Serigudam Sailu is a farmer from Telangana, India, with a mere half acre of fragmented land and without irrigation facilities. He depends entirely on rain to cultivate sorghum and pigeon pea to support his family. Without access to alternate water sources, conditions were difficult during low rainfall and long summer months.
The situation changed, once the first domestic wastewater treatment unit was established in his village in 2014.The treated wastewater is available free of cost and Serigudam now has steady yields and is able to rotate crops, which has diversified his income. The treated domestic waste water is obtained from the decentralized waste water treatment units; a technology which is an outcome of Water4Crops, a large Euro-India collaborative research project was co-funded by the Department of Biotechnology and the European Commission. At Serigudam’s village in Kothapally, ICRISAT worked with the local NGO READ to establish it.
In summer Serigudam grows sorghum on a quarter acre using treated wastewater and this gives him 600 kg that he sets aside for his own consumption. In the next season, he grows coriander for sale as it fetches a good price.
The European Union and Government of India co-funded project Integrating Bio-treated Wastewater Reuse with Enhanced Water Use Efficiency to Support the Green Economy in EU and India was initiated in 2012.
It has shown remarkable success in reducing water scarcity and helping safe reuse of wastewater in agriculture. By constructing wetlands with plant species such as Cann indica, lemon grass (Cymbopogon), napier (Pennisetum perpureum X Pennisetum americarnum), para grass (Urochloa mutica), typha (Typha latifolia), water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes) and a weed species Agaratum Conyzoides the chemical oxygen demand in wastewaters have been reduced by 30 92%. Moreover, yield evaluations have shown increased crop yields (14 to 40%) of crops like okra, brinjal and chilly irrigated with treated wastewater as compared to fresh water.
The initiative involved 11 Indian institutes and 21 EU institutes to bring about better management of water, land & crops aimed at a viable, stronger & sustainable green economy at an amount of 19 Million Euros.
Indian consortium partners have demonstrated the use of constructed wetland as decentralized wastewater treatment systems for both industrial and municipal wastewater. At the SAB Miller plant in Sangareddy, Telangana, and K.C.P. Sugar and Industries Corporation Ltd in Lakshmipuram, Andhra Pradesh, constructed wetlands were prepared to treat the effluent coming from effluent treatment plant of the factories. Similarly, constructed wetlands were used to treat municipal wastewater at multiple locations in the Indian states of Telangana, Andhra Pradesh, Maharashtra, Uttar Pradesh, and Karnataka.
On the basis of pilot sites at ICRISAT headquarters in Hyderabad and elsewhere, several watersheds supported by corporates under their corporate social responsibility (CSR) programmes as well as under the Government of Karnataka’s Bhoo Samrudhi program and Rythu Kosam the Decentralized Wastewater Treatment (DWT) approach is being implemented and popularized at 28 sites.
It has good potential for inclusion in the Swatch Bharat Mission to overcome health hazards and ensure safe disposal or recycling of wastewater used in agriculture.
The secondary treatment of waste water for agriculture leads to more tertiary treated water being available for domestic use; impacting the availability of potable water for domestic purposes.
ICRISAT has established several village-level wastewater treatment units, known as constructed wetlands, in partnership with local governments and private companies to supply safe water for irrigation. With 87% removal efficiency for pathogens, these units reduce health risks and provide water security to farmers.
Domestic wastewater continues to increase as the population grows and we must look at it not as waste but as an asset and source of value. If adequately treated, domestic wastewater offers a sustainable solution to everyone in the food production and consumption chain.
The decentralized wastewater treatment units consist of constructed wetlands with a filter bed of locally available sand/gravel and vegetated with specific wetland plants.
The movement spreads
The Kothapally wastewater unit has the capacity to regenerate 20,000 litres of wastewater every day to grow crops on one hectare farmland throughout the year. Following Kothapally’s success, another treatment unit was established in the nearby village of Bhanur, thanks to a partnership with Asian Paints.
Here, Sri Ramulu has also started using treated wastewater for his farm.
“Since the last two years of using treated wastewater, I am better off. I use this water whenever my bore-wells don’t have enough or when there is no rain. As I have water for continuous irrigation I harvest 6,400 kg rice from 0.8 ha land. Earlier with untreated wastewater the yield was about 500 kg less,” he said.
Continuous supply of treated wastewater allows small holder farmers to undertake crop rotation rather than keeping their lands fallow and provides fodder for livestock.
Constant access to clean water has provided fodder for his six buffaloes and diversified his income and his family’s nutrition as well.
“Now that there is water throughout the year, I rented 1.21ha of land near the wastewater source to help me with irrigation. On half an acre I grow grass for my cattle. On the remaining land I grow two varieties of rice, one for my own consumption and the other for sale,” he added.
This decentralised wastewater treatment system is now scaled out to 28 villages in Andhra Pradesh, Karnataka, Maharashtra, Telangana and Uttar Pradesh. With total treatment capacity of 863 m³ per day it can irrigate one hectare land at each village or provide water to nearly 3,000 rural households for domestic consumption.
Witnessing the success of this solution the government of Telangana is looking to scale it across the state.
Safe wastewater recycling should be encouraged to tackle the growing untreated wastewater use in agriculture. It provides an additional reliable water source for irrigation enhances crop yields for farmers and ensures safer food supply.