Septic Tank, Drywell & Cesspool

Abandonment Procedure FAQs

Buying a Home with Abandoned Septic: What to do FAQs

At a home I'm considering buying an abandoned septic tank is present: what should be done with it?

I am looking to buy a totally remodeled home located in Lake Ozark MO - Lake of the Ozarks.

There is literally an abandoned septic tank 6 feet from the front door. Home is now on city water and sewer. Should the owner have filled it in??? Since it wasn’t removed? This is the main concern I find with this home.

Do I need a separate septic inspection? I think the seller would have to fill it in for safety and health reasons.

I’m disabled and have many health issues including 3 autoimmune diseases. Concerned about the safety, smell, cave ins especially being disabled. Thank you for your time! On 2018-05-23 by Anita Ott

Answer by (mod) -

Anita

Check with your local building officials. Typically proper abandonment would have the tank filled-in.

If the system is not in use you don't need a "septic inspection" but your home inspector should certainly advise you of

- any apparent health and safety risks from the abandoned tank

- any signs of building water entry related to the tank's location close to the foundation

Watch out: an improperly-abandoned septic tank could risk a cave-in that could be dangerous or even fatal should someone fall in.

Details of what to do are

at SEPTIC TANK ABANDONMENT GUIDE

and safety warnings and examples of hazards from improperly abandoned septic tanks are

at SEPTIC TANK ACCIDENT REPORTS

An abandoned septic tank was found on the property we're selling: buyer wants it investigated & if necessary, filled-in

Buyer did a sweep of our property and found an old septic system (30 years or so) Apparently the entire neighborhood had septic before they brought in public water. There is no sinking and you cannot see where it even was.

They say we have to dig it up and inspect it before selling the house. No one in the entire neighborhood has ever had to do this to sell their home.

Is the buyer right or just looking for me to give them money at the closing toward it and reducing the price of the sale On 2016-07-09 by carole

by (mod) - your property may be unsafe

Watch out: when your home or propety is being sold various strangers are going to be walking around there; you certainly don't want the risk that someone falls into an old septic tank, risking injury or even death.

The main point I think we should emphasize is that some basic due diligence and appropriate warnings are important in these cases as though the chances may seem small, if somebody steps into or falls into a septic tank, even an old one that has been disused for some time, the result could be a quick and ugly fatality.

So you should simply ignore this warning; at a minimum you should have a contractor investigate to see the conditions of the old septic tank and if it needs to be filled in and safely covered it makes sense to do so.

See SEPTIC TANK ACCIDENT REPORTS

Contamination or Odors from Abandoned Septic Tanks FAQs

Bugs coming out of abandoned septic system drain piping

We bought a house that has a old septic tank on property -the house was hooked up to city.

After we moved in we had a plumber snake out our drain & he went backwards instead of towards the street.

He had to come back & redo it- problem being now we have millions of tiny black bugs that are coming up from the basement drain and dying as soon as the fly out. I’ve tried everything to get rid of the bugs vibrate they just keep on coming.

Please give us any information you might have to kill these bugs I believe are coming up from the septic . On 2020-02-11 by Eric

by (mod) - how to kill bugs coming out of an abandoned septic tank

Eric,

Just about any pesticide properly employed in the drain would kill the insects that you're concerned about. Or you could even temporarily simply put a rubber plastic cover over the drain. Opening in your building.

However, your question race is a far more serious concern. If the septic tank that was left on your property was not properly abandoned. Then there is a potential fatal safety hazard. If in fact someone should at some future time step over or near the tag and fall into it.

After all we have no idea of the tank age, type, construction materials, nor the most important: the security of its cover.

Proper septic tank abandonment requires that the tank be pumped clean and filled in. You should ask an appropriate excavation or septic contractor to find a tank and uncover the top and check its condition to be sure it has been properly abandoned if it has been the insect problem would be trivial. And a safety questions would have been addressed.

Septic Tank Abandonment Steps / Procedure FAQs

If a septic system has not been used for a time is it an "abandoned septic"?

Septic has not had water for 3 years or used. Would it be considered an abandoned septic system? On 2018-12-28 by Anonymous

by (mod) - NO; "abandoned" has a special meaning for septic tanks: the tank has been cleaned and filled - for safety

That's an interesting question, thank you.

My concept of abandoned septic system is specifically defined as one that is intended for no further or future use. That's not the same thing as a system that is in a period of this used but will be returned to operation. So for example a home that stands empty for several years but had a functioning septic system would not be considered abandoned.

