waving stuff out of the way:

Find the septic tank

Open the inspection cover over the tank outlet

Look at the level of sewage in the tank:

- if waste is at the top of or flowing over the top of the outlet baffle or tee then yes, waste is not leaving the tank

That can be traced to a blocked waste line out of the tank, a flooded D-box, or a flooded or failed drainfield

On 2017-03-28 by Sharon Powell

We just had our tank cleaned out in Jan. and our septic tank has started backing up again, it is a 1k gal. tank with a curtain drain. Hubby seems to think the water isn't going out of the tank. Any suggestions?

On 2016-10-25 by (mod) - water pooling around the pipe entering the septic tank

Darn.

Some excavating is needed to explore the problem.

First you want to find the septic tank cleanout lid and have your septic company open the tank to inspect the sewage level in the tank. If the tank is back-flooding then I suspect a blockage or failure at the tank outlet or drainfield.

The tech will perhaps next have you run water or flush toilets to see how waste flows into the septic tank and to inspect for leakage around the tank inlet.

We don't want sewage leaking OUT of the septic tank and we do not want ground water leaking INTO the septic tank either as that'll flood the system and drainfield and means septic system failure too.

If the problem is simply ground water around the tank and if the septic system is working, you can defer the cost of connecting to sewer by directing groundwater away from the tank and sealing the tank inlet and outlet piping at the tank wall if they are leaky.

On 2016-10-25 01:32:19.254850 by Beth

We are having water pooling around the pipe entering the tank starting at three feet from the house.

The pipe takes a sharp turn downwards to about three feet than veers to the left than into the tank. Since some of this pipe has been covered by a concrete patio (done before we bought the house) we haven't exposed the whole pipe.

We've gotten all kinds of possibilities including the tank needs pumping, the pipe is broken going to the tank, to the lid could be crushed.

There is not wetness in our drain field or anywhere else except around the pipe. Can this be fixed if it is the pipe? Of course the township wants us to hook up to the city sewer but that would cost was thousands. What do u suggest

On 2014-07-08 by (mod) -

Anon, the next point to check is the distribution box. Look for flooding there. Look at the flow of effluent into all the drainfield lines. Indeed the field may be shot but lets make sure.

Question:

(July 7, 2014) Anonymous said:

Water lvl in septic tank below effluent. Water did not drain back when pumping. inspector said he saw water in 5 foot length of pipe via video. Pipe goes into elbow then turns down into septic trench. He said we have a Malfunction and will have to replace entire absorbtion field to a tune of 30,000.

Reply:

Anon, the next point to check is the distribution box. Look for flooding there. Look at the flow of effluent into all the drainfield lines. Indeed the field may be shot but lets make sure.

Watch out: at FLOODED SEPTIC SYSTEMS, REPAIR we explain how to fix a problem with septic tank or soakbed or drainfield flooding.

But be warned, that while in an emergency we might pump the septic tank, simply pumping the septic tank won't fix this problem and worse, if the back-flow rate into the septic tank is rapid (as it often is) you are simply wasting your money as back-flooding from a drainfield or surface runoff will quickly fill the septic tank again in hours to days.

...

Continue reading  at SEPTIC TANK BACK FLOODING or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Septic System Flooding Diagnosis & Repair Articles

• FLOODED SEPTIC SYSTEMS, REPAIR
• PUMPER TRUCK OPERATION PROCEDURE where we explain how to spot backflooding during septic tank pumping
• PUMPING the SEPTIC TANK to continue with the septic tank cleaning & inspection procedure
• SEPTIC D-BOX FLOODING
• SEPTIC BACKUP PREVENTION for tips to avoid a septic problem during times of anticipated heavy septic system usage.
• SEPTIC DESIGN for FLOOD DAMAGE RESISTANCE
• SEPTIC DRAINFIELD FAILURE DIAGNOSIS
• SEPTIC SYSTEM BACK-PUMPING
• SEPTIC TANK BACK FLOODING
• SEPTIC TANK PUMPING MISTAKES
• SEPTIC SYSTEM BACK-PUMPING - pumping out the drainfield is not useful

Suggested citation for this web page

SEPTIC TANK BACK FLOODING FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to SEPTIC SYSTEMS

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

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.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Citations & References

In addition to any citations in the article above, a full list is available on request.

---

ADVERTISEMENT

---