På grund af jordbundens struktur og de forskellige strømme er det mange gange uklart, hvilken mine der er ansvarlig for det vand, der kan udgøre en trussel mod miljøet og skal holdes under kontrol.
Owing to the structure of the ground and various currents it is, in many cases, not clear which mine is responsible for such water, which could endanger the environment and has to be kept under control.