Assam: NEERI-ZAR water filters bring safe drinking water to flood-hit Jorhat villages

In a significant relief initiative for flood-affected communities in Assam, the CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur, has demonstrated and distributed NEERI-ZAR Instant Water Filters in Jonakimondal village of Jorhat district to help residents access safe drinking water during emergencies.

The initiative aims to address one of the most critical challenges during floods — the contamination and disruption of conventional drinking-water sources.

At Jonakimondal village, five household-based and five community-based NEERI-ZAR units were demonstrated and distributed among affected residents. The units are designed to treat locally available water and provide potable water during floods and other emergency situations.

As part of the wider relief effort, 70 household-based units and 20 community-based NEERI-ZAR units were also handed over to the District Commissioner of Jorhat for distribution among flood-affected populations.

The units were formally handed over by Dr S. Venkata Mohan, Director, CSIR-NEERI, Nagpur, and Dr V. M. Tiwari, Director, CSIR-NEIST, Jorhat.

Filters assembled locally in just two days

A key feature of the initiative was the local assembly of the NEERI-ZAR units.

All the units were assembled at CSIR-NEIST, Jorhat, using locally available materials within just two days. According to the organisations involved, this demonstrates the technology's potential for rapid deployment in disaster-affected areas.

The technology was developed by CSIR-NEERI specifically to provide drinking water during emergencies such as floods, cyclones and other natural disasters.

The initiative was carried out under the guidance of Dr S. Venkata Mohan, Director, CSIR-NEERI, and Dr Paras Pujari.

The team was led by Dr Atul Maldhure, Scientist, CSIR-NEERI, along with scientists Dr Amrit Kumar, Dr Rima Biswas and Dr Abhishek Bisariya. Scientists from CSIR-NEIST, Jorhat, including Dr Dhanjit Das and Dr Sumit Singh, were also involved in the initiative.

How does the NEERI-ZAR filter work?

The NEERI-ZAR is a gravity-based, non-electric water purification system designed for household and small-community use, particularly in rural and low-resource settings.

The system uses multiple stages of treatment. Water first passes through a layer of graded sand, which helps remove suspended particles.

It then passes through granular activated carbon. The carbon layer, which makes up around 20 per cent of the filter media, helps remove colour, odour and dissolved organic impurities from the water.

The system also incorporates controlled chlorination for disinfection. According to the technical specifications provided for the system, chlorine is dosed at an optimised concentration of around 2 ppm, while free residual chlorine at the outlet is maintained at approximately 0.2–0.5 mg per litre.

This treatment process helps reduce microbial contamination, including E. coli and total coliforms, while also improving parameters such as turbidity, colour and odour.

No electricity required

One of the major advantages of the NEERI-ZAR system during floods is that it does not require electricity.

Floods can disrupt electricity supplies and damage conventional water-treatment and distribution infrastructure, making access to safe drinking water particularly difficult.

The NEERI-ZAR's gravity-based design allows it to function without an external power source. It can also be deployed at both household and community levels.

The system is designed to be simple to operate and requires minimal technical expertise, with periodic cleaning and replenishment of disinfectant.

According to CSIR-NEERI, the technology can therefore provide a decentralised and relatively low-maintenance option for emergency drinking-water supply.

A potential solution for flood-prone Assam

For Assam, where annual floods frequently disrupt drinking-water sources and basic infrastructure, access to decentralised water-treatment systems can be particularly important.

Floodwaters can contaminate wells, ponds and other local water sources with sediment, sewage and disease-causing microorganisms. At the same time, damaged roads and disrupted supply networks can make it difficult to transport adequate quantities of potable water to affected communities.

Strengthening community resilience

The distribution of the units at Jonakimondal village and their handover to the District Commissioner of Jorhat marks an effort to strengthen drinking-water security among flood-affected communities.

The technology's ability to operate without electricity, its relatively simple design and its potential for rapid local assembly could make it particularly useful during emergencies when conventional water-supply systems are temporarily unavailable.