How likely is it to have tree roots get though 3″ schedule 40.
Last night while out clearing snow I walked past the septic tank & found inch thick ice on the lawn under the snow. Primary septic tank is over flowing, secondary tank is empty. No problem, just a clog in the 36′ of pvc pipe between the tanks. I had the tank pumped down this morning & tonight when I got home went to work on the clog. First thing is to run a power snake, Second thing, I got out a garden hose to flush out the line, but to no avail. I can get the hose into the pipe about 24′ & I hit something really hard, perhaps a elbow. When looking at the placement of the tanks in relation to each other, the only elbow would be a 45 at most. I also got out my fish tape thinking that would make the bend, again 24′ & I hit something hard.
After a lot of work, I now get a little water to flow threw but most runs back into the 1st. tank. I’m starting to wonder if tree roots can damage PVC. I have 3 – 20′ spruce trees around the 2nd tank & problem area of the pipe.
So the question, Tree roots & PVC? I’ll try a larger sewer machine in the morning.
Replies
My understanding is that tree roots get through the joints at fittings but not so easily through the pipe wall itself. I've seen miles of sewer line replacement in progress (entire towns doing it where I lived) and they use SDR plastic pipe and heat-weld the 20' lengths together without couplings.
Careful with that sewer machine in your plastic drains. Any chance you have a sewer contractor locally who can come by with a pipeline camera and scope the line for you? Any cleanout will get them in... should cost less than a hundred bucks if it's easy access.
Many times septic tank/sewer line installers do not glue the pipe. They also do not always set the tanks on compacted grillage (rock). Two things can happen in those instances. The tank(s) can settle and/or the pipes can seperate at the joints.
From what you have descriped, I would gues that the second taank setteled and pulled the pipe apart or broke it at the 45. I have seldom seen tree roots get into glued pvc pipe.
Paying for a sewer cleaner to take a look see with a camera, doesn't solve your problem. It only confirms what you aready know...it is stopped up, 24' from your clean out.
Save you hundred bucks for the backhoe and repair cost. You will know exactly what caused it, after you dig it up.
Dave
Sounds silly, but could it be ice?
Hi csnow,
After working on the problem for while my wife asked the same thing, and I told her no I don't think it could be that, nothing else is frozen in the first 24' of pipe so why all of a sudden at that point would it freeze.
Today I called a guy from Roto Roter & we had a good talk, He told me the frost is down 36" right now, Our frost footings are 48" here in S.E. Wis.
He said they see a lot of frozen pipes between the tanks due to the fact they are not that deep. Water in not ment to sit in these pipes but rather run though. I may have a build up of sludge, just enough to slow things up & freeze.
He told me the regular cable machines will not go though ice but he has a water jet that will, only $350.00 for the first hour.
This sat. I'm going to try hooking a hose to the water heater & run the hose back in to blast/melt it out. When I ran cold water in the other night I did finally get a little water to go though.
I'll keep you posted.
PJE
Depth of freezing is a function of:
soil type / moisture type (dry gravel freezes deeper than wet silt/clay
average ambient temps (duh)
radiant losses to space (clear nights, no tree coverage)
snow cover (your 10-12" should help a fair bit, but maybe not enough)
underlying ground temps (i.e. groudwater temps)
I've seen city water mains freeze at 14 feet and we don't have especially cold winters here (rare -40F, usually -20F for a week or two). My service line and leach field are at 11 feet but in unplowed areas with ground cover growing back. Added another 2" of bluefoam under the driveway which gets plowed.
Try the hot water, through a hose stubbed right up to the blockage. Cold water melts ice pretty slow. Hot water should tell you if you've got ice, as long as the blockage isn't a long length. Next house you build, put a frost-proof hot-water hose bib on the outside of the house. I love mine. Wash the dog, fill the hot tub, instant window de-icing, etc.David Thomas Overlooking Cook Inlet in Kenai, Alaska
Thanks for the input.
I tried the cold water thinking it was just some sluge build up & after a while I did get some water though. After talking to others I'm starting to think it could very well be some ice in the pipe. I think/hope the hot water will do the trick.
PJE
"He said they see a lot of frozen pipes between the tanks due to the fact they are not that deep. Water in not ment to sit in these pipes but rather run though. I may have a build up of sludge, just enough to slow things up & freeze."
Right, I have pipes above frost line in my relatively new 'up to latest codes' system, which is why I mentioned it. Not a problem unless things start to backup...
Success,
The pipe is clear & open. Ran a larger sewer machine with a root grinder. Water is flowing, life is good. Also test the discharge pump & mound plumbing seems to working also.
