Experience with Alternative septic drainfields?

[jharkin]

So today while I am digging up the output pipe of my septic tank (a long story) I am pondering this conversation I had with our Septic guy yesterday.

So my spectic system is what they call an "alternative system" Rather than perforated pipe and gravel, the leach field is composed of these "Quick4" chambers which are basically a plastic half dome, open on the bottom that are simply placed in a sand lined trench and back filled.

Looks something like this( not my house):



My septic guy (not the outfit that installed our system - that was done by the PO with another excavating company) says that these alternative systems where really popular in the 90's/2000's and in the last few years they have been doing a lot of replacements of systems failing at less than 10 years old. He says that without the traditional gravel bed the domes are filling up with sand and failing early. they are now abandoning this technology and recommending only the traditional gravel bed install.

My system (2008 install) is still functioning and my guy recommended that I get it pumped every year religiously and try to conserve water to keep my daily use under half of the system design flow to reduce stress on the field and avoid a costly failure.

I was a bit skeptical at first as the pumping schedule says we can get away with 3-4 years with our 1500 gallon tank and family of 4 - so he stands to sell me a lot more pumping visits... However he insisted that I call the town building department who would verify a high number of replacement permits for these systems.

I know a couple other people in town dealing with these failures as well.


Question is do any of you have one of these alternative systems and whats your experience? I did a lot of googling and after you wade through all the Infiltrator systems company marketing I do find some homeowner horror stories. Of course its hard to tell if its a legit design problem or these families where dumping grease down the drain and bleaching all their laundry.

Thoughts?

 

[firefighterjake]

I wouldn't call my septic system an alternative type system, but it definitely is an odd design. Instead of going out and then branching out into three or four lines from the septic tank it has one long straight run. So far it seems to be working pretty well for the wife and me.

 

[johneh]

In 1984 we had a filter media system installed was told at the time
that they were the best system ever . 2 years later system failed Luck would have it
still under warranty . Replaces with dome system but used gravel instead of sand
as installer said sand would cause it to fail with in 5 years . Have never had a
problem with my system . 2people in my area have had system failures
and had used sand and not gravel . My system was also covered with a fabric to keep
soil infiltration to a min. Been using this system 20 years now and having it pumped
every 3rd year.

 

[DickRussell]

Going on six years ago we had a new system put in for the new house. It's the "Enviroseptic" design (http://presbyeco.com/products/enviro-septic/). It uses 12" ribbed and perforated plastic tubes covered with fabric, buried in sand and then topsoil. Our leach field (aka drain field in other places) is on a slope, with the tubes perpendicular to the fall line and connected in series. There is a low point vent and a high vent up by the distribution box. There are six 40-ft lengths of pipe, sized for five bedrooms. It's quite prevalent up here, at least in my general area of NH. The picture shows the ends of the top five rows and the U-tube connections, plus the d-box, ready for inspection and final covering.

 

[begreen]

The tank gets pumped out to remove the eventual build up of solids. How long between pumpouts will depend on the number of people using the system and their lifestyles. At one end could be a family of 6 that showers every day and always flushes the toilet. At the other end of the spectrum could be a family of 3 that showers every other day and lets the yellow mellow. We've been told that for our lifestyle and family size (was 4, now 3) that pumping out every 4-5 years is fine. This of course is based on a healthy septic system. If a lot of antibiotics or chemotherapy drugs are getting into the system then pumpouts need to be much more frequent.

 

[sportbikerider78]

From what I have researched, septic systems get damaged when they are not pumped out regularly and the solids overfill the tank and plug the septic leach field. Is that fairly correct?

The little kid in me thinks its hilarious us grown men talk about the best way to get poop under our lawns.

 

[johneh]

From what I have researched, septic systems get damaged when they are not pumped out regularly and the solids overfill the tank and plug the septic leach field. Is that fairly correct?

The little kid in me thinks its hilarious us grown men talk about the best way to get poop under our lawns.

You are right about the solids in the leach field but all systems installed in the last
number of years have a filter which is removable and cleaned with a hose . The guy
who pumps my tank also cleans the filter their is very much stuck to it

 

[jharkin]

Yes, solids in the field will kill it for sure.. But that's not the only things that kills them and that's not what I am talking about here.

The issue my septic guy is telling me is that these alternative leach fields installed without gravel beds are getting filled up with dirt prematurely. He is telling all his customers to pump more often and reduce water usage to lighten the load on the system and help avoid this premature failure. What Im asking is if anybody else has one of these no gravel systems and has had problems.


The engineering plans for my system show that there are 3 inspection pipes in t field. If I can find one and open it up I can take a look and see if there really is risk of sand and dirt clogging up the domes.

 

[johneh]

The ones that I know of that failed were not properly installed
All by the same company .
I think your honey wagon driver is shooting you a load of horse balls
So he can make more money

 

[peakbagger]

The Presby design is real popular in NH. Even if abused they seem to survive and since a lot of the soils are too shallow mound systems are needed. A Presby is usually requires about 1/3 the square footage of leach field which saves hauling in lot of gravel.

