Tracing a mystery pipe

[MOS3522]

tl;dr Found a drainage pipe and don't know where it's coming from. How can I trace it?

Long story: So I found some mysterious white drainage pipe buried in my backyard.

Background my house is on a gentle slope from the street that ends with a river in the backyard. My house has driveway drains, French drains and downspouts all tied into an underground drain system that empties into the creek. It moves the water quite well and keeps the house area bone dry as it should be. Recently repaired much of the system at great cost, so I've seen all of it and is now in 100% shape.

I had a muddy spot in the backyard in the 5 years I've lived here and blamed it on the creek. When I repaired the old drainage system last fall the muddy spot migrated to a new area about 10 yards away which made my question what was going on.

So I excavated in the muddy spot and low and behold I discovered a mystery drainage pipe. Looks like a 6"white PVC pipe, pretty old, and directly under my recently repaired drainage pipe. Putting in my new green pipe must have damaged the mystery line at this spot. And there is no outlet to this mystery line. Wherever it terminates, it's under my lawn not in the river. I can see the entire riverbed at low tide and the only outlets are the ones my current system is connected to.

This mystery pipe is draining quite a lot of what looks like very clean water. Maybe a gallon every 4-6 minutes. This is even though it's been very dry the last few weeks and my main drainage system is bone dry. So it's coming from somewhere, but it's not draining anything I can figure out. That's why my lawn has been so muddy.

I'm afraid to cap this pipe. Given the amount of water coming out, capping it will cause a backup somewhere else and may cause this old PVC line to rupture in a much worse place.

So I want to trace the pipe upstream to find out where it comes from. What's the best way to do that, short of excavating the whole line?

 

[Fav Onefour]

I've had sewer guys run cameras with tracers. They did need an open end to insert.
Cost varies, but I found a guy that did my drainage line for $250.00. Some wanted twice that to start.

 

[DGersic]

Could be tied to your foundation drain tile, inside or outside. Get a plumber to locate it with their tracing tools is probably the cheapest way to find out where it goes.

 

[PCustoms]

How's the water taste?

Jk

Are you on septic, or sewer?

The only way I know to trace this is a plumber with a snake and locator head. Probably run you their base/hourly fee.

 

[minke]

I live in CO too, in the front range. When my house was built >30 years ago they found clay that needed to be eliminated and under that a stream. They made a drain with PVC to a nearby ravine and it always is dumping water. Perhaps what you are seeing is the same.


I was amused by your mentioning “low tide”.


Hope you learn what’s going on and that it isn’t a problem.

 

[larry4406]

I have managed construction on a several homes. Some we have encountered springs and/or excessive groundwater during excavation.

Have installed many collector drainage systems to get the water away continuously.

One house we had to install vacuum pumps to **** the soil while geotech watched and concrete was poured. Pumps ran for days/weeks while foundation went in (no basement, tidal area).

Excavate and was fine with excellent bearing strength. Wait 1-2 hours water would cover the pad.

 

[ybnormal]

you don't live near a golf course, do you? you said street so that would imply a local muni-water system. what type of local soil do you have?

 

[MOS3522]

you don't live near a golf course, do you? you said street so that would imply a local muni-water system. what type of local soil do you have?

Soil is sand/clay and we have water mains on the street that always seem to be leaking somewhere. Water migrating down from a broken main is my leading possibility but it's 150 feet or more from the street to the rupture.

 

[Leaflessshadetree]

How far would you have to extend it so that it empties into the creek, (just in case this is the cheapest/easiest option)?

Any neighboring structures that this could be coming from?

 

[PCustoms]

So are you septic or sewer?

 

[Metal-Marc]

Pipeline?

 

[MOS3522]

I'm on sewer, and it's definitely not a soil pipe. Sewer and water main runs quite far away and on a different side of the property, so unlikely to be the source. Also the water coming out is crystal clear which rules out sewer and probably soil drainage as well.

I can tie it into my existing drainage system albeit at some cost. That's a last resort if I can't stop this flow at the source by tracing the line.

 

[ybnormal]

Soil is sand/clay and we have water mains on the street that always seem to be leaking somewhere. Water migrating down from a broken main is my leading possibility but it's 150 feet or more from the street to the rupture.

true, but since you don't know how the original layout was...

for years, I thought I had a natural spring that flowed extra heavy on wet weather. around 10 yrs ago, met the father of a girl who wa my daughters friend at school. turned out he lived behind us, across the street up a few houses on the golf course, and was a developer. he said "no, that's the sprinkler system for the golf course". what? "yeah, the grass is really thin on the course so the hard rock is less than a foot down. water goes down and isn't retained by the soil, then travels sideways downhill towards your property and down your driveway."
he was right, once the golf course shut down with no more irrigation we saw a LOT LESS water flow.

 

[ybnormal]

I'm on sewer, and it's definitely not a soil pipe. Sewer and water main runs quite far away and on a different side of the property, so unlikely to be the source. Also the water coming out is crystal clear which rules out sewer and probably soil drainage as well.

