Analysis of key technical points for hazardous waste identification of contaminated soil

Hazardous waste identification of contaminated soil is a special case within the framework of environmental management of hazardous waste identification. An analysis of work briefings released by hazardous waste identification expert committees at all levels revealed that some identification institutions do not fully understand the technical requirements for identifying hazardous wastes in contaminated soil stipulated by Technical Specifications on Identification for Hazardous Waste (HJ 298-2019). This deficiency has resulted in prominent technical shortcomings in identification reports, a high dispute rate, and questionable accuracy and scientific rigor of the identification outcomes. With reference to the relevant norms and standards for hazardous waste identification, the study systematically analyzed the cases of hazardous waste identification reports of contaminated soil publicly disclosed on the National Hazardous Waste Identification Information Disclosure Service Platform. Then, the key technical points in hazardous waste identification in contaminated soil were analyzed. The results show that in the process of screening detection factors, it is necessary to fully utilize the available information from the stages of soil pollution status investigation and risk assessment to analyze characteristic pollutants and comprehensively identify the hazardous properties. The screening of toxic substances should focus on the sources of contaminants and soil characteristics, excluding substances that are unlikely to be present. The sampling process should employ zoning according to the degree of soil pollution, with heavily polluted areas identified separately and lightly polluted areas divided into reasonable sampling units. The delineation of exceedance areas should be based on the non-exceedance point connection method, supplemented by dense sampling points based on the golden-section method to scientifically reduce the extent of exceedance.