Microorganisms in water are currently detected at Vigyan Ashram using a colored broth called Mac Conkey.  The broth is incubated at 37 degrees Celsius in an electric water bath for 48 hours; if microorganisms are present, the broth changes color from pink to a pale yellow as the broth is digested and excreted.  If no microorganisms are present, there is no color change.

Power cuts are common in Pabal (there is normally no power for eight hours a day) and there is sometimes no power for several days at a time (from the 1st to the 16th of June there was no power in Pabal or the local area).  Reliance on an electrical heat source to keep a constant temperature is not ideal, so maintaining a constant incubation temperature is difficult.  To increase the sensitivity of the water testing at Vigyan Ashram a more reliable heat source is required.

As an extension to this project, the DelAgua water testing kit used by Oxfam could be made lighter and more suitable for use in the field if it was not reliant on a battery-operated heating system.  Vigyan Ashram would like to be able to offer water testing to rural farmers in Pabal, and a cheaper water testing kit that is unaffected by power cuts would be useful, especially if it could give an accurate result within a few hours.

Two potential projects have been identified:
1) To develop or modify an existing water testing system. The new system should, as much as possible, use the apparatus already available at Vigyan Ashram.
2) To design an incubator that does not rely on electricity and can be manufactured by Vigyan Ashram. The local community should eventually learn how to make and use the incubator, thereby becoming self-reliant and having the capacity to design water testing systems themselves in the future.

The implementation of improved water testing facilities will potentially reduce the income of doctors and pharmacists in Pabal and will also encourage a reliance on technology, where there is no urgent need. However since the solution is designed for Vigyan Ashram, an educational establishment, they are well placed to deal with these issues.

Many people currently treat water indiscriminately by boiling, filtration or chlorination. Others only treat their water after they have become ill. Drinking potentially polluted water is expensive in terms of medical bills and discomfort and indiscriminate treatment of water is not good for the environment and reduces people's natural immunity. Therefore, routinely testing water supplies seems a suitable way of reducing the chance of illness in a more sustainable way than the current practice.

Although electricity is relatively cheap and readily available, there are regular power cuts. Solutions should take this into account.

Although some people have car batteries for lighting during power cuts, this is a luxury enjoyed by the wealthier villagers. Vigyan Ashram uses batteries for lighting and to ensure that staff have access to email. People are unlikely to happily use anything reliant on batteries, as the following example illustrates: Vigyan Ashram was given a solar cell and battery to run an additional tube light during power cuts, but found that the batteries in the system only last for one year. So, while the system saves Vigyan Ashram Rs. 400 on electricity, it costs Rs. 800 to replace the battery, and so the solar cell is no longer used.

Fuel is relatively expensive and so is often used only when absolutely necessary or where it provides a valued luxury such as hot water for washing.

Refer to the engINdia Final Report for further details.

Many people use a form of ceramic filter technology that is produced locally by the kumber (potter). Essentially it is a pot made from a mixture of clay and charcoal placed on a stand above a collecting basin. The pot is filled with water, which is presumably filtered as it percolates through the pot and then drips into the collecting basin. A similar system based on compressed rice husks has also been developed in a nearby village. Both systems have the potential to provide a replacement for the membrane necessary in a Del Agua-style water testing kit.

When designing a method of incubation it should be noted that the ambient temperature in Pabal is higher than in the UK (see the engINdia Final Report). This may mean that an alternative heat source (such as the heat of the sun) is more viable than it would be in the UK.

The testing procedures carried out by Vigyan Ashram are not as accurately performed as we would expect in the UK or US. This possibly reflects the scarcity of resources, the fact that accuracy does not seem to be so heavily valued as in the US and UK or the rural location and level of training at Vigyan Ashram.

Vigyan Ashram has:

Electric water bath (set at approximately 40°C)
Thermometer (-10 - 360°F)
Mechanical balance (1mg - 100g)
Masses (200mg x 6, 500mg x 3, and one each of: 1g, 2g, 5g, 10g, 20g, 50g, 100g)
Burettes (1ml 1/100, 2ml 1/50)
Pipettes (5ml, 10ml)
Plastic dropper
Pressure cooker (capacity approx. 7 l)
Paraffin stove
Test tubes (x5)
Thurum tubes (very, very small test tubes, x5)
Plastic beaker (200ml x 1)

The water test currently used by Vigyan Ashram is as follows:
o Weigh 1.2g of Mac Conkey Broth powder and dissolve it in 30ml of distilled water.
o Boil this for 2 minutes to expel any O2 from the solution.
o Allow this to cool, then pipette 5ml of solution into each of 5 test tubes.
o Use a dropper to fill a thurum tube (very, very small test tube) with solution from the test tube and then drop an inverted thurum tube into each of the test tubes. (N.B There must not be an air bubble in the thurum tube that sits inverted at the bottom of each test tube.)
o Fill the end of each test tube with cotton wool and place all 5 test tubes into a plastic beaker.
o Prepare a pressure cooker with an inch of water at the bottom, half fill the beaker with water and place the beaker into the pressure cooker.
o Heat the pressure cooker on the paraffin stove. Once the pressure valve has risen and fallen 3 times, turn off the stove and allow the pressure cooker to cool. (This sterilizes the solution and test tubes.)
o Once the pressure cooker can be opened remove the beaker, pour out the water and allow the test tubes to cool for 5 minutes.
o Then pipette 5ml of potentially polluted water into each test tube and place the test tubes in the pre-warmed water bath (set at approximately 40°C, a thermometer was not used to confirm this) for 48 hours. (This pipette was not sterilized before or after use.)
o If three or more of the five test tubes show a colour change from pink to yellow then the water is not safe to drink (this shows that pathogens are present since the nutrient has been digested).
o If three or more of the five test tubes have a floating thurum tube then the water is not safe to drink (this shows that pathogens are present since CO2 has been produced).
o In other cases the water is considered safe to drink.

Vigyan Ashram was asked to test some rain water that had been collected. This water appeared to be unsafe to drink from the level of floating organic material and its smell. However it was passed as safe by the above test and so was drunk by a so to confirm this result a member of the team drunk only this water for four days with no ill effects showing that this test is probably useful in spite of its limitations.

For more information on this project, please contact engindia@mit.edu.