Despite the fact that water supply and sanitation have been known since ancient times, only in the mid-nineteenth century people associated outbreaks of infectious diseases in cities with the quality of tap water and sewerage systems. Until that time, they used to believe that dangerous diseases were spread exclusively through the air. Since then many things have changed, and the efficiency of urban communications is best illustrated by the water treatment and sanitation system of New York, which is one of the largest metropolises in the world.
Where Does the Water Come from?
Water enters New York through aqueducts, which connect 19 reservoirs and 3 lakes (the Hudson Basin and the Catskill Mountains) with a communications system of more than ten thousand kilometers long. Part of the water enters the system from wells. For example, water comes from wells in Long Island.
The main part of the water supply system is arranged in the form of large-diameter tunnels. It permits greater throughput compared to pipes.
The Quality of Water
If we talk about the quality of tap water, the city is lucky, as even unfiltered water is of very high quality, and its additional purification using ultraviolet disinfection units makes tap water much better than bottled water, which people can buy in a store. It is worth mentioning that the cost of tap water is about a thousand times lower than bottled water.
In order to monitor the quality of water, the Department of Environmental Protection makes more than 630 thousand samples both from natural sources and within the city on a yearly basis.
The Way the City Achieves Reliability in the Operation of Water Supply Systems
Water supply to consumers in New York is provided by pumping stations. As it happens in many other countries, the pumps are equipped with asynchronous (AC) motors. Frequency converters help to increase the efficiency:
- help reduce energy consumption;
- help achieve much higher equipment reliability;
- increase its durability and efficiency;
- equipped with various protection algorithms for trouble-free operation of the electrical part of the system, etc.
An equally essential aspect of the life of a huge metropolis remains not only water preparation, but also the wastewater cleaning process. For this purpose, there are 14 treatment plants in New York, and the sewerage system is as long as the water supply system itself (ten thousand kilometers).
New York has been treating wastewater since 1890, and the modern process consists of five steps. These are preliminary, primary, secondary cleaning, disinfection, and treatment of solid residues. As a result, the purified water of 95%, is returned to the water area of the city harbor, and the dry components after processing are used for agricultural purposes.
After cleaning and separation processes, all sewage effluents undergo the process of chlorination. As a result, there are no pathogenic microorganisms and bacteria left in the water. Methane, which is also a by-product of purification, is used to supply energy to wastewater disposal facilities.
About the Author
Ravshan Esanovich Akhmedov is a highly qualified specialist and one of the key employees of the Samarkand city water utility. He made a significant impact on the modernization and development of the city water supply infrastructure. He is an active public figure and a teacher at the Samarkand State Institute of Architecture and Construction. Over the years of his professional activity, he has repeatedly received national awards of the Republic of Uzbekistan.
Ravshan Akhmedov is one of the co-authors of the textbook “Organization of the operation of water supply and sewerage systems and their use,” which is widely used in technical schools and in practice.