I have a "standard" septic tank consisting of a 500 gallon cement solids tank, a 500 gallon cement liquids tank, and a leach field.

This setup has always been an issue and several years ago I installed a small pump tank to aid in the process of getting the waste down the leach field. The pump was a simple submersible pump @ around $100 and the tank is a 55 gal plastic drum with several risers and a dome lid at ground level. Total cost was probably around $150 and it's been chugging along for about 5 years now with no issues.

I am now looking into aerating the septic tanks in order to allow aerobic bacteria to thrive and clear out the sludge that is no doubt lining the leach field. I have looked into pre-packaged solutions but they all seem to want $500, $1,000, or more for what is basically an air pump, plastic air hose, and some sort of diffuser device at the end to make the bubbles smaller (the idea being greater absorption of oxygen into the water).

I was wondering if anyone had ever looked into creating their own septic aeration system or would know where I might be able to go to source an air pump?

I was discussing it with my Father-In-Law and he was thinking of creating a large circle made out of small pvc pipe that would sit at the bottom of my septic tanks with tiny holes drilled out of it to aerate the water..this would of course be tied to a small pump.

"Luft" pumps are the only thing I can think of at a reasonable price, and would be efficient.
I would also consider putting it on a timer to come on sporadically instead of having it constantly run.
The warmer the water is the less dissolved oxygen will be in it. So you may need to run it more during the summer than the winter.

This thread stinks.

Clever, Durachko

How about some kind of fish tank air pump? Except maybe more heavy duty(DIY modified?) to run outside and all the time.

edit:typo

That is what a "luft" pump is...

I looked at the luft pumps and the price is right...I'm just not sure how big of a pump is needed to properly aerate a 500 gal septic tank? This was says it's used for pond aeration but how big of a pond?

Luft Pump

I'm guessing an "airstone" is some sort of pourous rock that diffuses the bubbles for greater absorption? I'll have to make something that will tie into the pump and spit out teeny tiny bubbles.

I have no experience at all for this application.
The pump may not even work for this.
You have to remember it is going to have to push the air through ~ 5000# of water.
Do you have a link to the prepackaged solutions?
Maybe we can get some specs and see what kind of pressure and volume are needed.
I am not confident that a diaphragm based pump will be able to withstand the back pressure here.

Maybe a circulating pump with a "T" tied into the intake with a valve at the surface to let it "suck" in some air without feeding it so much it breaks the siphon?

Do you use any bio-additives to assist in breakdown of the sludge? Do you avoid using bleach like the plague? I've got a conventional, two-tank (sludge/settlement and dosing tank) system with just shy of 20 years on it and I've only had it pumped out once (maybe twice). Depending on where you live you may be regulated as to how often you must pump your tanks out? I swear by using some kind of enzymatic additive mixture and not using bleach EVER. I didn't use anything for a number of years and had stinky vent pipes. I used a little yeast at someone's recommendation for awhile with no noticeable results. I then spent a fair amount on a commercial MIRACLE additive (which is mostly sawdust but does have significant enzymatic activities as per some lab assays I ran) and use only a fraction of what they recommend and have seen very noticeable results. They would keep calling me and telling me I should have already used the supply I purchased but I explained to them what I was doing and of course they said "That's not recommended." Well, they quit calling after a few years. I routinely inspect my tanks and even have a peek at the leach field now and then by simply looking down the six vent pipes - which are cut to just below grade so I don't smack 'em with the mower.

Sigh . . . whatever happened to a good old outhouse?

Oh yeah - poop at work.

Edit:

Is the aeration a proven bonus or just a theory?

My system uses the second large cement tank as the dosing tank. I'd guess having a bigger dosing tank like that would be a little better than just a 50 gallon drum? I guess it depends on the design of the leach field though. If it was designed for gravity leaching then it may not be happy being force to try to swallow hundreds of gallons per dose???

Wow D...you sure know a lot about poop....


We have had great success with the simple additives for your septic system. I think we use Rid-X. We use bleach as recommended and have never had a problem.

