Managing hydrocarbon-contaminated runoff in permeable pavements
- 2 days ago
- 2 min read
Overview
In French Guiana, intense rainfall between mid-December and mid-July generates high volumes of runoff that saturate drainage networks and increase flood risk. In road and parking infrastructure, source infiltration has become a preferred strategy to restore the natural water cycle and limit downstream overflows. However, runoff from trafficked surfaces carries hydrocarbons and PAHs, which are toxic to soils, ecosystems, and human health.
Without a dedicated treatment stage, infiltrating this water transfers pollution directly into the ground. On a 22,000 m² permeable parking area in Matoury, the design integrated OSMORIA® Indigreen®, an aquatextile installed within the pavement structure to ensure stormwater quality management before infiltration. An aquatextile is a technical textile that manages stormwater quality. Its function is not simply to infiltrate runoff, but to clean up pollution while allowing infiltration to occur.
Challenge
The project had to manage significant stormwater volumes generated during the rainy season while preventing soil contamination. Runoff from parked vehicles accumulates hydrocarbons and polycyclic aromatic hydrocarbons, which can migrate into the subsoil when permeable pavements are used.
The core challenge was to combine hydraulic performance with effective depollution, without relying on soil quality or specific environmental conditions. The solution had to remain highly permeable to maintain infiltration capacity, while ensuring irreversible fixation of hydrocarbons and PAHs. In addition, long-term performance was required, with measurable efficiency based on the aquatextile itself rather than surrounding soil conditions.
Solution
OSMORIA Indigreen was installed in the ground between the formation layer and the bedding layer of the permeable pavement. When rainfall occurs, the highly permeable aquatextile allows water to pass through while irreversibly fixing more than 99.5% of hydrocarbons and PAHs transported by runoff. This irreversible fixation prevents any subsequent release of pollutants into the soil.
At the same time, the textile matrix diffuses nutrients that stimulate local microbiota, including bacteria and microfungi naturally present in the soil. This optimizes the processes of fixation and biodegradation of hydrocarbons over the long term. The use of local microbiota ensures systematic and accelerated biodegradation of micropollutants, independent of soil quality and environmental variability.
Once treated, stormwater continues to infiltrate and humidify the soil, supporting groundwater recharge while protecting underground biodiversity. By integrating a depollution stage directly within the infiltration structure, the system improves hydrocarbon retention and biodegradation compared to natural soil alone.
Designed through biomimicry and backed by more than ten years of research and development, the aquatextile provides a durable, autonomous solution with a service life exceeding 50 years. It operates without maintenance and avoids costly resizing of stormwater drainage networks. The result is a high-performance, nature-based approach to managing hydrocarbon-contaminated runoff while preserving soil function and biodiversity.
