Possible underground plumbing problem

[Sibley]

I may have an underground plumbing problem. There's a hole in the ground, and it's right above where I think the water line is. The hole first appeared about 2 years ago, but I thought it was due to surface drainage. Which made sense, because I was digging and I did find some voids. There's moles, so a few voids made sense. I pretty dramatically changed how water would flow, so I thought that the voids had collapsed and that was all. So I had filled in the hole and called it good.

Well, that hole came back. Except I had cut down a tree last fall, so I thought that was it. I filled it in again. Now its back. Thus, possible plumbing problem. Both the water line and the sewer line are in this vicinity. I don't know exactly where either one is, but I do know that the cover for the curb shutoff is pretty much a straight line to the hole. Previous owners had replaced the sewer line as well, so it's unlikely to be that. Which leaves the water line. Also, the grass in that line is suspiciously healthy given the drought we're in.

Per the town ordinances, it appears that I am responsible for repairs to the water line in this location. The town does the sewer main and everything up to the box, which is in the tree lawn. After the box is my problem.

I texted my plumber and asked if this was something he could take a look at or if he could recommend someone. He doesn't do underground plumbing work, but recommended a company. Will give them a call and have them come take a look.

This has the potential to be a big deal. What don't I know? I need knowledge.

[GilesMM]

Does your water bill suggest a leak? If you shut off all your water does the meter still spin? Have you dug up the wet spot down to the pipe?

[Sibley]

My water bill would not indicate a leak. The water meter is after this point. If there is a leak, the Town would see it in the difference between what they're being billed for water and what they're billing customers. If I didn't have a sink hole, I wouldn't have a clue.

And no, I haven't dug out the hole further. I won't be. I don't have the equipment to dig super deep, the knowledge to do so safely, or the time/energy. It's busy season at work. Even if I got down to the pipe, I'm not equipped to diagnose anything not super obvious nor am I equipped to fix it. Plumbing is not my thing.

[uniwelder]

I'm confused by the response.  The leak is happening between the meter and your house?  I think yes, but wording is unclear.

My water bill would not indicate a leak. The water meter is after this point. If there is a leak, the Town would see it in the difference between what they're being billed for water and what they're billing customers. If I didn't have a sink hole, I wouldn't have a clue.

As GilesMM is suggesting, shut off the main water valve inside your house, then take a look at the meter.  Even if you can't visually see anything spin or blink, keep it shut off for an hour or more, then come back and take a look.  It's best to take a before and after photo so you can compare them side by side.

Water is so cheap where I live, you'd probably have to leak over 30 gallons per day before you'd see a difference in your water bill.

[Sibley]

The issue is between the street and the meter. So my water bill is not relevant.

And I'm an auditor. I audit governments, including water utilities. "unbilled water" is a test that we do. My town doesn't have the water treatment plant, they pay another town for water. Then, my town bills all the residents/businesses for water. The difference between those is unbilled water. A lot of it is leaks, water main breaks, etc.

[GilesMM]

My water bill would not indicate a leak. The water meter is after this point. If there is a leak, the Town would see it in the difference between what they're being billed for water and what they're billing customers. If I didn't have a sink hole, I wouldn't have a clue.

And no, I haven't dug out the hole further. I won't be. I don't have the equipment to dig super deep, the knowledge to do so safely, or the time/energy. It's busy season at work. Even if I got down to the pipe, I'm not equipped to diagnose anything not super obvious nor am I equipped to fix it. Plumbing is not my thing.

Oh dear. Digging is not something you want to pay plumber's rates for if they will even do it.  If you can find a casual laborer and a shovel they should be able to dig deep enough to find it. Just follow the sink hole and dig around 3 feet.  Open it up enough that the plumber can get in and patch it.  It is going to be tricky to patch with the water pressure on (since there is no valve upstream of your meter).  Are you sure it is your responsibility on the city side of the meter?

[Sibley]

Apparently I did not explain this well. Picture. On the right is the street. There is a box/shut off valve. The town is responsible for all that. Everything to the left of the vertical line is the homeowner's problem. The horizontal line is the water line. Far left is the house and the water meter. The sink hole is circled.

If there is a leak, which seems likely, it's BEFORE the water meter but on my property and thus my problem to fix.

And yes, I can probably get someone to dig if it makes sense to save that money. I haven't called them yet, I don't know what they'll charge. Frankly, it's worth some money to me to have them dig it up and fix it, because if they make it worse then they have to fix that too.

[CowboyAndIndian]

Around the area of the sinkhole, do you see greener grass or more healthy plants? That might indicate the leak location. (I'm an idiot, I just reread your post and you are seeing "healthy" grass)

If you want to find the leak, I believe that digging is the only solution.

