The Accidental Smallholder Forum

Smallholding => Techniques and skills => Topic started by: chrismahon on October 21, 2020, 10:30:18 am

Title: Septic tank- emptying by aeration?
Post by: chrismahon on October 21, 2020, 10:30:18 am
When we moved here the septic tank wasn't working properly- it stank! After a lot of effort (mice, enzymes, cecal chicken poo, prebiotic and no unfriendly chemical cleaners) it seems to be fine. Apparently it was emptied two years earlier, but that means an accumulation of three or four years of undigested material potentially.


I know that some modern tanks use aeration to make digestion more efficient, I think perhaps to the extent that they don't need emptying? I started thinking that perhaps aeration could be used occasionally in moderation to break the stuff up and digest it. The idea is to connect a low pressure air pump to a plastic pipe and leave it bubbling in the first tank for a few hours.


Anyone any thoughts about this? Has it been done before?
Title: Re: Septic tank- emptying by aeration?
Post by: Womble on October 21, 2020, 12:29:49 pm
We just used a long hoe, but your idea seems more elegant.

I'd say go for it.... just beware of splashy bubbles!  :o
Title: Re: Septic tank- emptying by aeration?
Post by: doganjo on October 21, 2020, 01:24:02 pm
What's wrong with having it emptied regularly?  Mine is in my field and is shared with my two neighbours - we each pay £60 a year for the council to empty it.  It's automatic - the Council environmental officer phones to say when they are coming, usually in February, ask me to open the gate, empty it, send me the bill in a week, I copy it and put into my neighbours and get the  cash immediately
Title: Re: Septic tank- emptying by aeration?
Post by: alang on October 21, 2020, 03:45:28 pm
Same here Doganjo. We have a shared tank with three other houses and it costs us 30 a year to Scottish water.
Title: Re: Septic tank- emptying by aeration?
Post by: Womble on October 21, 2020, 05:03:32 pm
What's wrong with having it emptied regularly? 


Just because if it's working properly, it shouldn't require it (at least not that regularly).


Ours has gone a decade so far without emptying, and shows no sign of needing it.
Title: Re: Septic tank- emptying by aeration?
Post by: arobwk on October 21, 2020, 06:07:50 pm
I have a friend (I've probably known for about 20 years) who lives on the cliffs in NE Cornwall.  I once asked and he's never had his septic tank emptied.  (Whether previous occupants ever had it emptied is unknown - Edit: it has never been emptied in 32 years.) 

I guess it is all about getting the septic tank volume right (large enough) and being very very careful about what gets flushed into it !?

Emptying my friend's tank would be (will be one day) not easy or cheap as the head is some 35m (cliff-top road to tank) and the length of suction pipe required would be some 200m (or some 70m if it proved possible to lay suction pipe as the crow flies - still a long run !).


[How the original owners/builders got the septic tank down there in the 1st place and how they managed to excavate the necessary pit is totally beyond my ken!]


   
Title: Re: Septic tank- emptying by aeration?
Post by: Dreich Pete on October 22, 2020, 08:56:37 am
I'm no expert on this subject (I don't know sh!t) but when we had a drain blockage I got the local company out and they did a full inspection while they were here as I didn't know when the tank had last been emptied - and I assumed it was something that had to be done.

They told me that our tank was fine and unless we started to notice a smell for more than a few days we shouldn't need to empty it. The system, as I understand it, is supposed to work partly as filter and allow water to overflow and soak-away, while solid matter is digested and breaks down over time.

The only time we ever have any issues (other than that one blockage) is when we've had a week or so of dry, warm weather, and then I just make a point of running a bit of extra water down the drains.

I know you're not supposed to put bleaches and some other chemicals into the system, but we do put a small amount in when cleaning the toilet etc, and I've not seen any evidence that it's killed off the bacteria.

