Safer water flows in only six months

It’s just one example of how mobile filtration is helping to solve a critical global issue.

Guadeloupe is a French archipelago in the eastern Caribbean, and water security here is a fragile thing. Tourism strains an ageing network. The island sits squarely in the Atlantic cyclone belt, where storms can overwhelm infrastructure, contaminate sources and cut off communities without warning. And the drinking water plant that serves this particular corner of the island had, until recently, been running on borrowed time.

In the first half of 2024, two of its four sand filters had failed without warning. The plant draws water from a mountain river and normally treats it at a rate of 400 cubic meters per hour. With two filters out of service, that figure was halved. Downstream, a hospital with a dialysis center was now dependent on a facility that could no longer guarantee supply. For patients receiving dialysis treatment, reliant on pure water, there’s no margin for interruption.

“SMGEAG (Syndicat Mixte de Gestion de l’Eau et de l’Assainissement de la Guadeloupe), the public authority responsible for water and wastewater services across much of Guadeloupe, found itself under direct pressure to find a solution, and fast,” says Frédéric Granet, Business Application Manager – Water & Environment at ANDRITZ Separation. “It was vital to restore full production before the Atlantic cyclone season began, meaning a very tight deadline of roughly six months – that’s why they called on ANDRITZ for help.

NOT A NEW PROBLEM, BUT A NEW KIND OF ANSWER  

Drinking water crises are rarely caused by a single dramatic event. They are usually the product of years of deferred maintenance, underinvestment and ageing infrastructure, with one unexpected failure finally pushing a system past its limits. Guadeloupe's situation contained all of these pressures – and it is far from being unique. According to a UNESCO report, 2.2 billion people currently do not have access to clean water, many of them facing exactly this kind of slow-building, infrastructure-driven crisis.

ANDRITZ was already a trusted supplier to SMGEAG, having worked alongside the authority on sludge treatment equipment. Prior to the AMFU, SMGEAG had contracted ANDRITZ to supply a containerized system to dewater the sludge produced at one of its wastewater treatment plants. The Bailiff WWTP – an isolated site with only light infrastructure – was equipped with a container-mounted screw press designed to handle around 10 m³/h of municipal sludge. The efficiency and reliability of that mobile solution were proven in the field.  

So, when the emergency arose, the team offered another plug-and-play solution: the ANDRITZ Mobile Filtration Unit, or AMFU for short.

Launched in 2023, the AMFU is designed to address this very challenge – offering water filtration quickly, in locations that are hard to reach or on timescales that make conventional construction impossible.

ANDRITZ's answer was to take an open gravity filter – one of the oldest and most reliable processes in water treatment – and rebuild it inside two 20-foot shipping containers, factory-assembled, factory-tested, and ready to connect.

The technology at the core is deliberately straightforward. Gravity filtration works by passing water downward through a bed of sand, activated carbon, Filtralite or other materials, and collecting the cleaned water below through an underdrain system.

Operators all over the world already know how to run gravity filters, which means a local team can take ownership quickly after a short training period. What the AMFU adds to this proven process is ANDRITZ’s own underdrain technology, stainless steel 316L construction, a fully autonomous PLC, a user-friendly control interface, and remote access to all operational data.

The process container completes the package with a backwash pump, air blower, dispersal ramp, chlorination system and UV disinfection. In locations without any existing downstream treatment, the two containers together constitute a complete drinking water plant. The available capacities are 50, 100 and 200 cubic meters per hour.

For Guadeloupe, the answer to the arithmetic was straightforward. One 200 m³/h AMFU would stand in for the two failed sand filters and restore the plant to its full 400 m³/h output. 

TIME-PRESSURE, TIGHT SPACES  

Notification of the award came in June 2024. From that point, the race was on to beat the cyclonic deadline.

The AMFU’s standard-range design proved critical here. Because the unit is a defined product rather than a bespoke build, engineering and procurement could be rolled into a compressed manufacturing cycle without starting from scratch. The containers were assembled and fully tested at the ANDRITZ workshop in Scorbé-Clairvaux, France, then loaded onto a ship. Five weeks later, they arrived in Guadeloupe.

The site waiting for them was not generous. The plant is built into a steep slope, and the footprint available for the new installation was tightly constrained. Each container measures approximately 6 x 3 x 3 meters – compact enough to fit where a conventional civil-works expansion never could have, and certainly not in time.  

The ANDRITZ team arrived on the island twice, for about a week on each visit. On the first visit they connected the units to the existing plant and brought them into service, on the second visit they completed the final performance adjustments.

By March 2025, the unit was running, reaching its rated 200 m³/h capacity shortly after.

Full capacity was restored. The dialysis centre had water. The cyclonic window was still months away. 

THE GLOBAL POTENTIAL OF THE AMFU

The first AMFU sold – a 100 m³/h unit – has now been operating continuously for three years. Installed at a site where a once-clean groundwater source had deteriorated to the point where filtration became essential, it went in quickly and secured the community's supply. A 50 m³/h unit is currently being manufactured. The Guadeloupe installation is the largest of the standard range to date.

Each of these installations tells a version of the same story. The obstacles to clean water are varied – remote geography, failing infrastructure, contamination events, natural disasters, the slow creep of climate pressure on vulnerable systems – but the underlying need is always the same: reliable filtration, wherever the water is, whatever the local constraints.

And that track record spans more than one kind of challenge. "ANDRITZ has experience and expertise with supplying mobile solutions. Our plug-and-play units, whether for water filtration or for sludge dewatering, are reliable, CAPEX efficient and easy to operate solutions. With these, we support our municipal and industrial customers to be resilient and meet their infrastructure challenges for clean water or wastewater treatment. Our references at SMGEAG are perfect examples of such performing, resilient systems," says Thibault Voisembert, Regional Sales Manager – Environment Industry.

The AMFU was designed to solve a very specific and recurring version of that challenge: a situation where you need a working filtration plant quickly, in a place where building one from scratch is not an option. As a plug-and-play solution grounded in the fundamentals of gravity filtration, it is quick to test, ship and install – and it can be operated and maintained by local teams.

In Guadeloupe, the AMFU restored a community's lifeline just in time for cyclone season. But clean water crises are not unique to the Caribbean – and neither is the solution. Wherever supply is under pressure, the ANDRITZ Mobile Filtration Unit is ready to move.