Listening to onsite system expert Bill Stuth talk about “Repair and Recovery of Sand Filters” at an Oregon Onsite Waste-water Association annual conference a few years ago, I noted his advice.

“Don’t rush into a system repair until you know the cause of the problem,” advised Stuth, from the state of Washington, an onsite consultant, trainer and inventor of the Nibbler treatment unit.

That caused me to reflect on many septic repairs I have seen where the problem was other than the drainfield failing. Jumping to conclusions about the cause of a septic system problem frequently leads to wasted money, unnecessary yard damage, and less space available for other uses. It seems that when problems arise, the knee-jerk reaction with homeowners, installers and many regulators alike is: “Let’s put in a new drainfield.”

No effluent

An extreme case a colleague told me about illustrates this point. A system had apparently failed after only 10 years. The site was fairly well drained, and the standard system was permitted, inspected and approved on completion. The contractor hired to fix the problem got a repair permit for drainfield replacement without any real investigation.

After completing a major portion of the new drainfield, the contractor dug into a portion of the old drainfield and found the gravel virtually clean, as if it had never been used. Investigating further, he found that the “failed” drainfield had never received any effluent from the septic tank.

At this point, the contractor realized he had found the real problem. Digging upstream from the drainfield to the septic tank, he finally located it. Evidently, during system construction, or soon after, the effluent sewer line had sheared completely off at the tank outlet, probably during backfilling. For 10 years, the loose, well-drained backfill around the tank excavation had absorbed all the septic tank effluent without backing up.

This illustrates the value in first taking a little time to troubleshoot and evaluate the septic system to determine the cause of the problem and proper course of action. The problem may be less complicated than you thought.

Just a blockage?

Many septic systems have been replaced that were not failing but merely had blockages or other minor problems that could have been corrected easily with a minimum of time, expense and impact to the property.

Another example: A few years ago I received a telephone call from a man telling me his system was failing, and he needed a new drainfield. The matter was urgent, he said, because an outdoor wedding was being planned for his daughter, and a new system had to be installed ASAP. According to the owner, the system was 16 years old and had five 100-foot drainfield lines; the problem lay at the first line.

I obtained the installation drawing from the county and then visited the site. The drainfield was located on a gentle 3 percent slope, and the top line was indeed surfacing. The disposal field was installed not with drop boxes but with the serial distribution and the up-and-over fittings popular some years ago. These fittings were plumbed in a serpentine fashion, tying the five lines together.

I told the owner that a drainfield on a slope like that virtually couldn’t fail on the top line. If it did fail, it would normally fail at the weakest point of the lowest line due to hydraulic pressure. The problem, I said, was likely something else.

I suspected that the difficulty may be with the up-and-over fittings at the end of the top line connecting it to the next lower line. Probing the line to where I thought the fitting was, I dug down and found that it had become disconnected, probably again during the original backfilling, and no effluent had passed this point to the lower lines.

I recommended abandoning the serpentine up-and-over fittings and replacing them with a series of drop boxes installed at one end of the system to connect the lines. I told the owner that the cost would be considerably less than he feared, and that there would be minimal damage to his yard. He thanked me for taking time to diagnose and fix the real problem, and he was happy to pay the modest cost of that extra work.

Lay of the land

To diagnose a septic system problem effectively, it is necessary to know where all the components are and what they consist of. A critical piece of information is the as-built drawing, done at the time of the installation. This should be available from the local agency that regulates the onsite program. It provides a lot of useful information for an accurate assessment of the system and problem.

The first clue of problems is probably the age of the system. A properly sited and installed septic system, installed in reasonably well-drained soil, should last at least 30 years. If the system is much newer, like the one described above, the problem may not be failure of the drainfield but something else.

Another clue might be found in the landscaping and irrigation layouts. Landscaping and irrigation systems typically come after the septic system is installed. Home-owners have often called, telling me that landscapers had just pulled up white pipe and gravel with their trenching equipment.

This can have a serious impact on the system, cutting off and damaging a number of the drainfield lines and thus shortening the life of the system. Often, this damage, if known, can be repaired and the lines reconnected, making the system almost whole.

Identifying the true cause of a septic system problem may avoid the cost of installing an unnecessary system. It requires a significant effort and experience to do this properly. Homeowners need to be educated on the value of this professional service, and we should never be reluctant to charge for it.

A preliminary investigation, carefully done, can save money, needless yard damage, and wasted space for future repairs. Most customers will gladly pay for it.

Zan Ewing is a registered environmental health specialist with 35 years in the industry as a regulator, installation contractor and consultant. He is past president of the Oregon Onsite Wastewater Association and a designer/consultant in Salem, Ore. He can be reached at ewingzan@aol.com.