How do cities dispose of excreta? What is the most sustainable way to do it? CSE-organised workshop attempts to look for answers
Down To Earth cover story unveils how our cities are actually disposing of the shit – mostly, in a very unsafe manner
Says Sunita Narain: “Cities are drowning under their sewage, but we believe therein lies an opportunity to do things differently. Reuse this excreta, this faecal sludge, as nutrient for the land. Do not waste water in flushing it away”
New Delhi, April 5, 2016: Even as cities plan for water supply sourced from locations that are far, they forget about managing the waste – the excreta and sludge that is generated. Most cities have no clue how they will convey the waste or treat it. In fact, a humungous 78 per cent of the sewage generated remains untreated (as per official statistics) and is disposed of in rivers, groundwater or lakes. This was said by Sunita Narain, director general at a workshop – “Mainstreaming Citywide Sanitation: Opportunities and Challenges in Excreta Management” – held at New Delhi on April 5-6. The workshop has been organised by CSE, which in 2011 had published its seminal study on the subject of water and wastewater, Excreta Matters.
The water-waste conundrum
Explaining the co-relatedness of water and supply issues, Narain said because water was sourced from far away, as in the case of Delhi, it led to an increase in the cost of supply as well as high distribution losses. “The farther is the source, the more are distribution losses and the less water there is at the end of the pipeline,” she said. Due to the high cost incurred in water supply, cities were not able to recover costs of supply and had, therefore, no money to invest in sewage treatment.
Eighty per cent of water leaves homes as sewage. Since cities do not have any accounts of the sewage they generate, they cannot plan and do not have the capacity to treat all the sewage they generate. The gravest implication was for the rivers where the facial sludge was dumped. “We are a generation of lost rivers. How many will we lose before we remember that unless sewage is managed, the river-cleaning operations will not work?” asked Narain.
A Down to Earth (DTE) cover story has put the number of faecal waste being generated in India at 1.7 million tonnes a day, a staggering volume. The CSE analysis points out that the amount of sewage generated in 2009 was 38,255 million litres daily (MLD), while India’s capacity to treat was only 11,788 MLD, which was a mere 30 per cent of the total waste generated. However, the actual sewage treated was even less -- 8,251 MLD, which was about 22 per cent.
Managing the sludge
Experts at the workshop said that a large quantity of water was being used worldwide in carrying human excreta. “This is not the best use of water,” said Suresh Rohilla, CSE’s water programme director. Rohilla said the current technology – using water to flush down excreta and carry it away – was not sustainable. The solution, he said, was on-site faecal sludge management using modern septic tanks and other technologies so that the excreta did not use contaminate water bodies. “The current piped sewerage systems do not treat sewage but merely transport it away. They are toxic and extremely polluting for the rivers and lakes where they are dumped,” he said.
The magazine report has found evidence of alarming methods of sewage disposal. While in India only 33 per cent of houses (Census 2011) are connected to sewer systems, only around 38 per cent use septic tanks. These septic tanks do not treat waste and have to be emptied periodically. The report points out that entrepreneurs who service septic tanks, pump out the sludge from the tanks and empty it into drains, fields – just about anywhere.
• Plan deliberately to cut costs of water supply
• Invest in local water systems
• Reduce water demand
• Spend on sewage not on water
• Cut costs on sewage systems
• Plan to recycle and reuse every drop
• Connect water conservation to sewage management
For further information, please contact Souparno Banerjee, email@example.com, 99108 64339