Negotiating the threat

The Mamata Banerjee government has taken significant strides in arsenic mitigation in the state and is hopeful of completing all the major projects in connection with it by the middle of 2021.

The green tribunal in connection with a case on the problem of arsenic in water has recently directed the Bengal Government to speed up its ongoing projects on arsenic mitigation and complete the same by June 2021.

"75 per cent of our major projects in several arsenic-affected areas which include Falta in South 24 Parganas, Gaighata in North 24 Parganas and Amta in Howrah have already been completed. So we are hopeful that with the current work progress we will be able to meet the deadline of the green bench," said Saumen Mahapatra, state Public Health Engineering (PHE) minister.

There are 83 affected blocks in eight districts that include Malda, Murshidabad, Nadia, North 24 Parganas, South 24 Parganas, Burdwan, Hooghly and Howrah. 15 surface water-based water supply schemes that cover seven in Murshidabad, one each in Nadia, South 24 Parganas, North 24 Parganas, Howrah and four in Malda have been commissioned benefitting a population of 68,70,121. Presently eight surface water-based mega schemes are ongoing in the affected districts that include two in Murshidabad, four in North 24 Parganas and one each in Malda and Hooghly which will cater to a population of 61,60,355. Two projects out of four in North 24 Parganas will also cater to some affected blocks in South 24 Parganas and Nadia.

Arsenic and fluoride in groundwater have emerged as one of the prime water quality issues in Bengal which was reported first during the '80s and '90s through clinical manifestations of hyperpigmentation, leucomelanosis and keratosis due to long term exposure.

The interventions on the part of the Government to mitigate the problem has been through a slew of long, medium and short term measures.

According to sources in the PHE department, the long term measures include implementation of surface water based water supply schemes in the affected districts. 15 surface water-based water supply schemes have been commissioned benefitting a population of 68,70,121. Presently, eight surface water-based mega schemes are ongoing in the affected districts which will cater to a population of 61,60,355. Two projects out of four in North 24 Parganas will also cater to some affected blocks in South 24 Parganas and Nadia.

Another major intervention has taken place through ground water-based piped water supply schemes based on deeper groundwater aquifers are generally considered to be a medium-term measure.

Presence of high arsenic is generally restricted to the upper aquifer up to a depth of 150 m but the deeper aquifer may also get contaminated due to leaching. A large number of piped water supply schemes based on groundwater have been implemented. So far 779 groundwater based piped water supply schemes are functioning in the affected districts, covering a population of 92.21 lakh. Moreover, 139 nos of PWSS (Piped Water Supply Scheme) are under implementation in the affected districts and expected to be completed by 2021 benefiting a population of 12.10 lakh.

Interestingly, several groundwater-based PWS started yielding unsafe water, which was found to be safe during implementation. In all such cases, arsenic and iron removal plants (AIRP) have either already been installed or it is in the process of implementation as a medium-term measure. Presently, 131 AIRPs have been commissioned in the most arsenic affected districts.

During the last two years, a considerable number of arsenic affected habitations have been covered and it has been found that water quality has significantly improved. Around 1,392 affected habitations are still to be catered. Until then, several short term measures have been planned to be implemented to provide potable drinking water to the affected population within December 2020. Such measures include implementation of community water purification plants, ATUs fitted with hand pump tubewells, the extension of pipelines from existing schemes, water ATMs etc.

The state PHE department has also taken up behaviour change communication (BCC) as an interim measure to identify vulnerable households and divert them from consuming water from an unsafe source to a nearby safe source within accessible distance and simultaneously displaying an alert message on the unsafe source. BCC programme, through participatory Rural Appraisal (PRA) mapping, has presently been piloted in Chakdah in Nadia district and will be scaled up in other blocks of Nadia. In Murshidabad BCC programmes are presently ongoing in Domkal, Raninagar I & II, Suti I & II. In North 24 Parganas BCC has commenced in the blocks of Baduria, Basirhat I & II and Hasnabad simultaneously. BCC intervention had been conducted earlier in 9 blocks of North 24 Pgs and three blocks of Murshidabad. It was found that over 57 per cent of vulnerable households could be shifted from an unsafe to an existing safe drinking water source as a result of BCC intervention.

The department has also taken up Community Awareness by organizing health camps, conducting household health surveys and testing of water sources to map the prevalence of the arsenic associated diseases with water quality for necessary intervention for arranging potable water to the vulnerable population.

According to a senior PHE department official currently, there are 217 functional rural water testing laboratories in this state-funded by the PHE department and managed by PHE as well as NGOs. 97 of such laboratories have the infrastructure to test arsenic. A few of the arsenic testing laboratories at the state and district levels are equipped with sophisticated instruments which can accomplish testing of a large number of samples in a short time with high precision and reliability.

A unique strategy adopted in the state is the introduction of smartphones in water quality monitoring mechanisms. Every laboratory is equipped with Android-based smartphones loaded with survey apps to facilitate geotagging of sample location, photographs of the drinking water source and updating of chronological water quality results in a water quality dashboard in real-time creating a paperless and instant database of results. The data from smartphones and laboratories are combined and processed to provide a wide range of data which acts as a DSS (decision support system). Water quality reports are also shared with gram panchayats and safety status of each tested source is intimated accordingly.

As per data placed at the green tribunal over 44 lakh people in 50 household areas are affected with arsenic. Environmentalist Subhas Dutta had moved the green tribunal in 2015 based on some surveys and reports that suggested that Bengal is one of the worst affected states by arsenic.

Views expressed are personal