Great educational material as usual, Peter. Thanks…
…but, you actually touch that stuff bare handed? :shock:
Thanks Larry. Ya, HA HA, is was debris left in the ground. That sewer line was replaced a long time ago and the new one has since failed also.
Here’s another good example of why it’s important to locate and inspect the D-Box. This is a fairly new system that was operating OK. I opened the outlet end of the tank and noticed there had been a backup, soap scum on the bottom of the cover. I used my probe and followed the main lateral until I found the D-Box. When I opened the D-Box I found the front of it packed with sand and two out of the four laterals were clogged. Further investigation of the EDA revealed rows one and two are getting overloaded with effluent, which can cause failure.
Note the distinct layering in my inspection hole over row one and two. At the top there is clean loam, next dry sand, then when you get about 6 inches over the laterals the sand gets wet. I did a load test on the system after the D-Box was cleaned out and it worked fine but had it remained this way the first two rows would most likely clog due to over use. Also notice the same pink, soap scum staining around the D-Box cover.
New Hampshire septic evaluations continue despite cold weather and heavy snow.
I guess it don’t freeze above the tank huh! 
Or, in this case, the leech bed…Still not easy in this weather.
Well I swear you are a gopher with a dirt ripper on his tail for this time of year. :mrgreen:
Great job in finding those things Peter, this time of year.
What did you find on this one?
This system was actually in good condition which is surprising because it was a serial sloping system with 14 rows of laterals. Effluent has to flow through each row versus having a DBox. This type of system it’s not unusual to see failure at the beginning and the end be dry. Nice house on the lake. 5000 square feet, 6 bedrooms, 9 bathrooms.
Peter, have you thought about writing a HI’s guide to septic system inspections? I would buy it with no hesitation as I am sure many others would. You have a wealth of knowledge on this subject matter.
Hi Jeff, Ben approached me about it a few months ago and I have tons of images but I am always so busy I can’t seem to find the time to put it together. We talked about a home inspectors field guide to inspecting septic systems.
Thanks for the kind words, I appreciate it.
Still inspecting septic systems in New Hampshire. This is an Elgen sand filter which is built on a bed of sand. There was 21 filters laid out in three rows. Once I got past the frost I was able to dig a trench across the middle of the rows and dig down between the filters.
This lake front home was built in 2008 but I conducted a record search and found the system was installed in 1998. Average life expectancy for this system is 20 + - years. This system was actually in good condition as the property was used as a summer home only.
The day I did this inspection the wind chill factor was -10 with wind coming off the lake at 10 MPH sustained with 20-30 MPH gusts. Also inspected the main home, 2 car garage, guest house, boat house and two sheds. Over three hours inspecting the exterior of the property and septic system. Dressed in layers with my insulated bibs and at one point was actually sweating.
You got to tell me how in hell you did all that in 3 hours.
It would have taken me 3 hours just to find out where to dig for Krist sake. :)
I had the plan for the septic… plus a helper.
Well, that explains a little.
Still at it even though there is 30 + inches of snow on the ground. Here is a 26 year old stone and pipe system set up in a butterfly configuration, almost like two EDA’s, one to the left of the D-Box and one to the right. Each had six rows of laterals. When I arrived onsite I immediately noticed a large area where the snow had melted or not accumulated, at first I thought this was where the tank was. By using the plan I obtained from the town and taking a few measurements I realized this area was the beginning to middle of the EDA.
I dug one inspection hole in this area and it was completely saturated and the hole filled with effluent. The second and third hole’s were dug to the left and right and looked good. No staining in the material and no standing effluent.
I conducted a load test on the system which accepted water fine with no back ups. So whats going on? Why is the beginning of the EDA wet and the middle and end dry?
Since this system is 26 years old my opinion is the EDA is in it’s later stages of life and replacement should be expected (my recommendation to my client), but, there is always a chance there could be a problem with the D-Box, possible corrosion, broken pipe, ETC. I was unable to locate the D-Box due to the amount of snow and ground conditions but in the end there is significant saturation of the EDA and that will have to be removed, at that point you might as well replace it.
Notice the amount of black septage on the stones that were removed from the inspection hole. This has been an ongoing problem for a long time and I suspect this area stays saturated all year long.
