Questions & answers about the schedule for pumping out septic tanks:

This article describes frequently-asked questions that help explain when, how & why to pump septic tanks, cesspools, drywells and related systems.

Septic Tank Pumping & Maintenance FAQs

These questions and answers were posted originally at the home page for this topic is SEPTIC TANK PUMPING SCHEDULE - please see the table of recommended septic tank cleanout or pumpout intervals given there.

On 2019-12-13 by Jack

jack said:

I love that you suggested to base your pumping schedule based off of how many people occupy your building. We are trying to figure out when we will need to pump our septic tank, and it will be important for us to choose the right time, so we could avoid any issues. When we build a schedule, I will be sure to consider how many people we have in our home.

On 2018-08-05 - by (mod) - The DANGER of letting the pumper return "clear water" back into your septic tank

That explanation makes no sense whatsoever. It is in fact patently absurd and in my opinion self-serving nonsense.

In normal use a typical septic system tank, after emptying, fills up with wastewater in a few days to a week. Figure 100-200 gallons of water used per day per occupant, figure a 1000 gallon tank or even a 1500 gallon tank and do the math.

There is nothing you need to do, and perhaps where you live there are no other septic tank pumping companies nearby.

See SEPTIC TANK PUMPING SCHEDULE based on time, occupancy, usage, tank size

There is nothing you can or need to do right now but you should schedule the pumping of your tank based either on the tables in the article I recommended, or else o actual objective data from actual measurements of the thickenss of sludge and scum in the tank - also described in this article series. That objective data is not normally obtained nor given to you by a septic pumper company nor can a homeowner safely do those measurements, that's why people rely on the tables instead.

Next time your tank is "pumped" insist that it be left empty.

Watch out: The DANGER of letting the pumper return "clear water" back into your tank is that more-honestly it's not "clear water" it's septic effluent" from which the larger solids may have been removed, but the fine solids are now agitated and dispersed in high numbers thanks to the agitation and grinding action of the pumper truck.

Pumping fine solids BACK into the septic tank saves the septic pumper company money (reducing the amount they have to pay to dispose of the sewage they removed by reducing its volume) but it risks reduction of the life of your septic drainfield.

That's because filling a septic tank with fine floating waste ("clear water" is a misnomer) means that the fines are pushed out of the tank into the drainfield, clogging the soil and reducing the field life.

I would not accept that .

On 2018-08-05 by Gabe

Hi Dan,
Thank You for your response. The Septic Company that I pumped clear water back into my 14,000 gal tank, about 75%. He said that an empty tank will fill up faster and that he didn’t want to return in less than a year half. I don’t know what to do.
Thank You again

On 2018-08-04 - by (mod) -

Absolutely none. There is NO functional reason and no benefit to pumping water "back" into a septic tank after it has been pumped. Not ever.

The only benefit from that operation is a reduction in disposal cost to the septic pumping company - the septic pumper is reducing their expense by pumping the septic tank, charging you for it, and then un-pumping your septic tank.

On 2018-08-04 by Gabe

What % of water should be placed back into the septic tank, after being pumped?

On 2017-07-21 - by (mod) -

Sue

I'm guessing that you are describing a septic system that pumps effluent up to a drainfield, and that the effluent pump is in a separate, or final chamber past the main septic tank. If inspection doesn't find a thick layer of sludge nor any floating scum in the pumping chamber - as should be the case - it doesn't need to be pumped.

If inspection does find sludge and scum in the pumping chamber then either there's a baffle missing in the upstream septic tank compartments or the system has gone too long without pumping. IN that case I'd have the chamber cleaned out.

On 2017-07-18 by Sue

Hi,
I have read your site several times. Great, detailed information. I could not find anything on the septic pump tank. I asked the septic pump service if they also pumped out the pump tank in addition to the septic tank. Their response was if the pump is working fine, they don't mess with it. Should the pump tank be pumped on a regular schedule and what should be done? Or am I better off not messing with the tank with the pump components? Thanks for your advice!