I have been looking at this line for a while. Their drain cleaners have a good reputation.

Not near as much as that place you referenced!!! They've got a specialty blend for everything. It's like a fecal-degrading cornucopia!!!

Edit: Funny . . . usually people tell me "You don't know s__t!!!"

I've been using rid-x for quite some time or some derivative of it, but from day one (since I moved into the house 7 years ago) my drain field has been saturated with sludge (or I assume..never dug it up) as the effluent (processed poo and stuff) isn't seeping into the ground as it should b/c there is a big wet spot at the end of the drain field.

I'm not sure what a dosing tank is? The submersible pump was originally in the liquids tank, but I had a couple issues with it early on and having to dig up a 500 gal concrete tank lid and drag it off to get to the pump was more than an inconvenience. The smaller tank with the riser allows me to access the pump relatively quickly. that's really the only purpose for the smaller 3rd tank..is just to allow me to get to the pump easier. If the drain field were operating properly and letting the wastewater flow down into the ground then the pump wouldn't be necessary.

Based on what I've seen, the aerobic bacteria are much more aggressive at breaking down the waste and can even clear out the "biomat" left behind by the aerobic bacteria within about a years time, supposely restoring the drain field.

Here are a couple pre-packaged solutions:

cheapest: http://www.aerator.us/
1,000 dollar kit (can't find specs on motor): http://www.aero-stream.com/

i've seen many more but now when I try to find them I can't..i'll add more later

The aerobic thing is interesting.

A dosing tank is just a reservoir which holds the liquids and has a pump and trip switch. Once a certain amount of fluid has collected the pump kicks in and forces all the liquid into the leach field in a single "dose". This helps to evenly distribute the liquid over the entire leach field and avoids any low spots prematurely clogging. At least that's my understanding. A totally level leach field is the best. You can imagine in a gravity system the closest spot to the tank collects sludge very quickly. I dunno - maybe old gravity systems actually were built with a slightly out-of-plumb leach field? Who knows?

I've been told if/when my field clogs I can go in and dig up the pipe at intervals and drill bigger holes in the pipe grid to gain more service life out of the field. Also, one can apparently (given enough real estate!) put in a secondary field and switch between the two every few years and they will naturally clear themselves given enough time???

But the best solution is as I said - poop at work!!!

Ungh . . . be right back.

I contacted a place and explained my situation..to my surprise they recommended the cheapest kit for my tank..it's still $380, but perhaps something that's got research/experience behind it is worth more than trying to save a couple dollars (i know, blasphemy!).

http://www.septicsolutions.net/store/SepAerator.htm <-- They suggested the sepaerator value package.

Mine is a gravity system, so technically the pump isn't needed. I also have enough land to dig a second line if I wanted to, but that would cost quite a bit more than trying to fix the existing one. I'll be selling my house in about 3-4 years and I don't want to leave them with a hack-job of a septic system...in fact I probably won't be able to sell it with my "modified" septic system. The idea is the aerate it to restore the field, then remove the pump/fill in the pump tank and reconnect the main 4" line directly back to the field line. The aerator of course could stay.

I try to always poop at work, but the wife stays at home with our son, who is beginning to add his poop to the tank as well .

It's been a while since I've posted on this thread..but I was also reading about just digging a huge leach pit at the end of the line to repair a failing septic system. You basically get a leach pit tank and dig a huge hole at the end of yourseptic line..fill it in with gravel and stick the tank in it with the septic line running into it.

I'd still like to aerate the whole system but it looks like that aerator has gone up in price

This is some interseting shit.

We only have one tank, although it may be subdivided internally as it has two vent pipes. We have it pumped every two to three years, as is the recommendation, (here at least). I think our leach field is problem free but they typically have a life span of 10 years, or so I've been told, and we're just about at that point. Anyway, we have plans to move in the next few years and build a new house, so this will be one area that we need to think about in detail.

Right now we're moderate users of bleach and don't use any additives for our septic system. It may be time to reconsider.

They say home brewers have the best septic systems...

