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Septic tank collapsed - need advise on new Septic Tank

Posted by roguebabe (My Page) on
Tue, Feb 27, 07 at 14:08

We had an inspection yesterday and found out that our septic tank has collapsed and must be replaced. We were told based on access to our property, we have 3 options, plastic, fiberglass or concrete. Which is best, lasts longer? Any pros and cons of each?
Any other recommendations you might have with regard to this major expense?
We are thinking that the best way to go is a whole new system, new tank and new field. Thoughts?


Follow-Up Postings:

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RE: Septic tank collapsed - need advise on new Septic Tank

I would go with a concrete tank. A concrete tank will last for decades.


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RE: Septic tank collapsed - need advise on new Septic Tank

Based on your previous post, this news comes as no surprise.

Go with the concrete tank.


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RE: Septic tank collapsed - need advise on new Septic Tank

Surprisingly enough, concrete septic tanks do deteriorate. All the bugs have not yet been engineered out of the "fiberglass" tanks. So the concrete remains as one of the better choices.


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RE: Septic tank collapsed - need advise on new Septic Tank

If the septic field hasn't also failed, I don't see the advantage of replacing it now. The tank alone is a much smaller job.

Features to consider for your new tank: 1) Two-compartment configuration, helps keep the solids within the tank, thereby protecting the septic field; 2) Filter in the outlet tee, for the same reason; 3) Risers on access manholes, bringing the access covers to the surface. You might also want to step up to a larger size tank than is legally required, to increase the interval between tank pumpings, and for generally better settling performance (again, to keep solids within the tank).


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RE: Septic tank collapsed - need advice on new Septic Tank

Are you kidding? Now is certainly the time to do the septic field if it's more than a couple of years old....if you can afford it, you'll save a hassle later.

I heartily agree with everything else suburbanmd says though, although I've never heard of a filter in the outlet tee (where the tank runs to the septic field?)

Absolutely go for the larger tank, when my dad and I put the septics in for our cottage, we put two tanks in series, plus two large fields - in all the time my parents lived there (eventually full-time) there was never any problems, and no need for a pump-out. Like the two-compartment thing, the second tank probably had very few solids.


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RE: Septic tank collapsed - need advise on new Septic Tank

I guess i have to disagree. Septic fields often last forty years so why would anyone rip up their backyard to replace a tile field that is "more than a couple of years old"? Depending on soil conditions, some new fields cost over twenty thousand dollars to construct and can change the entire contour of the area they occupy.

Secondly, many towns have sanitary sewer projects in the planning stage so if the existing field is working fine, why dump thousands of bucks into a field that you might be forced to abandon in a few years?

As for tank size, that should be dictated by the expected water usage of this home. If a 1000 gallon tank barely meets the reqirement, then it's wise to go to the next larger capacity. If a 500 gallon tank would suffice but the code calls for a 1000 gallon tank, then where is the wisdom in going to a 1500 or 2000 gallon tank?

To me, that's just pissing money down the toilet.


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RE: Septic tank collapsed - need advise on new Septic Tank

Also, what are the requirements in the owner's area for replacing leach fields? If he was in Vermont it would have to be an engineered system. By messing with the leach field there is a possibility that a mound system could be required (about $10,000). I know, Vermont is nuts on this stuff. My theory on the leach field is that if it was a "designed" system and it's working okay, leave it alone. If you have heard that new state or county requirements are coming in the next few years, then it might be prudent to consider replacing it now to avoid some expensive fix a few years down the road. And, as someone said, if you are in a region where there is the possibility of having to hook on to a municipal sytem in a few years, then you might want to consider the cheapest fix you can get for now.
The last one I had installed/designed called for an outgoing filter. The builder said he would never do another system without it. Pull it once a year or so and hose it off.
On the pumping...when I owned mobile home parks I had about 20,000 gallons worth of tanks to keep pumped. In this area it's extremely expensive to have them pumped. I found that it was senseless to pump all of the liquids out of the tanks. Liquid was always on the bottom and would go out to the leach field anyway. We would just pump the first 2 or 3 feet making sure that all the scum and solids and semi-solids were cleared out.
Think about it..if you pump the whole tank, within 3 or 4 days the tank is filled with liquids again.


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RE: Septic tank collapsed - need advise on new Septic Tank

Forgot to mention another tip for the OP: There may be a distribution box near the septic tank. It would be good if the contractor comes prepared to replace it while the hole is open. Unlike the septic field, this is truly a case of "might as well replace it while we're in there".

Castoff, I figured it was worth the couple of hundred dollars extra (installed) to get a 2000-gallon tank instead of 1500-gallon. Less frequent need for pumping will recoup at least some of that cost. Also, since some septic systems do seem to fail eventually, even when installed according to requirements, I figure it isn't really a science. Therefore "bigger is better", even going beyond the legally required size. Larger tank: $250. Protecting a septic field that would be expensive and disruptive to replace: priceless.


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RE: Septic tank collapsed - need advise on new Septic Tank

I was told that according to code if we do not replace the field, we have to have it blown out to clean out the pipes/baffles in the septic field. The price for a new field is only slightly more. In addition, when we had our washer running (we had to start using the laundromat) we had problems with the septic backing up, therefore we have septic field problems already. In addition, our yard is going to be damaged anyway by all the heavy equipment that has to be brought in to collapse the old tank, dig a new hole for a new tank and bring in a cement truck to pour the new tank. Just having all that heavy equipment driving over my old field makes me worry about how it would perform if I didn't replace it. In addition, we bought this house a little over a year ago and we have no paperwork that even tells us where all the lines are for the field. The contractor that came out will map out the new field and give us a copy so that we have it for reference when we decide to do any landscaping. They will keep that map on file for the future if we ever need it. We have no idea how old our current system is. It just seems to make sense to start over and this way insure we have a good working septic system for years, even decades to come.


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RE: Septic tank collapsed - need advise on new Septic Tank

I don't believe they will pour a new septic tank. They usually are precast and trucked to the site and lifted off the truck into the hole. I have never seen a septic tank constructed on site.


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RE: Septic tank collapsed - need advise on new Septic Tank

Yeah, my concrete tank was precast and trucked to my house. But it was plenty heavy, and the truck made quite a mess of the yard, especially where it had to make a tight turn. One claimed advantage of plastic and fiberglass tanks is their light weight. Of course you still have to bring a backhoe to the site to bury a lightweight tank...but a backhoe damages the turf less severely than a truck with high pressure road tires.


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RE: Septic tank collapsed - need advise on new Septic Tank

A concrete tank will survive longer if a heavy vehicle is accidently backed over the tank than a fiberglass or plastic tank probably would.


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RE: Septic tank collapsed - need advise on new Septic Tank

Have a back flow test done on your leach field before digging it up. You might even have a leach pit. I hate those things. Unless you have tree roots growing into your leach field or for some reason you let heavy equipment drive over your leach field it should be all right. The biomat could have been affected. The biomat is a bacterial slime layer in the soil below the leachfield and around other wastewater disposal systems, is a critical component of private septic systems - it is responsible for treatment and reduction of biological solids and pathogens in septic wastewater effluent which is discharged into the soil from a septic tank. The most common and most expensive failure of private systems occurs as soil clogging and failure of the absorption system to continue to accept water. Knock on wood.


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