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Drinkwell in the news

Chattogram WASA Managing Director Selim Md Jane Alam and Drinkwell CEO Minhaj Chowdhury hold the signed MoU under the ceremony banner, Chattogram WASA boardroom, 13 September 2026.

Chattogram WASA 2026 94 more Water ATMs for Chattogram A five-year agreement with Chattogram WASA, signed 13 September, to add 94 Water ATM booths to the six already serving the port city. Read the Daily Sun report

Minhaj Chowdhury receives the Schwab Foundation award certificate on the World Economic Forum stage, Davos 2026.

World Economic Forum 2026 Social Entrepreneur of the Year Named by the Schwab Foundation for Social Entrepreneurship at Davos for climate-resilient water infrastructure at scale. Read the story

Minhaj Chowdhury of Drinkwell, Maria Tran of the Asian Development Bank and moderator Jennayne Ong of Imagine H2O on stage at Singapore International Water Week 2026.

Asian Development Bank 2026 Dhaka's model, to every ward of Narayanganj Through a partnership enabled by Imagine H2O, the Asian Development Bank is underwriting the sovereign's ability to replicate the Dhaka WASA Water ATM model in every ward of Narayanganj City. We told the story together at Singapore International Water Week. Watch the talk at Singapore International Water Week

The WIST India team on stage at the ASSOCHAM India Water Leadership awards, 2025.

ASSOCHAM 2025 National Water Award Recognised for arsenic mitigation in West Bengal's most contaminated blocks. About the awards

Customers with their water jugs at a Drinkwell Water ATM in Dhaka.

Meaningful Business 2026 MB100 Global Leaders Named among 100 leaders combining profit and purpose to advance the Sustainable Development Goals. See the profile

The problem, and the answer

Build. Neglect. Runaway.Operate. Regenerate.

Drinkwell breaks the water sector's Build, Neglect, Runaway cycle with a Build, Operate, Regenerate model that pairs proprietary water filtration resins with public-private partnerships. In Build, Neglect, Runaway the private sector is a contractor: paid to build, gone by year two. In Build, Operate, Regenerate it is a true partner, paid for the water that flows and still there in year ten. That is the private sector participation it takes to serve everyone, forever, and truly end the water crisis.

#PartnerNotContractor

Year 1

Drag the year, or let it run.

The sector's way

Build. A capital budget is spent and a deployment is commissioned. This part works, and it is the part almost everybody is willing to fund.

Neglect. Year two arrives with no operating budget. Media exhausts, a pump fails, a repair has no line item, and output falls long before anyone records that it has.

Runaway. Whoever built it is already somewhere else. Households go back to the tubewell they were warned about, and the next programme puts a new deployment beside the defunct one.

Ten years, four deployments, one still running.

The Drinkwell way

Build. A deployment engineered to the basin it draws from, commissioned with the operator named and the operating budget identified before the ribbon is cut.

Operate. Our own crews and remote monitoring keep the deployment producing water, paid per litre delivered rather than per plant shipped.

Regenerate. Every six to twelve months the media is regenerated on site and put back to work. No replacement, no landfill, no new deployment beside the old one.

Ten years, one deployment, still running.

deployment producing water deployment defunct media regenerated on site

The promised land

Imagine a city where the pipe, the kiosk and the household filter are one graded system, and nothing in it is thrown away.

The utility's plant treats the aquifer for the wards the pipe reaches. A prepaid Water ATM two hundred metres from home serves the wards it reaches badly, at the utility's own tariff. A tabletop filter serves the households it never will. The same operator runs all three, every plant carries a public A to F grade, and the media in every one of them is regenerated instead of replaced: on site at the piped plant, back at the factory for kiosk cartridges and filter candles.

water to people regeneration and residue residue to glass the swap truck: exhausted cartridges out (rust), regenerated back (blue)

In the field

1 Kiosk / Water ATM

The Jeevan Jal fluoride removal kiosk in Dhar district, Madhya Pradesh, doors open with operators inside. — A neighbourhood; ~790 built since 2013; 753 active sites.