There is a new system I see adds for that adds an aerobic stage downstream of the tank. There is chamber full of plastic packing and a compressed air header in the bottom. Air is bubbling up through the packing. Its an old design but can be very effective but requires a compressor running all the time.

Chamber systems were popular 20 years ago. I have heard many comments that they tended to fail due to the installer using poor materials. basically they were using sand fill instead of screened gravel. Presby requires certified installers and the installers have to use gravel from certified suppliers.

 

[jharkin]

I think your honey wagon driver is shooting you a load of horse balls
So he can make more money

That's what I was worried about but I have used these guys for years and they dont ever push extra services on me. In fact I had this conversation with him while he was at my house to help me diagnose a potential leak. He figured out what it was (break in the output line from the pump tank) and gave me advice on how to fix it myself without charging me a dime.

Chamber systems were popular 20 years ago. I have heard many comments that they tended to fail due to the installer using poor materials. basically they were using sand fill instead of screened gravel. Presby requires certified installers and the installers have to use gravel from certified suppliers.

Which is what this guy is telling me. They are chamber systems and he says he is seeing them fill up with sand.

The thing is I dont know what type of fill was used. I think I need to go hunting for the inspection pipes to get a look inside....

 

[semipro]

You are right about the solids in the leach field but all systems installed in the last
number of years have a filter which is removable and cleaned with a hose

If you don't already have a filter one can be installed. You'd be amazed the amount of synthetic fibers sent to your leach field by the clothes washer. This stuff doesn't degrade and clogs up the works.

 

[jharkin]

There is a filter. Its a mound system. 1500 gallon two chamber tank with a filter on the output of the second chamber. That feeds into a 1000 gallon pump tank. Barnes sewage pump from there pumps uphill to the leaching fields which compose of 5 rows 25ft long of these quick4 domes. As far as I understand no gravel, either covered with sand or just backfilled.

the system design flow is 330 gal/day and we use on average 160-180 gal/day actual per the water bills (probably only 150 goes into the tank as that figure includes garden watering, etc)


I think they used those dome systems a lot because we have challenging conditions with a high water table , old houses on cramped lots.

I usually get it pumped every t3 years , which is safe for 4 people and a 1500 gallon by the chart - but he is trying to tell me he sees systems failing early even used well under capacity. Thats what I'm trying to figure out.

 

[Lake Girl]

Which is what this guy is telling me. They are chamber systems and he says he is seeing them fill up with sand.
The thing is I dont know what type of fill was used. I think I need to go hunting for the inspection pipes to get a look inside....

The local health units here usually have all the design info on file if a permit was taken out. Very possible the same info would be available to you with your comparable office/agency.

 

[jharkin]

I have a copy of the design plan. As best I can tell its a well designed system, everything was to code at the time (08), full permits and it passed the Mass septic inspection (Title V).


The plan (below) shows the quick 4 domes and states "Infiltrator quick4 domes to be installed per MFG standards by an Infiltrator sys certified installer" Doesn't say anything if they used gravel sand or just dirt to back fill. It also shows 3 inspection pipes installed but doesn't have the exact locations.

 

[Lake Girl]

Long shot but any chance that there were any metal portions in the install? Metal screws for joining irrigation chambers? Metal detector would help with locating ....

Just checked an install guide and they use drywall screws for connecting sections... not sure if that is enough to pick up a general track on the lay-out.

 

[Highbeam]

My favorite topic. Yes, I'm an engineer and this poop is my bread and butter.

The frequency of pumping has everything to do with solids accumulation and nothing to do with how much water enters the tank. So taking shorter showers, letting yellow mellow, or using high efficiency clothes washers, toilets, shower heads, or dishwashers has NOTHING to do with pump frequency. The only reason you pump the tank is to remove the solids from the tank before they rise (sludge) or fall (scum) to the tank outlet level and contaminate your drainfield. Sludge is the solid stuff that sinks to the bottom and accumulates into a firm mud. Scum is the white/brown floatable solids like grease and fat that float to the top and create that nice floating layer on top. The clear zone in the middle is the good stuff that will eventually leave the tank to the drainfield after all of the solids either float up or sink down.

The only good thing a premature pump out does for a tank that wasn't needing it is that it gives your drainfield a rest. The rest period is good for a marginal system because if the drainfield is overworked it is saturated with water too often and only anaerobic bacteria can live like that. A drainfield is supposed to be full of aerobic bacteria which need oxygen to quickly eat any remaining nutrients that leave your septic tank. It should take a week or so to refill an empty tank before the first effluent leaves the tank to the rested drainfield.

The above rest is why drainfields are designed with a daily flow rate. The drainfield must remain unsaturated, the ground must accept the effluent faster than your house is dumping it so that the bugs stay aerobic and oxygen levels high. Less flow is always better since it gives you the best chance of staying unsaturated.

