A Hydro‐Biogeochemical Tracing Method for Soil‐Groundwater Organic Contamination in Industrial Sites: Development and Validation of a Micro‐Disturbance System

The heterogeneity of soil and groundwater media, combined with the complexity of contaminant hydro-biogeochemical behavior, limits the effectiveness of traditional high-disturbance, low-density methods, such as drilling, for characterizing contaminant transport and transformation processes. To address this, we developed a micro-disturbance detection and data interpretation method based on multiprocess coupling theory, focusing on key hydro-biogeochemical processes of organic pollutants. Validation was conducted at a petroleum-contaminated site in North China using a phased approach that integrated micro-disturbance screening with drilling verification. The results showed that the micro-disturbance screening successfully delineated a plume of approximately 1542 m², consistent with shallow soil exceedances and groundwater contamination, thereby demonstrating a strong correlation between surface gas anomalies and subsurface biogeochemical processes. This study enhances source-plume delineation capability, provides technical support for tracing contaminant biogeochemical processes, and offers a scientific basis for implementing remediation strategies such as enhanced natural attenuation.