Question: Recent Septic System Repair / Pumpout

I had some work done recently and if I sent a picture of the work, can you give me an idea of the quality of work? BTW, I love your site. - Syd

Reply:

A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem. And certainly from a photograph alone one can't make a full nor accurate evaluation of the condition of a septic system.

That said, I'll be glad to look at your photos and if the initial Q&A is sufficiently modest I will reply pro-bono. Of course as you gave no information about the topic, I can't say in advance how much I can comment on the pictures.

Reader comment - follow up:

I appreciate it. I used the information extensively when I bought this house. It is what clued me into the FPE panel I had and why when walking on the floor above the panel, the lights would sometimes dim (the breaker for the water heater was loose and arcing to the bus bar). I replaced the panel, breakers, etc..

Here are the specifics: Built in ‘84, in TN 4 BR, 2 bath, split foyer. Just my wife and I live here. Previous owners had 5 kids. The washing machine is on a proper grey water disposal system. The dish washer will be added soon.

Here's the story.

What started out 2 Friday's ago with a day off, I called the honey wagon to pump the tank.

I have lived here for nearly 4 years and when I bought the house, the previous owners had the tank “inspected” and were informed that the tank did not need to be pumped. They lived here for 7 years and never had it pumped or checked. Now, the truck shows up and we start digging.

Turns out that its not possible that the people that the previous owners had check the could have.

The amount of dirt disturbed vs what I had to dig was way off. So the truck leaves and I dig a hole that is 5 feet deep by 4ft by 3 ft. By hand.

Fast forward to yesterday, truck comes back and we open the lid. This is when we find out that its approximately 2000 gal precast cement tank with 3ea 2.5x4ft hatches.

Apparently this is rather uncommon around here. Also find that the exit baffle is nearly disintegrated however still in place. There was not an input baffle, in fact, it was a pipe that just poured waste onto the surface. The scum layer was 5 to 8 inches thick. I do not know how thick the sludge was, I had to go to home depot to get some pipe.

Also, the input was right next to the output.

The driver pumped as much as he could (truck filled, he was expecting a 1000 gal tank which is common in this area), he got most the sludge and scum, 2/3 total volume removed.

He recommended that a piece of pipe 2 ft. long be added to the input and to add a 4 in pipe with a tee on it.

His method for installing the tee was to use PVC cement to a 2 ft long pipe, stuff the pipe down the output and secure with expanding polyurethane (great stuff) foam. You can see all of this in the picture.

The pipe leaving to the drain field is ORANGEBURG PIPE .

Here is what I think I know to be true: The tank was never correctly installed. I should have had the input moved and a tee or baffle installed. I should have asked him to come back to pump the rest of the liquid.

I need to replace the orangeburg pipe soon.

So here are my questions: Since the system has been running like this 27 years and not pumped in at least 11 (could be 27 as well), do you think ill get another 10, maybe 20 out of it? Since the tank is rather oversized and its only the two of us, I think its safe to say the system is not taxed that much.

We put a half gallon of spoiled buttermilk down the drain each month.

Thank you again for your assistance and for providing such an informative site with ACCURATE information. Feel free to use my picture of a hall of shame or whatnot. 

Reply: Buttermilk is not a useful treatment to add to a septic tank

About your note and photo - just in order of thoughts & your note:

7+4=11 years, probably longer than recommended for pumping the septic tank - see https://inspectapedia.com/septic/Septic_Tank_Pumping_Schedule.php

2000 gal precast cement tank with 3ea 2.5x4ft hatches - probably a good tank, certainly decent size; if the liquid/sewage levels were normal then the tank is not cracked, damaged, leaking.

It would have been better to pump the whole tank out completely - we don't know really if the sludge was adequately removed from tank bottom, though it's possible for the pumper to probe and measure the sludge thickness that remained.

It was absolutely correct to add the tee at the inlet - it reduces sewer gas and sewage backflow into the incoming sewer line; I'm not experienced with using expanding foam to secure the tee

if it works both to hold the tee in place AND there is no groundwater leaking INTO the tank at that end, you're in good shape.