Here’s an Elgen sand filter system in failure. These filters measure 3’ X 4’ X 7 inches thick and are laid out on a bed of sand. Inspection of the d-box revealed regular back ups as the sand was wet with black staining. Two inspection holes were dug in the EDA and both filled with effluent. This is a pump up system and after activating the pump the D-Box and inspection holes flooded out.
While this system is 18 years old I suspect it’s been in trouble for awhile. Elgen systems do not have a good history and many only last 10-12 years.
Recently did a septic inspection on a vacant house (length unknown) and as shown in the attached overall photo, I noticed a depression in the yard where I dug up where a tank that was not directly out from the sewer line that left the house at the very left of the photo.
The first thing I noticed was the top of the tank sloped 1 1/2" per foot, back towards the house. Water was freely flowing from the house and from the inlet photo, it was apparent to me that the tank had backed up in the past, based on the sludge above the inlet line. Water level in tank was well below discharge outlet but when I noticed the perforations in the sides of the tank, I realized this was a dry well system and also noted there was a second tank that the first one discharged into when it reached that level.
Since it was obvious to me that this dry well tank, with a heavy layer of sludge in the bottom, had been completely filled to the top with floating sludge in the past and, even though the water level had drained out into the soil while the house has sat vacant, I my opinion, with the back slope on the tank alone, I informed my client that the system had a major problem, it may work for a while after they moved in but would soon be backing up and be in total failure, recommending a septic installer investigate further.
They sent out a septic guy who apparently dug up a septic tank ahead of the dry well I dug up and told them the system was ok. The buyers then met him out there a couple of days later, showed him my report, he dug up the dry well tank and still said the system should be fine.
My client sent me an email telling me about this, said they were going ahead with the purchase, retracting their amendment to their offer to FannieMae that the system be repaired and insisted I refund my fee for the inspection.
My response to them was I could not possibly understand how this system could possibly work for any length of time but, for their sake, the septic guy was right & I was wrong, refunded my fee and washed my hands of the whole deal.
I would certainly like to hear some comments on this from some of the experts that have previously posted on this thread.
Thanks.
Hi Gary, evidence of back ups can be from a prior clog which will leave behind a scum layer. The best way to evaluate a drywell is to dig down along the down sloping side of it as far as you can go. You need to look for staining in the stones that surround the drywell as well as standing effluent (may not be present due to vacancy). Once this is completed I would do a heavy load test on it to see how well it drains or if effluent backs up in the inspection hole. Sometimes more than one hole should be dug to be sure.
Also, I would stay away from predicting failure and in this case recommending a septic contractor to further evaluate would have been the prudent thing to do.
Hope this helps. Not sure if I understood your post completely, was there one treatment tank and two dry wells? If so, a second or serial drywell may have been added to make up the volume of the first one, if saturated.
Drywells can be very effective EDA’s but the problem is they’re more of a vertical dispersal system rather than a horizontal system. Sometimes, the bottom of the drywell could very well be in the water table, in NH this would be considered a failed system by state standards, even if working.
Thanks for the reply Peter:
Based on the reply I received from my client, the septic installer they called said there was a treatment tank ahead of the drywell that I dug up and took the photos of. (I titled the photos but I see they apparently didn’t show up so this may have been confusing.)
From what I observed, in the bottom of the first dry well tank, that I opened up, was about 18" of sludge in the bottom of this tank. So, this must have been an indication that the treatment tank must have been overloaded in the past to have even allowed sludge to flow into this tank. My main concern at that point was with the visual evidence, in my opinion, that that tank had backed up above the overflow tee to what was assumed to be flowing into the second dry well tank caused, most likely by a saturated drainage layer around the tank. When adding the fact that the outflow elevation of the dry well tank was well above the inlet (discharge line from the treatment tank) this, could put the operating level of the system, due to the back slope of this tank above the inlet into the treatment tank from the house sewer line. This of course would cause the line to back up into the house.
In hind sight, I should have probed to locate the treatment tank, opened it up, done a load test to determine if the system could handle the flow but, I felt at the time, and still do feel that a roughly 12" back slope on the primary dry well tank should be enough to fail this system and felt I stated that in my report.