Plugging Sanitary Sewer Laterals (Trenchless?)
Plugging Sanitary Sewer Laterals (Trenchless?)
(OP)
Hello,
We need to plug several sanitary sewer house laterals on only one side of the sewer which runs down the middle of the road. My first thought was to TV inspect the sewer and note the distances of the house laterals. A contractor could then dig at specific locations and plug the laterals.
Has anyone had success useing techless technology to plug house laterals?
Thanks,
Mike
We need to plug several sanitary sewer house laterals on only one side of the sewer which runs down the middle of the road. My first thought was to TV inspect the sewer and note the distances of the house laterals. A contractor could then dig at specific locations and plug the laterals.
Has anyone had success useing techless technology to plug house laterals?
Thanks,
Mike





RE: Plugging Sanitary Sewer Laterals (Trenchless?)
In dealing with sanitary sewers there are many different ways to go about it. Unless you are in need of detailed line information such as the inside integrity I wouldn't recommend TV....it can be pricey. Smoke testing works for identifying lines, it is cheap and easy.
http://www.usabluebook.com/opnotes/OpNotes5.html
Now I am not clear on if you are plugging lines or abandoning lines. Because (following permiting guidelines) I have been able to plug lines in the manhole with a hydraulic cement. This negates any excavation and saves money. The only thing to keep in mind is confined space issues. I completed a rather large Sanitary Sewer Evaluation that started out with only a couple of as builts that were from the 50's so we didn't have much to go by. In order to get all the required information and complete the tasks at hand we used inflatable temp plugs, temp plugs, permanent cement plugs, TV inspection, smoke testing, and to top it off I even performed the classic "pour water at one end to see which pipe it comes out" trick.
If you can provide more details I can assist you a little more.
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
The laterals are being plugged because the residences on one side of the road are being demolished due to the widening of a roadway. The contractor that is demolishing the house now is supposed to be plugging the laterals at the edge of pavement.
We have enough budget in the project to seal the laterals at the trunk sewer but I'm not sure if we need to go that far. We are not currently at the site to inspect the contractor’s work and if he does not plug the laterals correctly then that sewer will receive severe infiltration.
One thought we had was to wait until the contractor is done demolishing the houses and then do a smoke test. Even though the laterals are buried, we should be able to see smoke rising out of the ground if he did not plug the laterals correctly.
I agree that we should CCTV the sewer first to inspect the condition if we opt for trechless rehabilitation. However, if the line did not have a prior problem and a smoke test would determine if there were any leaks, should we plug the laterals at the trunk sewer?
Thoughts/comments are appreciated. Thanks again,
Mike
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
Regarding the laterals, I would be concerned about leaving a pipeline that will never be used in the future under a new roadway; it leaves the potential for settlement if the lateral is ever compromised. I would be particularly concerned if the pipe material is VCP (which has many joints) or ACP (which is prone to shear breaks).
I know others may disagree with my opinion, but I would rather be safe and pay for the mainline to be evaluated by CCTV and the laterals to be terminated at the main connection rather than face the potential of a repair or sink hole in a brand new road.
As far as your original question of trenchless methods to complete the lateral abandonment job, I do not have personal experience of the technology being utilized in this manner, but I would suggest contacting a sewer grouting contractor. You would want to ask specifically if the contractor owned a "lateral packer". A lateral packer is a bladder inserted into the lateral service remotely from the mainline. Perhaps the packer could be utilized to isolate the service at the main and grout or cement could be pumped into the lateral from the open pipe at the property line? You would want to make sure that the pumping fills the entire lateral and does not leave an air pocket. This may require pushing the pump hose down the open lateral and pulling it back slowly as fill material is pumped into the pipe. As I mentioned before, this is only a thought. Start a dialogue with the grout contractor and he may have a better idea.
Good luck with your decision.
p.s. If you use the packer idea, the contractor will need to CCTV the mainline anyway and could be there to do any mainline grouting or repairs at the same time. You could get all the work done at once!
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
By the way, don't rely on smoke testing to locate these services. We have found smoke tests only locate some of the leaks. If the service is sheared deep underground you will never see the smoke.
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
RE: Plugging Sanitary Sewer Laterals (Trenchless?)
Thanks
RE: Plugging Sanitary Sewer Laterals (Trenchless?)