DIY Home Improvement Forum banner
1 - 20 of 29 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Hi All - thanks for taking a look at this. I understand that a professional will handle this, but I wanted to know if anyone here has ever experienced this situation?

Septic tank found under driveway -:vs_mad: what are my options?

We are looking at a home, built in 1980 which has been renovated over time. It sits on 5 acres. Permits show that a driveway was poured in 1990. When attempting to find the septic tank so it can be inspected, 2 septic companies and a GC could not find it. They use standard probing. The Realtor hired a plumber who first wanted to try a snake method vs using the line locator. He used a Sectional machine and put the cable down the vent pipe on the roof. Turned it on and we went hunting. Turns out we heard the rattling under a particular part of the driveway slab, perhaps poured at a different time, as the expansion joints looked different than the original.

My assumption is that they will rip up the concrete, locate the septic, pump it, fill it with sand, get access to the drain line and hook up a new septic in another part of the yard and bring everything up to code. They are not sure where the leech / drain field is.

I am curious if "they" think they can save money and reuse this somehow and put a manhole cover over it. I don't think that is acceptable. I assume you should not be driving over a septic tank to begin with, and that a driveway over a system is not up to code.

Any stories to share?

Thanks all - have a great night
 

·
Registered
Joined
·
14,096 Posts
The final answer MUST come from your local code enforcement. Now that the can of worms have been uncovered they can't just hide it and go forward. A new septic design has to be done and then submitted to the town/city for approval. Whether they take action against the current owners is up to them, but the current owners will only be digging themselves in deeper if they make any modifications without following the proper steps.

Bud
Not an engineer just a contractor
 
  • Like
Reactions: mtarallo

·
Registered
Joined
·
3,325 Posts
There's absolutely nothing wrong with having the septic tank under the driveway as long as the top of it is reinforced well enough to handle the weight. Actually, it's quite a good space as long as you have a nice access hole with a removable cover. Easier than having to dig up a space in your yard every time you want to look for the cover and have a tank pumped. It's done quite often in different areas of the country.
 

·
Registered
Joined
·
3,471 Posts
I'm not sure I'd want my tank to be under a driveway. But in any case, that would not be allowed here. We are in part of the Chesapeake Bay watershed, and the rules for septic systems are quite strict, as we found out when we built our house about 6 years ago. Concrete tanks are not allowed; ours is some sort of plastc. And the access cover cannot be buried; it must remain above ground and accessible. We also had to designate a 1/4-acre portion of our property as "septic reserve." That's a location for another septic system if the first one ever fails. Nothing permanent can be built in that area. Essentially, you can't build a house on any lot that isn't at least 1 acre in size.
 

·
Registered
Joined
·
729 Posts
Under most circumstances I would require it be fixed and brought up to code, or else estimate the cost of doing that and get it knocked off the price. But others are right--you really need to consult the local code authority, because YOU don't want to be in the position down the line of selling a house someone won't buy because the septic is under the driveway. Also, you note that this part is "perhaps poured at a different time," and the current owners didn't even *know* where the septic tank was, so keep in mind it may not have been pumped in more than a decade.

Which itself makes it likely the septic field has less life left in it than you would like.

This would make me concerned about whether other maintenance tasks had been neglected, and I would suggest getting a good contractor to look over the house and check other key systems. (Oil or gas tanks, radiators, roof leaks, signs of water leaks, really anything maintenance-related).

Of course, you might be willing to take on the costs and risk of fixing the septic if they lower the price enough. That's a bargaining decision you can make once you have more price information.
 

·
Registered
Joined
·
1,991 Posts
I am no expert at all, indeed I know little to nothing about septic systems. But generically we all drive over city sewer systems that run under roads. It seems a septic tank is a similar concept. Granted the sewer system is designed to accommodate vehicles above and that may not be the case here. But the fact that its under a driveway doesn't seem like some inherent, cosmic flaw.
 

·
Registered
Joined
·
3,471 Posts
I am no expert at all, indeed I know little to nothing about septic systems. But generically we all drive over city sewer systems that run under roads. It seems a septic tank is a similar concept. Granted the sewer system is designed to accommodate vehicles above and that may not be the case here. But the fact that its under a driveway doesn't seem like some inherent, cosmic flaw.
Well, as you yourself said, you do seem to know nothing about septic systems. If the tank is underneath a concrete driveway, the issue isn't vehicular traffic, it's access. Septic tanks need to be pumped out every few years, and if one is under a driveway, there's no way to do that without busting up some concrete, which could cause damage to the tank as well. And as I mentioned in my earlier post, in some places the access cover cannot be buried.
 

