Energy Detective: The Case of the Buried Leaky Pipe
Jan. 14, 2015 — A few weeks ago, my pal Manny, a contractor, came to me with a frustrating problem. A client's co-op was using a lot of boiler makeup water and did not know why. The co-op had already found one leak underneath a first-floor apartment. Then Manny noticed the water meter on the boiler feed line was running backward and recommended the co-op install a new one.
The new meter showed that the leak was still about 70 gallons per day — it should have been more like 70 gallons a year. The number-one suspect was the condensate return pipe that ran under the beautiful lobby floor.
"But if it is leaking, they'll just dig up the floor again, replace the pipe, and bury it again," said Manny.
"…until it leaks again, and they have to do it a third time," I added.
"Yes," he sighed. "A few years ago, they replaced the buried steel pipe with copper pipe. Now someone is telling them it was the wrong material."
"You can replace steel with copper as long as you don't allow contact between the two dissimilar metals, which is easy," I said. "If this fairly new copper is leaking, it is most likely for a different reason. Did they by any chance re-cover the copper with dirt and then re-bury the pipe without making it easy to re-inspect?"
"Of course," he said. "When they dug up the apartment floor, they only took a few photos; they didn't measure anything and just repaired the leak and buried the pipe in the dirt again — just like they did in the lobby."
Since there weren't even drawings of the steam system, the key actions to take were to:
1. Eliminate the conditions that cause the leaks.
2. Keep track of how much new water is going into the boiler.
3. Make it easy to find and repair any leak that crops up.
I told Manny he should try to convince the building to install a small condensate pump on one side of the lobby and run a pipe up the wall, across the ceiling at a wall junction, and then back down inside the super's office. If they had aesthetic objections, they could cover it with molding or a soffit.
Failing that, they should run the pipe along a wall above floor level or, worst case, run it under the floor again but inside a concrete trough covered by removable floor panels. And whatever they did, they should take lots of measurements and photographs for future reference.
The idea is to eliminate buried (especially buried in dirt) and inaccessible condensate return pipe by either digging it up, making it accessible, or both. In this way, the likelihood of leaks is reduced, and when they occur they are much easier to detect and repair.
Case closed — or was it? "I gave them your suggestions," he told me. "But they've got their own ideas. Their plan is to dig up the floor, replace the pipe, cover it with dirt, and repair the floor."
"Don't they recall what an expensive, disruptive mess it was to dig up the pipe in the apartment? Maybe you should ask your boss to weigh in and let these guys know that their plan is ridiculous."
"That's the worst part of all!" he cried. "My boss says that 70 gallons per day of boiler makeup water is 'normal' and that they don't even need to repair the existing leaks."
"Manny," I said, "Welcome to my world. Unlike the Mounties, sometimes we don't get our man."
Tom Sahagian is Senior Program Director, Technical Services, at Enterprise Community Partners.
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