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Constructing a Helophyte Filter for a Regenerative Community

Using plants as a natural wastewater treatment system

A Natural Grey Water Filtration System for TDF

Located in the countryside of Portugal, Traditional Dream Factory is a regenerative community that recently attained a status as the first land-based Decentralised Autonomous Organisation (DAO). We spent the whole fall season helping out the community to construct a helophyte filter system for sustainable wastewater treatment. Being a DAO means that everything is built in a communal, bottom-up manner. This process is not always easy but the use of volunteers and low-tech solutions was ultimately very rewarding.

How does it work?

A helophyte filter is a type of constructed wetland that uses plants and their associated microorganisms to purify wastewater. These systems are natural, eco-friendly, and require little maintenance. The helophyte filter at Traditional Dream Factory consists of a three-stage process: a grease trap, vertical filters, and a horizontal filter. These stages work together to break down and filter out pollutants from the wastewater, and the filtered water is pumped back up for irrigation.
3D model

A challenging build

Designing the filter required careful consideration of the rocky ground and potential for landslides or punctures in the waterproof liner material. After a long planning and design process, construction took approximately four weeks using volunteers and low-tech solutions such as gabion walls. To ensure the system’s sustainability, the team decided to build only half of the pond, allowing for redundancy and the ability to continue treating wastewater even if one side were to break down. This also allowed for the possibility of building the other half at a later time.

Low tech, high effort

Leading a project in a community is not always easy. We faced the challenges of working with volunteers who were not professional builders, and the project took three times longer than expected. However, the sense of community and the enthusiasm of the volunteers made the project a fun and memorable experience. We were able to stay within budget by using low-tech solutions and the final result was a sustainable, effective wastewater treatment system. Despite the challenges we faced, the sense of accomplishment and pride that came with completing the project made it all worth it.
The 8-stage process:
Helophyte 2
Phase 1:
Digging the hole
Helophyte 3
Phase 2:
Landscaping the basins
Helophyte 4
Phase 3:
Building the wall sections
Helophyte 5
Phase 4:
Preparing the filter beds
Helophyte 6
Phase 5:
Lining the filter beds
Helophyte 7
Phase 6:
Installing the plumbing
Helophyte 8
Phase 7:
Filling the filter basins
Helophyte filter
Phase 8:
Finalising the filters

What we learned:

Any questions?

Florijn de Graaf
Founder & Engineer
+31 (0)6 124 00 985