so this doesent specifically pertain to my garage but it's effecting it. About two years ago i had my entire septic system replaced. The new system is aerobic. All plumbing in the house was unchanged. The system performs as designed with no issues. The problem i have is during hot days especially this time on year you will get a occasional sewer gas smell emitting from the main vent. This is caused by the fact that your pumping outside air into your tank forcing your normal vent system to become an exhaust of sorts. Thus time of year and pretty much any time the temps are above 50 the ground is cooler than the outside air causing the sewer gasses to fall when they leave the vent stack on the house. Im told this is normal and an unfortunate side effect of this system that some have issues with. It's a relatively easy fix you install activated charcoal filters on your vents. This is where the plot thickens. The filters fix the smell instantly. BUT the minute the filters are on they immediately add a little restriction hence pressure to the system resulting in my toilets intermittently gurgling and emitting sewer gasses into the house i assume this problem is a combination of issues. I have low flow toilets witch im guessing are more sensitive to venting. I have tried two different brand filters aswell as reducing the amount of charcoal in the filter with no luck. I even tried a couple of those rv diffuser/ venturi devices with no luck. I'm looking for any input. I believe that a 4" main vent would be the preferred solution. Mine is 3 and changing it is not realy feasible. My current idea is to put the pump in a air tight box and run a intake pipe to the tank basin essentially reducing the volume of outside air that is pumped in and making my main vent return to a primarily inlet vent again. Hope this all makes sense thanks in advance for any help. Hopefully their is somthing painfully obvious im missing.
Plumbing vent and aerobic septic
- Thread starter Jking24
- Start date
kj_mustang
Well-known member
Every aerobic system I have seen, including mine, has a vent stack at the aerobic tank to release the gas pressure so they don't enter the house. I have three pvc stacks coming up from mine. One is a vent, mine is a capped 4 inch pipe with many small holes drilled around the top close to the cap. Others I have seen in this area are a 2-2.5" pipe with a couple 90 fittings on top to make a turned down U. My other two stacks are a observation port and one for pumping out the aerobic tank section if needed.
Something like this.
Something like this.
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Thanks maybe that is the route i should go adding some venting at the tank. Do you have any smells. My tank and feild are so close to my house they're is no way i could have a open vent without an odor problem it would have to have a filter in it
kj_mustang
Well-known member
Mine is about 30' from the corner of my house. Yes, if the wind is lightly blowing from that direction, I can smell it on the back patio. It is not too bad a smell, earthy, not like piles of poop smell. My install design may be different than yours too. I have a MicroFast aerobic system and that part does not get any solids. My solids stay in the first settling part of the tank and liquid only flows over to the Fast side where the venting is.
my sytem is similar it has three stages the last feeds the drain feild we do not use the effluent for anything else so no chlorine or pumps. I suspect my smell is a little worse because of the fact that it is drafted through the first tank aswell as the whole house plumbing system. I have a clean out right at the beginning of my drain feild. I have had it open in the past and not smelled anything to bad their maybe ill try venting their and see if that helps balance the system pressure . Thanks