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LARGER IMAGE: unsafe septic tank cover discovered by simple exploration - we roped this area off and placed heavy plywood over the opening - it was by a children's play area.Septic Tank Covers

Septic tank covers, openings & access ports:

Here we provide a guide to septic tank covers, finding, types, and septic tank cover safety. Assuring the septic tank cover is safe. Where to look for the septic tanks, septic tank covers, or septic tank cleanout lids.

What are the types of septic tank covers, how do we assure the septic tank (cesspool, drywell, or seepage pit) cover is safe;

How deep is a septic tank cover buried, & do we find & remove septic tank covers?

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Septic Tank Covers

Concrete septic tank cover photo s howing the cleanoutOnce the Septic Tank has Been Located How Deep is The Septic Tank Cover & Is the Cover Safe?

Septic Tank Cover Depth & location

Tank Cover Depth: How deep will the septic tank cover be?

The top of the septic tank is often about one foot below the surface. But this depth varies a lot.

However the septic cover can be several feet deeper.

If you note the depth at which the waste line leaves the building foundation wall, say perhaps 3 ft. below the top of soil (grade level) then if the site were dead flat and if the tank were

Found 12 feet from the foundation wall, at a typical waste line slope of 1/8" to 1/4" per linear foot of run, the septic tank's entry port for the waste line would have to be roughly 3 ft. 3" below grade level.

Obviously if the site is not flat these septic tank cover depth estimate numbers change.

Septic Tank Cover Safety Procedures

Be absolutely certain that the covers and cleanout access covers over the septic tank are secure and durable so that it will be impossible for someone to fall into the tank (which is often fatal), and so that a child could not remove the cover.

If your septic tank is in an area where vehicles may drive over it, special heavy-duty rated covers are available. Discuss this option with your septic tank contractor.

LARGER IMAGE: unsafe septic tank cover discovered by simple exploration - we roped this area off and placed heavy plywood over the opening - it was by a children's play area. PHOTO of the septic tank cleanout cover.

If there is the slightest doubt about the condition of the septic tank cover (such as seeing subsidence over the tank location) you should rope off the area and prevent anyone from walking over it, again because falling into a septic tank is likely to be fatal.

Reader Question: septic tank cover collapse

11/28/2014 Scott C. said:

I have a septic system with a power assisted pump tank. The lid collapsed under the weight of the soil it was buried under. There was about 3'2" of clay type soil that the installer covered it with. The lid thickness is 4". Is that up to standard for that much soil? -

[This question was originally posted at SEPTIC TANK DEPTH]

Reply:

Scott,

If you want to investigate the adequacy of the lid over a septic tank you need a bit of data. Septic tanks are indeed rated for different weights and loads.

See SEPTIC TANK DESIGN STRENGTH SPECS

The thickness of the septic tank lid alone is not enough to know whether or not it was adequate - as we don't know if it contained steel reinforcement or if it did, on what spacing and using what material, nor do we know the quality of the concrete, nor its history (e.g. prior vehicle traffic over the tank) nor do we know the septic tank and size.

Reader Question about septic tank cover security regulations in Alberta

04/30/2015 Septic Tank Lids said:

Can you please inform me of the Regulations in Alberta regarding Septic Tank Lids?

We have a concrete Bell & Siphon and I notice the lower and smaller lids (one form each compartment) being are left at the top on the larger lids and under a cover on our concrete patio.

When I question the owner of the pump truck company...he said "that is a good place for them as they are a nuisance...they have to pull them up with a hook...

. they get stuck with dirt...and the metal hooks break...and then they have to get down and smash them with a mallet".

We have had the same tank system for 40 years and keep it covered and never had a problem until I noticed this recently, that someone had thrown the lower lids on top of the larger lids and under our cover. THak you Jane

This question and reply were originally posted

at GRAVITY/SIPHON DOSING SYSTEMS.

Reply:

Sure STL:

Here is an Excerpt from the Alberta septic tank code

3.1.2.3. Access Opening Lid/ Cover

1) All access openings shall be equipped with a secure lid or cover.1

1 Intent: Sentence (1) — To increase safety by preventing unauthorized or accidental entry into the access opening of a septic tank or holding tank.