The point of Abandonment is that when a septic system is no longer going to be used we don't want to leave an unsafe condition or unsanitary conditions at the property.

Is it OK to simply leave an old abandoned septic system alone after we connect to municipal sewer line?

I'm hooking up to county sewage system and contractor says it's ok to not dig up septic system I haven't had any problems with it is it ok to leave it? On 2015-05-01 by Kathy

by (mod) - NO, it is not ok to simply ignore an abandoned septic tank

Watch out: "Leave it" does not mean leave a possibly fatal hazard to be encountered in the future. If the tank is emptied and filled that's safest.

If the tank has a solid concrete lid and child safe covers that improves safety until the tank can be emptied and filled.

I would not base your decision on the contractor's advice. Check with your local health and building departments and let me know what they say.

In many jurisdictions local law requires that an abandoned septic be filled-in or removed properly not just "left alone"

The septic drainfields can usually be left alone because, except for chamber systems, a drainfield comprised of 4" diameter buried pipes ought not present a significant settlement hazard.

But

Watch out: if your septic system has failed and left sewage or septic effluent on the ground surface, that may be a sanitation or health hazard that means the area needs to be left alone or even treated (perhaps with lime) to give time for soil bacteria to break down the sewage pathogens.

How to abandon a septic tank in Australia - can we fill and build over it?

Does anyone know if when a contractor is hired to change a septic system over to a town sewer line is filling the abandon septic tank part of the cost and is it required in ,ma (May 25, 2014) Michelle

We are connected to sewerage and the septic tank has been crushed and filled in but we want to build a guest accommodation/home office where the old transpiration pit was. - Michele (Aug 1, 2014) Michele

Reply by Moderator:

Michelle: Take a look at Massachusetts Title 5 Septic Regulations for requirements in general. But the contractual obligation of the contractor is another matter. You'll need to review with your attorney the contract that you signed for work to be performed to understand the scope of work that was required.

Generally to be sanitary and safe an abandoned septic tank should be emptied of sewage and then filled-in.

Typically an abandoned septic tank or similar component is emptied, then filled-in to avoid collapse risk before constructing over the site. Check also with your local building department to determine whether or not there are local requirements.

Michele: if the septic tank was emptied, cleaned, drilled with rubble, it's properly abandoned in my opinion. Building over it should be ok.

But I'd not bear a structure such as a column or post directly on an abandoned septic tank as a structural support.

At our old Poughkeepsie office the prior owner had constructed a wood-framed porch over an old steel septic tank. He left a trap door in the porch floor to permit tank pumping but no actual tank inspection nor repair. We had the tank emptied, cleaned, and filled with stone and concrete rubble.

There were no subsequent odor problems. But none of the porch structure was borne on the tank itself nor on nearby piping trenches.

One of the most common complaints readers report about abandoned septic systems is subsequent subsidence or collapse - not only safety worries but serious problems for anything built atop the septic tank.

Michelle said:

Thanks for your reply The septic tank has been emptied crushed and filed in I was wondering about the transpiration pit or drainage area where the effluent would drain into from the septic. I live in Australia so maybe our designs are a little different but will call my local council and see if there are and regulations around this. Thanks again Cheers Michele

Reply: transpiration pits

I'm not sure what you really mean by transpiration pit. IF you actually had a seepage pit rather than a drainfield, it too needs to be emptied and filled-in. If you refer to an excavated hole into which was put a pre-cast drywell or cesspool or soakpit structure to dispose of effluent then such devices also need to be filled-in to avoid a future collapse hazard. - Mod.

Michele said:
Thanks Dan it would be what you call the drainage area or absorption area

Reply: difference between a transpiration pit and a soakbed or soakaway bed

OK Michele, but a "pit" as opposed to a network of perforated pipes draining effluent into the soil is what we call a drywell, seepage pit, or cesspool.

Those methods of disposing of sewage effluent are effective for a limited time as "disposal" methods but ineffective as a treatment method.

Details are at CESSPOOLS

If we were abandoning a conventional soakbed or soakaway bed or drainfield, not a drywall, not a seepage pit, nor other underground cavity, there is nothing to fill-in.

Health department wants a certification of the septic tank as being decommissioned

Prior to building we had the excavation company remove an abandoned septic tank. It was pumped, lid broken and was in pieces by the time they were able to get it out of the ground. I had them take it about 100 yds away into the woods and bury it in pieces.

