Everybody that I’ve met so far in Moscow and in St. Petersburg drinks bottled water instead of water from the tap. The bottles we get are in increments of liters:  I have nearly gone through four 5-liter bottles during my stay here. Ashan (they sell everying from nylons to kulich Easter bread) is the cheapest place to buy water, but it’s a bit of a hike, especially while carrying a large jug of water. Solution? If you don’t mind spending a few rubles more, the mini-marts in the Glavnoe Zdanie is much closer.

In Russian 150, I wrote a research paper about the drinking water quality of St. Petersburg but I only found one source that had been updated within the past five years. There have been water quality checks from outside sources, finding subpar results. Since then, Vodokanal (the company in charge of providing sanitized water to the city’s people) has implemented new technology and opened new water treatment plants. They assure that the water is safe to drink, but the population tends to buy bottled water despite this, perhaps out of habit.
In my paper, I did not research Moscow’s water quality, but the situation seems similar to that of St. Petersburg. At the dorms, we are told that even if the water tastes fine and we don’t get sick, there may be heavy metals (carcinogens) from the pipes webbing through the our homely monolith. We have chainiks (electric tea kettles) to boil water, but heavy metals don’t boil away.
It is impossible to know the water quality situation exactly – recent English sources are lacking and in St. Petersburg, Vodokanal does not make all of its statistics publicly available. Perhaps the water in both cities is drinkable and there are pipes (privately owned) that unintentionally add contaminants. We do as the Russians do; we drink bottled water. It is simply a safety precaution.