·
Registered
Joined
·
1,991 Posts
Well, as you yourself said, you do seem to know nothing about septic systems. If the tank is underneath a concrete driveway, the issue isn't vehicular traffic, it's access. Septic tanks need to be pumped out every few years, and if one is under a driveway, there's no way to do that without busting up some concrete, which could cause damage to the tank as well. And as I mentioned in my earlier post, in some places the access cover cannot be buried.
There is no shortage of access to sewer lines under streets. I can see one out my front window 20 feet from my driveway.
 

·
Civil Engineer
Joined
·
5,832 Posts
I don't really understand the OPS situation. From the description, he is "looking at a house". To purchase presumably? If the OPS is thinking about purchasing the house, then of course he will want a complete inspection of the septic system to determine if it is in compliance with local rules and regulations. Not sure where the OPS is located, but where I live (MA) a septic system inspection is mandatory, paid by the owner of the house, prior to sale.

At least in my area, the local Board of Health has the best records about the design and location of the septic system. Again, no idea where the OPS is located, but the place to start to review septic system installation records is with the Board of Health. If there is no Board of Health, or there are no records, things get more difficult. From the description of the process, the first three companies had no idea where the tank was, suggesting either there are no plans on record, or the companies failed to review the plans before beginning their search, or the plans on record were not accurate.

As to whether a tank can be under a driveway, from the posts it should be clear that local regulations vary considerably, so there is simply no way to make a blanket statement as to whether a tank under a driveway is acceptable. It is accurate to say that from a design standpoint, any tank under a driveway needs to be designed to withstand vehicle load, and not just a car, but a load such as a dump truck. In my town, you can put a tank under a driveway as part of the permit process, but the tank need to be rated for H20 loading, and the cover needs to be at grade (accessible). Your local regulations are likely to vary.

Recommendation: Talk to the local Board of Health. Review the plans on file if there are any. If you still want to pursue the house, hire a local, authorized septic inspector to prepare a written report on the condition of the system. Ask the inspector to prepare a written cost estimate to bring the system up to compliance with current standards. If still interested in the house, negotiate a price consistent with performing necessary work to bring the system into compliance.
 

·
Registered
Joined
·
1,991 Posts
And what does that have to do with access to your septic tank???? Answer: absolutely nothing.
to the contrary your the guy who said access to a tank was a big reason not to put one under a driveway. I'm pointing out access to a tank under a driveway is just as doable as access to a sewer line under a street.
Not sure what I did to piss you off but if you want to bang on me at least bring logic to your argument.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #19 ·
First - THANK YOU ALL - all of you are awesome - and please no disrespecting one another - you all have valuable information and are entitled to your own thoughts regardless if they are accurate or not. That is my responsibility to do the research. All the info shared is very much appreciated.

So here is the thing - YES - I did consult with the DOH - and NO - they have no record or survey of the original system. They only have records as far back as 1990. I checked with code enforcement as well - and NO - you cannot have a tank or drain field under pavement or driveway - unless it is constructed for that manner. You need proper evaporation, support etc. This house is out in the sticks and I am sure much work was done without permits. The driveway was expanded without thought about the location of the tank. So they definitely poured over it - we confirmed that. The Seller is taking care of the situation and we are exposing the tank to check it out. If the tank passes - we have a number of options that are minimal cost. However if it does not, who knows what will happen. As the tank and drain field will need to be relocated. If you want updates let me know, I'll post them for you with pics. Should know more next week. Have a great weekend all.
 

·
Registered
Joined
·
3,471 Posts
to the contrary your the guy who said access to a tank was a big reason not to put one under a driveway. I'm pointing out access to a tank under a driveway is just as doable as access to a sewer line under a street.
Not sure what I did to piss you off but if you want to bang on me at least bring logic to your argument.
Well, you didn't piss me off. Sorry if I gave that impression. But I still stick to the opinion that a septic tank under a concrete driveway is a dumb idea.
 
1 - 20 of 29 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top