Drinkwell system, Borigaon village, Nalbari, Assam (3.5 min)

2 Piped scheme

Aerial view of the Dakshin Jhitkipota treatment plant in West Bengal: pressure sand, iron removal and arsenic removal vessels beside the chemical and pump rooms. — Whole villages; Dakshin Jhitkipota, 83 m³/hr, commissioned Sep 2025.

3 Household filter

A girl fills a steel cup from a two-chamber Drinkwell tabletop filter at her home. — One family; CSR buys the filter, the recharge is the annuity. ~170 units, India, 2024–26.

Domestic arsenic & iron filter (1.5 min)

Our approach

The 5-H framework.

Five words we use internally for every site we run: a habitat, a horse, a harness, hay, and a habit. A plant keeps producing water only when all five are in place, and four out of five is how you get the cycle above. The rest of this page takes them one at a time.

All five gears turning together is what powers safe water for everyone, forever.

Habitat

the basin

The aquifer or river a site draws from, what is in it, and how that changes with the seasons. It decides the treatment train before anyone draws one.

Chapter 01

Horse

the treatment train

The chemistry and the vessels around it that turn raw water into safe water, efficient enough that treated water can be sold for a fraction of a rupee per litre.

Chapter 02

Harness

the deployment

The form the train arrives in, sized to the geography: a household filter, a kiosk, or a government piped scheme.

Chapter 03

Hay

the financing source

The money that covers running costs after commissioning. Tariffs, taxes or transfers, named site by site.

Chapter 04

Habit

operation, maintenance and marketing

The operator on the ground, the regeneration schedule, and the work of keeping people coming back to the tap long after the ribbon is cut.

Chapter 05

700+

Treatment plants deployed

2.5B+

Litres processed

Countries deployed: Bangladesh, India, Nepal and Laos

2017

Earliest systems still in service

01 · The habitat · the basin

We test the water before we design anything.

Every site starts with its source: the aquifer, river or pond it draws from, what is in that water, and how it changes between the dry season and the monsoon. A raw-water analysis decides the treatment train before anyone draws one, and where the source itself can be improved, that comes first.

Raw-water analysis

Before design

Arsenic, fluoride, iron, manganese, nitrate, hardness, salinity, pH and bacteria, tested in an accredited laboratory and read against IS 10500 in India and the Environment Conservation Rules 2023 in Bangladesh. The train is sized to the result, or we say plainly that ion exchange is the wrong tool for that water.

Monitoring after commissioning

On a schedule

Treated water is sampled on a fixed schedule and tested by independent laboratories: icddr,b, NGO Forum, SGS, BUET and BSTI in Bangladesh, CSIR laboratories in India. Every report is kept in one register, so a plant's grade rests on a test, not a claim.

Source-side works

Where the water allows

Rooftop and community rainwater harvesting, pond-sand filters, managed aquifer recharge and source protection, so there is less in the raw water for any treatment train to remove. Our Majuli and Nalbari programme with Safe Water Network (2020–22) carried a rainwater-harvesting mandate.

800+

Raw-water reports in the register

340+

Source locations tested

3,500+

Treated-water tests at Bangladesh booths since 2019

02 · The horse · the treatment train

HIX-Nano: a hybrid ion exchange bead the size of a grain of sand.

HIX-Nano is our proprietary hybrid ion exchange media: a durable polymer bead, about 0.5 mm across, impregnated with iron and zirconium oxide nanoparticles. The polymer gives it the strength to survive years of flow and hundreds of bed volumes; the nanoparticles give it an enormous internal surface that binds arsenic, fluoride and iron selectively in near-neutral groundwater, on contact, while harmless minerals pass through. A rinse of 2% salt and 2% caustic then makes every binding site let go at once, so the same bead is regenerated on site and put back to work instead of going to landfill. Invented in the USA, manufactured in our own plant in Kolkata, and listed in the Ministry of Jal Shakti's Mashelkar Committee compendium.