Now the health department wants a certification of the septic tank as being decommissioned before they will sign off on our new as built an acre away. What are your thoughts? What can I tell them that would satisfy the requirement or their need to require a certification of decommission status? On 2019-11-29 by Harley -

by (mod) - septic tank decommissioning or abandonment procedure

Harkey

Thank you for an interesting septic tank decommissioning or abandonment procedure question. I would approach it as follows.

First I would have done it by the city and Country where the building or property is located then I would find the septic codes for that jurisdiction. In those codes you will probably find a description of what's required for an acceptable septic tank abandonment.

Usually those requirements are intended to make sure that a tank full of sewage isn't left at the property and that a tank isn't left unprotected such that someone could fall in and be injured or die. So the usual procedure is at the tank is empty and either filled in place or removed.

Ask the health department to be more specific about what they need to know.

Let me know what you find out about your local septic tank abandonment requirements and I may be able to offer more specific suggestions.

What Fill Material to Use when Abandoning a Septic Tank FAQs

What is the proper fill to use when abandoning a septic tank

What do you use to fill an abandoned septic tank ? Dec 8, 2014 - Roger

Reply:

Roger an abandoned septic tank can be filled with stone rubble or sand. You might use dirt (soil) but I'd watch for future setttlement or compaction problems.

Don't toss old tree branches, appliances, or junk into a septic tank to be abandoned as the decay of those items is likeliy to lead to a subsequent collapse.

Can I fill an abandoned septic tank with concrete?

If an old, empty concrete septic tank is partially under a slab on grade home addition, could the abandoned tank be filled with poured concrete?

The existing small access holes would make it nearly impossible to spread and compact sand or dirt. On 2019-11-08 by Doug Thomas

by (mod) - yes but that's expensive; why not break a larger fill-opening?

Sure, Doug, assuming the tank has been emptied. Geez though that sounds expensive. What about breaking up a bigger opening and then filling with gravel and sand?

Is it ok to fill a concrete septic tank with sand?

Can you fill a concrete septic tank in with sand? We are preparing to hook up to city sewer and need to know what the best cost-effective way to handle our septic tank will be. - 8/13/2012

Reply:

Cassandra, the tank gets pumped, cleaned, and filled - sand should be acceptable to your local building department.

If the tank is steel, and recommended even if the tank is concrete, fiberglass, or plastic, the contractor may punch a few bottom holes so that even sand-filled the abandoned septic tank doesn't become a water reservoir.

Can we fill in an old septic tank without harming local garter snakes?

We have an old unused septic tank near our house. We want to fill it and cover it but we also have garter snakes in the area.

We know rock or loose substances will attract them . What can we fill it with to avoid this? On 2017-03-20 by Carmen

by (mod) - Yes; Rocks + sand would be fine and do not hurt the garter snakes

Rocks + sand would be fine. By the way, garter snakes are harmless and in fact may help you out by eating bugs.

More accurate information about garter snakes is in

• Huey, Raymond B., Charles R. Peterson, Stevan J. Arnold, and Warren P. Porter. "Hot rocks and not‐so‐hot rocks: retreat‐site selection by garter snakes and its thermal consequences." Ecology 70, no. 4 (1989): 931-944.
• Matthews, Kathleen R., Roland A. Knapp, and Karen L. Pope. "Garter snake distributions in high-elevation aquatic ecosystems: is there a link with declining amphibian populations and nonnative trout introductions?." Journal of Herpetology 36, no. 1 (2002): 16-22.

Abandoned Septic Tank Cover Requirements FAQs

What kind of cover is needed over an abandoned septic tank?

After filling should I put the concrete top back on it or bust it up and put in tank with the SB2 gravel On 2017-07-24 by Norman

by (mod) - reasons to restore the top on an abandoned septic tank

I'd restore the top for a couple of reasons:

1. less subsidence of the covering backfill later

2. I want to minimize the water that will still want to run into the septic tank - risking causing a smelly or stagnant or bacteria-laden pond even with the gravel in place. (so seal the top too as best you can)

Some contractors claim they break a hole in the tank bottom before backfill. That'd be nice but not worth killing somebody: it can be fatal to descend into even an old septic tank unless the worker is trained, has proper safety gear, and is working with a support team.

Improperly-Abandoned Septic Tank FAQs

Abandoned septic tank found filled with water

I have an old unused concrete septic tank in my yard that has not been used in at least 20 years or longer,

I have had water standing under my house for awhile now, had a plumber out to look, no leaks in water line or drains, the tank is about 5 feet from my house, he took the top off the tank and it was full to the top with water, I am going to have it pumped out and filled, question will SB2 gravel be a good fill or do I need to use something different. On 2017-07-24 by Norman

by (mod) - groundwater entering an un-used septic tank means it wasn't filled

Norman,

It's common for ground water to find its way into a septic tank, especially an old one whose pipe seals or access cover seals were probably leaky. Proper abandonment would include just what you say, pump out and fill with stone or rubble.

