Failed septic system on new build, clay soil!

[theoldun]

This post is going round and round the houses and not being delivered.
Read all the posts on this link below first Will not give you an answer but will confirm that other people have the same problem.
Since this post we have looked into this type of problem further and we may be able to give you one solution. As post will be fairly long will try and post it tomorrow.
Would suggest at present you stay well away from Building Control
oldun

www.diynot.com/forums/viewtopic.php?p=1885744#1885744

 

[mike180]

Thanks for your replies!

I had a local drainage firm visit this afternoon, and he took one look at the murky water in my inspection hole i dug, and after a bit of discussion said our soakaway has had it. He talked about a method of building another soakaway further down the field, going deeper into the ground and using some special cube shaped modules instead of stone which dramatically increase the capacity.

He's gone away to make me a quote, but some things still arnt answered in my opinion. He skirted round my questions about lifetime, as i assume, like me, he doesnt think the new soak away will be any more effective long term than the old one.

He said the effluent colour was normal, which i had thought was the case (septic tanks are NOT treatment plants, they release highly toxic effluent which requires secondary treatment in the soil, having a very high level BOD and SS mg/l and a soak away doesnt provide this in most cases... mine is acting like another tank!) oh, and my tank is an onion, which apparently produces lower quality effluent

he also told me a treatment plant could discharge into the ditch at the end of our drive, if the EA approved. but these things are damn expensive, even the cheaper units that install after the tank start at nearly £2K, im not sure i could even find 1K at the moment.

i'm avoiding building control for now, as i'd rather they didnt know what has happened. Since the previous builder has bluntly claimed "drain fields have a short life, yours has come to an end, and you need another. i didn't guarantee it, so take no responsibility" i have very little comeback on him, and even less of a budget to make these repairs on... the house itself went way over budget and still isnt completely finished, this is the last thing i wanted. oh, and to make matters worse, one of the only people i can find locally who pumps tanks, and usually does ours, has gone for a weeks break... so im not sure what we are going to do in the meantime, i certainly dont want waste water backing up on the drive.

i'm considering borrowing a neighbors digger, and digging up the old soakaway... i will probably have to pump the water in the pit out, but then maybe i could dig deeper, hopefully to a better draining layer of soil, and put the soakaway back in, delaying the inevitable for a good year or so, while we find funds to get a treatment tank.

 

[jeds]

Did the contractor carry out percolation tests? Or are you happy to go for another 2, 3, 4 year solution? Or maybe more, or maybe less? Also bear in mind the system must be registered with the environment agency before 1st Jan 2012 otherwise the septic storm troopers will come and arrest you.

 

[RedHerring2]

As I understand it, and as Jeds inferred in his first post, the problem is not the capacity of the soakaway, but the concentration of effluent into one hole. This clogs up any percolation that the ground did have, reducing the percolation capacity quickly. In your case, in three years.
A leach field last so much longer because it disperses the effluent over a much wider area.

So, it seems to me, you have three choices:
1. Another soakaway that will last perhaps another three years or so.
2. A properly designed leach field that may last 5 - 25 years. Or
3. A water treatment tank installed after your septic tank which can outflow to the ditch.

Saokaways are for surface water, not effluent!

 

[Nige F]

? Also bear in mind the system must be registered with the environment agency before 1st Jan 2012 otherwise the septic storm troopers will come and arrest you.

Indeed - The Sheibenstaffel will be after you

 

[merlin50]

do a percolation tests if it fails it will not work, simples
http://www.wte-ltd.co.uk/percolation_test.html

 

[mike180]

Hi All, i thought i'd show my face over here again - see what people think of my problem now. Almost 9 months on and i havent yet got a solution in place!!

We have had numerous companies suggest without harming a blade of grass many fancy soak away systems, and a surprising array of tanks and treatment plants. I've got a contact at the environment agency watching my case, and providing advice, but no holes were dug.

We had some time back decided to dig a hole over the soak away, where we discovered just a couple feet down, standing water. This we thought was water trapped, sealed in the soak away.

