My Septic System Experiment

[Pettrix]

Just saw this thread. Thx for posting.

I have always loved aerobic systems. They have been around for many years. My folks had one
in central Ohio in the early 70s where there was no leachfield at all, and the effluent from the tank
went out to the storm drain system. It was clear and did not smell much at all.

I have a pump-up septic here that uses Infiltrator chambers and 2 1500-gal tanks. I had the main
tank pumped for the first time after 15y of use. ($450 for one hour's work, no problems, easy access.)

Clearly, that is more than an aerator system could cost, as you have demonstrated. I may
have to install one.

I run a bubbler and vent fan in my 5000-gal water tank to remove sulphurous gases and it has
worked great. Note that an air stone failed there, so I just use a silicone rubber 1/4" weighted line and
an aquarium bubbler.

You definitely want to use a rubber/EPDM diffuser and not stone, since the stone will break down and clog. The EPDM will last a lifetime and never need cleaning.

There's no smell when you open the lid on the tank. It only smells "earthy" as in soil after a rain. The effluent is really clear.

Anaerobic (no oxygen) settic systems put out dangerous gases like methane, sulfur and other toxic gases. The effluent is usually black or brown and clogs the leach field with time. Aerobic (oxygen) systems like mine make a HUGE difference.

 

[hawkeye08]

This is on my "to do" list. I have not decided whether I want to spend the money on a turnkey solution or buy the parts. I know buying the parts will be cheaper so am leaning that way. Keep us informed about the status..

 

[dfkrug]

PETTRIX: how did you decide on a diaphragm air pump of that size? I just checked the smaller 25 L/min
34W twin of your 40 L/min. Hakko unit. At 24c/KWh, that will cost $6/mo to operate here.

I suspect that a much lower volume of air will also work. I experimented for years with my potable water
aeration/ventilation system before I got it right. My initial design called for a timer, but a lower volume
pump and fan that runs all the time is more reliable and less costly to implement.

I even tried a small air pump that I was hoping I could directly run off a small PV solar panel, without
a battery. No success there.

Since I have a pump-up septic system, I have a 2nd septic tank (aka holding tank) that is also 1500 gallons,
to assure the black water has no solids. The water is actually cloudy and light colored. The pump vault is
installed inside this tank, designed by Orenco Systems.

 

[Pettrix]

It's been a few years since my last update. The system is now over 3.5 years+ old.

Still no solids in the primary tank. Effluent is still clear and odorless (besides earthy smell). No issues and the air pump is still going strong with no maintenance except cleaning the air filter on it.

I've cleaned out the effluent filter on the secondary tank and it mainly had an algae like substance on it. No toilet paper or other solids on it. System is great and I am very happy with the results.

Neighbor had to have his septic tank pumped and he paid $550 to do so (1,750 gallon tank). It's expensive out here as they can't dump the sewage locally and must transport it 100 miles away. Not having to pay $550-$600 every few years is a plus with my system.

 

[cqaigy2]

Thanks for the update. Is your air pump on constantly?

 

[Pettrix]

Thanks for the update. Is your air pump on constantly?

On weekends it runs 24/7 but during the week, it runs from 4pm - 7am.

Eventually I will probably have to replace the diaphragm in the air pump. I think they go for like $50 or so.

 

[dfkrug]

Still no solids in the primary tank. Effluent is still clear and odorless (besides earthy smell). No issues and the air pump is still going strong with no maintenance except cleaning the air filter on it.

Nice! Thx for the update.

Last summer, I installed a small aquarium air pump, which runs all the time. I will open up the tank in the spring to see how it looks inside.

 

[Pettrix]

I run the Hakko 40L air pump which is good for around 2,000 - 3,000 gallon pond so one would assume that it should suffice for the same size septic tank.

Amazon.com : Hakko Linear Pump, 4 LPM : Pond Water Pumps : Garden & Outdoor

Main thing is to get a good EPDM air diffuser and NOT a stone diffuser as stone will break apart and clog over time. EPDM with PVC pipe is the best.

I ran a 3/4" PVC pipe (rated for 180 psi) from the air pump to the tank (pics on page #1 of this thread). I believe the 40L air pump produces around 10 psi max so no issues there.

 

[dfkrug]

Main thing is to get a good EPDM air diffuser and NOT a stone diffuser as stone will break apart and clog over time. EPDM with PVC pipe is the best.

I did not use an air stone or other diffuser. An airstone clogged up when I tried them in my freshwater tank years ago. I just run the 1/4" poly line on a stainless steel weight right into the water.

 

[Hilbilly]

I just stumbled onto this thread and thanks for posting this Pettrix.

I've had occasional sewage smell in our house since it was first built. I've had the plumbing contractor, who installed the system, out several times to try and find the problem and fix it. 12 years later and the problem still persists, mainly in the colder months. I am going to see if I can find the materials you listed at a local supplier and install this system. You may have made huge improvement to my home without even knowing it.

