My preparation for moving from modern suburbia to old rural continues.
Previous houses have all been connected to mains sewerage but the one we're moving to has a septic tank, about which I know very little. After a little research I now think I know: not to install a waste disposal unit, not to put coffee grounds or grease down the sink, that it will need pumping out every 3-4 years and that the leaching area around it may need reconstruction every 20 years or so. Is this correct? What else do I need to know?
Not a lot. We've been in this property for 17 years, and only had ours pumped twice. It's probably due for a third fairly soon. The frequency rather depends on how many there are of you in the property. There's only two of us. I think the charge for emptying one hereabouts is about £100. I've seen it suggested they should be pumped every two years, which seems excessive to me, but maybe the modern 'round-bottomed flask' Klargester types have a smaller capacity in which to accumulate the sediment.
Ours is an old rectangular two-compartment brick tank, probably put in when the property was built, early 1950's. It overflows into an old well. Never given the 'drainage area' a thought; we don't have one as such and the whole thing just works.
As you say, avoid neat fat or grease going down the plug-hole, and also quantities of strong bleach, although the occasional spray of bleach around the kitchen sink or bathroom 'facilities' is OK. I would be wary of a 'loo blue' or similar, although they might be perfectly OK, it's just that I'm not sure how the bugs in the tank would cope with a fairly frequent dose of whatever's in those things.
You can get septic tank starter kits, i.e. a tin of dried bugs that you add to the tank when it's new to get it going, but the traditional method before tins of bugs were available was to chuck in a sheep's head. We don't come across them too often, but a road-kill is a good substitute. But an existing tank won't need anything like that. Even after pumping out, there's still squillions of bugs left behind to carry on the good work.
Years ago we moved into a 6 year old bungalow with a septic tank. Previous owners had knocked a hole in the side of the tank amd directed the outflow into a soakaway. I installed land drains, one of which inadvertently went through the middle of the soakway. Where it came out into a stream, probably about 75yds away, the water was clean and did not smell. 8 years after that main sewerage arrived. I connected a year or so later when the septic tank was beginning to overflow. We had it pumped out and later when I extended the property the septic tank was filled with earth from the footings.
I have a septic tank and we have only once had something go wrong and that was a blockage in the drain system. OH rodded it out.
A lot may well depend on the type of tank you have. My mother and allegedly me too, have the type that do not need regular pumping. My mothers hasnt b een done for over 30 years, mine has been going to my knowledge now for 20 years. I was once told it was the sort that didnt need to be pumped out at all.
They ( as in powers that be) do say they should be pumped out regularly.
Dont use too much bleach in the toilet. Make sure you dont put a lot of gr ease down and check it every now and again. I have a tendency to not use a lot of chemicals mainly because I am a bit sensitive to them myself so rec kon so is my septic tank. If you read thin gs like dishwasher tabs and rins e aid ( if you use it) they will usually say " safe for septic tanks" Ditto cleaning and washing powders etc. I have only met the odd one or two produ cts that say not suitable for septic tanks.
You will soon know if you have a problem - it will overflow from the inspec tion hatch.
I've heard it said that you shouldn't use plungers or anything else which gets rid of blockages by raising the pressure upstream of the blockage. You should only use rods which break up the blockage and then allow liquid to wash it away.
My parents have a holiday cottage that has a septic tank and as far as I know they have never had to have it pumped out in the 40 years they've owned the property, although it doesn't get as much use as if we lived there full time.
Funny story: when we bought the cottage, the present septic tank had been installed but there was also an open-topped breezeblock-lined pit in the back garden, with an earthenware T piece sticking out of a pipe half-way up the wall of the tank. Talking to the locals, we heard the tale. The previous owner had the cesspit (*) dug and the pipe installed to the toilet and kitchen sink. Before the builders put the "roof" on the tank and covered it over with topsoil, they tested it. And the discovered that the outlet into the tank was about 2 feet higher than the toilet outlet. Shit doesn't flow uphill! So they (or maybe another company) had to dig the new tanks which are under the drive and are definitely below the toilet level. The old tank came in very handy for dumping building waste, old storage heaters etc as we were redeveloping the cottage - easier than carting it all to the tip. Once we'd finished, we got one of the farmers to use his JCB to fill in the remainder of the hole with soil from the rest of the garden and then to roll it to compact it. That was about 35 years ago and there's not been any sinkage of the ground and the rockery that they put on the land.
But I'd love to have been there when the people tested the original septic tank that that'd just dug - literally an "oh shit!" moment :-)
(*) DIfference between cesspit and septic tank: a cesspit is a single tank which simply stores the sewage and doesn't process it or have any outflow of treated (safe) sewage, and so needs to be emptied frequently, whereas a septic tank is two tanks which act as a mini sewage works to decomposes the sewage and allow the treated liquid to drain away, and so it doesn't need to be emptied as frequently.
Septic tanks accumulate sediment that isn't gobbled by the bugs. Although you may think that you never put anything down the drain that's not organic and digestible, even turds will leave ash when burnt, mostly from the vegetable matter that you eat. Then there's the small amount of grit and other mineral matter from washing clothes etc. It all builds up, decreasing the effective volume of the tank, reducing the residence time for what's passing through, and risking foul cloudy water being discharged into the drainage field, which clogs it and shortens its life.
I stand corrected. My earlier post refers to a sceptic tank. It was in fact a cesspit. That was why the previous owner had knocked a hole in the side and drained it into a soakaway.
After I haggled the price at the last minute, the previous owner was delighted to explain to me what I had bought,
I now avoid putting any cooking oil or fat down the drain to avoid them becoming 'fatted up'.
It is worth checking exactly how the drains work. What I have is a large cylindrical soak away. I do wonder how well it works when the ground is very wet. Some years ago the local council put in mains drains. I have not connected to them because my present arrangement has very low running costs.
Good one, but I think it's a little unfair on the tank - that at least "inwardly digests" unlike its presumed cursorily glancing at Daily Mail articles namesake.
They may not take too kindly to the No Bleach, no tampons, no 'towels', no dirty underwear, No 'obselete or lost' mobile phones, No more using an entire bog roll in one go .....
A common practice in the past, I believe. The farmer/householder/owner would construct a cesspit and have it inspected and approved by the relevant authority, then knock out a couple of bricks in the side before the mortar had fully hardened to convert it into a septic tank of sorts.
You can put almost anything down a septic tank, If it doesn't break down it will get sucked up when you empty it anyway
I strongly advise however that you install a Klargester bio-disc or equivalent. I've had both and the Klargester is far more active, breaks down more, pongs less and doesn't need a soakaway. The water is classed as good enough to release into a ditch or other surface drainage.
Probably around £8,000 installed and worth every damned penny
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