Technical Requirements for Site Soil and Groundwater Pollution Investigation and Risk Assessment (hereinafter referred to as "Technical Requirements") was compiled by 15 domestic unit, in which the Hydrogeological Environmental Geological Survey Center of China Geological Survey was the undertaker and presided over the compilation. Beijing Normal University, Jilin University, Graduate School of Chinese Academy of Sciences, SGS, China Geological Environment Monitoring Institute, Shandong University of Science and Technology, Chang 'an University, Nanjing Geological Survey Center of China Geological Survey, China Testing Technology Co., Ltd. (CTI), Hebei Geology and Mineral Resources Center Laboratory and other 14 units participated in the compilation as assisting units.
The working procedures required by this technical requirement are mainly based on the management mode of geological survey project of China Geological Survey, and organically integrated into the staged on-site investigation and evaluation procedures generally adopted in the world. Site pre-study in technical requirements is equivalent to a part of international preliminary site investigation and exploratory site investigation, and site investigation in technical requirements is equivalent to a part of international exploratory site investigation and detailed site investigation. In fact, it is a reflection of the grading evaluation procedure in developed countries to evaluate the pollution and risk of soil and groundwater respectively in terms of technical requirements.
This technical requirement begins with the investigation task and defines the purpose of the investigation. According to the task requirements, carry out on-site pre-research work before design preparation. On-site pre-research work provides a basis for design compilation from the aspects of working methods, contents and physical workload, and is mainly composed of three parts: data collection, reconnaissance and preliminary analysis. Data collection is the basis of pre-research stage. Try to collect all the data related to the site completely. On this basis, reconnaissance is carried out to verify the reliability of the data and further obtain the field data. After completing the data collection and reconnaissance, the preliminary work results are analyzed and the basic characteristics of site pollution are preliminarily understood. According to the work in the pre-research stage, determine the working methods and workload, and design and compile. After the design is approved, according to the design requirements, pollution source investigation, soil pollution investigation, hydrogeological investigation, groundwater pollution investigation and site pollution receptor investigation will be carried out in turn. After the investigation is completed, the risk assessment of soil and groundwater pollution will be carried out on the basis of soil and groundwater pollution assessment. According to the investigation and evaluation results, arrange long-term monitoring of groundwater. Finally, integrate the results of investigation, evaluation and monitoring.
This technology requires strong consistency of working procedures and highlights the characteristics of geological work.
This technical requirement focuses on investigation, and risk assessment, as the output of contaminated site investigation, predicts and evaluates the soil and groundwater of contaminated site. The five investigation contents required by this technology, such as pollution source investigation, soil pollution investigation, hydrogeology investigation, groundwater pollution investigation and pollution receptor investigation, not only consider the systematicness of site pollution investigation, that is, investigate the pollution source, soil and groundwater as a whole, but also consider the migration and action process of pollution, that is, pollution source-way-receptor. The content of the preliminary investigation is the basis of the follow-up investigation, taking into account the needs of the follow-up investigation and avoiding duplication of workload. In a word, the setting of investigation content ensures that the investigation process is a comprehensive, systematic, orderly and continuous process.
The survey methods such as ground survey, portable instrument screening, geophysical exploration, drilling, sample collection and detection given in this technical requirement are written into this technical requirement according to the development status of China's productive forces and the common methods of geological survey. Other investigation methods can be recommended, such as remote sensing technology, isotope technology and microbial technology. The above survey methods run through all the survey contents, some serve proprietary survey contents, and some can serve multiple survey contents. There is a cross-synthesis and verification relationship between methods. For example, the relationship between geophysical prospecting and drilling investigation is to use geophysical prospecting technology to find out abnormal points or abnormal zones of contaminated sites for drilling, and then drilling will conduct detailed, direct and in-depth investigation and verification.
The evaluation methods used in Technical Requirements for Soil and Groundwater Pollution Assessment are all common methods, and the scientific expression of the evaluation formula is not discussed in depth, but the essence of its expression is simply expressed. Risk assessment of soil and groundwater is discussed separately in this technical requirement. The risk assessment of soil pollution is mainly based on qualitative assessment, and can also refer to other quantitative methods for quantitative assessment. Groundwater pollution risk assessment adopts standard concentration inversion method and process simulation method, and its core content is to use water solute transport model to simulate and calculate under natural purification conditions.
Groundwater monitoring is to grasp the long-term dynamic changes of groundwater flow field, pollutant concentration and pollution plume distribution range, verify the assumptions and conclusions of groundwater pollution risk assessment, and put forward the direction of groundwater remediation and treatment in contaminated sites.
Second, the scope of application and application examples
This technical requirement is applicable to the investigation of site pollution caused by toxic and harmful chemicals, not to the investigation of site pollution caused by radioactive pollution.
This standard is applicable to the investigation of site soil and groundwater pollution composed of loose sediments, and can be used for reference in the investigation of site pollution in bedrock cracks and karst areas.
It has been applied in projects such as oil contaminated sites, sewage irrigation contaminated sites and pesticide contaminated sites undertaken by the Hydrogeological Environmental Geological Survey Center of China Geological Survey. And the effect is good. In addition, other units also tried this technical requirement, which was well received.
Third, promote the transformation mode.
The results of Technical Requirements for Investigation and Risk Assessment of Site Soil and Groundwater Pollution will be released to the society and professional teams in the standard way of China Geological Survey. Through personnel training and technical consultation, its test scope will be expanded and its influence in the field of site pollution investigation will be improved.
Technical support unit: Hydrogeological Environmental Geological Survey Center of China Geological Survey.
Contact: Cai Wutian, Wei Yumei
Mailing address: No.0/305, Qiyi Middle Road, Baoding City, Hebei Province.
Postal code: 07 105 1
Tel: 0312-59085/kloc-0, 03 12-590867 1.
E-mail :caiwutian@yahoo.com weiyumei@chegs.cn