 

[the old grind]

If a house is too airtight gas fired WH or furnace may be back-drafting through drain vents/stacks when chimney draft creates negative pressure.

I have unused bathroom fixtures downstairs and when I get the odor I go around and refill traps that have dried up. (sinks, stools, & a shower stall)

btw, Pettrix, nice work as always. Love the results.

 

[Hilbilly]

We have electric hot water and a wood stove for heat. I've sometimes seen where the chimney will downdraft if there are enough appliances, like bathroom fans and the cloths drier, running at the same time. I've also tried going around and making sure all the traps are full but it doesn't solve the problem.

If the aerobic system Pettrix has described works as well for me as it does for him, then my problem should go away. I'm anxious to give this a try but will have to wait until the snow melts away in the spring.

 

[riptides]

I just stumbled onto this thread and thanks for posting this Pettrix.

I've had occasional sewage smell in our house since it was first built. I've had the plumbing contractor, who installed the system, out several times to try and find the problem and fix it. 12 years later and the problem still persists, mainly in the colder months. I am going to see if I can find the materials you listed at a local supplier and install this system. You may have made huge improvement to my home without even knowing it.

Previous house had drain plug issues for the HVAC system, they would dry out and the smell would come through the house. Ended up making sure all drains had water in them throughout the cold months. Maybe try that? HVAC?

 

[pmsmechanic]

We used to every once in a while when the wind was right get a sewage smell in the house. Finally found an unused trap and capped it. Problem solved.

 

[Hilbilly]

No HVAC system here, unless you count the AC unit I put in the window in the summer, lol. Real simple living in the country. Well water, septic system and wood heat. I've chased this problem many times and can't figure it out. The smell usually comes from one of our sink drains or the bathtub and it's most notable on the second floor. I'm really hoping the aerobic system Pettrix described will eliminate the smell issues. I've already done some digging and found lots of septic air pumps on Amazon.ca and also discovered that I can't install the pump outside. It gets too cold here in the winter and pretty hot in the summer too. Not a big deal but a lot more work to install in the house and I'm concerned about the noise the pump will make. It's really quiet in our house at night but I'm sure we could adjust to a new noise if it wasn't too loud or obnoxious.

 

[ponytug]

Could you put a small insulated hutch outside with the pump in it; the pump would keep itself warm?

All the best,

Peter

 

[Firemanbuck]

Thurston County.

I don't mind the septic permit and periodic inspection fees, if it means keeping shellfish harvesting safe and healthy. I do mind that the County doesn't even begin to consider installing cutting edge systems like peatmoss drain beds to increase denitrification.

My house has a sand filter that pumps to a mound. I have the mound disconnected and the sand filter pumps to my yard and my trees...don't tell the county. When we sell, I'll hook it up right and the new owners will have years left on their mound.

 

[Hilbilly]

Could you put a small insulated hutch outside with the pump in it; the pump would keep itself warm?

All the best,

Peter

Not sure if it would keep warm enough in -40C temps during the winter. Although those temps are rare, we still normally get -25C to -35C in the winter (except this year, so far). We also get +35C to +45C in the summer, so I would have to remember to remove the pump from the hut in the summer. With my memory being what it is, I doubt the pump would survive one year in an insulated hut, lol. Best to install it in a more stable environment.

I'm looking forward to doing this in the spring, if I remember.

 

[aczlan]

Put it underground. 3x3x3 box 6" underground with 4" of foam on the sides, 6" of foam on the roof, a 10" diameter 4' long piece of plastic drain pipe going down into the ground out of the bottom of the box (filled with washed stone) and a small (100w?) heater on a "freeze proof" thermostat inside will likely never freeze. Use a piece of 2" conduit to bring power in and make that the air inlet as well (pulling air from the house so that it's warmish).

Aaron Z

 

[Hilbilly]

Put it underground. 3x3x3 box 6" underground with 4" of foam on the sides, 6" of foam on the roof, a 10" diameter 4' long piece of plastic drain pipe going down into the ground out of the bottom of the box (filled with washed stone) and a small (100w?) heater on a "freeze proof" thermostat inside will likely never freeze. Use a piece of 2" conduit to bring power in and make that the air inlet as well (pulling air from the house so that it's warmish).

Aaron Z

The underground idea is great but I think that will involve almost as much effort as just running it from the house. Thanks for the great idea but I think I will just end up running it from the house. I've got lots of time to figure out what will be the best overall solution.

Took me awhile to reply, as our power went out about 45 minutes ago and I had to get the little Honda generator running and run some extension cords into the house for essential services, like the TV for the wife and the internet for me. :laughing: I also had to hook up a couple of lights so we could see where we are going.