In fact, we were wrong... after one expensive pumping session, we heard water re-entering the tank, but upon inspection it was coming back from the soak away. at first we assumed it was a small amount standing in the pipework, since we had allowed the tank to fill over the outlet but about a foot.

when the flow didnt stop after an hour, we decided to run the tank solely as a storage facility. We dug a hole in the pouring rain, right over the outlet pipe. As we dug down, we discovered water - clean water. only about a foot below the surface. by the time we reached the outlet about 2 and a half feet down, we were wading in water, which was visibly flowing through the hole. we disconnected the soak away and capped both ends of the pipe.

This hole has only been dry for about one week since we dug it over 2 months ago. it appears our water table has risen, since it cant have been at that level when they installed the tank!

so, soak away is now completely written off - theres no way i can even attempt a percolation test. The only remaining option was hundreds of meters of pipework, to pump treated water from a plant, over the hill and across neighbouring land to a river. This is the process i am now working on, while the nightmare of trying to limit the use of the 2700L tank which costs a pretty penny to empty continues!

We did reconnect the soak away when the water table dropped back down, but heavy rain one night brought the tank back up to its prior high level, and although in this state it doesnt overflow, i don't feel its good to allow solids to settle out in an inspection chamber, or for the untreated sewage to basically mix with rainwater then run off where ever that water rushing through the soak away is off to.

 

[Hugh Jaleak]

Going back to your original post, there has been a septic system and soakaway on the site for a number of years, with no apparent problem? I'm unsure why the water table has suddenly risen but obviously very little that can be done about that....

Have you tried some trial holes elsewhere to ascertain the water table is at a fairly constant level across the site? Might be a slim chance but its not impossible you have sunk a soakaway very close to an underground spring which has then found its way into your soakaway..... With the best will in the world no soakaway is going to work in saturated ground. As you have found they actually work in reverse, acting as a land drain.....

If the water table is fairly constant across the property I think your only option is going to be investing in an appropriate mini treatment plant (or adding additional apparatus to the 'onion') so the final effluent is suitable for discharge to the ditch at the end of the drive. (This can be pumped if need be.)

 

[BudinWales14]

Hi All, i thought i'd show my face over here again - see what people think of my problem now. Almost 9 months on and i havent yet got a solution in place!! ...


so, soak away is now completely written off - theres no way i can even attempt a percolation test. The only remaining option was hundreds of meters of pipework, to pump treated water from a plant, over the hill and across neighbouring land to a river. This is the process i am now working on, while the nightmare of trying to limit the use of the 2700L tank which costs a pretty penny to empty continues!

We did reconnect the soak away when the water table dropped back down, but heavy rain one night brought the tank back up to its prior high level, and although in this state it doesnt overflow, i don't feel its good to allow solids to settle out in an inspection chamber, or for the untreated sewage to basically mix with rainwater then run off where ever that water rushing through the soak away is off to.

Hi Mike!
I really sympathise with your plight as we have similar problem - soakaway in heavy clay soil (under lawn in garden) and despite new soakaway in last couple of years, having the septic tank emptied today revealed water pouring back into the tank from the soakaway!

There is a drainage ditch at the side of the road down hill from the garden - maybe we could investigate having a sewage treatment unit installed and sending the effluent down there?

How are things going? Have you made any progress towards a solution??

 

[Diggerjohn]

i install above ground soakaways when i come accross this problem. they work really well and are designed by a firm called wte ltd. no problem with the environment agency or building regs. but they are a wte ltd copyrighted design.
search for wte ltd and click on mound soakaways in their menu.

You need a sewage treatment plant though, not a septic tank as the soakaway would clog up.

 

[Hugh Jaleak]

Interesting concept, and possibly worth knowing about, especially for areas with heavy clay soils.

If anyone saw the recent programme on Channel 4 about the 2012 rainfall levels, a test was done on groundwater levels. IIRC at the test site the water table was less than 300mm below ground level, probably the highest ever recorded level! Little wonder soakaways are failing drastically...