I would let sleeping dogs lie and not try to fix this until it becomes a much bigger leak and you are seeing water.

[GilesMM]

Unconventional not to have shutoff and meter located together, but good news is you can shut off the water for the repair.  Just need to get it dug up.  I imagine some plumbing companies have "diggers" they use for that.


Another thing to try would be to shut off the water valve when you are out of town for a week and see if the system manages to depressurize through the suspected leak.


If you live on a hill, it could be artisan water rather than a water leak but it would be a coincidence if on the water line route.

[Sibley]

Not on a hill, it's an established residential neighborhood in the midwest. Ie, flat. This is 8 ft or so from my house, I don't want it to get bad enough to jeopardize the foundation. I already have a sink hole. Plus, I have an issue with wasting water like this. It's just not an emergency.

Giles, there's also a shut off just after the meter, but meter and shutoff are inside the house. The Water department needs a way to turn off the water that doesn't involve getting inside.

[thedigitalone]

As someone else suggested, get a $12 pressure gauge at HD (https://www.homedepot.com/p/Orbit-Pressure-Gauge-91130/327943219) and connect it to a hose bib and turn it on. 
Go to the city water valve at the street and turn it off, if the pressure drops you have a leak somewhere on your side of things.

X

[Sibley]

Update. Called Public Works, they're going to look at my hole and give me their thoughts. Given that they have way more experience with these types of issues, I'm fine with that! But yes, it's my responsibility to fix based on the location.

Update on the update. Public Works agrees that there's a problem, they're not sure if its water or sewer line. Both are in the vicinity. I have called the plumbing company that does the underground work. They're booked out a week or two, but will hopefully get a call from the guy this week. This company does a lot of the governmental infrastructure work too.

[Sibley]

Well, I have learned much about my underground plumbing. First, the sewer line is pretty crazy. It's not a straight line, it's not all pvc like I thought, and it will need to be replaced properly at some point in the future. There's several clay to pvc transitions (4 to be exact) and they're all letting roots in. No wonder it backs up periodically. It's also not where I thought it was, it's much much closer to the house.

The water line appears to be next to the sewer line. The plumber didn't have the equipment to trace the water line with him (and considering he didn't charge me for the camera, I'm not complaining). As for the hole, it's right above the sewer, and presumably water line. However, that section of sewer is pvc and it's fine. So, not the sewer. Plumber thinks its either a small water line leak or less likely, animal activity. He recommended to just fill the hole in. Unless I'm seeing water somewhere, leave it alone.

I'm going to take his advice and just fill in the hole. I do have longer term plans for the yard, and the condition of the sewer line throws a wrench into them because I don't want to landscape then have to dig it all up. But at least I know now.

[uniwelder]

How far is your house to the street?  It seems crazy the entire sewage line wasn't all replaced at once, especially if its originally clay.  I have a house from 1940 that had clay pipe which collapsed, and most other people I know in the neighborhood had to replace theirs by this point.

If you just fill in the hole, when do you expect to replace the line?  Spring?  I'd have both water and sewer done at the same time. 

I'm sure others will have a good reason (animal chewing) for not doing this, but when I replaced the water line to my old house, I rented a trencher and dug parallel to my existing line, about 12" away.  The existing line was steel pipe, so I wasn't too worried about cutting through.  Then I buried 3" corrugated drain pipe at the bottom and snaked the plastic water line through that.  If there were any problems in the future, I could replace it without digging. 

[Ladychips]

Thanks for updating us. I always appreciate knowing what happened!

[BlueMR2]

How far is your house to the street?  It seems crazy the entire sewage line wasn't all replaced at once, especially if its originally clay.  I have a house from 1940 that had clay pipe which collapsed, and most other people I know in the neighborhood had to replace theirs by this point.

I just went through this...  Found there was a 10 foot section of clay that fills up with roots when all the rest out to the city is PVC.  Had that clay section replaced and in the process also found out that the cast iron in the house was also leaking.  Ended up with the whole house plumbing replacement done (as touching the cast iron required bringing everything else up to the latest code).  A horrendously expensive mess, but it should all outlive me now...

[lhamo]

If the sewer line is not TOO degraded you might want to look into having it lined -- that's what we did on our last house.  Whole project cost us close to $25k, but that was less than it would have cost to dig the whole thing up and replace 150ft of steep landscaping (our house was built into a very steep hill.

The lining process basically creates a new durable plastic sleeve inside the old pipe. 

[sonofsven]

Thanks for the update!
Fill in the hole and call it good.
"It looks good from my house" said the contractor.

