Caddisfly for Lake Monitoring

Posted by Ishan Gupta on 2018-05-03 00:00:00 +0000

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The lakes in and around cities serve as the site for many functions: for citizens, for flora, fauna and for the water and waste management systems of the urban environment. In cities such as Bangalore, chemical, pharmaceutical and manufacturing industries discharge their effluent waste and wastewater into lakes. Lakes are becoming waste repositories for cities.

In monsoon, inflammable froth is sometimes found floating above the water surface of freshwater urban lakes. Bellandur lake is one example, where heavy metal contamination has led to a toxic froth, which is a health hazard for people, plants and animals around it. The froth has reportedly caused itching, burning sensations, skin and eye irritation and respiratory problems.


Contaminated water in lakes percolates through the lake bed and mixes with underground water aquifers, contaminating these sources in time. Heavy metals like Chromium and Lead are being detected in tests of groundwater from sources around lakes. In 2016, interns working with the Caddisfly team tested groundwater around some of the lakes in Bangalore and found unsafe concentrations of Chromium VI. Such contamination does not produce a distinctive taste or smell in the water and can be consumed by unsuspecting people, animals and birds. High concentrations of Nitrates, Phosphates and sudden changes in pH were also noticed, which can explain the rampant eutrophication seen.

It is imperative to monitor water quality parameters regularly to support lake maintenance activities and measure the impact of human activities on lake ecosystems. Testing can be used to inform decision making with regards to clean-up operations, water flow regulation, and even to surveil suspected contaminating industries.

Monitoring of lake water has been traditionally expensive and cumbersome. The tester had to collect a sample of the water from the lakes and deliver it to a testing laboratory. Certain parameters (such as Dissolved Oxygen concentration) change significantly over time. Laboratory results take time to be delivered, subject to the vagaries of supply and demand and also to the delivery mechanisms.

ffem has developed the Caddisfly smartphone-based water testing kits that measure pH, phosphates and Nitrates in-situ and use apps to geo-tag the results, allowing water quality data to be chronologically and geographically logged. The collected data contributes to an open database on water quality, helping build a publicly accessible repository of data on water quality.


Our testing kits give comparable results with the laboratory methods. For Nitrates, Phosphate and pH, the price per test is considerably lower than commercial laboratory methods.

ffem recently supplied Caddisfly kits to Ashoka Trust For Research in Ecology and the Environment (ATREE) for evaluation and to aid in their field data gathering activities towards research they are carrying out on lakes in Bangalore.

In December 2017, ATREE invited FFEM to present Caddisfly at a summit on “Rethinking Bengaluru’s Water, Wastewater and Lakes where a variety of perspectives were presented along with original research. A number of proactive citizens and citizen groups were also present, who were encouraged to take on the responsibility of lake monitoring to aid government and NGO efforts. Demonstrations of Caddisfly to the public garnered a lot of interest from attendees and particularly the citizens and groups seeking affordable technology to aid in their lake monitoring activities.

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