YOU SHOULD open the OUTLET end of the tank and be sure that there is an outlet tee in place - this is critical to avoid sending solids into (and ruining) the drainfield

ORANGEBURG PIPE : old, very old, questionable condition; I'd like to see any photos if you dig up any of that material.

If you find there was no outlet tee, combined with infrequent pumping and orangeburg pipe, you will want to be saving/planning for drainfield repair/replacement.

Inspect the septic drainfield area for wet spots, smells, evidence of failure.

Minimum steps:

• make sure there is an outlet tee
• inspect for evidence of field failure
• plan for field replacement

Desirable:

• finish pumping the tank; as you need to open it again to see the outlet tee side, that's an opportunity for the pumper to finish cleaning, though usually we see them pump from the center access if that's accessible
• install a septic riser over the center access port so that on next pumpout schedule you can clean the septic tank without so much digging.

I can't for sure predict how much life remains - a lot depends on level of usage, soil conditions. I've mentioned the tee - a predictor of field failure if it was missing.

Buttermilk is not a useful septic system treatment, though it won't hurt anything. You don't need to treat the system and in fact some treatments are harmful, even illegal. See https://inspectapedia.com/septic/Septic_Tank_Treatments.php 

Reader follow-up comment:

I think I may have been misleading.  The input from the house is the 3 inch pipe towards the top of the picture (under the shovel). 

It originally was just a 3in 90 that poured onto the top of the surface.  The outlet is the field is the 4in tee. 

The input is now under the scum layer and does not have a tee.  My picture shows what should be the output, however, when installed it appears that the contractor put the input on that side as well.

Question: trailer park septic pumps run too much

(Apr 23, 2014) Anonymous said:
if you have a trailer park and on weekends the pumps are pumping all day long what can you do so that the pumps don't run so continuously through out the weekend .

Reply:

Anon, I don't know the design for the septic system you describe but it sounds odd to me for a pump to be running continuously. Perhaps the pump control has failed, or there is no pump, or the float broke so someone just leaves the pump on (burning it or them up ahead of time).

Or perhaps the inflow exceeds the pump capacity, or an outlet line is blocked.

Or perhaps there is surface water running into the septic system.

If none of those worries turn out to be the case then it sounds as if one would need a larger pumping chamber and/or higher capacity pumps, or both, so that the pumps could cycle less frequently.

Question: toilet bubbles after flushing means time to pump the septic tank?

(July 7, 2014) Joe said:
When toilet bubble after flushing,is this a sign to get septic pumped

Reply:

Joe

No not exactly. Or at least not necessarily: A bubbling toilet means that the drain is partly blocked or clogged - which could be due to a backing up septic tank.

Pumping the tank gives you a few days to a couple of weeks of "relief" until the tank is filled again. That's all. Pumping a septic tank will NEVER fix a clogged or failed drainfield nor a clogged outlet pipe if that's the problem.

A more complete explanation is given at

inspectapedia.com/septic/Septic_Tank_Cleaning_Mistakes.php

Question: toilets don't flush and sewage is backing up - does this mean the septic tank needs to be pumped?

(Aug 17, 2014) Oona said:
My toilets are not flushing and my laundry tub in the basement is backing up(which happened previously when the tank needed pumped) but it was pumped in April 2013. I had a faucet leaking for about 6 months and was reading that that may cause it to fill up quicker. Could this be the case? Since April 2013 it has just been me living here. I'm 99% sure that they told me it's a 1000 gal. tank. x

Reply:

Oona what you describe sounds like either a sewer line blockage or a failed septic drainfield. A leaky faucet adds to the liquid load of a drainfield and might, if a LOT of water was entering the field, also have shortened its life, but I'd be looking for a blockage first, and a clogged, drainfield second.

Pumping a septic tank does not fix a clogged drain nor a failed drainfield.

Question: septic tank just pumped, what about septic filters?

