Water mains

[Shannow]

Originally Posted By: Al
Infrastructure in the U.S. especially underground pipes is in many cases living on borrowed time. Comparing the cost of initial installation to replacement in today's world. Its a no brainer that replacing will soon become un-affordable. Dark days are coming.


All that stuff was built with a design life of 40-50 years...then forgotten about.

There are some really clever people coming up with robots that trowell composites onto the inside, a "sock" that gets unrolled up the centre of the pipes...neither are a structural solution.

The AC pipes are interesting in that the acidic medicinal products that they put into the drinking water takes the Calcium from the cement.

You are right...nothing will get fixed until it's an absolute disgrace, and people get embarrased.

 

[Johnny2Bad]

Road (paving), sidewalks, and water/sewer improvements in my City are charged directly to the property taxes on the serviced street (both sides), amortized over 25 years. So the cost is not an issue, the City doesn't really pay it, and property taxes are not onerous (I pay $C 550.00/yr [$US 432.00]* which is 52% City and 48% School Board, the median** in the City is about $2200 [$US 1729], the most expensive (million dollar+) homes pay around $C 6,600 [$US 5,187].

* I'm currently paying for a repave (6 years ago) and new Water Main (5 years ago) plus my property assessment. Since virtually every house around here has a basement, and I don't, my assessment is lower than my neighbours.

** Median is the point where half pay less and half pay more.

 

[JHZR2]

Originally Posted By: Shannow
Underground pipes, if they are anything like Oz would have been installed in Asbestos Cement...Different Parts of my career I've managed 20 or so miles of above and below ground Asbestos Cement pipes...

The joints (shown below) are typically a muff type coupling, set up so that one end is spigotted, and the other has the ability to be moved through a couple of degrees...typically no bends (when they do, they are thrust blocked), but sweeping long radius curves...imagine stacking lengths of spaghetti end to end and then pressing on the free ends it wants to buckle...the bedding stops it.

Over the years, the O rings take a set and don't respond well to movement...crud builds up in the gaps, and pressures the O rings if the pipe moves. The crud also pressures the muff coupling and splits them.

So a coupling fails...dig it up, cut the pipe, and put one of these in...

So now there's two more degrees of freedom in the repaired bit, and the whole spaghetti string has to sort itself out again when it's repressurised...there goes the next weakest link.

Every leak that I fixed required at least two more pipe outages to fix the leaks arising after the repair.


For pressurized water supply?

Around here it's 100 year old cast iron pipe. It often has a very decent mineral buildup inside, so a typical 6" service might only be 3" ID.

Around here they used cast iron sewer pipe inside, but once it left the structure, it was clay pipe with cement joints. The tree roots attack the joints in looking for water, and cause clogs.

 

[Johnny2Bad]

Originally Posted By: JHZR2
Originally Posted By: Shannow
Underground pipes, if they are anything like Oz would have been installed in Asbestos Cement...Different Parts of my career I've managed 20 or so miles of above and below ground Asbestos Cement pipes...

The joints (shown below) are typically a muff type coupling, set up so that one end is spigotted, and the other has the ability to be moved through a couple of degrees...typically no bends (when they do, they are thrust blocked), but sweeping long radius curves...imagine stacking lengths of spaghetti end to end and then pressing on the free ends it wants to buckle...the bedding stops it.

Over the years, the O rings take a set and don't respond well to movement...crud builds up in the gaps, and pressures the O rings if the pipe moves. The crud also pressures the muff coupling and splits them.

So a coupling fails...dig it up, cut the pipe, and put one of these in...

So now there's two more degrees of freedom in the repaired bit, and the whole spaghetti string has to sort itself out again when it's repressurised...there goes the next weakest link.

Every leak that I fixed required at least two more pipe outages to fix the leaks arising after the repair.


For pressurized water supply?

Around here it's 100 year old cast iron pipe. It often has a very decent mineral buildup inside, so a typical 6" service might only be 3" ID.

Around here they used cast iron sewer pipe inside, but once it left the structure, it was clay pipe with cement joints. The tree roots attack the joints in looking for water, and cause clogs.


