Any experience of borehole deep soakaways?

[boreholedriller1]

There is no permeable media at the bottom of the soakaway to get "blocked". An example borehole would be 15 metres of impermeable clay overlying a per meable strata such as chalk. The borehole is advanced through the impermeab le clay and then advanced 10 metres into the permeable strata, this interse cts many fissures within the upper chalk. An H.D.P.E. liner is then install ed inside the borehole with a minimum internal diameter of 100mm. The liner is perforated in the permeable strata and plain casing is used to line the impermeable clay. The perforated liner is then surrounded with a gravel pa ck, the plain casing is surrounded with bentonite grout which provides a pe rmanent seal to prevent any potential contamination finding its way down th e outside of the installation. A syphon head is fitted to the top of the in stallation to prevent any floating debris from entering the deep bore soaka way installation. Many new builds are now not allowed to connect to the mains drainage and ha ve to provide their own solution to drainage. In circumstances where no oth er viable drainage solution can be found, this is a cost effective solution that provides excellent results, drainage in excess of 10 litres per secon d can easily be achieved. A few contributors seem to be under the misconception that the Environment Agency are against this type of installation. The Environment Agency consid er each application to discharge water underground on a case by case basis, taking into consideration the strata that the water Is being discharged in to, where the water table is in relation to the discharge zone, and any pot ential for surface contamination finding its way into the aquifer. There ar e many circumstances where the Environment Agency have granted permission f or discharge directly into an aquifer. I have been drilling for 40 years and have never had a client come back to me and say that the soakaway has failed. We are only a local company operating in the South East of England. Althoug h we don't cover any other areas, but I am perfectly happy to take a look a t the geology of any location in mainland UK and give free advice as to whe ther this could be a solution worth pursuing. We have been to many properti es where ground workers have installed very expensive land drainage schemes which simply don't work, or fail within a few years. I have added a link to our website which has a lot of useful information on this subject, but if admin feels that this is spamming, please feel free t o delete the link.

Mark Carpenter

[fred]

In article , [e-mail] writes

As Tony points out, relevant contributions from commercial operators replying to calls for help on this group are welcome but it might help to understand the medium to which you are contributing.

This medium is usenet aka newsgroups, their main purpose is for immediate discussion of interests, issues and concerns. It is normal to consider a discussion thread to be dead after 30days or so as responses after that time are no longer relevant to the poster's problem, they'll either have solved it or moved on since then and the 'news' element will have expired.

For that reason, responding to old posts is considered bad form, particularly one as old as 14 months as this original post was.

Many professionals contribute here, most are very discrete about it and only mention their businesses when it really would help the original poster.

They normally do this in a 'signature' field at the end of the post which is created by typing:

followed by up to four lines of information, which can include company details if desired

This signature will be present on your message but will be automatically snipped on further replies to save space.

The mechanism by which you are accessing this group (Google groups) is a useful resource but the archive search is really meant to be read only, it is google's lack of understanding of the system that allows their users to ritually necromance long dead threads into unintended life which is generally unwelcome.

Please keep a look out for the thread/post dates though and limit replies to an age to 30-60 days, I look forward to your future contributions.

Hope that helps.

[tony sayer]

In article , fred scribeth thus

Dunno if it is. If you were the OP wouldn't you be rather thankful that someone who does know something about an obscure subject has responded?..

Yes but very useful all the same, dint know that we've had bore-hole drillers here before, most interesting:)...

[Huge]

Oh, believe me, it is. The OP will have long since ceased looking for an answer.

[fred]

In article , tony sayer writes

You missed where I said generally then :-)

Except in exceptional circumstances, a year is too late to be of use to the original poster.

Agreed and the timely reply to a recent and relevant post is most welcome.

[alexjkennett]

Hi

I am looking at a borehole soakaway as I have a tanked basement but it has started to get groundwater flooding due this weather and someone suggested a soakaway next to the property

My postcode is SL6 7AZ - any ideas?

Thanks Alex

[harryagain]

This weather, a soakaway is unlikely to work, the ground will be as soggy as that around/below your cellar. A borehole is likely just to fill up with water.

[Vir Campestris]

If the ground water is flooding into the basement it will also fill any soakaway.

Andy

[Bill]

What do the panel think about drilling multiple boreholes around the building, extracting the water from them and disposing of it. So keeping the water table lower and away from the cellar walls.

I'm thinking back to when the Mersey tunnels were first built, according to something I read years ago there was a lot of private extraction in Liverpool at the time and the table was low. When industry moved away and also mains water was universal they had to add extra pumps to the tunnels to keep pace with the rise in the table.

So would it work on a smaller scale?

[newshound]

Surely better to put a sump at a suitable point in the basement with a single submersible pump.

[Bill]

Having been involved in 3 attempts, 3rd being relatively successful, to tank a cellar I would much rather take the water away before it got any where near it!

[dennis]

I have seen american houses where the basement is kept dry by doing a similar thing, A land drain around the periphery to get rid of the ground water and no damp proofing.

[The Natural Philosopher]

It is a standard way to do it with some buildings. Float switch and a pump.

Better us to do as I have here if possible

Trench round the property/ fill with hard core + a perf pipe and gravel top/ + a drain pipe going to Somewhere Lower.

[Sam Plusnet]

Note: Offers of "Somewhere Lower" are subject to availability.

[The Natural Philosopher]

Advice to people at the bottom of a hole...

Stop digging :-)

[Muddymike]

In message , Vir Campestris

Your talking about "de-watering" which has been used in civil engineering for years. Its not uncommon to protect domestic property in this way, depending on the subsoil conditions. It's usually done by digging a trench all the way around the property with perforated pipe at the bottom falling to one man hole. The trench is them filled with gravel.

Depending on ground conditions the manhole is then emptied by a pump or a single borehole down to porous sub strata.

Mike

[newshound]

If you know which direction the water is coming from (e.g. from a spring) you can target your borehole. Otherwise you might have to ring the property, go down to a depth of several times the property width, and of course have a pump in every borehole. Sounds expensive to me compared to a sump.

[Vir Campestris]

I doubt there will be any porous strata in the OP's area which aren't already full of water. He's near the Thames.

Andy

[boreholedriller1]

The elevation above sea level at your location is 32.50 metres A.O.D. The e xpected geology would be drift deposits (Clay and Flints) over lying sand a nd gravel, and then Chalk. The gravel layer is probably water bearing and w ill no doubt be causing the problem. Chalk should be encountered at a depth of between 3 and 6 metres. The standing water level in the chalk would be between 9 and 10 metres below ground level. The chances of a successful dee p bore soakaway at this location can be considered to be very good.

[boreholedriller1]

It would depend on the geology at depth, but I have seen properties surrounded by a French drain with a deep bore soakaway emptying the water collected in the French drain to a lower geology. Usually only 1 borehole would be required.