Can an improperly-abandoned septic tank leak under or around a floor slab?

If a septic tank is not properly disposed of,while hooking up to city sewer lines can it cause under slab leakage? On 2017-04-24 by Debbie

by (mod) - Yes.

Debbie:

Good question.

A septic tank is not usually disposed-of in the sense of physical removal, when it is to be abandoned; rather it is left in place and filled in with rock and soil.

Now some "IF's"

If the septic tank was not filled-in
and
if the septic tank is close to the building,
then

Yes I have encountered cases in which an abandoned tank close to a building foundation wall was a source of water entry into the basement or crawl area. The excavation itself can direct roof spillage or surface runoff into the foundation wall or under the slab.

More likely, though, when a buried septic tank (or oil storage tank) is placed within 10 feet of the foundation wall, the root cause of water entry is not the tank itself but rather the hole into which it was placed.

Roof spillage close to a building from overflowing or absent gutters or for a mis-directed downspout discharge too close to the building that might otherwise run downslope and away from the structure can sometimes find a previously-excavated hole whose backfill is less dense than surrounding soil.

Water then runs into that hole (or pipe trench) and flows towards the foundation.

Start with a close look at roof and surface runoff around the building. Most builders are not so dumb that they put the basement slab below a local high water table. That's why I suspect an above-ground water source.

Abandoned septic tank leaking into basement

A new septic tank was installed before we moved into our house. The old cement tank was filled in.

We are experiencing significant moisture problems in the basement on the wall that borders the old tank.

The old tank is located under the patio in the backyard so it is not that far from the house. Is it a possibility that the filling in and compacting of the soil round the old tank has caused an underground waterflow issue in the yard? On 2016-09-29 by Scott

by (mod) - moisture in house walls near abandoned septic tank

Thanks for the interesting question, Scott. If the old septic tank was just filled-in and no holes punched in its sides or bottom, perhaps it's collecting some water from surface runoff or roof spillage, then leaking that water back out at its entry or exit port. Hopefully the tank got filled well enough that it won't serve as an underground pool.

Compacting soil could damage buried downspout lines, footing drains (less likely unless they're near the surface) or might otherwise cause water to be redirected.

A more expert look at the leak locations and patterns, site shape, roof drainage etc. can probably diagnose this trouble. Search InspectApedia.com for BASEMENT WATER ENTRY to see details.

Building Over an Abandoned Septic Tank FAQs

Can I pour a basement slab over a properly-abandoned septic tank?

I'm buying a house in unincorporated town in Northern California. The original septic tank under the house in an un-finished basement, was properly decommissioned with permit, and a new, larger one was installed outside the home's footprint.

With the proper decommissioning, can I now pour slab over the original location during a permitted re-model of the basement? On 2017-07-06 by John Shelby

by (mod) - It may be OK to pour a slab over a PROPERLY decommissioned septic tank under a house

I can't be sure of an OK without knowing what decommissioning was done.

A slab on a rusted out steel tank filled with soft soil could settle or crack.

Further investigation of what's there and assurance that there is no further fill or cover needed. Then you can pour a slab.

We want to build a pool where an old septic tank is to be removed

After converting to the city's sewer system that is very closey located, We'd like to physically remove a property's septic tank and place a pool where the tank is currently located.

So far I've only read about filling in the tank. Is is possible to remove the tank and place a pool in the same spot?

Or would that not be advised because if compromise to the area or other structural difficulties? On 2017-05-29 by Surfvet

by (mod) - put a swimming pool where the septic tank was located

Surfvet

I think what you want to do is reasonable as long as you're not thinking of converting the septic tank itself into an in-ground swimming pool. (No joke, you'll find an article here describing a German couple's conversion of their septic tank into an underground storage facility).

It seems a near-certainty that the excavation for the pool will be larger than the original footprint of a typical residential septic tank. As you're connected to sewer, driving a backhoe over the abandoned drainfield, even if it damages it, isn't a catastrophe, but you will want to know what other buried lines may be present at the site and that need to be avoided or protected such as electrical and water mains.

DO keep heavy equipment well away from the foundations of the home itself - or the foundation could be damaged.

