Clean water: how it turns out

Water for the capital is taken from rivers and reservoirs, which are located in the Smolensk, Tver and Moscow regions. It is collected from an area of more than 50 thousand square kilometers. For comparison: this is the territory of Estonia or the Dominican Republic.

All the most interesting things happen at the water treatment plant. The water gets into the mixer and bubbles up like in a river. So it is mixed with a coagulant. This is a reagent, but do not be afraid of this word, it causes dirt particles invisible to the eye to stick together and form flakes. When water enters the flocculation chamber, it moves more slowly, and the flakes become larger. You can see them.

From the river, water gets to water intake facilities, where it is cleaned of large debris. Lattices hold branches and algae, grids hold the fallen leaves, small grass-blades. And so that the fish does not swim, it is scared away by air bubbles.

Powerful pumps pump water to one of four water treatment stations. From the Moskva River, water gets to the Rublevskaya and Western stations, from the Volga — to the Eastern and Northern ones. So if it seems to you that in one area of the city the water is softer than in another, then perhaps it doesn’t seem to you. It can really differ, while remaining within strict standards.

The water stops moving in a deep and long sump tank. Here the flakes become heavy and precipitate, and the water brightens. Of course, you can’t drink it yet, but it has already passed the first stage of purification.

Then the water is saturated with ozone. As a result, no microorganisms, organic compounds, as well as substances that give the water a smell remain.

Ozone-saturated water enters pools with granular coal. Its porous structure traps the smallest dirt particles oxidized by ozone at the previous stage. Every year for such filtration, about 10 percent of new coal is loaded into the pools to replenish losses, and every four to five years it is completely replaced with a new one.

Finally, the water is treated with an aqueous solution of sodium hypochlorite that is safe for humans. In Moscow, it has been using instead of liquid chlorine since 2012. Sodium hypochlorite protects water from re-infection by bacteria or microorganisms that could occur in water pipes. And there are more than 13 thousand kilometers of them in the capital. This is more than the length of Russia from west to east.

The next obstacle to water is a layer of sand almost as tall as a man, one and a half meters. Through it, water moves from top to bottom: it is cleaned and brightened. But the water will not get into the water pipes soon.

Ozonation together with subsequent purification with coal is called ozone sorption. This is a modern technology that has radically changed the quality of water in the homes of Muscovites.

Sodium hypochlorite is used in cities that are famous for the high quality of tap water, for example in London and Tokyo. And there are also very long pipes in these world capitals.

After the final checks, the water from the four water treatment stations enters the regulatory units. There are 19 of them in Moscow. Through them, water is distributed to districts and houses. In order for the pressure in the taps to be good, there are 24 pumping stations and 524 priming stations. They have a lot of work to do: about 2.8 million cubic meters of clean and safe water are supplied to the city network every day. It’s a billion a year, a small lake.

The whole process of water treatment takes from 8 to 12 hours. At each stage, from extraction to delivery, water is evaluated according to physical and chemical, microbiological and hydrobiological indicators.

Tap water in Moscow is absolutely safe and meets the requirements of sanitary legislation (SanPiN), which are updated every 10 years and, as a rule, are tightened. Even 15 years ago, the water in the capital was not cleaned as it is done now. Ozonizing, coal filtration, membrane filtration at some stations, global replacement of liquid chlorine with sodium hypochlorite — all this allows you to drink tap water safely.

> 6000
tests

continuously monitor water quality

500
devices

of daily on-line monitoring

Purification and supply from the river to the house of even one liter of water requires huge energy costs and human efforts. No less resources are needed to return the water back to nature purified again. That’s why it’s so important not to waste it. Many Muscovites understand this: they install individual counters, use dishwashers and washing machines. The population of the capital is growing, but every year we use less and less water — now 127 liters per person per day.

30
indicators

are conducted by Mosvodokanal per day