Water contamination unavoidable, but not terminal, City officials

Water contamination is a problem which pops its head every year in Thimphu but it is not hazardous, to say the least, as many residents in Thimphu have speculated.

Monsoon brings with it water contaminated with dirt particles and tiny wooden debris which eventually flows through the taps of Thimphu residences. This is the fate of town residents although not through the whole season but during the days of its coming.

For such times residents who can afford, normally buys packaged mineral water for drinking and cooking as well. However for the poorer sections they usually wait for the dirt particles to subside and then use the slightly clearer water from the surface.

A Motithang resident, Indra Bdr said, “When water becomes contaminated by mud everyone buys bottled water, but we can’t afford it, so we ignore the dirt and use contaminated water”.

Thimphu City Corporation (TCC) official said the water as such is not hazardous for once, but according to doctors at the national referral hospital (JDWNRH), it could affect a person’s immunity to bacteria and viruses which could make the individual vulnerable to diseases like Typhoid which has killed one person last year and a staggering 145 cases of diarrhea was reported.

The reports show that around 70% of last year’s water borne illnesses occurred during the monsoon. By these facts it would accumulate an alarming number of sick people with the rapidly growing population unless the TCC finds a solution to this problem.

Restaurants in Motithang areas said that their business can be gravely hampered especially when the water becomes completely turbid .They said the customers normally do not ask for bottled water so when they provide them boiled tap water the turbidity is still visible.

These incidences leave a permanent impression on the minds of the customers thinking that the establishment would always provide contaminated water.

A TCC official Naphel said it is an unavoidable circumstance especially during the rainy season. However he assured that this problem is not hazardous as one expects.

The water treatment plants in Thimphu located in Dechencholing and Motithang are doing its part in filtering the debris and dirt particles. The methods normally used are to add aluminum sulphate and lime which absorbs the sediments at the bottom of the tank reducing turbidity. Along with this chlorine is also added as a disinfectant. These chemicals are added according to the water volume.

The water treatment plant in-charge in Motithang, Karchung Dukpa said that sometimes even if the water is sent without impurities from the plant the reservoirs may have debris and dirt particles so the problem starts from there as well.

He said the overhead tanks on the building some times are not cleaned which too can lead to water contamination. The water plant incharge said the capacity of the plant is just 6500 cubic meters with four tanks but the plant processes around 8,000 cubic meters of water each day so this overload also contributes towards the turbidity, but not on a regular basis.

Karchung said that the turbidity level is always maintained below 5 Nephelometric Turbidity Unit (NTU is a unit to measure water clarity, low NTU signifies high water clarity and vice-verse) which is the safe standard level recognized by the World Health Organization (WHO).

He said if the water turbidity is higher than 5NTU then the chlorination process will not work effectively.

The Chief of water section at TCC said “we have sent repeated notices to all the building occupants to clean their overhead tanks frequently, but they fail to do so”.