(Sept 4, 2014) connie conniemkos@gmail.com said:

I just had my septic tank pumped after living in new home for 10 yrs. After having it pumped, I am now reading about septic tanks. Should have done this first. I have a 1500 gal. tank,(has 2 lids)
live alone, with occasional family guests on holidays. Only the inlet side was uncovered and pumped (took some time to locate) since this was the first time septic was ever pumped.

Man did not mention that other compartment should also be pumped as stated online. I also do not remember seeing a filter in the inlet side when he removed cover. His only comments were that it was normal.

My question is:

Should I have the out compartment checked, and should I have a filter installed, and can I wait 5 yrs. before I have this done again?

I haven't had any problems, never put grease down drain, and try to use detergent and paper that is recommended for septic. Would appreciate your help. Thanks much.
Connie

Reply:

Connie

If the sludge and scum layers were not so full that the tech was worried about having pushed solids to the second compartment you're probably OK. Next time open and check both compartments.

A septic filter will extend drainfield life but will also require periodic removal and cleaning lest you otherwise find the tank outlet clogging and worse, see a sewage backup. If you're willing to do the maintenance it's a great improvement.

Question: septic tank and seepage pit trouble

(Sept 5, 2014) Terri G said:
I replaced the septic tank and seepage pit March 2013, 1000 gallon, 5x26 seepage pit..... 2 adults 1 child occupancy.... plumbing started back up today? According to charts I've seen it shouldn't need to be pumped for almost 2 years.... Could there be a problem with the installation?

Reply:

Terri

A seepage pit is not a septic tank. If you are combining tank and "seepage pit" that's called a cesspool. Search InspectApedia for "Cesspools" to read about that system and its properties and maintenance.

Question: Canadian vs UK Septic Tank Pumping Schedule

(Oct 16, 2014) Janet said:
We have a cottage in Canada that is used for 6 weeks in the summer by 8 people and 4 weeks in the fall and 4 weeks in the winter by 2 people .

How often should we get out septic tank pumped out? We live in the Uk and have no prior experience with septic beds. We are very careful with not using bleach and only using biodegradable cleaning products.

Reply:

Janet, if the tank has never been pumped out I'd have that done to assess its condition. The pumping frequency you ask about could be calculated from the tables in SEPTIC TANK PUMPING SCHEDULE once we know the tank size. Without size data... Who knows?

Janet please see SEPTIC TANK PUMPING SCHEDULE

Question:

(Oct 25, 2014) Taz said:
SHOULD A TANK BE CONMPLETELY FLUSHED OUT WHEN PUMPED OUT, OR SHLOULD SOME WASTE BE LEFT IN TANK /

Reply:

Best practice is to empty the tank. If a worker leaves an inch that ought not be significant.

Question: leeches in the house and pinned septic system with yeast: what the hell?

(Oct 31, 2014) Anonymous said:
Any reason for a leech to be in the house? Is that mean the system has failed Justinian1954 live on lake in texas.use to be a bed and breakfast. When we bought the owner said she pinned in 1994. She just but yeast in it since.the gray matter line is house filling up with huge trash cans of worms and ouder inside

Reply:

Anon

I don't know what "pinned in 1994" means. Yeast in septic tanks is useless and can be destructive, agitating the seawage and pushing solids into the drainfield, clogging it.

Your description of in-house components is unclear but sounds unsanitary and in most jurisdictions a violation of health code.

Question: septic pumping company doesn't want to wait for owner to come home

(Nov 24, 2014) Nick said:
Hi, I was expecting the company that pumped my tank to call me and have me come home while they pumped it and kind of give me a report on the status of my tank. My wife and I moved into our house 2 years ago and have never had septic tanks before. Is it bad manner to call the company and ask for a status? They just left a bill in the door with the amount due. Thanks!

Reply:

Nick

I can't blame the septic pumper for not wanting to lose money waiting around for someone to come home. But indeed it's too bad you didn't get to see just what was done, including that the tank was fully pumped, inspected and found undamaged, etc. there is a lot about septic tank and field condition that an experienced pumper can discover during this job.