Arsenic

< 10 ppb

WHO guideline limit; removes As(III) and As(V) without pre-oxidation

Fluoride

< 1.5 mg/L

WHO guideline limit; rapid adsorption kinetics

Water recovery

95–99%

Against 40–50% for reverse osmosis; no reject stream

Regeneration

2% NaCl + 2% NaOH

On site, in hours; about 2 kg of stable solid per cycle

Service life

5–10 years

Per charge, regenerated every 6–12 months

One media platform

Golden-brown HIX 100+ iron removal resin beads heaped in a laboratory dish. — HIX™ 100+ Iron Fe²⁺ & Fe³⁺ up to 25 ppm Data sheet

Pale HIX-Nano 200+ fluoride removal resin beads heaped in a laboratory dish. — HIX-Nano™ 200+ Fluoride Up to 10 ppm Data sheet

Black HIX-Nano 100+ arsenic removal resin beads flecked with amber, heaped in a laboratory dish. — HIX-Nano™ 100+ Arsenic As(III) & As(V) to 1200 ppb Data sheet

Diagram of HIX-RO: raw water passes through a HIX resin bed and then a reverse osmosis membrane. — HIX-RO Salinity & TDS HIX bed, then membrane. Up to 80% recovery

Listed in the Ministry of Jal Shakti's Mashelkar Committee compendium. CSIR approved. The family extends to HIX-Nano™ 300 (hardness), 400 (nitrate) and 500 (ammonia).

What we remove

Eight contaminants. One treatment train.

Arsenic Causes cancer and skin lesions Fluoride Causes skeletal fluorosis Iron Causes metallic taste, odour and staining

Nitrate Causes blue baby syndrome in infants

Sulphate Causes diarrhoea and a bitter taste

Hardness Scales pipes, boilers and appliances

Salinity and TDS Makes water brackish and undrinkable

Bacteria Causes diarrhoeal disease

Every contaminant on this list is one we have been paid to remove.

How we reduce TDS

Dissolved salts do not bind to an ion-exchange bead, so salinity is the one job we hand to a membrane. HIX-RO runs raw water through a HIX bed first, stripping the iron, arsenic and hardness that foul and scale membranes, then through reverse osmosis. The membrane lasts longer, recovers up to 80% of the feed against about half for a conventional RO plant, and uses roughly half the energy.

Go deeper

How HIX-Nano works, in depth

The bind-and-release cycle step by step, two live demonstrations of the bead and the column, the full specification, the HIX-Nano family with its data sheets, independent validation and the evidence base. Open it to check the chemistry; the chapter continues below either way.

How HIX-Nano works

A bead that holds on, and lets go on command.

Conventional media fills up with whatever the water is carrying and then goes to landfill. HIX-Nano is selective about what it binds and gives it back during regeneration, which is why one charge lasts five to ten years instead of one season. Inspired by, and sourced from, our impact report.

How one charge lasts a decade

Bind

Iron and zirconium oxide nanoparticles are fixed irreversibly inside a macroporous polymer bead. They hold arsenic and fluoride against sulphate, chloride and bicarbonate at hundreds of times the concentration — the selectivity is the whole trick.

Regenerate

Every 6 to 12 months our crew runs a caustic and brine cycle on site. The contaminant comes off, the media goes back into service, and the waste leaves as a few litres of sludge rather than a bed of spent adsorbent.

Repeat

The nanoparticles do not wash out, so the bead survives the cycle. Five to ten years per charge, then the media is replaced and the vessel keeps running.

See it in action

Five minutes from the US-India Science and Technology Endowment Fund profile of Drinkwell (2017): the problem, the bead and the first plants. Watch on YouTube

Watch it work

The column, and one bead inside it Two beds of raw groundwater — arsenic, iron and fluoride mixed in with harmless minerals — HIX-Nano on top, activated alumina below. The dashed lens magnifies a single live bead from each bed. Watch the exhaustion front travel down: alumina spends its capacity on whatever touches it and eventually lets contaminant through, while HIX-Nano is regenerated in place before anything breaks through.