[uniwelder]

If the sewer line is not TOO degraded you might want to look into having it lined -- that's what we did on our last house.  Whole project cost us close to $25k, but that was less than it would have cost to dig the whole thing up and replace 150ft of steep landscaping (our house was built into a very steep hill.

The lining process basically creates a new durable plastic sleeve inside the old pipe.

Maybe you had a very complicated job, but when I had my sewage line replaced, a contractor did it for $1,500.  They finished in one day and got inspected during the job at lunchtime.  It did have a couple of bends because of the slope and it was only 60 feet long, plus this was 10 years ago, and I live in a LCOL area.  However, that is an enormous difference in price, and your 25k was the cheaper relining option.  Damn!

[lhamo]

If the sewer line is not TOO degraded you might want to look into having it lined -- that's what we did on our last house.  Whole project cost us close to $25k, but that was less than it would have cost to dig the whole thing up and replace 150ft of steep landscaping (our house was built into a very steep hill.

The lining process basically creates a new durable plastic sleeve inside the old pipe.

Maybe you had a very complicated job, but when I had my sewage line replaced, a contractor did it for $1,500.  They finished in one day and got inspected during the job at lunchtime.  It did have a couple of bends because of the slope and it was only 60 feet long, plus this was 10 years ago, and I live in a LCOL area.  However, that is an enormous difference in price, and your 25k was the cheaper relining option.  Damn!

IIRC the relining itself was about 15k.  The other 10k was the digging out it took in two different spots to be able to assess what was going on (since the line was completely blocked in two places and the scope could not pass through) and access the line.  Digging out would not have been less expensive since our front yard was zoned as a critical area/steep slope and would have required expensive permits and probably re-engineering.

Just one reason I am glad we are out of that house and my new house is on a flat lot with simple access!  And no willow tree/laurel hedge sending roots toward the side sewer...

[Sibley]

It would be around $4500 to replace the entire sewer line assuming no complications. 60ft maybe? I'm bad with distances. Water line is longer.

The clay sewer line sections look fine. The problems are at the junctions between clay and pvc. There's roots at each join, and in one spot the two pipes are misaligned from the other. The prior owner, who did put in the stuff that is currently PVC, was not smart. He was digging (twice!), he worked for the plumbing company and thus had access to equipment, and the idiot didn't replace the whole line. There is literally a 2 ft section of clay pipe between sections of pvc.

The problem is that the water line is RIGHT there. The one spot we know for sure where both water and sewer lines are, they're within a foot of each other. And we don't know what the water line material is. If it's galvanized or lead (and it's probably one of the two), and we saw it while digging (which we would), then I'd be required to replace the entire water line as well. So it's not just $4500, it's $4500 + complication money + likely having to replace the water line which would be minimum $10k, plus then fixing the landscaping and probably the fence.

I'm just leaving this whole thing alone for now. There's a lot of noise at the federal and state level about replacing lead pipes, so if I do have lead then I might get lucky and the water utility will do it. If it's galvanized then there's lead solder. If someone else is going to pay to dig up my yard to replace the water line, then I'll happily chip in the extra to do the sewer line at the same time.

Edit: See, I'm just gonna wait. Cross your fingers I have lead pipes. Early 40s, so hit or miss. I'm not sure when my area switched to galvanized.
https://www.reuters.com/world/us/final-rule-epa-requires-removal-all-us-lead-pipes-decade-2024-10-08/?utm_source=pocket-newtab-en-us

[uniwelder]

I suppose it might vary by state, but where I am, water and sewer lines are required to be separated by 3 feet, whether that be horizontal or vertical distance.  Something to keep in mind whenever the replacement happens, since it probably means digging two separate trenches.

[Sibley]

I suppose it might vary by state, but where I am, water and sewer lines are required to be separated by 3 feet, whether that be horizontal or vertical distance.  Something to keep in mind whenever the replacement happens, since it probably means digging two separate trenches.

Wouldn't matter. There's one spot where we would find the water line for sure, based on the sewer pathway. They're too close together horizontally, even if they're separated vertically.

[BlueMR2]

Maybe you had a very complicated job, but when I had my sewage line replaced, a contractor did it for $1,500.  They finished in one day and got inspected during the job at lunchtime.  It did have a couple of bends because of the slope and it was only 60 feet long, plus this was 10 years ago, and I live in a LCOL area.  However, that is an enormous difference in price, and your 25k was the cheaper relining option.  Damn!

Prices have skyrocketed the last couple of years.  When I first found the problem with the external section I was quoted $4000, but I just had it cleaned out to buy me a year as I had another huge expense coming up rapidly.  This year it was $7000...