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Ensuring 24x7 drinking water to all citizens : 9/15/2015

24x7 Drinking Water for cities ? Why are municipalities working hard on this matter?

In our last article, we discussed about some of the important functions of a multiparameter analyzer that can make it more reliable & user friendly.

In this article, we will discuss about a fresh new topic - Ensuring 24x7 drinking water to all citizens.


24 X 7 Drinking water solution

It’s a story of a city in central India. The Municipal Corporation wanted to promote an idea of Uninterrupted Water Supply to the citizens, popularly known as ‘24x7 Water Supply Scheme’, with minimum interruptions to the flow of water, on a Public-Private Partnership (PPP) basis. The scheme is under implementation.

The company that is a part of this Public Private Partnership (PPP) model, manages the water supply of the city from Source to Tap for more than 1,89,000 consumers within the city,through a network for 50+ water supply reservoirs and 2000+ km in pipeline. It is responsible for the operation and maintenance of the existing network, up-gradation of the same, wherever needed, supply of water to the public at large, billing the water consumed and recovery of the billed amount for Municipal Corporation. It manages the Municipal Corporation’s Water Treatment Plants (WTPs) at two locations, all the Elevated Service Reservoirs (ESRs), Ground Service Reservoirs (GSRs), Master Balancing Reservoirs (MBRs) commonly known as Water Tanks.




The Application:

Basic source for Drinking water is either surface water or groundwater. Groundwater is much cleaner and free from bacteria, hence need less treatment as compared with surface water. Surface water is exposed to different types of contaminations and hence needs treatment before consumption.

The goal of water treatment is to reduce or remove all contaminants that are present in the water. There are many treatment processes that are used for treatment of surface water and groundwater.

After going through various treatment stages, water is often disinfected before it enters the distribution system to ensure that the potentially dangerous microbes are killed. Disinfection kills most harmful organisms and pathogenic bacteria. Chlorine, chloramines, or chlorine dioxide are most often used because they are very effective disinfectants.

Excess amount of Chlorine dosage keeps water disinfected in the pipes that distribute water to homes and businesses. A minimum free-chlorine residual of at least 0.2 ppm is recommended in plants requiring sanitary protection through the whole water distribution system. At this stage in the process, the water is potable, palatable, and ready for consumption.




The Challenge:

The water after treatment & disinfection (Chlorination) is moved into Elevated Service Reservoirs (called ESRs) for storage through pumps. The water flows down from these tanks into the community and this water should have some amount of Chlorine called Free Residual Chlorine (FRC) present in it. The FRC will keep the water disinfected in the pipes that distribute it to homes and businesses. To ensure this, the company wanted to measure FRC in water at 27 nos. of ESRs spread across the city.

Real challenge in such scenario is the maintenance of these analysers, since most of the FRC analyzers available in the market require membrane and electrolyte replacement on regular basis. This has to be done with utmost care apart from frequent manual cleaning of the sensors. Some others may require frequent reagent/chemical replenishment & tubing replacement. Since these Elevated Service Reservoirs are spread across the city, it is difficult to keep a check on each of them.



The Solution:

The company went for Free Residual Chlorine (FRC) on line analysers which require very less or almost no regular maintenance. These analysers can work with least manual intervention and thus the company would not require sending persons to different locations on routine schedule. A good saving on manpower !

Few unique advantages of these analysers that made life easier for the user include :

  • Membrane-free sensor, thus no clogging problems
  • No electrolyte required, thus no worry about changing electrolytes which are difficult to store also
  • Automatic Sensor Cleaning (ASR) for reliable measurement, relieving operators from maintenance of sensors
  • Transmitter, valves, sensors & flow-through holders, together are mounted on back plate, thus making it user friendly & easy to operate
  • Three analog 4-20 mA output, which can be used for different purposes
  • No sample preparation or adding of reagent, thus relieving user from cumbersome procedures, handling of chemicals etc.
  • Integrated temperature sensor for compensation, which adds to the accuracy of results
  • Auto pH compensation for sample where pH values vary frequently, which again adds to the accuracy of results

The Result :

The company is already using these FRC analysers at their Water Treatment Plant and ESRs also.

This initiative would help them serve better quality of drinking water to the people of the City.

In our next article, we will come up with a fresh new idea.