Help - septic tank ( or not?)

Please help. I have spent all day clearing my drains following a back up into one of my loo's ( I have two, one out which was OK, and one in bathroom , not OK!).

I have been led to believe that I have a septic tank system.. When I couldnt get the second manhole to clear I lifted the cover on the septic tank to see if the problem was there , looking for the rodding point like it says in the diagrams in all the books.

I am new to septic tanks and dont actually know what its supposed to look like.

However, mine does not look like the diagrams. It is brick built , oblong,

5ft x5ft and very very deep it would seem, at a guess 20 ft deep. There are no visable inlet or outlet holes, no rodding t points, no vents and no baffle between two chambers.

I can see some vertical slits like the slats of a ventilator in the brick work at the water level. Not sure what those are. Cant find anything like it on a diagram of a septic tank online.

Whether it even has two chambers and I have opened the inspection hatch to the first only I do not know. I can only see this one.

I have managed to clear the intercepter drain into the tank but still cannot see an inlet point from the drains system.. I am guessing its below the water line.

Is this a septic tank?

I have a bungalow built about 1956 in Devon ( I state the location because I have found from experience that often things here are different to other parts of the country) on a smallholding. No mains connections available.

No recorded problems with this sytem as far as I know. I have not had a problem with my drains until now.

No stinks no other symptoms of problems.

I am thinking of draining it to see if I can find the inlets but water level is at least 13 ft down the hole. Depth of water/ deposits / silt I estimate to be about 4 ft at the bottom.

I am not sure if my land drain is blocked?

Indeed will there be a land drain and if so which way is it likely to be running? No plans to go by. Original plans of house say septic tank and show it as two boxes , but the whole thing seems to be further over in the original plans than the siting of this box.

No other manholes visable ( all grass area)

Anyone have something similar? Anyone seen anything similar?

Reply to
howardsend
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Sounds pretty much like one yes.

Used to have something similar, but not as deep.

In use a septic tank does have a lot of water in it and a lot o sludge on the bottom. The fact that its not overflowing means the water is seeping out - probably as it was designed to - somewhere.

Normally there are tow or three chambers. These are fed from inlets just above the base of the chamber (to allow for sludge build up) and drained from higher up to the base of the next chamber.

If yours is now working fine, leave it alone, but if it really has 4 ft of sludge in it, maybe getting it emptied (man with a hose and a tanker) is a good idea.

Then it should be OK for another 15 years :-)

Reply to
The Natural Philosopher

I would suggest the first thing was to get it emptied. Once that is done you should be able to see more and decide what it is. It could be a cess pit in which case it just needs emptying regularly. Ask around for a competent operator to do it. Where in Devon are you? If you are close to the Somerset border I can recommend someone.

Peter Crosland

Reply to
Peter Crosland

Some info on septic tanks that I accumulated when we moved into our present house (also west country, built 1952):

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't guarantee they all still work though, and they may not all relate to UK regulations.

As others have said, wouldn't do any harm to get it pumped out, then you can get a better idea of how it's built and what's happening (see Yellow Pages for contractors; I think ours cost £60 or £70 last time it was done). Ours is rectangular, about the same size as yours and maybe 8-10ft deep, with a baffle wall across the middle between the two m/h covers, the top of which is below the surface of the liquid which should have a crust or scum on it about an inch thick. The outlet from ours goes into a long-disused well now partly filled with large concrete rubble, but most have a herringbone arrangement of field drains running away from them under the adjacent garden, forming the drainage area and allowing the semi-clean overflow to soak away into the soil. These drains can become less efficient over time and may require re-laying, but get it pumped first.

When it comes to re-activating it when you've solved the problem, you can get expensive packs of bacteria in agricultural supply shops, but in these parts a sheep's head is recommended (ours had a skull in the bottom when it was pumped). But if you haven't one handy, a road kill will do very well (fox, badger, rabbit, whatever). Put it into the inlet side of the tank.

Reply to
Chris Hogg

In emptying the 'tank' one thing I have always been told is to look for "the blanket" which floats on the liquid and do not get rid of all of this. They say this blanket has lots of the organisms which make these tanks work, so save this at all costs while getting rid of solid sludge.

Reply to
OLDTOWNGUY

I've just re-read your post (a bit more carefully this time!) and what you describe sounds awfully like just an old well and not a septic tank at all: a) it's very deep, doesn't seem to have a partition and there's no sign either of an inflow or outflow pipe (I doubt the pipes are as deep as you're thinking; ours are only 18 inches or so below ground level) b) it doesn't smell (ours smells when the covers are open, not gut-wrenchingly, but it smells) c) from what you say, it's not where it should be from the plan of the property.

I suppose it's possible that it's an old well that's been 'adapted' for use as a septic tank, but I'm sceptical (!). Get someone to flush a loo while you watch to see if there's any sign of water movement in it, either running down the sides or in the bottom. It may be that your system is like ours, with an old well being used as the soak-away system, but I think I'd look elsewhere for the tank proper; manhole covers can get overgrown with grass. Drains tend to run in straight lines from m/h cover to m/h cover. Follow the direction of the pipe from the last cover (the one you lifted to unblock the system?) and see where it points.

