The Detailed Investigation study aims to characterize the physical environment in which the Contaminated Area under Investigation (CAI) is located, determine the concentrations and quantify the masses of the chemicals of interest, define the three-dimensional boundaries of contamination plumes, characterize the transport of chemicals and their evolution over time, and identify exposure scenarios necessary for the Risk Assessment phase. (CETESB, DD-038/2017/C).
The Detailed Investigation phase aims to delineate, both horizontally and vertically, and quantify the concentrations of contaminants present in soil and groundwater, which were identified and characterized in the Confirmatory Investigation study, to delineate contamination plumes in their different phases, namely: NAPL - Non-Aqueous Phase Liquid, dissolved phase, and sorbed phase.
Concluding the Detailed Investigation study with the development of the human health risk assessment, which identifies and characterizes the presence and transport pathways of contaminants in the area, as well as the risks to receptors exposed to the chemicals. It also involves the development of an intervention plan to define the measures and actions that must be implemented for the containment, reduction, and elimination of contaminants, as well as actions for the safety and preservation of receptors.
When to conduct the detailed investigation
The detailed investigation study should be planned based on the studies and results from the preliminary assessment and confirmatory investigation, as well as on the conceptual model 2 (CM2) developed in these previous studies. This constitutes the third stage of CETESB's contaminated area management.
The results of quantification and characterization, as well as the delineation of the plume, will be a fundamental basis for composing Conceptual Model 3 (CM3) and supporting the development of the human health risk analysis and the Intervention Plan.
Stages of the detailed investigation
After analyzing the site history, the results of previous environmental studies, and the investigation plan defined in the Confirmatory Investigation report, technical field services are conducted, including soil drilling and the installation of groundwater monitoring wells, vapor wells, direct push soil sampling, and other investigative methods. This results in the collection and analysis of soil, groundwater, and vapor samples with the aim of delineating the plume of the confirmed contaminant.
During this stage, it may be identified during fieldwork the need for additional drilling and well installation to obtain both vertical and horizontal delineation of the plume. This is a crucial aspect of environmental investigation for several reasons:
Extent Assessment: Delineation helps to understand the dimension and the area affected by the contamination, allowing for a more accurate assessment of environmental and human health risks.
Focus on Critical Areas: Identifying specific areas with higher concentrations of contaminants directs remediation efforts to where they are most needed, optimizing resources and efforts.
Definition of Remediation Strategies: Understanding the contaminant plume assists in choosing the most effective approach for site cleanup, considering the types of contaminants and the extent of the area.
Effective Monitoring: By clearly defining the affected area, ongoing monitoring becomes more efficient and targeted, facilitating the assessment of the effectiveness of remediation measures over time.
Protection of Public Health: By accurately delineating the contaminant plume, it is possible to implement measures to protect public health and the environment more effectively.
After the installation of monitoring wells and the collection of soil, groundwater, and vapor samples, following the sampling procedures outlined in SMA Resolution No. 100, published in the Official Gazette of the State of São Paulo on 10/22/2013, and in the Board Decision No. 310/2014/E/C/I of 2014, the samples are sent for physicochemical analysis conducted by laboratories accredited by INMETRO 17.025.
The conclusive technical report consists of the investigation results, ultimately generating Conceptual Model 3 (CM3), which serves as the basis for the human health risk analysis and intervention plan.
Human Health Risk Assessment in the Detailed Investigation
The Risk Assessment identifies and characterizes the presence and transport pathways of contaminants in the area, as well as the risks to receptors exposed to the chemicals. It defines the intervention measures and actions to be implemented for the containment, reduction, and elimination of contaminants, as well as actions for the safety and preservation of the receptors.
The Human Health Risk Assessment study aims to determine the risks and Maximum Acceptable Concentrations (MAC) for the human receptors identified in the study area in question. It is developed considering the results and information from previous environmental studies.
Intervention Plan in the Detailed Investigation
The Intervention Plan should be developed to define the intervention measures and actions to be implemented in the contaminated area. It includes the selection of the best technique to be employed, aiming at the containment and control of the contamination source to prevent further advances, the reduction of contaminant plumes to acceptable levels, and always preventing and controlling the exposure of receptors present in the study area.
Objectives for the development of the Intervention Plan:
- Control the identified sources of contamination;
- Attain an acceptable risk level for identified human and/or ecological receptors;
- Control the identified risks based on applicable legal standards.
The legal responsible party for the contaminated area must submit to the environmental authority an implementation report of the remediation system or other intervention actions and periodic reports for the measurement and monitoring of the efficiency and effectiveness of the services being carried out.
The deadline for the execution of the Intervention Plan will be defined according to the functions and means of implementation of the measures and actions outlined in this study, as follows: Short-term: with a duration of days to 12 months; Medium-term: with a duration of 1 to 5 years; Long-term: with a duration of 5 years or more.
Hiring Projeto Ambiental to conduct a detailed investigation study offers several essential benefits, including:
Experiência técnica: A team of experienced professionals specialized in various disciplines, ensuring precise and comprehensive execution of the study.
Conhecimento Regulatório: Estamos atualizados com as regulamentações ambientais vigentes, assegurando que o estudo esteja em conformidade com os requisitos legais.
Planejamento Estratégico: Desenvolvemos planos de amostragem e análise criteriosos, maximizando a eficiência e minimizando os custos envolvidos.
Desenvolvimento de Estratégias de Remediação: Propomos estratégias de remediação eficazes, considerando as características do local e os tipos de contaminação.
Comunicação com Partes Interessadas: Auxiliamos na comunicação com autoridades, comunidades locais e outras partes interessadas, promovendo transparência.
Time and Resource Savings: Otimizamos o processo de investigação, economizando tempo e reduzindo custos desnecessários.
Minimização de Riscos Futuros: Ao compreender profundamente a situação com a execução da detalhada, ajudamos a prevenir possíveis litígios e responsabilidades futuras.
Implantação da remediação: Fabricamos soluções para remediação, implantando e operando diversas técnicas eficazes e eficientes para recuperação da área contaminada, assessoramos você ate a obtenção do termo de reabilitação.