I can tie it into my existing drainage system albeit at some cost. That's a last resort if I can't stop this flow at the source by tracing the line.

have you tried contacting a leak detection surface? they use a microphone over the surface to listen for waterflow. they might be able to track the source back. or tell the city you suspect a water leak from their pipes.

 

[PCustoms]

have you tried contacting a leak detection surface? they use a microphone over the surface to listen for waterflow. they might be able to track the source back. or tell the city you suspect a water leak from their pipes.

A plumber with a locator head can run a snake down/up from the break in the pipe, they then use a purpose made detector to trace the head.

For 7 years I had no idea where my leach field was, but needed to do some grading near the suspected area. I paid for a tank cleaning (wasn't due) and he ran the snake out. Marked the D-box dead on and within 6" of the actual depth.

My guess is an exposed pipe like that, plumber would charge $200

 

[BillK]

Do you dare call the city and ask them ? Can you see the damaged spot ? Any chance of putting air pressure on it and see if you hear the escape somewhere ?

 

[MOS3522]

true, but since you don't know how the original layout was...

for years, I thought I had a natural spring that flowed extra heavy on wet weather. around 10 yrs ago, met the father of a girl who wa my daughters friend at school. turned out he lived behind us, across the street up a few houses on the golf course, and was a developer. he said "no, that's the sprinkler system for the golf course". what? "yeah, the grass is really thin on the course so the hard rock is less than a foot down. water goes down and isn't retained by the soil, then travels sideways downhill towards your property and down your driveway."
he was right, once the golf course shut down with no more irrigation we saw a LOT LESS water flow.

Neighbor just installed a koi pond near the leak and I had for a short while thought the pond liner was leaking and that was the source of the water. But the discovery of this drainage pipe rules that out.

 

[MOS3522]

Do you dare call the city and ask them ? Can you see the damaged spot ? Any chance of putting air pressure on it and see if you hear the escape somewhere ?

No way I am calling the city unless absolutely necessary. Never invite the man into your life! I see all sorts of horrible scenarios with the city calling this drain pipe un-permitted and making me dig it up, put in drywells/catchment, Lord only knows what else.

 

[PCustoms]

@MOS3522 have you confirmed there is a break?

I wonder if you repair the break and just let the water continue on if it will dry everything up....

 

[MOS3522]

@MOS3522 have you confirmed there is a break?

I wonder if you repair the break and just let the water continue on if it will dry everything up....

My first thought too but there's no outlet for the pipe. I think if I dig the other way (towards the river) I will find it just laying under the lawn where the mud spot used to be. I need to either stop the source or tie it into the river system.

 

[larry4406]

If its municipal water, it will have chlorine in it. Groundwater shouldn't have chlorine.

Can you get a test strip to see if it has chlorine? If it does, then your public works water main has an issue.

 

[PCustoms]

My first thought too but there's no outlet for the pipe. I think if I dig the other way (towards the river) I will find it just laying under the lawn where the mud spot used to be. I need to either stop the source or tie it into the river system.

Did you call digsafe last year before your big repair to your drainage system?

 

[BillK]

You still have not confirmed that you can actually see the break in the line ?

 

[MOS3522]

Did you call digsafe last year before your big repair to your drainage system?

Yes, my drainage company did so. There's no utilities crossing my property other than my house's supply (natural gas, water, sewer and power). All of those are within a couple of feet of each other on the far side of the property. My cable/internet is up in a tree so not buried.

 

[MOS3522]

You still have not confirmed that you can actually see the break in the line ?

The line is definitely broken, I saw it. It doesn't photo well because it's directly underneath the new green line in the picture above. And it is flowing even today, after 2 more days without rain.

 

[MOS3522]

If its municipal water, it will have chlorine in it. Groundwater shouldn't have chlorine.

Can you get a test strip to see if it has chlorine? If it does, then your public works water main has an issue.

Oh thank you that's a brilliant idea. I am doing that today.

 

[Hooked]

How deep is the pipe? Can you use one of the probing tools to trace the pipe?

 

[larry4406]

Time for dowsing rods?

 

[Jblount3]

I’m just watching to see the outcome, good luck

 

[MOS3522]

Well, I’ve called a pipe tracing plumber to come out tomorrow. I’ll see how far upstream I can track the line and determine what to do with it then.

 

[larry4406]

Well, I’ve called a pipe tracing plumber to come out tomorrow. I’ll see how far upstream I can track the line and determine what to do with it then.

He may want you to have the pit pumped dry vs wading in it. Been there.

 

[Jim greengo]

tl;dr Found a drainage pipe and don't know where it's coming from. How can I trace it?

Long story: So I found some mysterious white drainage pipe buried in my backyard.

Background my house is on a gentle slope from the street that ends with a river in the backyard. My house has driveway drains, French drains and downspouts all tied into an underground drain system that empties into the creek. It moves the water quite well and keeps the house area bone dry as it should be. Recently repaired much of the system at great cost, so I've seen all of it and is now in 100% shape.

I had a muddy spot in the backyard in the 5 years I've lived here and blamed it on the creek. When I repaired the old drainage system last fall the muddy spot migrated to a new area about 10 yards away which made my question what was going on.