I'm not positive what the size of our Water Mains are but I guarantee they're not six inches. Maybe 24 or 30 perhaps. They don't seem to be bothered by roots (of course, different trees than Oz) but roots can clog sewer pipes to the house. The City will come and Roto-Root your sewer line from the cleanout in your basement or crawlspace to the main for free once a year. I've never had to have mine done.

 

[Shannow]

Originally Posted By: JHZR2
For pressurized water supply?

Around here it's 100 year old cast iron pipe. It often has a very decent mineral buildup inside, so a typical 6" service might only be 3" ID.

Around here they used cast iron sewer pipe inside, but once it left the structure, it was clay pipe with cement joints. The tree roots attack the joints in looking for water, and cause clogs.


Yep...pressurised, potable water...zero reinforcing, as the Asbestos fibres form the composite element.

http://www.mtpinnacle.com/pdfs/CD_M.pm_02.30_Williams.pdf

Mains around here are around 24"...the branches for streets are tapped off and iron I think.

 

[JHZR2]

Originally Posted By: Johnny2Bad


I'm not positive what the size of our Water Mains are but I guarantee they're not six inches. Maybe 24 or 30 perhaps. They don't seem to be bothered by roots (of course, different trees than Oz) but roots can clog sewer pipes to the house. The City will come and Roto-Root your sewer line from the cleanout in your basement or crawlspace to the main for free once a year. I've never had to have mine done.


Mains may not be the best selection of wording. Something like Shannow's post above, which isn't to me a 24" pipe, maybe I'm off with my scales though. These are stret level pipes, servicing say, 10-12 homes. I'm sure the feeders are much larger from there.

 

[Blaze]

I still remember back in the 60's as a young boy watching the city workers dig up an old wooden water pipe that was wrapped in wire. They were replacing them during the repaving/curbing project in front of our house.

 

[Garak]

Originally Posted By: Johnny2Bad
I'm not positive what the size of our Water Mains are but I guarantee they're not six inches. Maybe 24 or 30 perhaps. They don't seem to be bothered by roots (of course, different trees than Oz) but roots can clog sewer pipes to the house. The City will come and Roto-Root your sewer line from the cleanout in your basement or crawlspace to the main for free once a year. I've never had to have mine done.

I think we have some pretty big mains, too. I've never seen root problems with water mains, but the sewers have been, and I've seen that all over the province, of course. I'm not sure how big the house service line is, of course, or even how it compares to some businesses, out of curiosity.

Since winter began, I only saw one water main break. The summer was a disaster, though. They left a lot just running for days, since they couldn't get enough people on the scene for all of them.

 

[MNgopher]

Lot of bad info in this thread.

A watermain, in a normal definition is the water distribution system located underground that delivers water to the local user. This is not the pipe from the steet to the house. That is a water service.

Watermains the US typically are Cast Iron, Cast Iron Cement Lined, Ductile Iron, Asbestos Cement, PVC or Pressurised Concrete Pipe. Design life on the low end (assuming corrosive soils or poor installation or bedding) is 50+ years, with properly installed and corrosion protected pipe being 100+ years.

To everyone who complains this stuff is expensive, it is - to install it correctly and inspect it accordingly.

Places didn't "cheap out" and use cast iron in lots of places - it was what was available and corrosion wise, was the best choice. Steel suffers from corrosion issues that require more protection that cost significant amounts of money. What was cited as a weakness of cast iron - its lack of give - versus steel - is actually one of things that makes it an easier pipe to install - it is not nearly as dependent on the backfill around it for its ultimate install strength as many other materials.

Cast iron is no longer used for pressurized water main service since the 1970/80 timeframe in the US and has been replaced by Ductile Iron - which is stronger and better yield properties.

The bulk of watermain service is typically 6 or 8", with only large transmission mains being larger. In otherwords, down a typical city street, you will find 6 or 8" pipe - not the 24"+ size as mentioned in other posts. I live in a city of 65,000, and the biggest pipes in our system are 24" - and there are only a few hundred feet of that - taking treated water from the water treatment plant out to the distribution system.