DO be sure that the soils are properly compacted lest your new swimming pool collapse when portions of the soil under or near it subside further.

Interested in building an above-ground pool over an abandoned septic tank

I was interested in purchasing a home and just discovered that the old septic tank was left untouched. My concern is that there is an above ground pool over the old tank. What, if any, concerns should I have. (Nov 1, 2014) Jo

Reply: safety warnings when building a swimming pool close to or over and abandoned septic tank

Swimming pool collapse, injury, unsanitary conditions come to mind, Jo.

Along with some extra costs to access and properly abandon and fill-in the septic tank

 

Drain Holes Needed in Bottom of Abandoned Septic Tank FAQs

Do you drill holes in the bottom of an abandoned septic tank?

Found abandoned septic tank -2 of them in backyard. These are cement and intact. These old "septic wells" are dry and made of cement .

Do you have to drill holes in the bottom and then fill with sand and stone? Is that ok? On 2016-09-14 by Brenda

by (mod) - holes recommended in bottom abandoned septic tanks - with exceptions

I prefer to see a drain hole in the bottom of an abandoned concrete septic tank as that avoids accumulating of standing water that might otherwise leak into the tank even after it has been filled with rubble or stone; but often a contractor simply fills the tank with soil and rubble.

But if the septic tank is being crushed or broken up (steel or concrete) then of course drain holes are not a concern.

Septic Tank Abandonment - Repurposing FAQs

Can I convert an old septic tank into a pond?

I've got an old septic tank in the garden of the house I'm buying. Is it possible to turn it into a pond? I was wondering if I could line it with butyl liner on a cushion of sand (to be more hygienic) - Victoria 9/25/2012

Is it possible to turn an old septic tank into a pond? I was wondering whether I could line it with butyl liner on a cushion of sand. - Victoria

Reply:

Victoria,

While the conversion you describe is technically feasible, it seems a bit deep, unsanitary, and cost-unbalanced an idea to me. To reduce the sanitation hazard you'd need to

1. remove or block off any abandoned sewer lines that drain into or out of the septic tank
2. pump, wash, and sanitize the septic tank
3. provide a security fence or similar measures as one would do around any pool or pond where it may be an attractive nuisance and child hazard
4. provide appropriate water source, aeration, drainage, etc.

Septic Drainfield / Soakbed Treatment When Septic Tank is Abandoned FAQs

When abandoning a septic tank what happens to the drainfields or soakbeds or transpiration pits?

Do I leave the leach fields as is or fill outlet with concrete (Mar 26, 2014) Anonymous

Reply:

Leave the septic drainfield or soakbed as-is.

Anon, no one should fill a drainfield with concrete. We're talking about 6" perforated pipes buried in gravel trenches or the equivalent; left alone. Only if there were structures in danger of collapse would a fill-in be appropriate. Then one would use rock and soil, not concrete when abandoning such a system.

Abandoned Septic Tank In or Under Building FAQs

What do we use to fill in the old septic tank being abandoned under a house floor?

I have a customer who has a septic tank under the floor of her house. We are installing a new septic system and I need to fill in the old tank with some sort of material (granular or alternative).

Can you suggest some options? I have to bring it in through the house, by pail, unless I can think of something that will work that can be put in by pump and hose. On 2015-06-11 by MeT

Answer by (mod) -

Me

A concern with any pump and hose system is that you need first to empty the sewage from the tank and then to fill it with rubble or sand.

If you can pump dry sand and not create or leave a moisture problem (or if it's a steel tank and you can punch holes in the tank bottom so that it wont' hold water after the sewage has been removed) that may work.

Perhaps you can rig up an extended trough such as those used by concrete delivery trucks to move sand or gravel to fill the tanki.

Sinkholes & Subsidence Hazards at Abandoned Septic Tanks FAQs

Tip: see also SINKHOLE DETECTION, WARNING SIGNS

Sinkhole near house suspected to be caused by old septic tank: should I worry?

I live at a residence that has a sinkhole right outside the back door. Everyone(meaning my boyfriend's family) has told me this is an abandoned septic and go on like it's no big deal.

Ok, obviously it was not filled in, I've been told it was just a hole in the ground with some sort of cover, which has failed. I am alarmed, especially now that his sister and brother in-law want us to purchase the home or sign a lease that states everything is in safe working order.

I guess my question is, is there cause for alarm, and I already know the answer is probably yes. Which brings me to the next question, what the heck should I do about it?

