The leak had gone undetected because my renter failed to transfer the water bill to their name – and therefore had not been aware of or even paying the water bill once since moving in.Upon finding out about the large water bill and the running toilet issue, I immediately scheduled a leak detection specialist and plumber to inspect the entirety of the water line and address any found issues at their soonest availability.

@Jimmy S.You're a landlord, not a detective. 

I know that you can't catch them all, but working on your screening process and detective skills will net you far more valuable rewards than insurance dollars.

We have rolled-our-own building monitoring and (increasingly) management system which lets us detect conditions and events at our properties before they become calamities.We are deploying electronic deadbolts which allow us to grant/revoke access remotely and permit us to let in locked out tenants using our phones/laptops rather than driving across the city.  

Good idea to pay for leak detection first, possibly be able to repair it rather than replace the entire line. 

The reason I only use those four is because others (I have a total of 22 features collected, many very sparse) didn't improve my models or made its performance even deteriorate.I also use principal component analysis (PCA) as a very simple anomaly detection algorithm on the data set.

This simolifies meter reading and bill backs while also providing you with an opportunity to detect leaks and major issues early via custom alerts.

My house needs a new roof now that leaks may been detected.

You are not a detective and are not required to go to extraordinary efforts to find them.

Google has pretty savvy algorithms that detect invalid/malicious clicks.Google on invalid traffic:"We help protect advertisers from invalid traffic by working to isolate and filter out potentially invalid clicks before they ever reach your account reports.