Most of those fellows do not give a written report but are glad to tell you if they saw any signs of trouble or if the tank is damaged or cover unsafe, etc. give the company a call and ask what they can and will tell you about what was done and observed.

Question: septic tank overflowed into the yard so we pumped it out

Bonobos Marcos said
My grandparents had a septic tank growing up. I don't think they knew how often to have it pumped because one day it started overflowing into there yard. If they weren't in a rush to pump it before, they were then. It took about a day to clean up the mess and have everything back to normal.

Daniel Cole said:

What a wonderful article to come across. I was just thinking the other day about septic tanks and how often they should be pumped. I will definitely use the information in this article and keep it in mind when it becomes time to get my septic tank pumped.

Reply:

Bobo

Pumping when the system has backed up may give a day or three of relief but does not fix anything.

Question: do we count two small septic tanks the same as one big one when deciding on pumping frequency?

(Jan 15, 2015) Jack said:
Question on your chart on how often to clean septic. I have '2' 500 gallon tanks so do I use the '1000' gallon listing or just the 500 gallon. The man who cleaned today said that the first tank is to collect solids which then flow to second tank which breaks it down further before releasing it as water.

Reply:

Good question, Jack.

I would expect most septic designers to treat the system like a single 1000 gallon two compartment tank.,but look with care at the sludge and scum levels when the tank is pumped as I suspect you'll find the levels are high, requiring more frequent pumping than the 1000 g table would suggest.

If we knew more about your design I could vibe more confident. In particular, if virtually no solids flow into the second tank we need to pump the first one more often.

Question: has this septic system soakbed or drainage field failed?

(Feb 17, 2015) Lauren said:
Hello, I recently purchased my home 1 year (Last Feb 2014) My fiancé and I are the only two who reside in the home. The home was built in 1989 and for the last 7 years only had 1 old lady living there alone. He husband died 7 years ago. When asked if she had the septic tank emptied prior to us purchasing the home she said she had it done 2 years ago.

Well this past august (6 months after purchase) we had a major back up into the home. My main bathroom shower and toilet backed up and overflowed. No other drains seemed to be affected at that time. I called Roto-Rooter and they came to pump the septic. The septic tank is a 1,000 gallon tank and was full all the way to top when they took the lid off.

He advised me that since he did not know how long it had been full like that, that my drainfield could be damaged and to keep an eye on it. He showed me where I could removed a lid to a pipe to aerate it if it backs up again.

Fast forward to a week before Christmas, the same thing happened. I went to the cap where he showed me and took it off, leaving it off the let air in.

This pipe was completely full of water. After approximately 5 hours of leaving the cap off and checking it every 30 min. The water went back down. At that time we began to use our water sparingly making sure not to do much at once like to many showers and laundry at the same time.

Then on Super Bowl Sunday, it happened again. This time when I went to take the cap off in the front yard it was full of water just like before; however, it was strictly laundry water. No smell or anything.

I have walked over the drainfield area and found no wet soggy areas nor have we noticed any foul smells since we had the septic pumped in august. I know without looking you can't properly diagnose my situation; however, does this sound like a drainfield issue and/or septic tank problem?

Any help you can give me would be so much appreciated.

Reply:

Lauren

Pumping the septic tank regularly can extend drainfield life but it can never fix a failed drainfield. From your description I suspect either a failed drainfield or a partly blocked sewer linr.

A failed soakbed does not always show up as wet spots or smells.

Question: is it necessary to pump a septic tank serving only the laundry?

31 March 2015 Don Stephens said:
I have two tanks; one regular (1000 gallons) and one for the laundry. Two people have lived in the house for 20 years; ages 78 & 74. I have the regular tank pumped every 4 years, but have never had the laundry tank pumped. Is it necessary to pump the laundry tank?

Reply:

Don,

Is your laundry "tank" a drywell or does wastewater flow out of it into a drainfield? If the latter, it would be prudent to have it cleaned. If the tank is really a drywell then you won't gain much by pumping as the clogging that occurs is in the soil surrounding the drywell bottom and sides

If you're unclear on this search InspectApedia for DRYWELL DESIGN & USES to see the difference between a drywell and a septic tank and a cesspool

Also take a look at GREYWATER SYSTEMS.

Question: metamucil or psyllium impact on septic systems

(Apr 20, 2015) Vern said:
How does the use of Metamucil (psyllium) impact the frequency of pumping required?

Reply:

Vern if you mean human consumption of Metamucil (psyllium) and thus its appearance in feces and thus sewage, I seriously doubt that there is any measurable impact whatsoever. It's a harmless biological material that adds a bit of bulk to stools - not enough to explain a septic system failiure. Pump the tank on schedule and you'll be OK. So will the tank.

Question:

(July 8, 2015) Bill said:
I have a 1000 gal tank and just had it pumped out. The crust was between 3" & 5" and the sludge was 10" t0 12". This was in a 2 year period (within a couple days). What is the recommend crust and sludge thickness to allow before having it pumped?

Reply:

Bill in the article SEPTIC TANK PUMPING SCHEDULE please see LEVELS OF SEWAGE for a more detailed reply than I can type off the cuff

Question: septic pumpout schedule for a seasonally-used camp

(Sept 21, 2015) Bill said:
I have a camp with a 1250 gal. tank. It is seasonal, only used in the summer. We have shower, toilet and sink that empties in the septic. What schedule should I use to pump?

Reply: how to calculate the septic tank pumping frequency for a part-time use building

Bill you can take any point in the septic pumping schedule table and then increase the length of the interval between septic tank pumpouts by making this reasonable-guess:

1. Choose the number of building occupants to find the proper line in the pumping shcedule. Also choose the table entry for the size of your septic tank in gallons.

2. Choose the number of months during a year that the building is occupied

3. Calculate the new pumping schedule by dividing the number in the table on this page by the fraction of the year that the building is occupied.

Example:

Household size = 4
Tank size = 1250 gallons
Table pumping frequency: every 3.4 years (Keep in mind it would be ridiculous to think that we can know precisely the conditions in an individual septic tank - these are general guidelines)

3.4 x 12 = 40 months between tank pumpings

Months your Camp is occupied = 4

Months in a year = 12

Portion of the year your camp is occupied = 6/12 = ..5 or 50%

Pumpout Schedule from Table / Portion of Year Occupied = 40 / .5 = 80 months

Question:

(Dec 4, 2015) Danielle said:
How often does a septic tank need pumped ?

Reply:

Danielle,

either you follow the general guidelines in the table at SEPTIC TANK PUMPING SCHEDULE or someone has to open the tank and measure sludge and scum layer thickness to get objective data.,

...

Continue reading  at SEPTIC TANK PUMPING SCHEDULE based on time, occupancy, usage, tank size ased on objective data or measurements, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see SEPTIC TANK PUMPING SCHEDULE FAQs-2 - more-recent question and answers about the best schedule for pumping out the septic tank.

Or see these

Recommended Articles

• DISTANCE TO SEPTIC TANK
• SEPTIC COMPONENT LOCATIONS
• SEPTIC FAILURE SIGNS
• SEPTIC SYSTEM AGE
• SEPTIC TANKS FLOATING UP
• SEPTIC TANK INSPECTION PROCEDURE
• SEPTIC TANK PUMPING MISTAKES
• SEPTIC TANK PUMPING PROCEDURE
• SEPTIC TANK PUMPING REASONS
• SEPTIC TANK PUMPING SCHEDULE
• SEPTIC TANK SAFETY
• SEPTIC TANK LEVELS of SEWAGE
• WHEN to CLEAN THE SEPTIC TANK
• WHEN NOT TO PUMP A SEPTIC TANK

Suggested citation for this web page

SEPTIC TANK PUMPING SCHEDULE 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

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