In our area, we bury watermains a minimum of 7.5 feet below the ground surface to protect it from freezing.

Depending on where you live, you may have a ton of old stuff - like cast iron or even lead pipes in the water distribution system. All brand new construction here is now PVC watermain - which is NOT the same as PVC sewer pipe. All depends on local practices and need.

We have not had more than usual amount of breaks this year - we went through a much longer and colder outbreak with no snow cover a few years ago that resulted in that rash.

The example cited above under the freeway was a 12" pipe installed in the 1960's - cast iron - that was encased in a casing pipe (24") under the freeway. The pipe failed with an 11' long (yes, feet) crack that has been seen in some other failures in the area.

 

[JTK]

Originally Posted By: JustinH
Have heard of lots of water issues in Niagara Falls, NY as well. That city is literally going down the tubes.


Yeah, that one is right near where I work. STILL leaking. They threw a metal plate over it. Like said above, obsolete parts. Scary for somethig so critical.

 

[JHZR2]

Originally Posted By: MNgopher


The bulk of watermain service is typically 6 or 8", with only large transmission mains being larger. In otherwords, down a typical city street, you will find 6 or 8" pipe - not the 24"+ size as mentioned in other posts. I live in a city of 65,000, and the biggest pipes in our system are 24" - and there are only a few hundred feet of that - taking treated water from the water treatment plant out to the distribution system.

In our area, we bury watermains a minimum of 7.5 feet below the ground surface to protect it from freezing.

Depending on where you live, you may have a ton of old stuff - like cast iron or even lead pipes in the water distribution system. All brand new construction here is now PVC watermain - which is NOT the same as PVC sewer pipe. All depends on local practices and need.


Thanks, yes that's what we have. A 6 or 8" cast iron pipe down the street, and then 1" copper into the house.

Not a fan of pvc...

They just replaced gas pipes, and I think they went from galvanized steel to something else that's flexible, but not sure what. They used galvanized in our house.

 

[Carmudgeon]

Originally Posted By: JHZR2

They just replaced gas pipes, and I think they went from galvanized steel to something else that's flexible, but not sure what. They used galvanized in our house.


Polyethylene. The joints and fittings are fused together with irons. High pressure, smaller diameter, so new lines can often be threaded inside the existing lines to make the job easier. Can also be direct buried.

MNG is correct -- mains are in the street. Transmission mains go long distance.

Services are what supply the house (gas, water, electrical, telecom). Sewer laterals take the stinky stuff away.

All of this stuff is out of sight and out of mind, so ticking time bombs exist everywhere. Literally, in the case of natural gas lines.

 

[MNgopher]

Time will tell on the PVC watermain. We've used PVC for a long time in sewer pipe service and found it work well when installed correctly. One of the big advantages for PVC watermain for us has been their stability in corrosive soils. Lots of areas we are finding where our soils are dramatically shortening the life of iron watermain due to corrosion. Add to that lower install costs and so far it is working well in our system.

 

[Yah-Tah-Hey]

Omaha had many water line breaks during the recently -0 cold snap. Enough to keep two crews busing repairing the old cast iron water mains.

 

[Shannow]

Originally Posted By: MNgopher
Time will tell on the PVC watermain. We've used PVC for a long time in sewer pipe service and found it work well when installed correctly. One of the big advantages for PVC watermain for us has been their stability in corrosive soils. Lots of areas we are finding where our soils are dramatically shortening the life of iron watermain due to corrosion. Add to that lower install costs and so far it is working well in our system.


The blue stuff ?

We put in a 5 mile pipeline linking the power stations to transfer R.O. wastewater. Was around 100psi IIRC. About a dozen stop starts a day while the plant was running. Due to the nature of the product, leaks were verbotten, so we had to have flow meters both ends, and a function that compared flows to trip if leaks detected...none in 3 years.

Pipes were carrying corrosive product, through soils which were old mine sites, and had acid sulfate soils. "Tradiational" piping just wouldn't have done the job.