Acceptable protective measures include, but are not limited to, a padlock, a cover that can only be removed with tools, or a cover having a minimum weight of 29.5 kg (65 lb).

2) The opening of a manhole access that extends above ground shall be insulated to an equivalent R-8 insulation value to protect the tank contents from freezing.

The handbook offers this additional commentary on these practices:

It is imperative that the lid or cover of the manhole access opening be secure to prevent anyone from accidentally falling into a tank. Once fallen into a tank it is essentially impossible to get out without help.

his securing of the access lid must be provided at time of installation and is an ongoing responsibility of the owner to ensure it remains secure.

During periods of time the occupants are away on a holiday for a number of days or in time of very low flow the tank is much more susceptible to freezing without this insulated lid.

In sum, if the cover over your septic tank could be moved by a child so that someone could fall in, the risk is a quick and ugly death. Be sure the covers are safe.

Reader Question: how do I cap this wiring conduit at my septic tank cover?

2013/0318 NT asked:

Our dogs removed what appears to be a part of our septic which was covering wiring. Where can I fine a replacement?

Septic tank cover and plastic riser for pump wiring, possibly unsafe (C) InspectAPeida.com

Photo provided by reader NT. [Click to enlarge any image]

Reply: proper conduit and exterior electrical boxes are required for outdoor septic pump wiring

Septic pump wiring example from Chippewa DOH manual cited in this article at InspectApedia.comNT:

The white plastic "tube" in your photo (above) looks like a riser conduit for septic pump or alarm wiring. I cannot tell if it's a product designed for that use or a home-made conduit using downspout material.

I would start by giving your septic installer or maintenance company a call to ask what they used - that can save you a lot of digging around time.

Meanwhile be sure to place a makeshift cover over the conduit top to keep rainwater out. Even a plastic bottle would probably help.

Watch out: I am doubtful that the conduit used was proper and approved for electrical wiring. Normally underground electrical wires run outside are run through waterproof PVC conduit to a riser and an outdoor-rated electrical box and cover.

The illustration here [Click to enlarge any image] shows what I am describing: use of listed components for underground and outdoor electrical wiring with a riser well above ground. This illustration is excerpted from a presentation on proper installation practices from the Chippewa County Health Department in MI

...


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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2024-07-27 by Lana

I have searched multiple ways and still cannot find a good answer to this.

The septic tank at my property has three chambers and three flat concrete lids. I had noticed a 1/2 inch crack not far from the lid that had been used to pump, repair and inspect the system prior to the home purchase.

I had a little trouble getting a local company to come to check this for me including the guy who had done the the repair. Finally a septic service company came out and said that the lids were separating and put down corrugated, solid drain tile (he had no plastic sheeting) over the cracks (he located another area where the lids had separated) and then covered with dirt. He said this was the best thing to do and the lid/lids did not need replacing.

My question to you is this: Is he correct? I am just thinking that drain tile is only covered with a couple inches of dirt if that and won't it shift over time? What you recommend to do with this?

To qualify how he laid the drain tile - 1st he cut it in half so it was semi-circular to start before covering the cracks between the lids and putting dirt on them. Thank you.

On 2024-07-27 by InspectApedia Publisher

@Lana,

There are two possible issues here, the first VERY serious;

1. If the septic tank top (lid) or its access covers are not sound they could be unsafe: if someone walking over the septic tank falls in it's a quick, nasty death.

Just tossing some plastic drain tiles (I'll post a photo of what I think you described) over a damaged access lid and covering that with dirt could be unsafe.

The image below is of a 5" plastic drain tile (basically thin plastic pipe that's perforated) produced and sold by Erosion Products LLC, in St. Bonifacius, MN Web: https://www.erosionproductsllc.com/

That is not a structural product.

Your septic tank may be unsafe.


2. Even if the septic tank cover and access lids are safe and strong, cracks that can leak water into the septic tank can flood the whole septic system in wet weather, leading to septic failure and even a septic backup into the building.

So we want the cracks fixed if there's no safety issue. I might have made a temporary repair simply using silicone on a plastic lid if there's no danger of it actually breaking, or a masonry / concrete patch and seal compound if the crack is in the top of a septic tank lid itself.


