Kerala's drinking water sources face contamination threat

Anithakumari S, a resident of Thrikkannapuram near Kerala's capital Thiruvananthapuram, makes sure her family members drink boiled water although it was sourced directly from the open well in the courtyard of her house.

When the well was dug up around 26 years ago, her family and many people from her neighbourhood used to drink water without boiling it.

"We used to draw very clean water from this well then. Now, we have pollution around us and water is contaminated. That is why we decided to boil the water," said Anithakumari in her mid-40s.

Kerala Water Authority (KWA) officials, citing various studies, agreed with what Anithakumari said on the level of contamination of the state's water resources.

Also Read | Act now to avoid a water crisis

According to them, Kerala, known for its abundant groundwater and surface water, with 44 rivers, thousands of streams, lakes, and lagoons, is facing a serious water crisis.

More than 80 per cent of the open wells for which the majority of people depend for drinking water, and more than 90 per cent of rivers are contaminated with Escherichia coli (E. Coli) bacteria, they said.

Officials cite rapid urbanisation and pressure on land due to density of population as reasons for such a situation.

Research conducted by the Centre for Water Resources Development and Management (CWRDM) during different periods, for Kerala in total, and many urban regions in specific has confirmed the presence of E. Coli bacteria -- a few strains of which can cause severe stomach cramps, diarrhoea and vomiting -- in wells and rivers and has declared them unusable without boiling, officials said.

"Of late, these precious resources are getting contaminated by various contaminants and anthropogenic activities. Open wells in Kerala have the problem of bacteriological contamination," a report from a study conducted by the CWRDM in 2019 said.

The study has found out most of the dug-up wells in Kerala have faecal contamination due to poor or poorly maintained sanitation facilities.

"Our people are still unaware of the importance of keeping our water resources clean from pollution. In Kerala, we do not have a major issue with groundwater depletion but pollution is a major concern," John V Samuel, an IAS officer and director of the Ground Water Department, Kerala told PTI.

Officials said when water from wells is unsafe for direct drinking, open rivers pose a greater risk.

Last month, there were 11 cholera cases reported in Malappuram, where people drank water from a river. It was later found that sewage from commercial establishments was released into the same river upstream, they pointed out.

KWA, which supplies drinking water through pipelines to most parts of urban Kerala, is spending several crores to clean up this water before supplying it to the people.

According to KWA sources, when the comparatively cleaner water from Peppara dam in Thiruvananthapuram district is taken to Aruvikkara through the Karamana river for treatment, it gets polluted from E. Coli, heavy metals, and other chemicals.

The high cost involved in the treatment of contaminated water and a highly subsidised supply will soon make it unviable for KWA to ensure an uninterrupted water supply in Kerala. For treating 1,000 litres of water, the organisation is spending Rs 22.50 and this is supplied through a pipeline for just over Rs 14 per 1,000 litres to the public, they said.

"The water from Aruvikkara Dam is treated in four treatment plants. We supply 330 to 340 million litres of water to Thiruvananthapuram city daily. The water is treated through a seven-step process to remove all contaminants from the water," Manju Somanath, Assistant Executive Engineer and head of the treatment plants at Aruvikkara, told PTI.

The treatment process starts with pumping raw water into the aerator to infuse more oxygen into the water so that many contaminants are converted into oxides and released from the water.

It is then mixed with alum and lime, based on the turbidity and pH levels, mixed well with flash mixers, and then sent to flocculation tanks where soluble heavy contaminants are solidified and sunk.

The water is then taken to the plate settlers for removal of remaining contaminants, then to the sand bed for filtration of insoluble particles. The water is then mixed with chlorine gas after a lab test to ensure quality and pumped out for supply.

A National Accreditation Board for Testing and Calibration Laboratories (NABL)-accredited lab inside the premises tests both the raw water and the treated water for about 17 parameters as per World Health Organisation (WHO) recommendation every hour.

Though, KWA is taking utmost care and spending several crores on the treatment of the contaminated river water before supplying it, weathered pipelines with porous or broken surfaces often contaminate the water in transit.

KWA has a quality cell that collects samples from the consumer end and checks them for quality and takes remedial measures if they find contamination in the water supplied. This costly affair is depleting the resources of KWA due to the poor quality of water pumped from the rivers in Kerala.

"We must have better management in preserving the water very seriously. Pollution is increasing day by day and it is only because of our attitude toward using water," Samuel said.