Reply to
Chris Hogg

I can back up what Chris says about (a) smell and (b) the inlet being some 18 to 24 inches down. I've a two chamber brick tank about 5 ft square but not 20 ft deep, 6 or 8 ft I seem to remember. The inlet is a vented trap constructed from porcelain pipes. The water passes over a weir from one tank to the other and then goes out to a local burn via a field drain - again this outlet can be clearly seen on the side of the secondary tank.

It is worth noting that the first tank builds up a semi-solid cap where the 'crap' breakdown action occurs - I'm tempted to think that if your 'tank' doesn't have this, it's not the primary one. And rather than flush the loo, I would fill the bath with cold water and let that run out as it may take you some time to hear the water flow. I would also look for the vent to the trap into the primary tank.

A mucky septic tank story - at my second child's christening, the 3/4 year olds came up from the bottom of the garde saying there were jobbies down there - a nappy liner had gone down the loo and blocked the trap to the septic tank with a corresponding outflow from the vent

- just what you want when grannies, great aunts and all the rest are there. Rob

Rob

Rob

Reply to
robgraham

On Sun, 12 Mar 2006 01:29:39 +0000 (UTC) someone who may be "howardsend" wrote this:-

There is often confusion between a septic tank and cesspool. I think some of this confusion is deliberate, with those selling houses actually knowing the difference but deciding not to mention the it.

If there is only one chamber then you have a cesspool and this will need emptying from time to time. It seems most unlikely that the inspection hatch to one chamber would be visible, but the other would not be.

In theory a brick built cesspool could be converted to a septic tank, assuming you could get the appropriate permissions and have space. Septic tanks are an excellent way of disposing of sewage in remote locations. Whether the expense of such a conversion is worth it compared to having the cesspool emptied regularly depends on your circumstances.

Reply to
David Hansen

Thank you all for your replies. I had a look at this the weekend and can report a little more detail. It is large.

There is a second chamber which I couldnt see when I first posted because the baffle(?) between the two chambers was under the water level ( and it was dark and I couldnt quite see it!)

The inlet pipe is quite low down the tank side - or whatever it is - and that was also on the water line at the time I posted. The following morning when I investigated further it was visable ( water level having dropped somewhat).

It is a bloody large tank! Much biger than I envisaged but it two chambers apparently.

I am not sure what a crust is supposed to look like - will I see it or is it under the water level? Does it circulate on top somehow? I may in facty have one I am not sure since I am not sure what I am looking at ( that makes me sound really thick I am sure but frankly septic tan ks and sewers have never been high on my agenda previously.

I have , I think, now cleared the blocked drain and all the crap sailed into the chamber through the hole followed b y much water that I flushed down to clear it away.

I have for the moment put the man hole back and am waiting to see how it goes.

I am unsure whether I need to get it pumped - maybe I should anyway in case in neds re starting for decomposing since I have been stamping about ( metaphorically) in there.

My new worry is why my drain blocked. I am not sure b ut I may have a dropped drain . I rodded down into I thought was about six inches of the outlet into the tank and hit a block. I rodded back from the tank into the drain and went back about 18 ins before hitting a block.

Short of escavating I am not sure how to establish if I have any problem.... or was it just a hard blockage and have shifted it?

Reply to
howardsend

Its a sort of scum, dark brown to black, and slightly lumpy or uneven, that floats on the surface of the liquid waste. It provides a barrier that prevents too much air getting to the liquid underneath, and so allowing the anaerobic bacteria to do their stuff. It's best not disturbed if you can help it, but obviously when the tank is pumped, most of it will get sucked away and it will have to re-establish itself, which it will. But if your inlet pipe is significantly above the liquid level, the splashing that occurs when more waste enters the tank will break up the crust; that's why most tanks are fitted with the T shaped inlet and outlet pipes (on their side, inlet through the leg of the T, IYSWIM).

Is there any sign of an outlet pipe? It still sounds like an old well to me, modified to be a septic tank. Are there rungs going down the side? If there are, don't _EVER_ be tempted to climb down them; the gases down there will suffocate you very quickly.

The vertical slits that you can see at water level may be slots in the brickwork that allow the water to infiltrate from the surrounding aquifer. But that process can go the other way, with water diffusing outwards, as it does in the well in my setup. If it is an old well, then the liquid level should very with the water table (remember we've had a very dry winter).

It won't need re-starting unless you pump it; there are still plenty of bugs down there.

You could try shining a torch into one end and seeing if you can see it from the other end, if you can get close enough to the ends, that is. A mirror or two might help. Raid the wife's handbag!

Reply to
Chris Hogg

On Tue, 14 Mar 2006 15:50:58 +0000 (UTC) someone who may be "howardsend" wrote this:-

That's good, but not ideal. The inlet should be a dip pipe, so that the scum is not disturbed by inflow. Like the Persil adverts, dirt is good. To prevent large flows passing straight through the tank there should be a deep baffle (or a tank in two sections as below).