I think the clog was just sludge maybe a little ice, The machine blew right threw what ever it was. Rental for the machine was only $51.00.
I also run hot water to completely flush the pipe out.
Thanks to all for your input.
PJE
Thanks for the update as I was lurking and curious as to how this was to work out for you.
Good thing you didn't listen to me! I would have had you out there in sub-zero temperatures with a shovel.
Al
I figured renting a sewer machine was a gamble but starting to dig was a much bigger one. Plus guys around here say we have 36" of frost.
I'm gald all went good & now I can get back to regular life.
Are you going to do anything to try to keep it from happening again?
Yes, heres are some things I will be doing.
Clean the tank discharge filter more than twice a year.
Run a high pressure water hose down the line every fall.
Add bacteria to the system once a month.
Continue to have the tanks pumped every 24 months. Required by code.
Wash hands before eating, especially after working on the septic.
Brush & floss after meals.
Say prayers at bedtime, "And God bless the septic"
1-4 are my real plan, 5-6 are for grins.
Any other ideas would be appreciated.
Thanks.
PJE
Carpenter,
I am an underground utility contractor. I disagree with the other posts about tree roots penetrating PVC, I see it all the time particularly with SDR35 gravity sewer pipe. It is thinner walled than sched-40 and likely what you have running between the septic tank and the d-box, because-- sched 40 is plumber's pipe and generally ran out of the house to tie into a sanitary lateral or septic tank, but from there the 500' or so of finger system is thinner material. So I would hit it with an electric eel with a root-cutter head and rule that out.
I agree with Dave about not wasting time camming the system. It is expensive and only makes sense on my kind of stuff, i.e. a problem in a sanitary main buried deeper than 15'. You're going to have to dig it up anyway if it's not a root. The settlement sounds like a pretty likely scenario.
As to it being frozen, one thing that always amazes me is how much heat grass and concrete hold into the ground. In my area the frost level is 48", but this is for bare clay on the ground. And since this is a possibility at some point after the install that's how deep you have to bury water and sewer. BUT if you go out on the tenth zero degree day of the year and lift up a large concrete stepping block, the ground will be noticeably warmer than you expect. Ditto for under grass. I would guess freezing is not the issue.
remodeler
First of all, Thank you to all of you for responding,
As for ice, I would bet the farm its not that, the entire length of pipe was full of water perhaps days & no other ice was found anywhere in the system. We also have a good snow cover about 10-12 inches & when I took a pick the lawn I could drive it in.
It has been cold & that makes this problem fun to work on, its -8 right now.
I thought about the camera & found someone for $70.00, That may be a option/gamble.
As for the pipe, it is sched-40. I even have sched-40 on the discharge side of the second tank which goes into my mound system, then it turns into the thinner walled stuff.
As for snaking from the 2nd tank back, I would love to but, the manhole & collar leading down to the tank is full of pipes & electrical for the pump to the mound making it impossible to get into the tank without pulling the pump. The 2nd tank is a 800 gal. tank with the inlet on one end & the manhole on the other end so I can't even see the inlet from up top. Also the collar below the manhole cover & top of the tank is about 2' long.
So, I guess my options are, 1-Camera 2-Root cutter or 3-Dig it up.
Maybe I can find a guy with a Root cutting camera mounted on a backhoe!
Thank again everyone.
PJE
How old is the system? If it's pretty new, I'd be inclined to think the problem was caused by settling rather than roots. How deep is it? Since it's a localized problem, you could dig it by hand...if it weren't so dang cold.
I tend to agree with Dave...By the time you get done with cameras and root-cutting augers, you could have dug it up and repaired whatever it is.
Al Mollitor, Sharon MA
The system is 15 years old. As for digging, were talking about 3' deep & how ever big around, If its settling I'll have to do a lot of digging to repair & repitch everything. I'm not afraid of that part. I think l'll try the auger & camera deal before making a big mess with digging & all.
Thanks for the input.
Good luck! Let us know what happens.
Last year I spent a couple of days digging up parts of my system, and weeks agonizing, just to figure out that my soil perks slowly and when we've had lots of rain the water level rises. We tend to take our waste systems for granted...Until something goes wrong!
Al
Like CSnow, ice came to my mind also, although a combination of depth and heat from the biological activity in the system makes that seem unlikely.
Can you snake back from the secondary tank to pin-point the problem to limit your digging? How deep is it? In our area, the town engineer measures the location of the components of a system. This can come in handy when you need to dig (or avoid!) something underground.
Al Mollitor, Sharon MA