The columns HIX · regenerations0 effluentsafe Alumina · effluentsafe

The beads HIX · hands on toxics0 / 14 regenerations0 toxics missed0 Alumina · hands wasted0 / 14 toxics missed0

Arsenic and fluoride ions Harmless ions

Regeneration — every hand lets go at once The bead arrives saturated. A rinse of 2% caustic soda with 2% salt shifts the chemistry so every binding site releases at once, and the captured ions wash into the spent-rinse tray. Nothing vanishes: that concentrate is precipitated with ferric chloride and stored as a stable solid, about 2 kg per regeneration against roughly 100 kg of exhausted media if the sorbent were single-use.

Cycles0 Hands filled14 / 14 Ions in tray0

Released arsenic and fluoride Brine rinse

Both demos are ported from our impact report, which carries the peer-reviewed source behind every number in them. See the sources

Media specification

Operating capacity

3–12 g/kg

Arsenic, on HIX-Nano™ 100+.

Bead size

0.3–1.2 mm

Macroporous polystyrene, divinylbenzene crosslinked.

Empty bed contact time

2–4 min

At a bed depth of 900 mm or more.

Operating pH

4–8

The media itself is stable from pH 2.5 to 13.

Operating capacity depends on influent concentration, pH and competing ions. Figures are from the HIX-Nano™ 100+ product data sheet; the treated-water limits, recovery and service life are in the bead section above.

Circular by design

Regenerate

6–12 months

The media is regenerated on site with a caustic and brine rinse, restoring capacity. No replacement, no new plant beside the old one.

Reuse

5–10 years

One charge survives repeated regeneration cycles, which removes the annual replacement that single-use filters depend on.

Recycle

Jars and bottles

Containers from our jar-delivery network are collected, cleaned and returned to service instead of leaving as plastic waste.

Built for the field

Locally sourced materials

The bead carries iron and zirconium, both stable and non-hazardous, and is manufactured in our own plant in Kolkata.

Simple operation

A single-stage process run by a trained local operator. No specialist technician is needed day to day.

End-to-end

Media, vessels, controls and operations come from one company, so there is nobody else to wait for when something breaks.

Grid-tolerant

About half the energy of conventional reverse osmosis, which suits rural sites where power is unreliable.

Against the alternatives

Same stream in, very different water out

Stream width is the share of the water: blue is product delivered for drinking, amber is reject and rinse. Ion exchange passes the whole stream through the bed and loses only backwash and regeneration rinse — a few bed volumes per ten thousand treated. Published RO field figures are often worse than shown here, with half to four-fifths of the feedwater discarded.

Reverse osmosis

Rejects everything, including the calcium and magnesium people need, and throws away half the water. HIX-Nano recovers 95–99% because it takes out one contaminant and leaves the rest of the water alone.

40–50%

RO water recovery

Activated alumina

The default defluoridation media. In an identical column test at a 10 mg/L fluoride feed, alumina crossed the WHO limit before 600 bed volumes; the hybrid media ran past 1,400.

< 600 BV

before breakthrough

Single-use adsorbents

Every exhausted bed becomes contaminated solid waste somebody has to bury. Regeneration cuts that volume by about 95%, and the residual is contained rather than dispersed.

~95%

less waste to dispose of

The HIX family

Six media, one regeneration protocol.

Supplied to qualified utilities, EPCs, OEMs and system integrators subject to technical qualification. Every one of them is regenerable and reusable.

HIX-Nano™ 100+Arsenic and iron Primary media for arsenic removal from groundwater, with iron taken out in the same bed. Data sheet HIX-Nano™ 200+Fluoride Selective fluoride removal for endemic regions; the media that stops skeletal and dental fluorosis at the tap. Data sheet HIX™ 100+Iron Manganese-based iron removal, ending discolouration, metallic taste and staining. Data sheet HIX-Nano™ 300Hardness Softening media for calcium and magnesium, protecting pipes, boilers and appliances. Request specs HIX-Nano™ 400Nitrate Selective nitrate removal for agricultural belts with elevated groundwater nitrate. Request specs HIX-Nano™ 500Ammonia Ammonia removal for groundwater and wastewater applications needing nitrogen reduction. Request specs

