Do's and don'ts of septic tanks.

[pieman]

Could anyone put down some tips for the use of a septic tank. The tank was new in 1972 and is made of brick, I cannot tell what kind of system it operates.

Do's and don'ts please and points to watch out for.


Thanks all.

 

[Nemesis]

Here's a start:

http://www.periodproperty.co.uk/article005.htm

 

[pieman]

I have heard numerous different ways to keep the septic tank working efficiently, eg not using bleach etc etc, and one strange suggestion of putting a bit of road kill in there to bolster the bacteria.
Are there any prefered cleaning products that won't disturb the tanks balance.

Nemesis thanks for the link very informative.

 

[Nemesis]

Well - I'm not too convinced about the road kill, I know some think it helps, but we have had looong disagrrements in the past about septic tanks and the best way to deal with them.

Basically bleach isn't a great idea, although some think it OK in very small quantities, and I always use eco-friendly stuff to clean and do laundry with.

Don't overload it either, try to space out laundry and baths etc.

You will get some who say you never need to get them emptied, but then others who do...

 

[Flyfisher]

All the advice I've ever heard is 'if it's not giving any problems then just leave it alone'.

Is there a specific reason for asking the question?

 

[Lime]

I've no intention of getting into disagreement either.
Some household chemicals will readily kill bacteria and these you want to avoid.
when I had a septic tank I found that many products specifically said on their labels that it was safe to use.
I have heard stories that a dead chicken is a good starter but I can't see why good-old human faeces doesn't do a better job. After all it is full of all different types of bacteria which is what septic tanks are all about.

 

[Jane Smith]

Septic tanks are just settlement tanks, and are intended to remove the gross solids from the effluent by allowing them to settle out. The liquid waste then runs off into soakaways (usually) where it disperses into the ground.

From all the research that I've done (we installed our own tank a few years ago, and I wrote several articles about septic systems at the time) you'd need to put in a huge amount of bleach and bio powder to overwhelm the huge amount of bacteria present in what goes down there. I could find no real evidence that road-kill, dead chickens or special septic tank enhancer mixes (and yes, they do exist) helped anything along at all.

As it's a settlement tank, a septic tank contains the solids and retains them. After a time, depending on how many people contribute to the tank and what size it is, a septic tank will need emptying. Which is just a matter of having the tank pumped out, and all the stuff taken away.

The most common cause of problems with septic tanks is actually soakaway failure, in which the soil into which the liquid effluent disperses becomes blocked and/or saturated with the effluent, and so stops absorbing any more. When this happens, the whole thing starts smelling and you often see nasty black run-off trickling out. This can sometimes be helped by pumping out the tank, but usually a new soakaway is required.

And finally, reed-bed systems are NOT a substitute for a septic tank. Reed beds are used to clean the liquid effluent, and still require a septic tank to remove gross solids before they reach the reeds.

So there.

 

[Penners]

I've had four houses with septic tanks, and I echo every word that Jane has written. My only little addendum is that you should establish a strict household rule about what goes down your drains.

Nothing other than your own bodily contributions and toilet paper should go down loos. No oils, fats, or general food grot should go down your kitchen waste.

 

[Nemesis]

Which actually brings me to ask - what do others do with oils?

I don't in general use much, not being a chip pan person, but we do buy at times jars of stuff like artichokes in it - and disposing of any remainder gets complicated.

I don't care much for using it for cooking and it ends up getting thrown out with the jar rather than recycling as I can't think what to do.

I recall Jane saying a long time ago that milk products are not good in septic tanks. So I try to avoid disposing of anything milky.

I also have a tiny dishwasher - very small, very economical - and I did read recently that dishwashing is actually better than handwashing as it turns fats to soap.

I'm no scientist so... any thoughts welcome.

I also agree about getting these emptied every now and again. I know some consider that all solids should vanish but they don't. We inherited a tank which the previous owners had been paranoid about not putiing anything down which may stop the bacterial action. It was blocked solid just about with the sludge, not having been emptied for eight years.

We had a looong thread about this a while ago and I posted links to a number of sites, including research which said that a certain level of sludge made it work better - but there must be limits!

Too much and putting vast amounts of water down without giving it a chance to work will disrupt the action.

As the one in the original question is relatively new I assume it is a two chamber tank, which should help with sorting out the solids into the first chamber before the watery waste goes into the second - that all helps.

 

[Jane Smith]

Penners is right about septic tank abuse. The stuff you expect to go in it doesn't cause problems: it's the stuff which doesn't belong there that makes it slow down and back up. Including vast quantities of water. A septic system works better if not subject to high levels of dilution.

When we still had poultry, we solved the oil issue by mixing it with the poultry feed. Now we feed some of the oils to our dogs, but only a small bit as they're porkers all ready; we don't seem to generate much of the stuff. The rest we bin, well-wrapped in a couple of layers of waste paper (as Sheffield council won't collect recycling stuff from us, because the bin lorries won't come up our track).

Evelyn's right about milk products being especially bad for septic tanks: they really slow down the bacterial action. As do oils and fats. I don't think that using a dishwasher would turn the fats to soap but I can imagine that it would emulsify them quite efficiently, and if that emulsion holds then they'd not be so harmful to the tank.

Emptying: well, we put ours in in 2002 and had it emptied last summer, for the first time. It's very large for just the four of us, but will be needed when/if we ever get round to having paying guests. As it's oversized for just us, it doesn't need emptying so frequently. Generally, the rule is empty every year.

 

[Penners]

I also have a tiny dishwasher - very small, very economical - and I did read recently that dishwashing is actually better than handwashing as it turns fats to soap.

Great! It's so much nicer to lather yourself with chip-fat than with Imperial Leather.

 

[Nemesis]

I use best vegetable oil soap I'll have you know!

But I don't really cook many chips... so don't have chip fat.

 

[Penners]

But I don't really cook many chips

Geddoff! You're from oop north, aren't you? You all live on chips up there.

 

[Nemesis]

We buy 'em from the chippy of course, to be eaten wi' mooshy peas an a pickled onion. Out of a paper.

Our local chippy is Listed at Grade II.

http://www.imagesofengland.org.uk/search/details.aspx?pid=1&id=240745

 

[Penners]

Our local chippy is Listed at Grade II.

There's posh.

 

[chuckey]

As I understand, septic tanks contain two chambers, the first is where the real action is, the second appears to contain clean water. the theory is that it takes say 20 days for the bacteria to eat up the nasty bits in the first tank, and the process is then repeated again so the outlet is pretty clean. The only reason septic tanks require to be emptied is that they have been filled with a lot of "indigestible" matter. As number twos are actually only 2% ash, this is the only residue. Not being very scientific about this , I suppose that the volume of one days number twos could be 300ccs (I am open to correction on this point!). This would amount to 6ccs of ash per person per day. As the typical septic tank has 1800 litres in its first tank, if we say it requires emptying when it reaches 50%, this is 900 litres. 900 litres/ 6 ccs = 150,000 people days capacity!!
To back up this claim, I took the top of an old septic tank which we had used for a couple of years, during this I managed to drop a chisel into it. So I fished about with sticks and magnets to recover the chisel and found that the tank had about 1" of slime on the bottom and not 2 feet of congealed **** and found out that the filter tips from cigarettes are also indigestible.
frank

 

[Nemesis]

That's apart from those which don't have two chambers of course. And those smaller than that.

 

[Penners]

number twos are actually only 2% ash

Unless the perpetrator has a real penchant for curries.

 

[Nemesis]

Or eating charcoal.

 

[Flyfisher]

I think this topic is getting perilously close to being too informative :shock: