septic field frozen

[PILOON]

I agree with EGON, that feed line MUST to be dry between pumping operations, in other words it must NOT be level but needs a decent slope to drain out from either end. (preferably to the field.)
And from any field that I have ever been involved with the field MUST be perfectly level (no slope) as otherwise all effluent will rush to the low end and promptly saturate that field end.
Yours is 4:1 slope??? something wrong there.
A field is meant to EVENLY be fed so that absorption is slow even and gradual.

Big unanswered question still remains:
How long is that line from pump to the field? and is that rigid or flexible? What size? That line wants to drain perfectly dry after each pump cycle.
All appearances are that the feed line is darn close to the surface and therefor extremely suspect to freezing, especially since your field is 'above ground'.

 

[PILOON]

I agree with EGON, that feed line MUST to be dry between pumping operations, in other words it must NOT be level but needs a decent slope to drain out from either end. (preferably to the field.)
And from any field that I have ever been involved with the field MUST be perfectly level (no slope) as otherwise all effluent will rush to the low end and promptly saturate that field end.
Yours is 4:1 slope??? something wrong there.
A field is meant to EVENLY be fed so that absorption is slow even and gradual.

Big unanswered question still remains:
How long is that line from pump to the field? and is that rigid or flexible? What size? That line wants to drain perfectly dry after each pump cycle.
All appearances are that the feed line is darn close to the surface and therefor extremely suspect to freezing, especially since your field is 'above ground'.

From your pics I get the impression that your 'above ground field' is a fair distance from the house/tank.
And to feed the field the feed line is for sure barely below the surface.

 

[Billrog]

With a sand mound if you have freezing problems it can only be in the indexer ( not well insulated) that switches the affluent from one run to the next or the pipe going to the field is not on and up hill slope so it can drain back into the pump chamber. I order for it to drain back into the chamber the installer drills a 3/16" hole it the riser from the tank so that when the pump quits the line can drain back.

 

[cat fever]

Sure sounds like a freezing issue to me. You will need to find out where exactly to remedy the problem.

On a different note about good septic tank health; First, I am a Master Plumber and have been for over 25 years.


Lots of poop with little water is good. Poop from different people is a good thing. (different bacteria) so when friends come over, offer a drink and sweet roll and don't let em leave until they poop. A little plain yeast down the drain every month or so is a good thing. Do not use anti-bacterial anything to clean with. (that will end up down the drain) Last, and I'm serious, the best bacteria starter you can get is a dead cat in the solid's side of your septic tank. You simply cannot get better bacteria than a decomposing cat. Lastly, when/if you have the tank pumped out, fill it back up with water as soon as the pumper is gone if it's a single compartment tank. This prevents solid's from leaving the tank and plugging the distribution box.

There is another problem called "biomat". Usually this only forms on old poorly maintained systems. I doubt this is the case here.

The picture (avatar) was taken a week ago; the lid on my distribution box rotted away and caved in letting dirt in and backed up my whole system.

 

[v8only]

I agree with EGON, that feed line MUST to be dry between pumping operations, in other words it must NOT be level but needs a decent slope to drain out from either end. (preferably to the field.)
And from any field that I have ever been involved with the field MUST be perfectly level (no slope) as otherwise all effluent will rush to the low end and promptly saturate that field end.
Yours is 4:1 slope??? something wrong there.
A field is meant to EVENLY be fed so that absorption is slow even and gradual.

Big unanswered question still remains:
How long is that line from pump to the field? and is that rigid or flexible? What size? That line wants to drain perfectly dry after each pump cycle.
All appearances are that the feed line is darn close to the surface and therefor extremely suspect to freezing, especially since your field is 'above ground'.

From your pics I get the impression that your 'above ground field' is a fair distance from the house/tank.
And to feed the field the feed line is for sure barely below the surface.

Yes the main feed line is dry between pumping operations as i have seen the pump drain back after it shuts off and i have verified there is no one way valve in the line. The slope of the mound is 4:1 it is the standard construction requirement based on the size of your mound.

I will try to find information on the main feedline depth and type of line.

 

[Billrog]

I think by 4:1 you may be referring to the slope of the perimeter of the mound the lines look level as they should be in your pic.

 

[v8only]

yes sorry for any confusion.

 

[v8only]

OK I got some additional information:

-4" ABS PVC from the house into the 2 stage septic tank (solid side/liquid side)
-submersible pump inside the liquid side that runs into the 1-1/4" poly pipe schedule 75 6' below ground
-the poly pipe (runs from the septic tank to the field) transitions into a brass fitting turns UP into the manifold and then distributes into 1-1/4 perforated PVC.

 

[PILOON]

From what you say my take is the problem lies in that 1 1/4" poly pipe especially with the upturn brass to the manifold.
There is no way for that line to empty itself dry for 2 reasons.
1st poly just can not be laid flat enough to drain
2nd the upturn brass end holds fluids back.

My take is you freeze the contents of the poly pipe run however 6 ft deep generally should be below frost* level.

While all being said effluent (contents of the poly) generally should not freeze unless the household uses way to much water.

*frost level can go deeper in a wind blown field as snow is actually a decent insulation.

One solution I can suggest is to excavate down to 6-12"(closer if you dare) above the poly line and cover with 2ft wide strips of high density foam insulation (centered on the poly pipe line) and re cover with fill.
The theory being that ground heat will be retained under the foam insulation which also will prevent deep frost penetration.
I have used this system for pumped pure lake water lines and that with even less ground cover. (like even 6-12")
One septic system I did (25 yrs now) has merely 12" of cover without any insulation however it self drains after each pump cycle. (make that 2 systems)

An alternate method ( but more difficult and costlier) would be a heated tracing wire adjacent to the poly line to keep it above freeze levels. Some modern tracer line is self regulating and economical to use but pricy at purchase.
For that matter you could for that usage simply buy roof gutter heated cable and lay it adjacent to the poly pipe and wrap it on the vertical riser section.

I would not believe any of the above solutions would need be mentioned to the authorities as in effect they do not technically modify the approved field plans.
I would think your installer could be coerced into assisting with the excavation in order to protect his reputation. Worth a try.

From the pics you posted an old fashioned snow fence or even a cedar hedge upwind of the field should create considerable snow drifts to generate a snow layer of insulation.

 

[v8only]

Not to contradict but i like a good conversation:

If the poly line was freezing why would the field freeze? In my opinion IF the poly line froze the field lines would be empty and there would be a blockage/ice in the poly line or middle of the system. The field would be able to discharge the effluent from the last cycle making the field lines open and not full of ice like I saw. (remember I have access ports into my field)

second:
when the field first froze and I turned the pump on manually and shut it off, effluent drained back into the tank from the poly line.

It is possible that the line does not fully drain back causing a blockage (ice) in the manifold or mid way in the line, but then again the effluent would then empty in the field and leave me open field lines with a blockage else where.

I do need some extra information:
earlier in my post I mentioned: "system was sized for 330 gallons per day with a .15 Efflucent soil loading rate"

I know for a fact that there is no way the two of us are using 330 gallons a day, we each have a quick 5-8 minute shower in the morning, leave for work come home at supper bathroom a few times. This is our daily routine with the addition of the dishwasher 3-4 days a week and laundry one a month. I know we put in more water than "bacteria/poop".

I feel our issue is not using enough water, not creating enough heat, and not enough coverage.

thoughts?