Although a box of Rid-X once in a while seriously couldnt do any harm.

I have used rid-x but I don't know what they used the first 15 years of the septic systems life...my understanding is a "biomat" forms over time along the line and keeps the septic juices from seeping into the ground...and the aerobic bacteria are supposed to eat it up...there's some other chemical stuff you are supposed to be able to pour straight into your field line to eat it up but I don't know if any of it really works...

I beleive my field line is saturated because the ground is always damp at the end of the line and theres a hole there as well...it also smells like septic goodness...so the stuff definitely isn't flowing into the ground. The aerobic bacteria are also supposed process the waste more fully and eliminate the odors..

so I'm thinking about this some more..and I'm probably going to have my solids tank pumped again soon just because it's been 5 or so years since it's been pumped...and looking around I see I can get pond aerators for less than $300 that will supposedly aerate a 2000 gallon pond which will be occupied with plantlife and fish breathing up the oxygen instead of just aerobic bacteria...so I dont' understand why a septic aerator is twice as much?

The only question I still don't understand is how to ventilate the septic system so the tanks don't get pressurized...

There is a machine that will air entrain your septic leach field, what happnes generally the ground after years of leaching becomes compacted so metal tines are jammed into the earth and styro pellets like you use in potting soil are injected making the soil able to filter the water once again. It is significantly less than digging up the entire system.

They also use it to fieed tree roots the machine was developed in Gemany to feed the roots in the balck forest.
and it also has an application to renew putting greens.
the name of the machine is called Terralift I know this is not exactly what you are talking bout but it can save you from digging up a leach field.http://www.terraliftinternational.com/

The amount of air required for the aeration of a septic tank depends on several things, the main ones being

1. The number of people using the tank
2. The size of air bubble
3. The depth of water being aerated

The formula is 600 cubic feet of air for every person per day if you are using a coarse bubble diffuser, which is the one you would need in the FIRST tank chamber. The coarse bubble diffuser has the ability to turn the sewage into a 'soup' for bacterial digestion, wheras a fine bubble diffuser doesn't have the 'churning' power. For every 6 ins less depth, increase the air supply by about 15%.

I would go to the expense of buying a proper wastewater diffuser (about £30 in the UK and I can put you in touch with our mail order supplier) as you cannot really make a diffuser that will supply the correct sized bubbles. Aeration stones are just not up to the job either, as they are meant for aerating pondwater, not wastewater which requires the 'lumps' to be broken down.

As an example, using the above formula, a 6 ft deep under the water line septic tank with a fine bubble diffuser, used by 6 people will require

6 x 600 = 3600 cubic feet/day plus 15% = 4140 cubic feet/day or 173cubic ft/hour - 2.87 cubic feet/minute compressor. A Hi-Blow, Gast, Secoh, or Bibas linear motor diaphragm blower will be ok, but don't buy one made for pond aeration as many of these don't have the power to blow at depth. All blower manufacturers will supply a graph which shows the performance at varying depths, so make sure that the blower you buy can perform. The blowers are about £90 in the UK.

Weight the diffuser to the bottom of the tank by fixing it to a stone or other heavy object and use solid pipe for the part of the airline which is under the water. It makes lifting the diffuser out much easier for periodic cleaning.

Also, buy a septic tank filter which fits into the vertical part of the 'T' on the outlet pipe. These prevent suspended solids from exiting the tank and are made in the States by Zabel, Sim-Tech, etc. They cost about £15 and we wouldn't fit a tank without them.

I hope this helps

Waste Tech Environmental Ltd.

thanks for the great info! I haven't been on in here a while but I'm glad I popped in to check things out..so it sounds like I could peice together the system for under $300! If you've got suggestions on the specific components you think would be best I would be happy to buy them. I've got 2 500 gallon cement tanks and the bottom of the tank is probably about 10-12' underground. When you say to put the filter in the "T" I'm not sure what that is..the outlet on both my tanks look more like an "L" . I guess you mean just have the filter attached to the outlet.