Forgive me for being an old chickenhearted guy but I'm way too familiar with septic system cave-ins and fatalities to bet your life and those of anyone else who might walk over the septic tank. So until you know that this tank cover and its access lids are absolutely safe, keep people from walking over the septic tank - rope it off or whatever.

Please read SEPTIC & CESSPOOL SAFETY at https://inspectapedia.com/septic/Septic_Tank_Safety.php

Daniel

perforated drain pipe

On 2024-07-27 by InspectApedia Publisher

@Lana,

Look at the septic tank access lids or covers to see if there is a manufacturer;

Check with septic tank suppliers near to your home - usually septic tanks come from nearby as they're expensive to transport.

The original septic tank provider would perhaps have replacement covers.

And if you're unsure about the condition and safety of the septic tank top or lid and its access covers, have it excavated and inspected by someone with more experience and caution.

and if you think I'm exaggerating about the safety concern see

SEPTIC TANK ACCIDENT REPORTS

https://inspectapedia.com/septic/Septic_Tank_Accident_Prevention.php

And more for you to read if you want:

SEPTIC TANK LEAKS https://inspectapedia.com/septic/Septic_Tank_Leak_Causes.php

SEPTIC TANK BACK FLOODING https://inspectapedia.com/septic/Septic_Tank_Flooding.php

On 2024-08-17 by Lana

@InspectApedia Publisher, Thank you Daniel for your thorough reply. This information is helpful. From what the one guy said the lids (concrete) had shifted but then he doesn't appear to have correct ideas so who knows. I am am glad to know that this is not a good "fix" for this in any way.

I have contacted the local city building department with some questions and I will be attempting to find someone to provide a real solution such as replacing or reseating the lids. Your points on safety are noted.

The concrete lids and surrounding area do not show signs of deterioration or instability but will keep an eye on this until it is repaired properly. Thank you again for the information and links. Much appreciated!!!

Yes your picture is of what the guy used cut in half and tried to flatten to cover the crack where lid had appeared to have shifted exposing a crack.

On 2024-08-18 by InspectApedia Publisher

@Lana,

Thank you for the follow-up.

Cutting plastic drain line in half and putting it over cracks wouldn't harm the safety of the septic tank as long as that's not being used as a substitute for a structurally sound and safe tank cover.

I also don't think that those halved plastic lines would help prevent water from leaking into the tank and in fact they could actually crease surface water leaking into the septic tank.

But that might help keep some dirt from falling through the crack into the tank.

I'm glad you're keeping an eye on the safety question. That's the first and most important concern.


Readers asking about replacing damaged septic tank lids:

On 2020-11-24 by Jonathan bruno

I ran over the top of the concrete cover how do I figure what size I need

On 2020-09-24 by Janet

Can I replace my concrete septic lid with a pvc lid?

On 2020-07-29 by James Williams

I need to replace my concrete lid on my septic tank, 26" X 56" to put a riser on. Do you make a pad or do you know where I can get one?

On 2020-07-24 by Al

I have an old concrete septic tank with a concrete slab top. One corner of the lid cracked and fell into tank leaving a hole in one corner.

Was told by contractor that was not a problem and put an outdoor sprinkler box to cover the hole so it would be easier to pump out.
Problem with sewer fly’s, could this be because the top is not sealed?

On 2020-11-24 - by (mod) -

For all of the readers above:

you will need to excavate just enough of the septic tank at least at the corners to measure the dimensions of the tank cover.

Watch out: Meanwhile: when a septic tank tank cover is damaged or missing, be sure to rope off and keep people away from the area as if someone falls into the tank it's a quick and nasty death

The new septic tank lid must be safe (falling into a tank is fatal)

That means it needs to be strong enough and it needs to be bolted to the tank top;

On 2020-07-17 by Cristian - how do I replace the cap on a septic tank cover/vent

Hi,

I had a contractor run over one of the vent pipes and now is just exposed.

I’m looking to put a cap on - does it needs to be vented or slotted?

Can I use something like a pipe fitting

(Grainger part no. 22FJ41 https://www.grainger.com/mobile/product/LASCO-PVC-Cap-22FJ41)?
Thanks!