Tabletop fluoride filter: User leaflet for the household filter

In the field

Arsenic removal

Community water system

Rural arsenic mitigation, institutional partner

300Households

1,000LPH capacity

4,650Litres a day, average

Raw waterTreated

Arsenic240 ppb1 ppb

Iron2.10 mg/L0.24 mg/L

Prepaid RFID dispensing · Online dashboard · Solar-powered

Fluoride removal

Community water system

Endemic fluoride zone, public-private partnership

200Households

6,000LPD capacity

2,250Litres a day, average

Raw waterTreated

Fluoride3.92 mg/L0.47 mg/L

TDS282 mg/L148 mg/L

Prepaid RFID dispensing · Online dashboard · Local operator

Municipal scale

Urban Water ATM network

Dhaka WASA, public-private partnership. Water sold per litre; the utility oversees water quality, we operate and monitor remotely.

~280Water ATMs

24/7Metered, card-operated

PPPUtility keeps tariff authority

Utility integrated · Digital metering · Remote monitoring

Independent validation

Tested in the laboratory and in the field, with letters and certificates from research institutions and government task forces. Every document is the original, as issued.

CSIR-IMMT Bhubaneswar Laboratory study of arsenic and fluoride removal on HIX-Nano 100 and 200, 2019 · PDF R. A. Mashelkar Committee, Government of India Ministry of Jal Shakti compendium of approved technologies · PDF Indian Institute of Science, Bangalore Fluoride validation, 2016 · PDF IIT Roorkee Arsenic, fluoride and phosphorus validation, 2016 · PDF Institute of Technology of Cambodia Arsenic validation, 2013 · PDF West Bengal Arsenic Task Force Validation certificate, 2018 · PDF West Bengal Fluoride Task Force Certificate · PDF

The evidence base

Two decades of peer-reviewed work sits behind this media, most of it published before Drinkwell existed and none of it ours to grade. The full bibliography, with the numbers each source actually supports, is on our impact site.

Hybrid anion exchanger with dispersed zirconium oxide nanoparticles: a durable and reusable fluoride-selective sorbent Padungthon, Li, German & SenGupta · Environmental Engineering Science 31(7), 2014 Transforming a global water crisis into an economic opportunity: unmet needs and lessons learned during the last two decades SenGupta, German & Chen · Journal of Environmental Engineering (ASCE) 147(12), 2021 Laboratory scale studies on arsenic and fluoride removal efficiency of HIX-Nano 100 and HIX-Nano 200 CSIR-IMMT Bhubaneswar, 2019 · independent government laboratory Evidence of economically sustainable village-scale microenterprises for arsenic removal German, Watkins, Chowdhury, Chatterjee, Rahman, Seingheng & SenGupta, 2019

Read the full evidence base

03 · The harness · the deployment

Governments procure a working deployment, not a resin.

The same media is delivered in whatever form the geography needs. Every harness arrives installed and serviced, with trained local operators, remote monitoring and scheduled on-site regeneration.

Tabletop and gravity-fed, for habitations a piped scheme has not reached yet.

In daily household use See the sites

1,000+ litre-per-hour kiosks with prepaid card dispensing, metered to the litre.

Jeevan Jal, Dhar district. Running since 2018 See the sites

HIX slots into the treatment train of an existing government distribution network.

Dakshin Jhitkipota, West Bengal. 83,000 LPH for WB PHED under JJM See the sites

0.25 m³/hr 500 m³/hr

Slide along the rail, or pick a harness, to see which one covers that output

Hand-pump retrofit to mega-PWS on one media and one regeneration model.

Deployments

Every site we run, on one map.

Three kinds of deployment, one media platform and one operating model behind all of them. Choose a type to filter the map, or open a site to see what it is.

The map needs JavaScript. Every site is listed in the data file it draws from: deployments.json.

Household filters are shipped by the crate rather than sited individually, so they are not on this map. Find your nearest Water ATM at find.drinkwell.com

Water ATM

Card-operated dispensing, metered to the litre, mostly on a city utility network.

Community kiosk

A treatment house and a counter, run by a trained local operator for one village or ward.

Piped scheme

Our media inside a government distribution network, feeding household connections. Four schemes for West Bengal PHED are under construction; the one with a fix on the map is drawn hollow.

Platforms and components

Modular treatment plants and skids

Skid-mounted and modular platforms across a wide range of capacities, for new deployments and retrofits.

