septic tank with no access

[Jemstone]

I'm buying a house which is not connected to mains sewerage. This is fine but I'm slightly concerned about the septic tank they have. Apparently it is a concrete cube with sides of 12 foot long. Additionally there is a soak away which extends into an area approx 50 foot by 30 foot.

There are 2 man hole covers which can be lifted to show the waste entering the septic tank along the drain. However there is no way to look inside the septic tank itself or to have it emptied.

The current owner says he's never had it emptied in over 14 years and as far as he knows it was constructed to never need emptying. Does this sound correct or am I going to be faced with a huge bill on the future?

Septic tanks should never need emptying - the system is such that the contents biodegrade and leach out into the soakaway and disappear. If they are the proper size for the home and you don't routinely pour ridiculous quantities of chemical in them then they should be fine. Cesspits need emptying, septic tanks shouldn't.

However, the big question is - is it big enough for modern day living? Was it put in in 1946 when people didn't have dishwashers or washing machines and shared bathwater once a week? If so it won't work, the stuff will wash through too quickly and I don't need to be too graphic about what I mean by Stuff do I?

It does seem a bit unusual to have absolutely no access into the tank itself. But firstly I would want to work out the tank dimensions and check with a modern supplier what size they would recommend for a home and family of your size.

there might be a hatch over the tank that has been paved over, or grassed, or had a garage built over it. People do that.

It's also possible that the owner, for one reason or another, didn't want you to look inside.

Sometimes old tanks leak, and the owners are filled with pride that they never overfill or need desludging.

We've had septic for over 20 years and at some point you need to pump out the solids, not very often though ours has been done every 10 years or so, they do build over time even though the bugs break it down and reduce the amount a lot. We also pumped it once when we thought it needed it but had a root in the pipe, so got that fixed at the same time.
Sometimes the lids to the tanks get buried, and you need the plans to find where they are. Maybe you can follow the pipe out from the house and find them that way.
Ours is a cement sqaure tank too.
We have the washing machine plumbed out separately to water trees (we are on a lot of land) and so that cuts down a lot of what goes into our tank.

Thank you. I think I'll stop worrying about it so much! It's 1700 cubic feet (43 cubic metres), from what I've read that seems pretty large. There's grass all over the top of it and the plans I've seen don't show any access hatch. I suppose if it all goes wrong I'll just be stuck with a huge bill :-( .

How do you know if it's not working properly and needs emptying or is leaking?

Maybe have a satisfactory septic inspection by a reputable company as part of the contract for buying. I know that will be part of our selling this house. We will have to pay for it to be pumped out before the exchange of contracts too (even though it was done last Spring), it's normal for round here.

"Septic tanks should never need emptying"

I have never heard of that before. We had a shared septic tank at our last house and it was emptied about once a year. Even though there was a soak away. The solids still need getting rid of.

You would have to be careful what you put down the toilets as well. And if it is shared you might have neighbours that aren't keen to share the cost of repairs/replacement/emptying. Personally I wouldn't buy another property with a septic tank.

I would step very, very carefully here. when we bought our house (1930s) we couldn't find the septic tank. We could see it on the plans, and we could find various inspection chambers but no lid to the tank itself. We bought the house.

Fast forward a few months and I had a drainage company come to find the septic tank, which they did without needing to use their cameras. They just followed the line of the inspection chambers and then dug about in a heavily wooded area. sure enough we found the septic tank, the cover had been buried by years of rabbits digging over it.

To cut a long story short we have ended up spending £20k to get the drains sorted, the tank sorted, new lid, new vent and a new soakaway. As someone else said, it was constructed to never need emptying (and it clearly hadn't for 10 years or so) but time and tree roots have done a lot of damage to the tank/drains. Plus soakaways weren't built the way they are now in the 1930s, and ours just can't cope with a family of 4 with showers/baths/dishwasher/washing machine.

If only I'd not been so hasty and spent £125 to get the drains/tank inspected by the drainage company using CCTV. I'd be the better part of £20k better off.

We have a septic tank and they do need emptying. Ours every couple of years but don't expect never to have any problems. Our first problem was caused by our daughter flushing facial wipes down the loo, they don't break down so beware. Some people say you should just use non-bio washing powders/liquids and not to use fabric conditioner. However, the man who empties the tank says the jury is out on this. One thing though, you should not use bleach.

One thing is certain, if you have a problem you will know about it. It may be a good idea to invest in some rods - these have saved us hundreds of pounds in sorting out the problems ourselves.

Spudbaloo is right about older tanks. Our neighbours had a state of the art one installed for about £30,000; it worked okay but she said she could not stand the faint whiff you get from them.

we had a septic tank and soakaway and it didn't work. It just used to fill up and in heavy rain it used to flood. We could look into both parts via manhole covers though and I would be quite concerned if there was no way to look in the soakaway. We used to have to have our emptied very regularly and eventually abandoned the whole thing and had a tight tank put in. Still needs monthly emptying but at least it works!

We had a "pozo negro" in Spain which is basically a septic tank which doesn't need emptying, just soaks away. Never had any problems in 10 years and in the first house it had been in sometime. Like all tanks of this kind we didn't use bleach down the loo or sink and tried to keep chemicals to a minimum so the bacteria builds. Ecover and no flushing wipes or sani items.

I worried about it at first but just forgot about it as the years went by.

We sold recently and there were a fair number of questions from the solicitor regarding the septic tank - proof of emptying (we had it done once in the 6 years we were there as the pump had failed and in order for it to be fixed it needed emptying), a drawing of the pipes to and away from it, location of covers etc. Get your solicitor to do the same and make sure he gets what you need - if the vendor wants to sell he needs to find this out for you.

Careful use of cleaning products will reduce the need for emptying, if it works as it was designed to then it will be fine. I believe there are things you can put in them to make the bacteria work more efficiently although I've never done so, nor have I actually seen them!

frosty we discovered that, after buying our house and having checked the records carefully about how often it was emptied (not much by the records), our vendor had been draining the tank in the dead of night down the lane so as to hide the problem with the tank not actually functioning anymore!

We've just had some work done - no problems with the septic tank per se but all the draingage from the house (including gutters etc) was going down the same drain towards the tank. So we have had new drainage dug so this now goes to a soak away area. When we bought the house we insisted the tank was pumped and we should probably plan to do it every few years.

Contact one of the tank pumping companies in your area and ask them the question directly. It might all be new to you, but they will have heard it all before. There may be a way of fitting an inspection top retrospectively? You won't know until you ask.

Thanks for all your help. I think I need to ask more questions and get someone who knows what they are on about to take a look

Jemstone, as a Granny with a septic tank I would speak to your local council, building control department might be the place to start for advice on a suitable service engineer for checking out your septic tank and drainage. The Environmental Agency too are very keen to make sure these tanks are now safe for the environment and rightly so. Remember your rainwater drains should not enter the tank. Don't put bleach down the drain nor coffee grouts, nappy liners or any sanitary wear and if possible use liquid washing solution preferebaly non biological. Need any more advice on this just ask.