Protecting farmland through integrated stormwater depollution
- 2 days ago
- 2 min read
Overview
In Monterblanc, Morbihan, a new greenway was developed to connect two cities and promote sustainable mobility. The 1.7 km route integrates a permeable bike path designed to manage stormwater directly at the source. Rather than directing runoff into conventional drainage networks, the system allows water from the roadway to infiltrate through the permeable surface.
Beneath 2,700 m² of the cycle path, OSMORIA® Geoclean® was installed to address a critical aspect of stormwater management: pollution control. This aquatextile manages the quality of stormwater during infiltration. As runoff passes through the structure, hydrocarbons and PAHs originating from road traffic are retained and treated before water continues into the subsoil.
The project reflects a broader move toward soil de-sealing and decentralized stormwater treatment. By combining infiltration and pollutant removal under a functional transport corridor, the greenway protects surrounding countryside and farmland while enhancing mobility.
Challenge
Runoff from paved surfaces carries hydrocarbons and polycyclic aromatic hydrocarbons that pose risks to soil health, groundwater quality, and biodiversity. In a rural setting such as Monterblanc, uncontrolled infiltration could transfer these pollutants directly into agricultural land and natural ecosystems.
The objective is therefore twofold: to manage the volume and quality of runoff to be infiltrated so that infiltration does not become a source of pollution.
The project therefore required a solution that would:
Infiltrate runoff at the source under a permeable bike path
Protect surrounding farmland and countryside from contamination
Operate regardless of soil quality and environmental conditions
Deliver long-term performance without maintenance
Solution
OSMORIA Geoclean was installed beneath the permeable cycle path, between the bedding and the drainage layer, to treat stormwater during the infiltration phase. As a highly permeable aquatextile, it allows water to pass through while optimizing the fixation and biodegradation of hydrocarbons and PAHs.
OSMORIA Geoclean works in two ways:
The aquatextile optimizes and systematizes the processes of fixing and biodegrading the hydrocarbons contained in runoff that passes through it. It fixes the hydrocarbons on its filaments by adsorption (irreversible fixation), thus preventing them from migrating into the subsoil. It then facilitates the sustained and long-term biodegradation of the fixed hydrocarbon molecules.
The textile matrix releases natural nutrients essential for biodegradation, which attract and support the activity of soil-endemic microorganisms, such as bacteria and fungi. These microorganisms multiply and accelerate the biodegradation of hydrocarbons, resulting in high and continuous long-term performance regardless of environmental conditions. This autonomous, natural, and continuous biodegradation process provides a constant reduction in the hydrocarbon load within the structure, thereby extending the longevity and performance of the installation.
By integrating stormwater infiltration with pollutant treatment under a 2,700 m² permeable bike path, the Monterblanc greenway demonstrates how decentralized solutions can reduce pressure on drainage networks, prevent flooding, protect agricultural land, and restore the natural water cycle while supporting sustainable mobility.