HIX-RO™ hybrid systems

HIX pretreatment ahead of reverse osmosis where TDS has to come down, for higher recovery and less reject.

Water ATMs and dispensing units

Automated dispensing with digital metering, RFID access and remote monitoring.

Household and point-of-use filters

Gravity-fed, non-electric systems for households, schools, clinics and emergency response.

Disinfection and electrochemical systems

Electro-chlorination and electro-coagulation for disinfection and specialised treatment.

Retrofit and upgrades

Media, components and technical support to bring an underperforming plant back without replacing it.

Download the India brochure (PDF)

04 · The hay · the financing source

Every deployment has a named source of finance.

Building a plant and running it are paid for differently, and both need a payer before the ribbon is cut. Capital comes from a government budget, a development bank or a funder; operations come from one of three sources, tariffs, taxes or transfers. We record which one carries each site before commissioning, because a site carried by none of them has a date on it whether or not anyone has written that date down.

The Drinkwell Partner Network

Tariffs

The people drinking the water pay for it, metered to the litre and priced to be affordable daily rather than cheap once.

Water ATMs across Dhaka and Chattogram, and every prepaid-card kiosk.

utilities and city corporations that set the price at the tap

Chattogram WASA
Dhaka WASA
Khulna WASA
Narayanganj City Corporation
Rajshahi City Corporation

Taxes

A public budget pays for treated water it has committed to supply to its own citizens.

PHED piped schemes under the Jal Jeevan Mission, billed on volume delivered.

public health engineering departments

Assam PHED
DPHE, Bangladesh
PHED, UT Ladakh
West Bengal PHED

Transfers

Philanthropy, CSR and outcomes payments from outside the water system, used to carry the years before a tariff or a budget line can.

Catalytic capital placed against a defined handover, not an open-ended subsidy.

development banks, CSR, foundations and grant-makers

Asian Development Bank
Cisco Foundation
The Coca-Cola Foundation
Danone Communities
Dovetail Impact Foundation
Gap
GIZ
Hirdaramani Group
Imagine H2O
JICA
Rippleworks
Swiss Re Foundation
Tata Trusts
UK aid
UNICEF
Unilever
US State Department
Vitol Foundation
Wells Fargo Foundation
World Bank

Debt is not a fourth source. Working capital from a development bank bridges against future tariffs, taxes or transfers. It does not replace them, and a site standing on debt alone is a site nobody has funded yet.

In kind, pro bono: EY Ripples, GLG Social Impact, Hogan Lovells.

05 · The habit · operation, maintenance and marketing

We are paid for water delivered, not hardware shipped.

That one choice puts the cost of a stopped plant on us rather than on whoever inherited it. We finance, install, monitor and maintain every site we build, with our own crews on a regeneration schedule. A plant that stops running stops earning.

Per litre

How we are paid

Revenue follows water actually delivered, not equipment sold.

6–12 months

Regeneration interval

Scheduled on site by our own crews. No media replacement, no landfill.

Remote

Monitoring

Flow, uptime and dispensing telemetered off every connected site.

Local

Operators

Trained and paid in the community the plant serves.

What operating means

Operations and maintenance

Day-to-day running, routine inspection, preventive maintenance, operator supervision and rapid response when service is disrupted.

Water quality monitoring

Regular testing against the public authority's standard, with transparent reporting and early warning of a plant drifting.

Utility integration

Aligning with the utility's operating procedures, tariff decisions and oversight, so the plant is part of the network rather than beside it.

Rehabilitation

Assessing and reviving existing plants when source water changes or performance slips, for the long run rather than a quick fix.

Community engagement

Local operators and technicians who are known to the people they serve, so the plant is trusted, understood and used.

Public-private partnership models

Structured private participation with public oversight: the utility keeps tariff authority and accountability, we keep the water flowing.

Work with us

One engine, sold at five depths.

Five gears turn at every site that keeps producing water. Whether you are buying a rainwater system, media by the cubic metre, or handing us a district, what changes is how many of those gears we turn for you after commissioning. Choose a rung to see the engine climb.