The outlet should also be a dip pipe, for the same reason. The outlet pipe should only just be lower than the inlet, to ensure flow through the tank is as slow as possible.

That is not the end of it. The liquid flowing out of the tank is not pleasant. It should then be exposed to bacteria that like oxygen, in a filter bed. An alternative is a land drain (if there is enough land available).

A septic-tank does not need the liquid to be pumped out. However, it does need the sludge removing occasionally. If it has backed up then, assuming the problem is not a tree root or the like, the problem is likely to be clogged land drains.

Excessive amounts of disinfectants and salt are not good for the bacteria in a septic tank, but will not cause it to back up.

Reply to
David Hansen

Well its an old fashioned but seemingly well made septic tank..

What you get with a septic tank is more or less this.

(i) all suspended solids like sand and grit fall down to the bottom of the first tank.

(ii) Any light solids go to te top

(iii) most of the organic chemistry takes place in between.

(iv) over time the organics break down into various noxious gases and various soluble chemicals.

(v) the first chamber is designed to more or less settle out irreducible solids, and to do the first digestion stage..

(vi) from the first chamber there is a pipe that starts somewhere near the base of the first chamber - not at the bottom or it get clogged, not at the top because it picks up nasty floating turdness, but somewhere in the middle. This pipe goes into the second chamber, but ends much higher than it started, the idea being that you want the water level in the first tank to be high.

(vii)Typically the final outlet from the second (or third) chamber will be AT the water level of the second or third chamber, as it generally runs downhill to a stream or soakaway from there.

(ix) Too much silt at the bottom blocks interchamber connectivity, and needs removing

(x) too much crust on top (looks like peat - actually probably IS peat) stops final outflow if it extends to the last chamber, and may block interchamber connectivity if its thick enough..

Thats all about te layers, and why you (occasionally) need to empty these things.

No. I think if you have no huge crust, and flow is happening between the chambers, then all is well. However....

Not good. Any trees nearby?

Its not that hard to excavate actually. Depending how deep.

A typical problem is that a tree root cracks a pipe, then root hair fibres get in, and slow the flow down making blockages much more likely.

Reply to
The Natural Philosopher

Just out of interest - what criteria does one use to judge when a spetic tank does require pumping out? The interpretation of the above thread is that a cess pool requires regular pumping - yearly? - but that a septic tank rarely requires this treatment. I suppose it does depend on the size of the septic tank and the domestic throughput, but that still brings back the question -- when?

I had mine done after fully 15 years recently and the operator wasn't too impressed ! What seemed to be upsetting him was that the crust was hard and therefore required more work to process.

Rob

Reply to
robgraham

I put in a query just now about the frequency of pumping tanks and remembered afterwards that I should have put in a warning based on my own experience. Unless the drains have been replaced, all older properties have porcelain drains and very often a distinct lack of access points for rodding. In my own case the run from the bathroom at the back of the house goes all the way round and down to the tank without access - a distance of pushing 100 yards with one right angle bend.

When I redid the bathroom I fitted a low flush loo. After 6 months when there was no bath in use the drains blocked - I had to excavate ! It was purely the lack of flow as I switched the loo to full flush and the problem never reappeared. The bath was not refitted for several years. New neighbours had exactly the same problem after a bathroom refit.

Rob

Reply to
robgraham

Well they all want you do do it yearly...but as you have discovered, you can leave it a long time.

Id say when the crust turns to something a cat can stand on, its tome to remove (the crust) and when the sediment compromises the interchamber exchanger then its also time to get THAT out.

My klargester seems to like about 3 yearly attention..its specced for a

6 bedroom house but there are only two of us. A big septic tank - every 5 years or so probably.
Reply to
The Natural Philosopher

YOU SHOULD have a manhole at every direction change these days.. building regs.

Occasional tipping of buckets of water down the toilet is a Good Thing too.

Plus a yearly 'leave the taps running for an hour' to see whether water is flowing freely and cleanly.

I always think opening up the drains and running hoses around annually is no bad thing. Preferably on a warm spring day, rather than in the depths of winter, in an emergency, when someone has flushed the electric toothbrush and a pair of tights down the loo by mistake ;)

Reply to
The Natural Philosopher

A cess pool / pit requires *emptying* - it is merely a storage container for the effluent. This might be as often as every 4 weeks depending on the size of the pit and the amount of effluent produced by the household.

A cess pit which does not need emptying is leaking, and illegal.

Owain

Reply to
Owain

On 15 Mar 2006 10:25:14 -0800 someone who may be "robgraham" wrote this:-

When the sludge is deep and so there is not much space for liquid. Infrequently.

Depends on the size and amount of liquid put into it. There is no one answer.

Reply to
David Hansen

On Wed, 15 Mar 2006 18:43:38 +0000 someone who may be The Natural Philosopher wrote this:-

You have to tell us more after teasing us like this:-)

Reply to
David Hansen

I can reccomend listening to "Laughter with a bang" the Blaster Bates record for an appreciation of dealing with a Septic Tank

Reply to
John

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