I probably should have stated that I am in twin falls county, Idaho. Since I do not own the property, there is not much I can do to remedy the situation. I feel it is unsafe and not just a hole in the ground that caves in every so often.

Am I right in feeling this way because my next step is to demand it be fixed and this could cause me to lose my house that I have rented for 3 years.there are not a lot of tenant protection laws here in Idaho. On 2016-10-05 by Shelley

by (mod) - Yes, Watch out: safety is the first concern when finding sinkholes near abandoned septic tanks

Shelley,

The first priority should be taking steps to prevent an avoidable injury or death that you know about.

Watch out: You should notify your landlord immediately both orally and in writing of a safety hazard, possibly risking a fatality.

You are welcome to print and give your landlord a copy of this septic fatality report article

SEPTIC TANK ACCIDENT REPORTS 

If it were my rental home I'd rope off the suspect area, prevent access to it, then notify the landlord in writing of a dangerous, potentially fatal condition if in fact there's a risk of someone falling into an improperly abandoned septic tank or any other hole or opening including a sinkhole.

There are other, easier to fix sinkholes that develop at properties, not true sinkholes but subsidences caused by poor drainage, improperly abandoned tanks, even rotting buried tree root or debris.

If it were truly a sinkhole, and there are some reported in your state, there may be risks to neighbors as well. In a severe case or with evidence of settling activity it might be appropriate to notify emergency services.

Patio built over abandoned septic tank is sinking

My parents paid a company to fill in the septic tank at their house and hook them up to the sewer.

Now, years later, the patio is sinking (right where the tank is) and the sinking is causing structural damage to the house. The steps leading to the back door are pulling away from the house.

The planter in the backyard has also sunk and the bricks cracked.

It is a terrible result especially after my parents paid over 12,000 for the work to be done. Do you think this was mainly a compacting issue? On 2015-01-03 by Cindi

by (mod) - patio is sinking - maybe over the old septic tank

Cindi,

First let's be sure the trouble is due to settlement at the old tank location.

If that's the case then I suspect either poor co paction or poor choice of fill contents. Anotherr possibility is a steel tank rusting out and collapsingg into a void beneath the old tank.

Most likely a large part of the cost you cite was the sewer hookup, so not all of that $ was wasted.

Surely no one built a structure bearing on the old septic tank did they?
In any event if a patio, presumably poured concrete, is settling or tipping towards a building foundation wall I'd expect problems with directing roof spillage or rain or melting snow water against the foundation as well as possible foundation damage from the patio weight against the foundation.

The fix may require removing the patio and proper grading and fill compaction before re-building.

What can we do about sink holes showing up where an old septic tank is located?

Septic tank has not been used for years. On sewers. Now we are getting sink holes where septic tank is. What can we do? I don't think my husband filled in septic tank when sewers put in On 2015-05-14 by Anonymous

by (mod) - safety warnings

1. Immediately: rope off and protect the area to prevent someone from falling into an opening and being injured

2. Contact an excavator to explore, open, and fill completely as needed the abandoned septic tank.

A huge hole opened when someone drove on the lot where a septic tank was left; other than filling the tank what else do we watch for?

Several months ago, we purchase a vacant lot that once had a house on it. The other day a huge hole (that we think is an old septic tank) opened up after someone drove up onto the property (and over the tank).

There is no liquid in the tank, and it is made of concrete. We had no idea it was there because the neighborhood is connected to the city sewer, and there doesn't appear to be any evidence of other parts of the system. Is there anything else we need to look for and fill in other than the tank itself? On 2016-08-05 by diane

by (mod) -

Diane:

Watch out: Besides filling in the abandoned septic tank, depending on the age and location of the property I'd be alert for other

• A broken or inadequate cover over an empty or inadequately-filled septic tank
• Other older or newer septic tank, drywells, dug wells, abandoned buried oil tanks &c.

Having a plot plan that showed the original house and knowing house age, type of heat, etc. can help sort out those risks.

Sinking and cave-ins in the yard may be due to old septic tank?

I discovered an area in my backyard slowly (over 2 year time frame) sinking.

Then in 3 weeks, the ground started to cave in and a hole is starting to get larger. Most happened after a couple of rains.

I have city water but was told that my house had a septic tank system when the house was built.

I am assuming the city properly closed the septic system. Is my yard sinking due to the old septic tank?

It appears to be in the obvious location for the tank. (June 7, 2014) Sue

Reply:

Sue we hope you roped off the area for safety pending further investigation or fill-in as needed.

Also see SINKHOLE DETECTION, WARNING SIGNS