So I excavated in the muddy spot and low and behold I discovered a mystery drainage pipe. Looks like a 6"white PVC pipe, pretty old, and directly under my recently repaired drainage pipe. Putting in my new green pipe must have damaged the mystery line at this spot. And there is no outlet to this mystery line. Wherever it terminates, it's under my lawn not in the river. I can see the entire riverbed at low tide and the only outlets are the ones my current system is connected to.

This mystery pipe is draining quite a lot of what looks like very clean water. Maybe a gallon every 4-6 minutes. This is even though it's been very dry the last few weeks and my main drainage system is bone dry. So it's coming from somewhere, but it's not draining anything I can figure out. That's why my lawn has been so muddy.

I'm afraid to cap this pipe. Given the amount of water coming out, capping it will cause a backup somewhere else and may cause this old PVC line to rupture in a much worse place.

So I want to trace the pipe upstream to find out where it comes from. What's the best way to do that, short of excavating the whole line?

Sump pump?

 

[MOS3522]

He may want you to have the pit pumped dry vs wading in it. Been there.

Luckily only about two feet deep and maybe 3x2 wide. I can empty it with a 5 gallon bucket.

 

[MOS3522]

Sump pump?

If so it's not from my house and quite far from the nearest neighbor.

 

[paredown]

Any chance that you have a local zoning authority that requires 'As Builts' to be filed after the home is completed. We would typically include a drawing on a copy of the survey showing the locations of water/sewer/gas as well as any drainage lines that we installed. especially if they were not called out on the original drawings. Maybe there might be a copy of something that could provide a clue?

The other possibility (and I know this from a local experience)--in some cases of excess runoff/ponding you can get drainage lines running from the back of properties all the way to storm sewers in front of property--our neighbors actually had the town step in and add such drainage because of the inadequacy of what was done by the original builder.

 

[MOS3522]

Paredown, good thoughts. There is a drainage plan in the blueprint set and this line is not on there.

And as far as I know there is no drainage anywhere other than the main house lines of which I know the location of the entire system.

But some houses on my street go back as far as the 1800s, although the mystery line is PVC and looks 1970s to 1980s. Possible the line originates on someone else's property but that still wouldn't explain the volume of water I am seeing. It's been too dry for the flow that's coming out.

 

[RyanE]

Couple of Q's:

Can you tell if it's continuous or intermittent flow?

Do you have additions or parts of your house that are of different ages (ie built in stages)?

Was your property part of a larger parcel that was subdivided and then your house built afterwards?

Distance to the nearest residence (ie - is this adjacent to a neighbours house that is older than yours?

I've come across several situations where previous owners have constructed additions (usually kitchen or laundry room remodels) and it wasn't convenient to tie the drains (greywater) into the main sanitary stack, so instead they plumbed them out to a "rockpit" in the yard somewhere. Usually rural properties, but can happen in more built up areas too. Unpermitted of course, but some jurisdictions have (or had) minimal oversight.

 

[Copymutt]

Can you dig a pit large enough to set a sump pump. Then when the pipe is partially evacuated send smoke up it with air pressure. Watch around the hood. You might even see smoke coming from roof gutters.

 

[MOS3522]

Well interesting developments with the plumber but no answers. Used a camera/sonde setup and traced the pipe about 60 feet uphill towards the house where it makes a 90 degree bend and heads across my lawn in a totally new direction.

Unfortunately the pipe is old and of very low quality materials so the condition is terrible. It is buckled up and down and narrowed in a few spots. Ultimately the camera and sonde were blocked by a collapse although water is still coming through.

The good news is the mystery line is immediately adjacent to my existing system, so a tie-in is possible.

 

[MoonRise]

Dig and get access to the mystery pipe as far 'upstream' as you/plumber could get to and try tracing further. Leap-frog further upstream as needed to get more into where the pipe and the water are coming from.

Could be an undocumented/unpermitted line coming from someone else's property across your property, or it could be a diversion line put in when your house was built or after it was built to redirect some 'uphill' source of water (spring, ground flow coming off the higher ground of the hill, etc) away from your house.

Did you run a chlorine test on the water from the mystery pipe? Ground water (as mentioned) should not have any chlorine in it, while municipal water has/had chlorine in it (but depending on how far a possible municipal water leak flowed through the ground to get to the mystery pipe it may or may not have any chlorine left in it to detect).

And I am rather surprised that you can discharge into a creek/stream/river (what is it?). Around here that is highly regulated and generally you can NOT directly discharge into a creek/river/stream AFAIK.

If the mystery pipe is not 'yours' and it's not on an easement across your property, plug/cap it and let whoever squawks fix it on THEIR property and their dime. Discharge of water from one property via a pipe to another property is usually NOT allowed, especially if undocumented and/or unpermitted.

Years ago I found a pipe in the uphill part of my lot that was intermittently draining soapy water. I plugged it with a rag. Turned out an uphill neighbor's lot had a (unpermitted and not documented) gray water drain line running from their lot all the way into what was my lot, because when they (or previous owners) put it in my lot was just 'woods'. They fixed (replumbed?) the line on their end and no more discharge into my lot after that.