sulabh swatchh bharat

Thursday, 17-August-2017

NANO-TECH AND SUN TO THE FORE

The state government is taking urgent measures, harnessing latest technology to take the bull by the horn

Taking on the serious situation of groundwater contamination, the Assam State’s Public Health Engineering (PHE) department is planning to install solar power pumps and an affordable nano technology-based water purifier to purify water across the state. 
 Assam’s drinking water continues to be contaminated with harmful pollutants like arsenic, fluoride and even lead. Groundwater in more and more habitations are reporting harmful levels of the contaminants, leaving residents, scientists and the government worried.
According to State’s Public Health Engineering minister Rihon Daimary, water sources in 23 districts of the State, including the state capital have been contaminated with arsenic and fluoride.
The State’s Public Health Engineering department has tested 3,25,079 water sources across the state. Out of that, 10,301 have arsenic, while 1,298 have presence of fluoride, Daimary said.
These tested water sources comprise only 59.14 per cent of the total water sources of the state, he added.
As on date, the number of arsenic-affected habitations stands at 3,726 and fluoride-affected is 155. These habitation have considerably higher levels of the chemicals in ground water. Among the districts, Jorhat (with 959 affected habitations) and Baska (with 821 affected habitations) have been the worst hit in terms of high arsenic level in ground water. Ninety three habitations in Dhubri district are affected by fluoride. Sources, however, said the actual number could be more with fresh tests confirming arsenic and fluoride in other areas as well.
Scientists blame the phenomenon on long dry spells which have led to less rain water seeping into the ground and replenishing the groundwater table. Indiscriminate cutting of trees has only added to the problem.
Another major reason is the increase in drilling activity for hand pumps and borewell pumps. With the lowering of the water table, the drills are also going deeper, thereby closing in towards the granitic rocks that are rich in minerals like arsenic and fluoride. Therefore, such chemicals are making inroads into the water pumped up.
In Guwahati, for instance, earlier people would bore 150-200 feet for water. Now with the mushrooming of flats and housing societies, the water demand has gone up. But since the water table has gone down, people have to bore up to more than 300-400 feet.
Recently, Associate Professor Dr Bibhash Sarma of Assam Engineering College and his M Tech student Priyanka Kotoky found excess amount of lead and arsenic in the Brahmaputra water samples collected from different areas between Noonmati and Pandu areas of the capital city Guwahati.
Usually such chemicals are not supposed to be found in surface water. The study has assumed that such contaminants were dumped in the river.
Worse, the study also found very high levels of untreated or less treated arsenic and lead in the drinking water supplied by the six water treatment plants (WTPs) of Guwahati city, which poses a serious threat to public health.
Prolonged arsenic contamination is known to cause cancer and skin diseases besides affecting reproductive health. Apart from Assam, arsenic-laced water is a serious problem in Bengal, Uttar Pradesh, Jharkhand, Chhattisgarh, Bihar and Manipur.
Consumption of water containing excessive fluoride causes dental and skeletal fluorosis and most of the fluorosis victims are children. The most pronounced symptoms of fluorosis are bent legs and discoloured and brittle teeth.

Tech Solutions
Alarmed at the increasing contamination of ground water, the State’s Public Health Engineering (PHE) department is planning to install solar power pumps and an affordable nano technology-based water purifier developed by IIT Madras to provide safe drinking water in the areas.
“The levels of these chemicals in ground water are serious. We are now adopting a two-pronged strategy to deal with the problem. Either we will have to clean the ground water used for drinking or we will have to supply the drinking water from surface sources,” said a senior PHE department official.
The PHE department has prepared 122 DPRs (detailed project reports) which have been submitted with the National Water Quality Sub Mission - launched by the Ministry of Drinking Water and Sanitation in March last. These 122 projects will cover 1,438 arsenic-affected habitations and they mostly deal with providing safe drinking water from surface water sources. Work is on in another 5,00 habitations.
In almost half of the remaining 1,788 arsenic-affected habitations, the PHE plans to install solar power operated pumps.
The Centre has recently launched the National Water Quality Sub Mission to combat arsenic and fluoride to provide safe drinking water to about 28,000 affected habitations in the country by March 2021 with an outlay of Rs 25,000 crore.
The PHE department is in the process of preparing the project reports for the solar power operated pumps. These habitations are basically remote areas, most of which do not have access to electricity. To purify the water, the PHE department will use the nano technology-based water purifier developed by IIT Madras.
The purifier developed by IIT Madras uses iron oxyhydroxide, a nano-structured material, to remove arsenic from drinking water. It functions without electricity or piped water supply. Once the filter reaches its saturation limit it has to be reactivated or recharged with new material.
The PHE department is also studying the water use pattern in the habitations, for building reservoir tanks of appropriate levels. In case of fluoride-affected habitations, the PHE has taken up seven projects, while work is already on in eight others.
Till the planned projects are executed, the Niti Aayog has funded a project to provide stopgap arrangements in the highly arsenic-affected 96 habitations. The PHE is using solar powered deep tube wells in these habitations and work has been completed in around 60 of the projects. The firms installing the solar-powered deep tube wells will have to do the operational maintenance of the devices for three years.