Using Treated Sewage in Thermal Power Plants: Diverting Resources From Agriculture to Industry?

Given the increasing competition for water for different uses like agriculture and domestic supply, it is clear that such problems are likely to increase in the future.

Pumps lifting sewage for irrigating fields from Solapur Sewage drain.

Pumps lifting sewage for irrigating fields from Solapur Sewage drain.

Stories of severe impact of water scarcity have been coming up with worrying regularity this summer. Among these are reports of how, this year, thermal power plants – in Raichur, Farakka, Parli and other places – have been forced to shut down because of water shortage. Thermal power plants, particularly coal based power plants, require huge quantities of water to run. This has had an impact on companies like Karnataka Power Corporation Limited (KPCL), National Thermal Power Corporation Limited (NTPC), Adani and Maharashtra’s Maharashtra State Power Generation Company Limited (MAHAGENCO).

Using treated sewage water

Given the increasing competition for water for different uses like agriculture and domestic supply, it is clear that such problems are likely to increase in the future. The government of India has also recognised the seriousness of the issue and has started taking steps to address it. The one measure that it seems to be relying upon in a big way is to require thermal power plants to use treated sewage rather than fresh water. In the revised (Electricity) tariff policy notified by the government of India on January 28, 2016, there is a provision that now requires that “the thermal power plant(s) including the existing plants located within 50 km radius of sewage treatment plant of any municipality/local bodies/similar organisation shall… mandatorily use treated sewage water produced by these bodies…” While recycling and reuse of sewage is a welcome step, it needs to be undertaken with great caution and only after assessing implications in each individual case. For sewage is not a waste.

NTPC in Solapur

Take the case of Solapur in Maharashtra, near which the National Thermal Power Corporation Limited (NTPC) is building a 1320 MW thermal power plant. The project had been promised water from the Ujjani dam on Bhima river, a tributary of the Krishna river. The government of Maharashtra has now told the NTPC that it will not get water from Ujjani, and instead, should use treated sewage from Solapur town. The NTPC has raised some issues about quality of this water, apart from the fact that the treatment facility was still not established. However, there is another issue of concern which no one seems to have realised. Several thousand people are already using this sewage.

As one comes close to Solapur, which is facing a severe water stress situation this year, one is astonished to see lush green fields, many of which are growing fodder. These fields are on vast tracks of lands near the city and their major source of water is the main sewage water drain of Solapur Municipal Corporation (SMC).

Farming and dependency on the sewage water

Nandakumar Babar is a young milkman from Degaon village, next to Solapur city. He has 20 buffalos which sustain his dairying occupation. He says his great grandfather came to this village and established the family business of selling milk. However, his family doesn’t own any land or pasture in the area. They source fodder for their buffaloes from the nearby fields, which are irrigated by drawing sewage from the local drain that carries SMC’s untreated sewage. The land owner gives this land on an annual lease for the collection of fodder. There are more than 100 such families near this village who earn their livelihood from this business.

The situation is same for Kashinath Kore, a farmer from Basweshwar Nagar village, whose farm is close to the SMC sewage drain of SMC. He says that the local drain has been flowing with sewage since the time Solapur city has been in existence. They have been using it for irrigation purposes for many years. Nearby villages like Belati, Degaon, Kavathe, Dongaon, Nandur Shelgi and Bale are all dependent on this sewage drain for irrigation water supply. According to the assessment of local farmers, nearly 20,000 acres of land is being irrigated from this sewage drain. Crops include, apart from fodder, the local favourite — sugarcane.

These farmers are now a worried lot. They have heard that the under-construction sewage treatment facility at Degaon will lift sewage water from the local drain, treat it and supply it to NTPC’s power plant. They realise that their farming and entire source of livelihood is on the brink of vanishing. Notices seem to have been issued already to the land owner of the fodder fields, asking them to stop water intake from the sewage drain for irrigation.

Using sewage water for thermal plants

Clearly, there are environmental and health issues related to using untreated sewage for irrigation – a practice prevalent all over the country – and these need to be addressed. Yet, one cannot ignore that in Solapur, this sewage is providing livelihoods to several thousand families, and the diversion of sewage to supply to NTPC will deprive them of these livelihoods, pushing them into difficulties of survival or even destitution. There doesn’t seem to be any assessment or study of the social impact of the diversion of sewage, and no thought whatsoever of how to provide replacement livelihood support the affected population.

Even where people may not be directly using the sewage, it should be noted that water supply to towns and cities has significant return flows (flows that come back to the hydrological system after the consumptive use), often as high as 80%. These return flows, of which sewage is a part, contributes to the downstream flows and uses. Diverting sewage deprives the downstream communities of this water.

Solapur is only an example of what can happen when sewage is diverted for other uses. As the government pushes for the implementation of its regulation, there are likely to be a number of such cases that would arise, giving rise to suffering, social unrest and conflict. Before rolling out this new policy for use of treated sewage by thermal power plants, there is a need to put in place a proper framework and regulations to ensure proper impact assessments and compensatory measures.

The authors are with the Manthan Adhyayan Kendra, Pune, involved in analysis and advocacy of water issues. This article is based on a recent visit to Solapur.