As far as the number of people..there are 3 people using the septic sytem right now (2 adults and one 3yr. old) and a maximum of 4 by the time I sell this house .

Also..I don't think I have a vent anywhere except of course in my house.....won't I need a vent if I'm pumping air into this somewhat closed system?

Also, should I start aerating at the first tank (solids tank)?

I thought they were anaerobic? And yes, the leach field is meant to be slightly sloped, otherwise how would the soakaway ever work for more than a few days? We installed a few hundred feet of holed pipe for the water to head down, and a load of gravel. Works great.

Because there's billions upon billions of bacteria, all through the water, unlike a pond, where that would be a disaster.

Also, you need the higher pressure to push the air down the tube against the water pressure.

Not sure about these concrete tanks you guys use, I've not seen one. UK ones tend to be fibreglass. Just install the biggest one you can get, and we were told the best way to prime it was to throw a dead sheep in it. Then just carry on.

The outlet pipe neds to be replaced by a 'T' fitting which is like a capital T on its sdie, with the leg of the T being the outlet pipe and the top of the T being the vertical bit. The filter slides into the vertical part.
If you vent the system then the vent should be to the inspection chamber prior to the septic tank and make sure that the end on the pipe is high enough to vent the gases away from nose level. The vent can draw from up to 10 yards away, so can be placed remotely.

The aeration needs to be ONLY to the first tank. The second tank then acts as the clarifying chamber.

The diffusers can be either the ceramic type or the diaphram type which cost around $30. Any wastewater company should be able to supply them as we keep spares.

ok so I'll look for the diffuser first then try to find a pump.

should I get my solids tank pumped (emptied out) before I install the aerator? it's been several years since it's been pumped...

Yes, it is always a good idea as the organic load will be huge when the aerators disturb the sludge from the base of the tank.

The cheapest pumps are Hilea and cost £67 for an 80 litre pump. Disc diffusers are OK for the coarse bubbles, http://www.stamfordscientific.com/coarsebubblediffusers.html and if you want super results, you could add a fine bubble diffuser on a dual manifold from the pump.

hey there, i'm located in ontario canada. I have been going through a nightmare with my septic system since the spring of this year. Through many mis guesses and ideas i did figure my drainfield is clogged with bio-matt. This occurred from failed baffles in the old tank and destroyed biology among other things( blech, water softener etc). Being faced with a huge bill of replacing the system..local bylaws don't even allow you to fix them here i needed some less expensive solution. i checked the premade units for sale on the net and knew i could build one. the science is sound, all i needed to do was create the environment for te aerobic bacteria.

Parts list: Pondmaster ap-20 air pump, 30' for 1/2inch plastic hose, 5-6' sections of pipe insulation, connectors and clamps, 2feet of soaker hose, 1/2 barbed "T"

all told taxes in this stuff was 160.00 CDN. plumbing to disconnect the washing machine, watersoftener and dishwasher from the septic tank.

i formed a loop with the soaker hose and the "T" and connected the 1/2" hose running through a 5/8" hole drilled in the top of my tank. I weighted the hose so it was held 4 inches off the bottom of the tank. I chose the Pondmaster AP-20 (1500cu/inch per minute) becasue i didn't want to turn over the tank too drasically. aeration occurs not just from bubbles but through the water but also agitation on the surface. I do think an effluent filter is a good idea even though i'm not using one yet. I primed the tank with a couple of different bio activators. I chose more than one hoping to introduce different kinds of aerobic bacteria.

Additional things i did buy was a concrete riser to have easier access to the tank through our dirty-rotten winters. this was a cool hundred bucks.

third week since install...the liquid in the tank is the colour of slightly tinged water. not the nasty stuff of before. odours are almost non existent. whenever i open the tank to look, all i can smell is the fresh concrete riser. the overflow into my yard is diminishing and only occures during extrememly high volume...like when the toilet gets stuck open for a day or too or my daughter gets depressed and spends two hours in a hot shower. at this point it seems like things are improving...i'll keep updates coming.