Choosing Pipe for Main Water Line
My driveway is 550′ long, and the water meter is at the road. So far I have determined I should be happy with a 1.5″ ID pipe, for the flow I am considering. I was all set to pull the trigger on HDPE pipe (NSF rated, 200 PSI), until I read some articles that claim this type of pipe becomes brittle with time when exposed to water disinfectants (read chlorine, chloramine, chlorine dioxide etc.), anything the utility puts in the the great lakes water to make it “safe”.
So back to the drawing board. The options:
HDPE CTS 200 PSI pipe
Still likely the best option, if I can determine my water company does not use chlorine dioxide (which can apparently shorten the life to 10 so years). Even the “better” disinfectants can bring the life down to 20 so years, which is not ideal. Fittings are expensive, but I can get it in 500′ rolls, which means only one connection. 1.20 a foot for 1.5″ ID
CPVC
By far the most available but the amount of connections and potential health issues from the solvent/glues are scary. In 20 foot sections I would have a lot of joints, all leak potentials. 2.25 a foot for NSF rated 160 psi. Cheap fittings.
Copper
5.50 a foot. The run would cost almost 3000$, in materials. Tried and true. Cheap fittings. Lots of connections, just like CPVC. Unknown performance 4′ underground (potential oxidation/pitting).
What would you select for your home?
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Replies
Mai Tai,
I wouldn't use CPVC. In Vermont, almost everyone uses black polyethylene that comes in rolls.
Copper is certainly a possibility -- make sure you use Type K copper if you go this route.
Mai Tai,
A plumber I hired recommended using PEX for a continuous supply run from the meter to the house's pressure reducing valve. Here is an industry presentation that might be helpful: https://plasticpipe.org/pdf/pex-plumbing-presentation-01-17-2011.pdf
The town I live in is currently replacing, at great expense, all polyethylene water mains and branch lines with copper because of leaks after 15-20 years. Don't know if it's HDPE or they cheaped out and used LDPE, but it's a data point. Sometimes you get what you pay for.
PEX can have similar lifespan issues if the water is chlorinated, and the anti-oxidants that protect against this are quickly destroyed by UV exposure.
Copper is a great option, but if your soils are unusual, it could corrode. Here's an article on the subject: https://www.copper.org/resources/properties/protection/underground.html
Another option is polymer-and-cement-lined ductile iron. With a polymer lining on the outside and cement on the inside, it should last effectively indefinitely. Probably not cheap, though.
Ask around: what did your neighbors use? Has it held up? etc.
I guess I will become part of the grand experiment regarding pipe lifetimes, but I think the HDPE is still the most sensible choice.
My own water line is 1400 plus feet and composed of two sections using different materials. The first 800' or so feet are what is called bell and gasket pvc pipe in 20' sections. When it was installed in 2003 that was the preference of the contractor. It seems to be working fine despite some worrying by others not so lucky. The second section installed in 2015 of 600' or so is the blue colored HDPE that is now almost universally installed for water in my area. The soils here are generally quite rocky so bedding any pipe properly is critical. The bedding for bell and gasket type is even fussier than the HDPE.
In any case, I dug into the failure question briefly and I suspect that the issue is of more relevance to utilities than individuals. The anti-oxidants in the pipe layer leach out pretty much in direct relation to disinfectant concentrations - ppm and water flow volumes. The embrittlement is real and some pipes have failed after only a few years. An important thing to note is a lot of the failures also involve mechanical stress the pipes from improper bedding or soils movement brought on by various factors. Municipalities move millions of gallons through the pipes so the wear and tear factor is much more than you would see for one household.
JM Eagle is the name brand around here with a few alternate brands that may be sourced from world markets. They claim 100 year lifetimes on their website which should suffice for most of us. I really can't support the idea of the cheaper black plastic coil pipe Martin speaks of. I grew up in the NE and remember using it in our well system with aging being apparent over 10 years or less. Admittedly plastics may have advanced since then but around my new home area the ranchers seem to regard the black pipe the cheap stuff for agricultural only. As for copper, it can be dented, the K wall thickness is lots of money, and bedding it would be most critical. There are those that rail against copper leachates. I only know PEX for interior house plumbing and I thought it is supposed to be better at resisting disinfectant oxidation even at elevated temperatures. UV shouldn't be an issue four feet underground.
I would also suggest that you up the HDPE pipe to 2" to maintain water pressure. I wanted to reduce costs and use 1-1/2 for the second leg and was (fortunately) convinced to go with 2". I did have an elevation rise to deal with which does need to be factored in when calculating losses from the meter head. The correct fittings for the HDPE are critical as the pipe is made in different size standards which means paying attention to the fittings being correctly mated with the pipe. As you note, the fittings are rather expensive, but it doesn't seem you will need many although you might want to add a shut off close to the house in addition to one at the meter.
Meantime, I made my commitment to HDPE based on what most everyone here has been doing for over 10 years now. Maybe we will all regret it like Nate G's town, but I don't think so.
Steve,
I can't believe I forgot PexA as an option. If I used Uponor 1.5" it would be about 1800$ USD for 600 feet, which should be plenty. On the pro side, you can used expandable Uponor rings and full size Uponor fittings. Con is this is a monster fitting and I would need to buy/rent the Milwauke M18 Propex tool to do the job (900USD retail). Of course your linked presentation highlights other fittings that are compatible, but I would consider it a waste not to use the great Uponor fittings with Uponor pipe. They would also not be susceptible to corrosion like the compression fittings could be. PexA is said to be much more resistant to chlorine than HDPE, if a bit less damage resistant.
Roger,
I also associated the black pipe with a lesser use case (irrifgation/livestock), but now I can't find the reason why. I suspect if it is NSF rated it should be good enough? Thanks for the name brand, i have a hell of a time finding HDPE sources. No rise to my property (actually a slight drop), so I suspect 1.5" will be enough. With 4degree C water and 15 gpm flow, i will lose 27.5psig o f pressure, which is low but probably usable. (I am about 2000feet from the pumping station, and I suspect the pressure will be 50psig at the road). Not to mention 15 gpm is A LOT of water in today's fixtures (2 x 5gpm irrigation lines and two 2.5 gpm shower heads simultaneously). At a more probable 5 GPM, I lose 5 psig which is barely detectable.
Interesting that JM Eagle is named in several lawsuits concerning HDPE pipe durability:
http://www.crainsdetroit.com/article/20160821/NEWS/160829993/potential-flint-water-pipe-supplier-has-rocky-legal-history
At this point, it looks like PexA is my best choice, even at twice the price of HDPE. I just have to find someone that can rent me the tool so I can use the best fittings for the job.
Well it certainly looks like my children will not be so thankful when we pass on and leave them the house. I will try to attach two pdfs that will add further terror for us all that have adopted the HDPE. Surprising that JM Eagle is the defendant in lawsuits, I would have expected the overseas suppliers of pipe to be more likely. In regard to PEX as the alternative - a brief look seems to show that 1-1/2" comes in 100 foot rolls which would mean many more joints than the blue pipe. Also, the joints need to be a polysulfone type material to avoid issues with the chlorine disinfectants according to one of the sheets I am intending to attach.
The Wirsbo brand is well respected by plumbers I know and they used it plumbing my home. I added some Sharkbite brand on my own and most people seem to be happy with them as well. Some of the super discount PEX available has been characterized as feeling stiffer than name brands. Resin levels and cross linking techniques seem to drive the properties and quality. For in floor use with pumped circulation, an oxygen barrier layer is required to protect the pump. I think it is more money. I would also note that most warranty data for PEX I have seen is for 25 years although articles speak of PEX as a 100 year plumbing system. Kinda like JM Eagle.....hmmm, when it rains it pours.
Last thing, I am fortunate to have almost 90 psi at the meter side and have regulated down to 60psi house side. However, that is starting in the basement and I would say that the second floor fixtures aren't any too energetic. The total rise from regulator to shower head is about 22' for the upstairs shower. If you think the pipe losses will drop you under 30 psi at entry you may well have problems as you distribute around the house as more losses occur getting to shower or kitchen. (Maybe Dana can weigh in on the issue with more precision.) It might be possible to do a work around by setting up a pump and pressure tank fed by the street line as if it was getting well water. That would allow for full pressure and even low flow heads need a minimum to squirt effectively.
OOPS. Only one pdf is small enough to attach. Will try to shrink other later.
Roger,
If the children are getting the house they can change the water line ;)
It's not all doom and gloom, the study states "premature" failure varies from 5 to 25 years. I would suspect the higher the disinfectant concentration in your water, the shorter the life. There is also a direct correlation with higher temperature and shorter life. If your utility uses chlorine dioxide, I would start shopping now, or at least make sure you have an eye on your consumption at all times. HDPE pipes exposed to chlorine dioxide had a 5 year! lifespan in Hamilton, Ohio (which is not that hot, so it could actually be worse at lower latitudes).
1/5" Uponor PexA comes in 300' rolls. So does 2" , although it is pricy (1700 USD for the roll). Because it's almost twice as expensive as 1.5", and because my municipality wants another 120$ a year to go from a 1.5" to a 2" meter, I'll stick with the 1.5". If I am unhappy with the pressure I will just add a booster, although I am sure it will be fine. I will be running dedicated 1/2" lines to the showers (cold and hot) so I'm hoping this will help mitigate pressure issues.
Good idea to install a pressure regulator, many water heater manufacturers will void your warranty above 60 psig. I was guessing at my at the meter pressure, i should find out for sure before I dig the trench. 90 psig would be great, and would make 1.5" a slam dunk.
Mai Tai,
Yes, if the ingrates don't want to fix a simple water line I will leave it all to the animal shelter >:( .
It sounds like you have the same report I couldn't post due to size restrictions. The name on it is - "Oxidative Degradation of High Density Polyethylene Pipes from Exposure to Drinking Water Disinfectants."
Fortunately, we do not have water treated with chlorine dioxide. One thing I made sure to do (completely on my own time) was bed the pipe in clean rock free gravel. Even though we moved the vehicle access well away from the water line I did not want to risk pressing on the line with the sharp sandstone cobble that is prevalent here. It seems that some of the failures mentioned in the report were due to just that problem.
Best of luck with the install and pray for warmish weather on the day you try to roll out the pipe. Cold mornings make it a real bugger.
Mai Tai,
I know this is is an old post but I am thinking about replacement my old galvanized main water supply line 200'+ so I wonder what kind of pipe you ended up using. I was thinking HDPE until I found MDPE but after youtube I only found most MPDE installation are in UK so not sure why it's not popular in US.
thanks.
Not sure if it's helps because of being on a well, not treated water, but everyone around here uses black plastic pipe. The stuff in my grandfathers house is still going strong and is well over 50 years old (he passed away in his 90s 20 years ago so I don't have an exact age, but I know that the well was dug just after his oldest daughter's wedding) .
The line in my mother's house is the same, but it's 45 years old.
The life expectancy of unprotected black iron pipe is highly dependent on your local soil chemistry. In some areas it will corrode much faster than others.
I would go with polyethylene pipe. Note that there are two types: NSF approved for potable water use, which you MUST use on a well, and non-NSF approved that is suitable for lawn sprinkler use only. Both are usually black in color, they're commonly available, and they're cheap.
HDPE is High Density PolyEthylene. MDPE is Medium Density PolyEthylene. There is also LLDPE (Linear Low Density PolyEthylene). They are all pretty much the same chemical compound, just made a little differently. HDPE is harder than the other two. In the telecom world, our underground ducts are made of HDPE and the jacket on the fiber optic cables is made of MDPE. LLDPE is commonly used for small water lines on reverse osmosis system.
I wouldn't worry too much about the exact composition of the pipe -- the letters before the "PE" -- as long as it's NSF approved for potable water and is rated for at least a good amount higher than the pressure you expect to be running in the line. Any of these materials is far superior to a metallic line in this application.
Bill
I'm contemplating running 1" PEX-A as my main water line from my well. I haven't completed plans yet, but I would expect total length to be somewhere around 30'. I would be looking to run it inside PE for protection as well as to facilitate possible replacement. 1" PEX is 1.25" OD. Would 1 1/2" PE (1.610" ID) be sufficient or should I go with 2" PE (2.067" ID)?
And in general, is there a rule of thumb for sizing sleeving (such as 25% or 50% larger ID than OD of the working pipe)?
Bigger ducts have less surface area in contact with whatever you pull through them, so they allow for things to be pulled in more easily. You can even get ducts made for the telecom industry that have ridges inside for this purpose.
Why don't you just use the usual PE pipe for your water line and save the hassle of essentially running a pipe to house another pipe?
Bill
Bill, it's a short length/shot. I want to be working with only my PEX-A fittings. I'd spent a lot of time trying to locate an acceptable PEX-A to PE fitting for another project: Supply House couldn't help me out (couple years back- perhaps they now have something?). The other is that I'd like a bit more flexibility in connecting up in my pump/well house: I'll be completely changing my layout to make it logically, as well as physically, flow better.
As there's lots of talk about running in-building, under-slab potable water lines inside PE I thought that doing the same with the main water line wouldn't be all that foreign of a concept.
You could use two threaded connectors and make the transition that way. I don't see any issues using an outer PE pipe as a duct, but you might find it easier to pull the PEX inside of PVC conduit (or pipe) on a short run. Rigid pipe will stay straight, which is likely to make the pull easier.
When sizing conduits/ducts, the more space inside the easier the pull. Electrical code only allows up to 40% fill by area for this reason, for example (although it's more complex with multiple wires, a single wire is allowed 53% fill by area). As long as you have a very loose fit you should be OK.
Bill
Bill, I'm thinking that the pex would be installed inside the PE and then both would get put into place.
I like that PE is a bit more pliable and less brittle than PVC.
It's all kind of make-work, but I'm trying to apply mitigation for peace of mind (which is really struggling on the notion of burying stuff under a slab).
Wisconsin has primarily been installing HDPE water lines for the last 35 years. The only problems I’ve ever heard is one case where a pinhole leak was caused by a sharp rock puncture, and a few cases where a compression coupling leaked. The couplings were not always installed with stainless steel stiffeners, which are now mandatory. One advantage of HDPE you may not have considered is that HDPE can be fused at the joints if you want to eliminate the amount of fittings. You can commonly get up to 2” in 100’ or 300’ rolls, but you can also gets spools of 1,000’. Directional boring with fused joints is sometimes cheaper to install after factoring in the costs of landscape restoration or if native soils aren’t good for backfilling the trench.
Copper has legitimate track record of 100+ year service life, but you will end up with many more couplings. I believe 2” copper has a max roll length of 75’. You must be careful when unrolling it to make sure it does not get kinked. I do know of one town in my area that had to replace copper lines after 20 years due to corrosion. This is a swampy area, which likely played a factor.
Also, keep in mind that you can always use a pipe bursting technique in hdpe or copper if the line degrades and needs replacement.