During our inspection workshops, we often talk about troubleshooting special problems. Some of the most common problems involve improper installation. Also, installers are often called to troubleshoot systems they did not install. Here, we describe a few common problems and how good installation techniques could have helped avoid them.
Odors are a common problem, and they often arise after new construction. Our usual line is that if they occur inside the house — they are the result of venting problems, in the realm of the plumber and not the onsite installer.
In this situation, you can have the homeowner check whether there are any pipes left open in the plumbing that would bypass water traps and therefore act as a sewer vent. Examples of this during new construction would be a hookup for dishwasher or washing machine or a basement tub for laundry left unfinished.
If you discover such a problem, you will be viewed as intelligent bordering on genius. The solution may be as simple as pouring water down to fill the trap. In older houses, ask the owners if they may have disconnected any pipes, such as a laundry tub or laundry standpipe. Also look at the seals around toilets: The wax seal may be broken, allowing odors to escape.
Odors outside
More in the realm of installers are outside odors. One common area for tanks to vent directly is the seal around manholes and inspection pipes. Make sure the manhole cover or any manhole extensions are tight fitting and do not allow air to pass through. This can easily happen on retrofit jobs where it is hard to get the covers or the multiple extensions to fit tightly together.
Here, a simple solution may be to use weather stripping where the parts fit together. Do not use any type of permanent sealant! Remember that service providers need to be able to gain access to the tank to perform routine maintenance.
If weather stripping does not work for outside odors, suggest that the homeowner have a plumber evaluate whether the vent stack is far enough above the roofline to prevent the wind from blowing the odors downward as they leave the stack. This can happen in hilly terrain, on roofs that are very steep, or in seasonal cabins nestled in among large trees. If the stack cannot be raised, the owner may have to install a carbon filter, which will need to be changed periodically.
Tank corrosion
A common problem identified by service providers is excessive corrosion in concrete tanks around the outlet baffle. The likely culprit, hydrogen sulfide, collecting at the outlet point of the tank — the gas is heavier than air.
This problem is almost always related to the lack of proper venting through the tank — an installation error. The supply pipe from the house to the septic tank can be angled into the tank because of improper bedding of the pipe or improper backfilling that leaves the pipe suspended over an open area of the tank excavation.
In any case, either immediately or over time, the pipe enters the tank at an angle and does not allow the air to escape out of the tank and vent through the roof stack. It is very important that the tank be installed level and that the pipes into and out of the tank be properly bedded and firmly supported.
This kind of installation error can cause other problems as well. In cold climates, it can allow sewage to freeze in the pipe, ultimately causing the pipe to plug and freeze shut. If the seal where the pipe enters or exits the tank is damaged it provides a ready pathway for roots to enter the pipe and the tank, and that will cause all kinds of backup and plugging issues. The solution is to replace and level the pipes, seal the joints, and properly backfill around the tank and pipes.
Another issue that can cause blockages occurs when the inlet pipe is pushed too close to the inside baffle wall. When this happens, there is not enough clearance to allow sewage solids, such as toilet paper, to pass freely into the tank. They begin to hang up between the pipe and the wall, eventually causing a blockage that can cause a backup into the house. Here again the fix is to dig up and reposition the pipe.
Root problems
If roots are present in the septic tank, pipes, drop boxes or distribution boxes, they indicate that the tank is not watertight and that the seals have been broken or compromised. Roots could also indicate a broken supply pipe resulting from poor installation or some type of traffic over the system.
In these cases, the leaky component and the point of entry need to be found. Today with inspection cameras in our tool kits, we can easily access the pipes and tank to evaluate how well the joints are sealed.
Once the problem is found, it needs to be fixed. Simply removing the roots and restoring flow is not a long-term solution. If a pipe is broken it needs to be replaced. If the tank cannot be properly sealed and made watertight, it needs to be replaced, as well.
If the roots are in the drainfield, the piping and boxes need to be opened and evaluated, again to determine where the roots are getting in. Any broken components will need to be replaced. In addition, the vegetation over the drainfield may need to be replaced with vegetation that has less invasive roots. Local plant nurseries and horticulturalists can help in the selection.
We have often seen major root problems in dry areas of the country such as the southwest. Here, plants are always searching for water and can establish very large root systems.
These are just a few examples of situations we have encountered as we troubleshoot or inspect systems. Remember that as the installer, you can prevent many of these problems by using sound installation practices. We will look at some other trouble situations in the future.