PVC Vent cap such as sold by Grainger.com 4-inch - at InspectApedia.com

On 2020-07-18 by (mod) - use proper vent cap on septic line or tank vents

Oatey septic vent cap at InspectApedia.comIf it's a vent, not an access or cleanout opening, then yes you need

1. a cover that will vent (slots is ok), That Grainger part is a solid cap - ok for push-on-pull-off access but not for venting

2. protection from surface runoff water entry -

See the example from Oatey, below and click the image to see details.

The PVC vent cap to which you refer is suitable for a cleanout access but would not provide venting.


 

 

On 2020-03-31 by Helen Myers - What size lid would I need for a 250 gallon septic tank

What size lid would I need for a 250 gallon septic tank you

On 2020-03-31 - by (mod) - lid size required for a 250-gallon septic tank?

Helen

There is no single right answer to your question about lid size required for a 250-gallon septic tank because tank dimensions vary all over the place.

But

Watch out: there is no 250-gallon septic tank that can be legal, code-approved, nor that will work properly for any normal building connection or use. It is considerably too small. The result is that your tiny 250-gallon septic tank will remain agitated and will push solids into the drainfield and will quickly destroy it.

That leads to discharge of sewage pathogens into your local ground, groundwater, lakes, streams, and potentially your own drinking water.

On 2020-02-03 by Donald Ray Dunn - four covers over my septic tank - found roots, tank makes burping sound

I have four green round covers on my system. It has an air pump and sprinkler attached. I'm sure it's an aerobic system. I can't find any information about who installed it. I have heard that four covers means it is a newer type and my home is only about 14 years old.

Are there different types of aerobic systems? I want to know what is happening in each tank and what looks normal and what should alarm me about the condition of my tank? I had burping when I flushed the toilet.

Had some one come out and they discovered roots they cleaned what they could and said they would pump it out. I purchased some rootX and used it going by the instructions. Four weeks later It started burping again.

I opened the covers to see what was going on. Tank one had a mass of roots floating ,which I removed tank two looked good tank three had large chunks of floating decomposed/ looked like dirt. I removed those chunks.

Tank four water level was very low.

The burping has stopped again. I just don't know if I fixed the problem I also wonder why there was so much chunks floating if they pumped it out

On 2020-02-03 - by (mod) -

Donald it sounds very much as if you're describing an aerobic septic system.

Root-X will not fix nor help your septic system - see SEPTIC TREATMENTS in the ARTICLE INDEX FOR DETAILS.

However it does sound as if your system needs cleaning and perhaps repair, and you'll want the service company to find how and where roots were invading the system as if that's not corrected the problems will be recurrent and risk both contamination of the local environment and a septic failure that backs up into the home.

When there are pumps and aerators in use on a septic system somewhere indoors or outside at the tank you should find a control box, perhaps with an audible or visible alarm, and on and in that box will be (or should be) a data tag with information about the system's brand, model, and installer.

Do let me know and attach a photo of what you find and we can comment further.

About floating solids - it's normal for there to be some floating solids in a septic tank: feces and toilet paper and possibly clots of grease; But not chunks of wood or roots.

The low water suggests that the effluent pump or effluent distribution system was not working and/or there's a leak in the septic tank.

On 2018-08-16 by pam - I can't afford a septic tank riser

I already have a riser on the one where the guys ticks the pump down to pump it. and I have another round concrete one which is over the sewage pump tank. a guy came to rewire the pump and it works fine but i can't afford a riser for that one and now it's all exposed.

I guess what I'm asking (is probably what u can't legitimately give me) is a way to cover it now that that area is dug down only a foot or so but rain and sand are going to get into it Jerry riggin like a tarp or a piece of plywood with a tarp i guess is what i'm asking

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

On 2018-08-16 by (mod) -

Pam

The worry here is in this order

1. without a proper and safe cover someone can fall into the tank and be injured or killed

2. surface water leaking into the system risks overloading the septic drainfield, destroying it and sending sewage into the local environment.

If you can jury-rig a cover, even using plywood and a tarp, that drains away from the pumping chamber AND IF you can also fence off and keep people away such that there is no safety hazard, you could try that, but I suspect that the time, trouble, and cost of those will be about the same as buying a new concrete cover from your local septic supplier.

...

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

Or see SEPTIC TANK COVER FAQs - questions and answers posted originally at this page.

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Suggested citation for this web page

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


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INDEX to RELATED ARTICLES: ARTICLE INDEX to SEPTIC SYSTEMS

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