Trick to find a septic tank

[Bosswhite]

Unless the lid has been replaced with a paving slab at some point in the past, in which case a metal detector would be as much use as a chocolate teapot.... In any case, follow Andy's advice, if you fall in you wont be getting out again unaided.....

How would a CCTV camera show the exact position of the septic tank, all it would do at best is show the inside of the sewer pipe. ?

A set of rods would at least show some sort of direction the pipe runs and if it comes to a stop this may indicate there is either a blockage or its reached the tank or inspection pit. , the rods can then be measured on ground level as to the approximate position, it would then be worth a try with a metal detector , I had a similar problem like this about a year ago, I used the sons metal detector that he had as a child, worked very successfully. At best it will detect the air pressure vent, venting off the septic tank
If the tank is covered with a concrete slab maybe a garden fork dug into the ground in several places would reveal its location.

 

[Hugh Jaleak]

CCTV will record the distance travelled by the camera along the pipe. (It will also show you whats down there, so removes some of the guesswork). Once the camera can go no further then that provides a point of interest for further investigation. Locating it can also depend on area to be covered. I have been to tanks in the middle of a field, one notable job involved the householder contracting us to empty it, and the local farmer to be on standby to pull the tanker out of the field if conditions became too soft!

You are assuming there is some metal to give away the location of any cover. If the tank entrance is covered with an old 2x2 paving slab, that will not contain any metal, and there are plenty of tanks out there with no vent pipe, let alone a metal one!

I have found large 'open' tanks, many feet deep, that had simply been covered with whatever was to hand, in one case, corrugated asbestos roofing sheets. My colleague at the time was standing on top of it at one point before we found it under the leaves. Someone was looking down on him that day!

 

[stardanny]

Does some of CCTV have radio thing to show where it is using a location detector?

Daniel.

 

[buck51]

A camera survey would give distances and you should be able to guestimate the angle off any bends along the way

 

[swbjackson]

We had a similar problem some years ago. Drains disappeared out the back of a property into a field. Southern water stated that the property wasn't connected to mains drainage as it wasn't on their map.

We hired a cable avoiding tool and signal generator. Attached a length of cable to a drain rod and fed it down the drain. We pushed as far as possible and then attached the signal generator and followed the line of the drains with the CAT.

Worked a treat and we managed to trace from inspection chamber to inspection chamber and discovered that the property was connected to mains drainage, Southern Water hadn't updated their maps.

 

[Richardthe3rd]

A quick check of the Building Regs around that time will reveal the standards in 1988. That'll certainly give you an idea of the tank's construction & type of manhole etc. As the Eire Regs are based on the British ones.

At that time, they were generally constructed with one metal manhole & two vertical vents/rodding points, one on the inlet & one on the outlet. There also maybe a 'disconnecting' manhole on the inlet, about 1Meter from the tank.
HTH

 

[Bosswhite]

A camera survey would give distances and you should be able to guestimate the angle off any bends along the way

So would Drain Rods, each one is normally One Metre in length so the number of rods would tell the length of the pipe

 

[Richardthe3rd]

A camera survey would give distances and you should be able to guestimate the angle off any bends along the way

So would Drain Rods, each one is normally One Metre in length so the number of rods would tell the length of the pipe

Yeah, chainage as I stated.

 

[rkinsella]

After much wailing and gnashing of teeth, its has been found!

By the way - take a bow, all those who recommended the "metal detector", that would have worked but in the end was unnecessary, as in a fit of frustration with the seller (and out of fear of losing his commission), the estate agent intervened and got a surveyor pal of his to find it. I was on my way to buy a "metal detector", when I dropped by the house and found I didn't need it after all (50 euro saving!)

Trouble was I started with unsound logic - I figure that nobody would ever put a septic tank near the tree line, it didn't occur to me until after it had been found that the tree line was probably planted on the boundary after the septic tank had gone in.

So for your viewing pleasure - an Irish Septic tank, circa 1974.

Access drain about a meter or two from the tank.

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• rkinsella
• 3 May 2014
• 1

The tank itself with ventilation.

Untitled

• rkinsella
• 3 May 2014
• 1

 

[Richardthe3rd]

Hmmm!! Nice boots!!!

 

[Hugh Jaleak]

Amazing how the fear of a lost commission spurs estate agents into action.....

 

[Agile]

Sounds like a very good tank that never gives any trouble!

At my other's house I discovered that the outlet had never been properly connected and had collapsed.

My friend there ( Cornwall ) found a contractor with a JCB in a nearby field and he spent about two hours digging a dispersal pattern and all for £30.

My friend laid about 40m on 110 mm plastic tube with about 10 of 12 mm holes in each length.