The source of the mysterious sound that wouldn’t let the people of Polichni at Thessaloniki sleep, has been located.
The phenomenon is called “water hammer” and it is caused by the increased pressure inside a pipeline which causes a shockwave when the flow is forced to change direction or stop abruptly.
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The technical team of Thessaloniki’s water company EYATH have made some adjustments on certain valves 2km away from Polichni, where the source of the problem was located, and they will observe the phenomenon to make sure it will no longer bother the residents of the area.
The reason the “thumping” begun at night is because the use of water is decreased during those hours and the pressure in the pipelines increases.