In fairness, our house was designed as a 4 adult occupancy and there's only 2 of us here, so that probably makes a big difference.
Title: Re: Septic tank- emptying by aeration?
Post by: chrismahon on October 22, 2020, 09:39:43 am
We might be able to get our neighbouring farmer to empty the sludge from the bottom? Contractors here cost an awful lot because of the French business and taxation systems, so best avoided at the moment. Not even sure there are specialist contractors, because it's only recently that septic tank systems had to comply to a standard and that's only applied when they house is sold. So any systems will be quite new, either on an old property or for new builds. We've seen plenty of properties with just a single tank and a pipe out into the field. Access to our tank is difficult, but certainly not impossible for a tractor and tank.


It's a small unit and if disturbed will need time to settle out, otherwise solids will get into the second chamber and potentially into the soak-aways. Perhaps I'll try a long 'something' Womble, to confirm there is sludge in the bottom before trying the air pipe?
Title: Re: Septic tank- emptying by aeration?
Post by: arobwk on October 22, 2020, 05:55:56 pm
[ Clearly the UK still had a lot to learn about being an EU member - iow, we applied more good rules and reg's (and monitored them) than anyone else and look where that got us !  Maybe we can show the EU how it should be done before too long !? ]
Title: Re: Septic tank- emptying by aeration?
Post by: SallyintNorth on October 22, 2020, 10:24:45 pm
[ Clearly the UK still had a lot to learn about being an EU member - iow, we applied more good rules and reg's (and monitored them) than anyone else and look where that got us !  Maybe we can show the EU how it should be done before too long !? ]

The rules and regs were all about creating jobs - for the civil service, for the companies that would set up and audit aherence to regulations, and so on.  It will all go, over time, as will many of our human rights, delivered over the period we have been in the EU. 
Title: Re: Septic tank- emptying by aeration?
Post by: arobwk on October 23, 2020, 12:20:16 am
Woh woh woh weh weh weh – please may I start the circle again:
I was making a remark about the UK being anal (pun intended) about complying with rules while now being told by the EU that we should still be controlled by them to make sure we comply with the rules that so many other EU nations pay lip-service to !!! (Anyone taking time to research evidential reports on other nations’ transgressions – fishing is a good example – will probably agree with that.)
BOTH the UK Gov’ and the EU Commission are very good at creating civil service jobs to monitor every breathe we take:  it’s just that I believe the UK civil service is more assiduous at doing the job than the EU Commission and the civil services of the other 27.
As to human rights: when one cannot expel a known exponent of terrorism from the UK because they have a pet cat …  ??? !!  Is that the Human Rights we actually want to uphold when a teacher in France has just lost his head because he was teaching his pupils about freedom of speech ? 


(I'm not going to make any further comment no matter what responses this post attracts !  I've said my bit on septic matters: I do, however,
wish ChrisM good luck with his tank.)
Title: Re: Septic tank- emptying by aeration?
Post by: SallyintNorth on October 23, 2020, 08:32:06 am
I knew I was close to, if not over, a line (no politics on TAS) so I agree, we must not continue that aspect of the conversation.  I'm going to give myself a timeout because that is really, really hard for me to not counter!  (My own fault, I know, I shouldn't have let myself be drawn into it.)

I too wish Chris luck and will be interested to hear how you get on! 
Title: Re: Septic tank- emptying by aeration?
Post by: Womble on October 23, 2020, 08:52:42 am
Wow, that escalated quickly!  :roflanim:
Title: Re: Septic tank- emptying by aeration?
Post by: chrismahon on October 23, 2020, 11:05:28 am
Thank you for your wishes Arobwk and SallyintNorth. I'll need a dry windy day when the land is too wet to do anything else I think. Will report back at some stage.


When we came here I was staggered at how different everything is. Whilst we have the same things fundamentally, everything is done to a quite different interpretation of the EU 'guidelines', which is how they are treated. And you can still drive after losing your licence! Enough said.
Title: Re: Septic tank- emptying by aeration?
Post by: bazzais on November 08, 2020, 10:02:52 am
We have an aerator system up on our campsite - Its full of plastic 'things' - literally full of them I guess they vibrate together and stop chunks forming and break up the air flow.  I would think that you might need something more 'agitating'.

I've heard putting a carcass or two in them works to get them 'fermenting' ?