Is the presence of mercury in water normal? Following the trail of Tsav's water

In September, mercury levels in several water samples from the village of Tsav in Syunik exceeded the permissible limit, after which residents were urged not to use the water even for household purposes.

One and a half months later, the Ministry of Health announced that new tests conducted in Armenia and abroad show mercury is now within permissible limits, and the water is safe to drink.

However, neither for the September tests nor for the recent ones was the exact concentration of mercury published. How much mercury was in Tsav's water, how much is there now, what changed in a month and a half, and has the source of contamination been identified?