@Noel_S , as per your question and comments:
- "Locating water leaks"
- "Mistakes do happen, but my manager confirmed the plumber showed up and dug up several of the lots."
I concur with @frankrolfe as per his comment:
- "My bet is that someone in this whole mess is not doing their job, with the most likely candidates being...2) your plumber not really doing the work, but just billing you for work not done."
Noel, you indicated that the manager confirmed that the plumber showed up and dug up several of the lots.
However, maybe the plumber missed one of the crucial areas that actually had the leak or maybe he did not have the know how or ability to fix the leak?
My Husband and I have 2 MHPs.
Our one MHP has a literal maze of underground plumbing pipes and we are the proud owners of those pipes.
We have underground leaks...lots of underground leaks.
Thus, we have tried a lot of plumbers.
We have found that fixing underground plumbing lines is a plumbing niche market.
Some plumbing companies that I have called can not comprehend that we actually own the underground plumbing lines. One told me to call the Water Company....(um...unfortunately, that would be us).
Thus, you need to find one of those niche plumbers.
I would recommend calling some nearby MHP Owners/Managers and find out who they use for their underground plumbing issues.
We have one plumber that is awesome. His Dad owned a MHP and he actually plumbed the MHP. This plumber will dig and dig and dig until he finds the leak. He will then replace whatever needs to be replaced.
We have had other plumbers (when our awesome plumber is not available and we have major leaks) who are not able to fix the issues.
One time we had a major leak. Since our awesome plumber was not available, we had to call another plumbing company. This other plumbing company sent two plumbers who came out, took a picture and then went home for the night. Yes, they went home for the night as water freely flowed out of our busted pipes.
Now, I am not a trained Plumber, but I could have most certainly dug a hole and taken a picture.
This leak was actually the result of a Mobile Home Mover placing a tie down directly into our main water line. Thankfully, the Mobile Home Mover eventually fixed the issue late that night.
We had another Plumber tell us that they (Father & Son Team) needed to come back the next day with another worker, because they (Father & Son Team) did not dig holes. They needed to bring back their "hole digger". Again, water is freely flowing out of busted pipes and the Plumbers wanted to come back the next day.
Start interviewing some new Plumbers. Find Plumbers who specialize in MHPs or new subdivision developments and that are familiar with underground water lines.
Our Water Company actually had a list of 'Approved' Plumbers who are authorized to do new developments. Check out the website for your Water Company and see if this information is available.
We wish you the very best!