Old galvanized water line work and modifications

So my 74 pad park has very old galvanized water lines in some sections, and we’re suffering fluctuating water pressure at the ends of the lines.

We’ve hired an engineering company to advise us (not easy, the first 10 engineering companies I called were too busy to take on our project) and $4,000 later they’ve built models of our system and are recommending a looping of the system which they project will easily solve the water pressure problems.

They’re predicting the permitting process and working with both the township and the state to be difficult in post Flint crisis Michigan, and are predicting around $12,000 in soft costs on the high side for engineering plans, permits, revision of plans after requests from the state/township, etc. The current plan is proposing the addition of 900 feet of new water lines, and 7 new home taps, for a rough estimated cost of $60,000 on the high end (but this hasn’t been bid out to contractors yet)

I’m obviously not happy about a fix that’s this expensive, but it doesn’t seem like we have many other options. (fwiw, two engineers estimated replacing the entire system would cost $250,000-$300,000 to replace)

I was just curious to put this out here, see if anyone else had done similar work, and see if there’s anything I should keep my eye out for. It seems pretty straightforward, but figured it doesn’t hurt to ask if there’s anything obvious I should consider.


Feel free to forward the engineering report and proposal to me. There may be a cheaper alternative but can’t really say for sure without looking at what you currently have and what the engineer is proposing.

Phillip Merrill

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@Noel_S , as per your post:

  • “We’ve hired an engineering company to advise us…and $4,000 later they’ve built models of our system and are recommending a looping of the system which they project will easily solve the water pressure problems.”

My Husband and I purchased a Turn Around MHP approximately three years ago.

This MHP springs leaks constantly. In 2015 we spent $4,300 on fixing water leaks. This amount does not include the increased water bills.

Thus, approximately three years ago we received a quote from a Licensed Plumber for approximately $79,000 to replace just the WATER LINES with meters in the MHP:

  • Total Lots: 65 Lots
  • Total Acreage: 11.9 Acres

The $79,000 quote was for Water (No Sewer):

  • Digging All Lines
  • All Lines
  • All Water Shutoffs
  • All Meters

This MHP is in the South, so the depth of the water lines is not as deep as would be required in the North.

This Licensed Plumber is a one man show who has replaced water lines in a MHP before.

This Licensed Plumber is a good plumber with good rates.

We have had lots of other Plumbers who have not been so good.

Three years ago we even had a Licensed Engineer create drawings to replace the lines.

The Licensed Engineer said that replacing water lines was similar to installing a giant irrigation system.

The Licensed Engineer did advise that we connect all the water lines and have separate shut off values (looping of the system).

We also did find on the City Water’s Website a list of “Approved” Contractors that did Small and Large Water Projects.

One of our friends (who is also a Licensed Engineer and does new subdivision utilities for a living) said that we should loop the water system.

We wish you the very best!

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@Noel_S , as per your post for a:

  • New Water System

I found this old post from @Rolf .

I thought it was a wonderful post ( Thank you Rolf! ) and I am saving it for the future :slight_smile: .

"Rolf May '16
No permit for potable water line replacement? You need some way better advice on this one.

As far as specifics, here are a few. I was a landscape contractor for many years and irrigation was a big part of my work. Irrigation actually requires way more design competence than a potable water system.

  • Always loop the lines. This will keep even pressure throughout the park.

  • Use isolation valves to block off sections of park for repairs. This keeps you from having to shut down the entire park to fix a leak. I am pretty anal about this and actually put in 2 isolation valves 4’ apart. One can fail but two failing is unlikely. I also use at least 2’ of brass pipe on either side of a valve because turning a valve puts LOTS of stress on pipes. Brass can take the stress.

  • Bed the lines in sand with a tracer line as was stated above. Really good advice.

  • Allow for all-weather risers in several places in the park. This will make your life much easier if they are ever needed.

  • Use top quality parts, especially valves, as the cheap ones will cost you grief and money over time. I always specified valves made in America or Italy and would never buy anything from China or Thailand. I learned early on that one call back to fix a POS part from China more than erased any extra money I “saved” on buying the garbage in the first place.

  • ALWAYS sleeve your pipes where they pass under roads. This keeps them from breaking when heavy trucks (garbage) pass over them repeatedly.

  • Get a qualified engineer to design your system. I would have no hesitation in designing a system for my park near Youngstown, but then I have years of experience doing this type of work.

  • Be on site the entire time the work is being done. People do better work when someone is watching. The garbage that contractors put in below the ground would amaze you. Who will ever find out?

  • If a contractor doesn’t at lease mention the above, you probably don’t want to be using that person.

Hope this helps.

Rolf "


Looping is the way to go. We just did 3 mainline repairs on a small 33 home system in the last month caused by glue joint failures on dead end lines. Every time you get a water surge or hammer it is trying to pull every joint apart.

Yeah, I kind of like my advice:-) Seriously, designing a potable water system is not very hard and neither is installing one. If you are not the DIY type, then you can still learn a lot on your own about how to design and install a system. This puts everyone on notice that it will be difficult to cheat you. At the very least, be onsite the entire time the work is done and specify that no trench is to be covered until you have personally inspected and photographed or videoed every inch of the system. Here are a several other tips:

Only backfill the trenches to within 6 inches of grade. Put in road base instead of dirt for the remainder. This is light gray and it will allow you to easily locate the lines in the future. Plus, the backfill will sink and then it is easy to put more road base on top.

You MAY be able to install the new system in sections vs. doing this all at once. It all depends on how your current system is set up. The benefit to this is that you can spread out the costs over a period of years and, after you see how easy it is to do the work, you might even be willing to take this on yourself. It also spreads out the disruption in the park.

Every time I upgrade a pad, I wind up installing a new riser. Just before I put in the 90, I install a one-way check valve. All I use is the flapper type, but you should check with your engineer. Residents complained that water would siphon out of their water heaters if the park water would shut off. Not sure if that is possible, but now they have one less thing to complain about.

Don’t just bed the pipes in sand - cover them. Water pipes move ALOT and that is how mine are breaking. There is virtually no friction when pipes are completely bedded in sand.

Specify in your plans that all plastic to metal connections must be male plastic into female metal. I see male metal into female plastic all the times and that is pretty much a guaranteed leak at some point. I also recommend BOTH Teflon tape and pipe dope be used at such connections.

Good luck and keep us posted on your progress.



Off topic but somewhat relevant…how do you locate leaks in buried main distribution lines to know where to dig for repairs if there is no evidence top side of the leak location.

If you have several meters or valves throughout the system you can narrow the hunt area down. Then pretty much the standard is acoustic listening devises (that is what american leak detection and other use) to hear the noise of the leak. Pvc is harder because it is not as noisy. Listen at each valve, hydrant, blow off or meter to narrow the hunt some more then listen over the mainline. Good leak detection equipment is $3000 to $6000 just for the acoustic side, then you may or may not need pipe locating equipment… I found a leak the last month because it was so noisy I could hear a water fall like sound 2 feet below ground. Just happened to walk over the area.


All great posts, but the only addition I would have is that I had a similar problem a decade ago in a park, and the most economical solution was to install one or more pressure boosting pumps into the system. Here’s what I’m talking about.


It was put together by a licensed plumber, and solved the problem, although I’m not going to say it was the smartest or best way to achieve the needed results. All I know is that it was relatively cheap and worked.

Would you guys recommend putting an air hammer in the park’s system?

I did that in a house I plumbed once and it worked great. Before that, every time the washing machine shut off the pipes rattled.

I would put a hydro pneumatic pressure tank with a bladder on dead end lines. Same idea as water hammer arrestor just bigger :slight_smile: