Case Studies

Germ-free research JalKalp model to provide safe drinking water

Here’s a low-cost water purifier suitable for rural, peri-urban and urban slum- segments to turn the contaminated water clean and healthy for living. Researchers call it ‘JalKalp’.rn
Germ-free research JalKalp model to provide safe drinking water

With modern lifestyle getting expensive along with natural basic amenities like food and water getting contaminated, the prices that human pays for it is health. Here’s a low-cost water purifier suitable for rural, peri-urban and urban slum- segments to turn the contaminated water clean and healthy for living. Researchers call it ‘JalKalp’.

The story of drinking water. How many of us know it? It’s said that the Egyptians were the ones who actually got the methods of treating water for drinking. They got this right. Boiling it on fire, treating the germs in sunlight and immersing a heated iron rod in water. They tried to civilise the group the ways to treat water before drinking and cooking that might help to reduce health challenges. This was around some 1,500 years ago.

Unfortunately, today’s legion is still confined in the bracket and development goals are set for them to provide safe and healthy drinking water. The challenge is huge and big in size. It’s the world’s population struggling with insufficient availability and potable quality of water.


The United Nations estimates that nearly 900 million people do not have access to safe drinking water sources. In places with no clean water or infrastructure for sustainable water sanitisation, people often obtain water from the same sources in which animals drink and defecate. This leads to water-related diseases such as diarrhoea, dysentery and cholera.

According to World Health Organization (WHO) estimates in 2008, deaths of more than 2.2 million children per year could be prevented by reducing the diarrheal and malnutrition impacts related to unsafe water, inadequate sanitation or insufficient hygiene. Deaths of children under 15 years are greater than the combined impact of HIV/AIDS, malaria and tuberculosis.

India lost more than 6 lakh under-five children in 2010 due to water, sanitation and hygiene (WASH) related diseases, such as diarrhoea and pneumonia. These diseases are caused by pathogens (biological contaminants). Iron and Arsenic contents in water over permissible limits are found across Bihar, Rajasthan, Sikkim, Tripura, Assam, Manipur, Nagaland, Chattisgarh, Jharkhand, Odisha and West Bengal. Thus, water- borne disease is caused by pathogens, iron and arsenic have an adverse health impact that leads to malnutrition and low immunity levels to other serious ailments.


A sustainable appropriate technological solution is therefore much needed to eliminate the risk factors prevailing both in rural as well as in the urban civilisation. Though the concept of filtering water through sand and gravel is very old yet the technology was not consistent at different locations due to varying nature of constituents and the methodology. A perfect technology was needed to be consistently effective and sustainable against the most prevailing contaminants.

Bring a solution, Dr David Manz of University of Calgary, Alberta (Canada) developed a water treatment device and called it ‘Biosand Filter’ based on the conventional sand and grit filtration. It removes pathogens (the leading causes of waterborne disease), as well as iron and suspended solid particles from water, making it suitable for drinking and other purposes. The filter can be easily adapted for arsenic removal also.

These filters are now being used in more than 70 countries throughout Africa, Europe, Asia, North, Central, and South America, the Caribbean, and the South Pacific. But still it had some issues unresolved. Conventional bio-sand filters are made of pre-cast cement concrete, which is prone to breakage. The rate of production is limited as it needs a mold and curing time, for each mold it is about 24 hours. Because of being heavy weight its transportation to remote villages on rural roads and undulating hilly tracks is troublesome and risky. Due to variations in construction materials the quality of produce is not consistent. All these triggered Sehgal Foundation to design and develop bio-sand filter in another material.

And therefore launching it in India, Lalit Sharma, Director, Adaptive Technologies at SM Sehgal Foundation developed and introduced the innovative model of Biosand Filter and named it ‘JalKalp’, a fabricated in stainless steel so as to overcome the limitations experienced with conventional Biosand Filter made in pre-cast cement concrete.


On the comparison level, the performance of the JalKalp model is found to be better than the conventional one. Besides, JalKalp offers increased filtration rate and better portability and production quality control. The water quality tests demonstrate its effectiveness against E Coli, Total Coliforms, Turbidity and iron contamination. The newly developed stainless steel bio-sand filter JalKalp, which is about 4.5 kg, has an edge over concrete filters (65 Kg), overcoming each of those shortcomings and providing better quality control.

There are a few differences the led engineer wishes to highlight between the traditional and new innovative design. Sharma describes that the fine grain sand prevents the passage of bacteria, parasites, and worms, which are relatively large, that the bio-layer which forms as the pathogens colonise on the surface of specially prepared sand particles in top sand layer which has a slight electrostatic charge. These pathogens predate the bacteria and parasites entering in filter with new water. The remaining microbes die off as there is no oxygen, light, or air further down in the filter.

The bio-sand filter does not require any replacements as there are no moving parts. It does not require any source of energy or online pressure, which makes it appropriate for rural or peri-urban settings. With time, the flow rate of filtered water may be reduced due to silt that comes with water and accumulates over the sand layer. Whenever this happens, simply lift the lid, pour water in the filter, take out the diffuser box, and do a ‘swirl and dump’ which means gently swirling the water above the top layer of sand and pouring out the cloudy water above the sand. This may be repeated 3-4 times to clean the top layer of accumulated silt and filter starts working at normal flow rate.

Water quality tests

Water quality tests were conducted for pathogen and iron removal to know the efficiency of JalKalp. Sharma states that the test was conducted on diluted sewage water also. The trend in efficiency of removing coliform from raw water is found to have improved to 95 percent on the seventh day of installation – which then improves the quality up to 98.5 percent till the 20th day and remain static thereon. Removal of E Coil from raw water was 100 percent from day one and continued.

JalKalp filter is also noted to remove about 99.9 percent iron content from raw water. Further tests need to be conducted on water with higher concentrations of iron, to validate the effectiveness of JalKalp in removing iron contamination in varying ranges.

Likewise, nanotechnology-based water purifier has been developed by Indian Institute of Technology, Madras that provides arsenic-free water at an affordable cost and will soon be installed in all arsenic-affected regions of the country. The purifier is already providing arsenic-free water to more than four lakh people in West Bengal at a cost of less than 5 paise per litre.


Sharma finds the product to be promising that might bring a revolutionary change and sustainable healthy lives for people. The product has proved to be efficient as proclaimed. Ability to produce sufficient amount of safe treated water to meet the daily household needs, JalKalp filter can treat 18-20 litres of water in each pour. Effectiveness in treating water with specific contaminants, it is successfully demonstrated to treat most commonly disease causing pathogens in water. Small user time to treat water; the filtration rate for JalKalp filter is 0.75 litres/minute. A low cost JalKalp filter costs Rs 3,000.

Availability of reliable, accessible and affordable supply chain for maintenance and replacement parts that is required for any such unit to sustain; Jalkalp filter is replacement free and requires simple maintenance routines that the user can do on his/her own without need for external support.

“The newly developed JalKalp filter is found to effectively treat the issue of water contamination at household level and is scalable to address common and widespread occurring water contamination – thereby promote community health by reduction of waterborne disease,” concludes Sharma. 

The Changing Face of Rural India