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- Factory: a leaking mains connection under the car park
Factory water main leak detection: low pressure, high bills and a leaking connection
Water pressure had dropped and the bills were unusually high, with no leak in sight. Pressure testing pointed to the incoming main, where a leaking connection was dug out and repaired.

What was happening
The factory had lost mains water pressure and its water bills were unusually high. Nobody could see any sign of a leak, so the cause of the low pressure and the extra water use had to be found.
What the engineer did
Pressure testing gave a positive reading around the incoming water meter. During the test the engineer noticed the meter did not appear to be turning or registering while water was being used, which suggested a problem with the meter itself. The incoming mains pipework was then investigated and excavated through the concrete of the car park.
What was found
A leaking connection on the black Alkathene (polyethylene) incoming main. The incoming mains pressure was also measured at below 2 bar, which the engineer considered particularly low for commercial premises of that size.
What happened next
ADI cut back and upgraded the affected pipework and repaired the leaking connection. A reliable retest after the repair was not possible: the stopcocks were turned off several times for testing, but the water kept being turned back on so staff could use it, so a second leak could not be ruled out. ADI recommended that the water supplier inspect the meter and the low incoming pressure, followed by a retest out of hours when the site is empty.
If you run a warehouse or factory
A site that is always using water is hard to test. If your supply needs a proper leak test, plan for a window when nobody on site needs water, out of hours or at a weekend, so the main can be isolated and the reading trusted.
More case studies
Factory: rain getting in through the roof and a stairwell window
Rain was dripping into the factory at several points and coming in at a stairwell window. Dye, tracer gas and thermal imaging showed the routes in, for a roofer and a window contractor to repair.
Factory unit: a hidden leak under the toilet floor
The meter showed water running all the time. Isolation tests traced it to a cold feed under the toilet floor, which ADI cut off and bypassed with new pipe.