So in summary. Only pump your tank when it needs it. 1500 gallons, family of 4, an easy 5 years. Your pumper can tell you how "full" the tank was and whether you could have gone twice as long or maybe three times as long. Better to be conservative and pump early until you establish this history. Still, don't cut it close. Lots of money at risk. The business also has a tool called a "sludge judge" that is a pipe that you insert into the tank to the bottom, put your thumb over the end and lift it out. The layers of sludge, clear, and scum stay separate and you can judge the need for pumping.

Chamber systems are fine if installed properly. The sand backfill is weird. Should be just native soil. The chambers are set onto the ground and since water is supposed to soak into the dry ground below, there is no use for gravel above the chambers. The reason you can reduce the required drainfield area with the chamber systems is that the trench bottom, the soaking area, is not partially blocked by gravel as it would be with a traditional gravel trench system. You've got to grade the trench bottom perfectly level as the chamber systems work by dumping the effluent into the chamber area and using the entire trench bottom for soaking.

Gravel backfill won't hurt though and will prevent an installation error from ruining the system. I suspect the method of failure is that the chambers aren't firmly bedded or sealed into the native soil so the sand easily washes into the chamber area as rainfall/surface water from above falls through the ground and wants to enter the chamber, taking sand with it. Not unlike how a leaky sewer main causes a sinkhole on the surface. Sand is the problem. Either gravel or real soil should be used.

Divert surface water away from the drainfield area.

 

[Laurent Cyr]

Going on six years ago we had a new system put in for the new house. It's the "Enviroseptic" design (http://presbyeco.com/products/enviro-septic/). It uses 12" ribbed and perforated plastic tubes covered with fabric, buried in sand and then topsoil. Our leach field (aka drain field in other places) is on a slope, with the tubes perpendicular to the fall line and connected in series. There is a low point vent and a high vent up by the distribution box. There are six 40-ft lengths of pipe, sized for five bedrooms. It's quite prevalent up here, at least in my general area of NH. The picture shows the ends of the top five rows and the U-tube connections, plus the d-box, ready for inspection and final covering.
View attachment 178201

I have the same system. In fact, the ground is all clay around here, and the municipality recommended Enviroseptic as the only solution for us acceptable for the environment. No smells, and it accomodates a five bedroom house. Mind you, they also suggested a special type of sand, and this system cost me an arm and a leg at 20K.

After 5 years and mandatory yearly inspection of the field, I have had no problems. Given that the field is on a little slope, I also need a pump to push the grey water to the field. There`s an alarm on the pump in case it fails. I would much prefer a gravity system, but it was not possible in my case.

 

[Highbeam]

Some parts of the country allow surface application, sprinklers, for effluent after the various treatment systems are finished. I always thought that this would catch on since you irrigate with the treated wastewater. We do it at the municipality level in WA instead of river dumping sometimes but not often enough IMO. The sprinklers would of course run at 2 in the morning. Septic tank, to whitewater (aerobic treatment system), with UV for final polish, and then pump out at night. My home uses 100 gallons per day so the sprinklers might run for 5 minutes.

 

[jeffesonm]

Nothing to add other than this thread is a good reminder to go clean my filters.

 

[Highbeam]

Nothing to add other than this thread is a good reminder to go clean my filters.

Funny, I was also reminded to clean my filter. Pulled it out and hosed off that schmuck onto the lawn. Those things catch a lot of synthetic fibers from our clothes that not only don't decompose but they also don't sink down or float up right so they stay in the clear zone.

 

[D9H]

Pipe in rock is still the best system. Less chance for failure. The quick 4 infiltrators can settle, anymore they want them to be placed on a geotextile grid. Infiltrators were pretty big for awhile because the labor to install isn't as much to properly install as a pipe in rock system. I have installed both kinds, overall I prefer pipe in rock, the actual price difference is nearly a wash depending on price of local materials, but properly laid pipe on a level grade is pretty well foolproof.

 

[sportbikerider78]

I have a traditional system, 25 yr old house and I have only been there 3 years. The soil is clay with not much topsoil. 2 kids...2 adults.

Lately, I have noticed some water oozing out of the ground where (I imagine) the septic tank is. Smells like a turd, so I thought that was a safe assumption. I'm going to have it pumped soon, to be safe, as I have no history on the system. I have also had zero problems with it, other than the turd'ish lawn emission.

Anything else I should look at?

 

[begreen]

That's not a good sign. Get a complete report on the tank health and the solids depth to start with.
(broken link removed)

 

[sportbikerider78]

Good read. This is just one area of the lawn (1sqft), and it is a pretty good decline from the house and far from the house. I'm thinking they just didn't use enough topsoil. The clay in this area is really dense and absorbs nothing. I think that it is running down the clay bed and seeping out at the end of the leech field.