# Concrete septic tank lifespan



## Golden view (Feb 16, 2012)

Can I get some education on concrete septic tanks, particularly in the PNW? Do they last longer than steel? When the leach field goes, can the tank often be reused? Looking at a 45 year old house. Surely things are near the end of the lifespan.


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## Seven-Delta-FortyOne (Mar 5, 2011)

Dang, helpful forum, huh? :blink:

What I know from my limited experience, is there is no reason why a concrete tank can't last 100 years or more. As long as it doesn't crack, and the baffles are not damaged.

Far more often, the leach field becomes saturated, and no longer functions as efficiently, or at all.

An inspection by a septic specialist is invaluable. :thumbsup:



Delta


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## Golden view (Feb 16, 2012)

Seven-Delta-FortyOne said:


> Dang, helpful forum, huh? :blink:
> 
> What I know from my limited experience, is there is no reason why a concrete tank can't last 100 years or more. As long as it doesn't crack, and the baffles are not damaged.
> 
> ...


My experience with leach fields as well. I only saw steel tanks in Alaska, but think it was for strength since they buried them 6-8 feet.


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## Randy Bush (Mar 7, 2011)

On my dads farm we poured one with a skip mixer back in the 70s and it is still work fine today. A bought one should last a long time seeing how the concrete is poured pretty strong in order to be water tight.


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## Fouthgeneration (Jan 7, 2014)

The tank should last centuries if not subject to frost or super wacky ph levels....concrete lined aqueducts are still carrying water in Italy.... 
Have the seller pump the sludge out and get a video of the grease trap, vault and flow divider box...

A surveyor could check the inverts of the sewer lines and grease box intake, if there is a chance of a faulty install.

If the leach field is infiltrated with fines, just dig new branches 3' to one side of the old branches, use synthetic geo cloth that won't rot over the washed septic rock or the new style tunnel arches. add air turn out/ups to increase capacity at far ends of the leach field runs also a field tile installed ran to day light,drainage ditch, water shed, or storm sewer, about 50 feet away "up hill" surface grade but actually below the depth of the leach field will keep the leach field above the local water table in the wet seasons/years, long term, septic action, anaerobic in the vault, aerobic bacteria action in the lateral leach field lines/rock beds


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## 91782 (Sep 6, 2012)

Golden view said:


> Can I get some education on concrete septic tanks, *particularly in the PNW?*





Seven-Delta-FortyOne said:


> Dang, helpful forum, huh? :blink:


Tank is the cheap part. 

The system on this old place started failing. Rules changed over the years. Had to be an elevated field, had to reuse the dirt (no hauling off), had to be a new tank (from 600 gal to 1200 gal), etc.

Bottom line, 18.5K


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## Big Johnson (Jun 2, 2017)

I heard draining water softener brine into the tanks will destroy them really fast. My guy replaces them all the time in ~10 year old houses from point-of-sale inspections.

Thousands gallon tanks are about $600 each delivered.


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## Fouthgeneration (Jan 7, 2014)

Is there a water softener on the place, here abouts, till very recently all brine rinse water would be sent down the floor/storm sewer/ field tile drain, so the salt didn't "sterilize" the septic chemistry every week or two.

You might look into using Potassium salt for the softener, More $ but healthier to drink and cook with.

Some studies have plumbed the brine discharge to distribution box(~100-200$) so the microbes aren't stunted and solids washed into the laterals.

The other thing to kill septic systems functioning is massive over use of bleaches in laundry and house cleaning.

I'd install a plastic tank if the old concrete failed from chemical/ph issues.

But fill IMMEDIATELY with water after installing and when cleaning.... they will "float"


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## Golden view (Feb 16, 2012)

It never occurred to me until now, but I've never seen a water softener in this state.


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## Fouthgeneration (Jan 7, 2014)

Check out a national rain Ph map...

Then look a the ground water Phs......

At an extra cost most of the local septic tanks have an added 200-500 gallon mixing chamber ahead of the septic tank, thus reducing the Ph change and die off of "good" bacteria.


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