The concrete face has been cracked many times by the movement, causing leaks.
The falling rocks had hit with enough force to cause leaks in some of the seams.
And other less exotic particles, like neutrinos, can also cause leaks.
The standard method is high-pressure water jets, but that could cause new leaks.
"We get more calls about leaks caused by planters than almost any other leak-related problem," he said.
Last year, a defect was found to cause leaks in about 5,000 vehicles, which were repaired by Chrysler.
Two bombs are dropped in the lake above the bunker, causing leaks and damages.
The most serious is an apparently unsealed room that causes major leaks all over the building when it rains.
I have considered replacing the valves, but am afraid this might jar the old pipes and cause leaks.