Lakes, Wetlands and Streams

Monitoring the impact of anthropogenic activities on the health of waterbodies in India.


Vishnu Nelavagal, Sumita Bhattacharyya and Priyanka Jamwal

The catchment characteristics have direct implications on Lake Health. Various activities carried out across distant regions in the catchment have potential to influence the lake water quality. However, it is more common to carry out local interventions to address the problems observed at the lake, like placing meshes at the inlets or setting up effluent and sewage treatment plants near the lake. While this helps to reduce the negative impacts, it is effective only at certain points where the interventions are applied, and resulting in a lot of non-point sources affecting the lake health being unaddressed. By looking at a catchment scale, long term holistic management approaches can be designed and implemented for maintaining lake health.
This project looked at the impact of catchments with different dominant land use on the levels of heavy metals in lakes. Two types of catchments were selected within Bengaluru city - industrial and residential, and two lakes from each catchment type were selected. The flow and water quality was measured and HM flux (both inflow and outflow) for the lakes were estimated for post monsoon season (year 2020). Results showed that the HM influx for lakes with dominant residential land use was lower as compared to the lakes with Industrial catchment. Lakes largely act as a sink for HM levels with an estimated 0.91 kg/day of Cr load being assimilated by lakes with residential catchment. The lakes with industrial catchment have potential to assimilate 0.14 kg/ day of Cr HM load. In residential catchments, HM load was in the order Mn> Ni>Cr>Cu>Pb. Whereas in Industrial catchments, we observed that Cu was the highest followed by Ni>Cr; Mn and Pb were being released from the lake (Mn>Pb).
We argue that accumulation is not equivalent to HM removal as the same would eventually result in heavy metal toxicity, which would impact the lake health, including the local plants and animals. Also, as the lakes in Bengaluru are interconnected through raja kalves and drains, accumulation of heavy metals can result in contamination of downstream lakes.

Anjali V Raj1, Priyanka Jamwal1 and Laurence Carvalho2

1Centre for Environment and Development, Ashoka Trust for Research in Ecology and the Environment (ATREE), Bangalore

2UK Centre for Ecology & Hydrology (UKCEH), Bush Estate, Penicuik EH26 0QB, UK

Long term water quality monitoring (2015-2020) was conducted to assess the effectiveness of a constructed wetland (CW) deployed as a polishing stage for a Sewage Treatment Plant (STP) at Jakkur lake. In addition to treated STP effluent, raw sewage was also discharged into the CW. STP discharge increased from 10 (2015) to 13 (2019) MLD, whilst raw sewage inputs increased from 3 to 7 MLD. Despite the increasing pollutant load over the years, the CW exhibited consistent removal of organic matter, with average BOD5 and COD load removal efficiency of 46 %, 42 % in 2015 and 51 %, 34 % in 2020. Nutrient load removal was more impacted: average nitrate-N removal efficiency increased from -29 % to 44 %, whereas orthophosphate-P load removal reduced from 38 % to -22 % and fecal coliform count increased by 1 log. Reasons for changes in removal efficiency will be discussed.

Springs are the most important source of freshwater for the Himalayan communities. Rapid development and climate change in the region has led to severe water crisis. Drying of springs and subsequent decline in discharge is regarded as one of the major reason for this crisis. However, poor water quality also adds to such crisis, which is rarely explored and addressed. Our research aims at understanding the water quality issues of the Himalayan springs and how these are affected by the anthropogenic activities. This talk presents some useful insights from preliminary analysis of water quality data for few springs in Nainital region in Uttarakhand. The data contains information for twelve water quality parameters, monitored for 71 springs. The data on these springs is collected by a Civil Society Organisation named CHIRAG over a period of nine years.

Akash Ashwinia, Priyanka Jamwalb, Abi Tamim Vanakc

aResearch Associate, Centre for Environment and Development, ATREE

bFellow, Centre for Environment and Development, ATREE

cSenior Fellow (Associate Prof), ATREE

Presence of antibiotic resistant pathogens in poultry and its products is widely reported, but there is limited evidence on the impact of the poultry industry byproducts such as wastewater and litter on its immediate and wider environment. Also the contribution of cofactors such as bio-medical wastes, medicinal drugs, antimicrobials used for crops vis a vis poultry byproducts to the spread of AMR is less understood. There is limited data to investigate the dissemination of these resistant microbes to the span of the human habitat areas like villages, and their soil and water bodies. In this study, we propose a methodology to assess the impact of expansion of the poultry industry on the prevalence of antimicrobial resistant bacteria in the environment. We did a pilot study to understand the prevalence of AMR by taking a case of poultry expansion in Baramati district. We placed our study in the catchment and selected four sub catchments/regions, viz areas with dense and with sparse number of poultry farms, agricultural fields and the village to assess the impact of use of antibiotics on the environment. Preliminary results show the presence of 7 Multidrug resistant bacterial species in chicken litter with 5 species having a MAR index greater than 0.2. In agricultural soil where litter is used as manure, 7 multidrug resistant species with 2 species scoring a MAR index greater than 0.2 were observed. No resistance pattern is seen in the soil and water surrounding the poultry farms as proper disinfection protocols are followed at the poultries. E.coli and Enterobacter species showed resistance in village soil and control soil with MAR index less than 0.2. This study provides a baseline to investigate the environmental effects of any animal husbandry farms, excluding the overlaps of anthropogenic interventions and reaching the extent of the effects giving a holistic conclusion.
Keywords: poultry, AMR, MAR index, bacteria, catchment, environment

1. AMR-Antimicrobial Resistance,

2. MAR Index- Multiple Antibiotics Resistance Index

Nature based solutions (NbS) are a great promise in addressing challenges in sewerage and water supply network of the country, constructed wetland is one such addressing complex challenges of water management. Plants, substrates and microorganisms are the indispensable components of constructed wetland that help in treating wastewater. Despite the plethora of information on constructed wetland, there is a knowledge gap in optimizing the combined effect of the contribution of plant species and their combinations, plant density and harvesting frequencies on nutrient uptake rates and its effect on rate constant in tropical countries. This work reviews the existing case studies of constructed wetland with specific focus on their treatment performance as a function of plant type, plant density and harvesting frequency. Finally, the existing literature on cost benefit analysis of constructed wetland has been examined to understand if the application of constructed wetland can represent a valid alternative to conventional treatment technologies, confirming it is as a sustainable solution for communities at local scale.