toilets bubbling, septic, vent on roof questions

[smnornes]

Our house was built 3 years ago with a gravity flow septic. Last year, we noticed all the toilets bubbling when we drain the bathtub or run the clothes washed (high capacity.) We have had the tank pumped twice since the bubbling started, and it seems to quiet the bubbling for a short time, but it hasn't fixed the problem. We have read to check the vent on the roof for clogs, so today we rented a Genie to get up there (we have a tall house!) and found one white PVC pipe, about 3 inches in diameter, sticking up from the roof. The only other things on the roof are exhaust vents. Upon inspection, we found a cap sealed on the top of the PVC pipe. In trying to remove it, it broke, so now that pipe end is exposed. Inside the pipe, there was moisture and a slight septic smell, so I'm pretty sure it was the right pipe/vent.

My questions...
1. should that pipe have been capped in the first place? Do we need to replace that cap?
2. are there any other places a vent would be? We have 2 or 3 PVC pipes sticking out the SIDE of the house by the fireplace. Could they be anything?
3. we read about high capacity washers and large tubs draining and how they may cause trouble with the amount of water being pushed through. Is this true?
4. last summer, I mowed the top of one of the PVC pipes sticking up from the ground above the septic tank. I never replaced the cap. Could this be an issue?

Thanks for any help or advice.

 

[Cass]

That vent cap should have been removed by the plumber after the final inspection passed. Do not replace it and be sure all of the cap is off.

The cap you mowed should be replaced. Sticks, ect. can get stuck and cause problems with flow. How many people in the house?

 

[Sponsor]

 

[smnornes]

there are 2 adults, and a 5 and 7 year old...so 4 total.

 

[Cass]

Well, based on the # of people you shouldn't be having that kind of problem. I recomend having your tank pumped every 2-3 years anyway. This will allow the system to work and the leach field to last much longer. Do you know the size of your tank? Do you know if you have a split field?

 

[smnornes]

All I can come up with is the zoning permit, which has the site layout but nothing specific to the tank. I believe we have a 2 chamber tank because we have a garbage disposal (that we rarely use and only for small things because we know better.)

 

[Abikerboy]

Uncap your vent as you have done. Replace the pvc cap that you mowed, and have the line cleaned of whatever may have went in from the damaged pvc cap (including plant matter and roots), and forget about it. All should work from then on. I pump my tank every 4 years regardless.

 

[Plumber1]

If you lived there for two years before you had bubbling and you say that pumping the tank relieves the situation for a few days, then irregardless of the vent situation, you should look for a field bed problem.

Open the top of the septic so you can see the water level. Run water and at the same time flush toilets and if you can see the water rising, your problem is with the field bed.