We interviewed Marc Medina, environmental director of works at Litoclean, to learn from an expert about the keys to proper CAD.
Companies and administrations are increasingly striving to implement environmental controls in construction projects, which makes the work of the Environmental Site Management (EMS) essential. This figure assumes responsibility for environmental monitoring during the earthmoving process on plots of land that have previously had a potentially contaminating soil activity or indications of contamination.
On the one hand, the environmental regulations required by current legislation must be complied with, minimizing environmental impact and protecting the environment and resources. On the other hand, the environmental conditions established in the authorizations and defined in the Excavation Plan prior to the execution of the project, which contemplates the works defined by the DAO, including waste management, must be guaranteed.
Litoclean is in charge of the Environmental Site Management (EMS), which provides advice during this phase of the construction process, from the drafting of the excavation plan to environmental monitoring and proper waste treatment. It is also in charge of certifying the quality of the soil and, if necessary, carrying out a residual risk analysis taking into account the intended future use of the site.
Proper management of excavated soils involves a prior assessment of the soil to determine its quality and possible contamination. If contaminants are identified, remediation measures must be implemented to minimize risks to human health and the environment during excavation work. If excavated soils are considered waste, they must be managed in accordance with current regulations, which include their transport, treatment and final disposal in authorized facilities.
The management of excavated soils in Spain requires a clear understanding of the distinction between contaminated soil and waste, as well as compliance with the applicable regulations and standards for waste management. Only through proper and responsible management can the protection of the environment and public health be guaranteed in the development of construction projects and infrastructure works.
Marc Medina, Environmental Director of Works at Litoclean, explains what the DAO consists of and how the whole process is carried out.
What does the work of the contaminated soil specialist consist of during the DAO?
As environmental site management, we need to ensure proper environmental compliance during the earthmoving phase. Therefore, it is essential to have expert technical personnel to evaluate the quality or characteristics of the soils at the excavation face, properly segregate the soils in differentiated stockpiles and ensure their correct management, either in a controlled deposit or through valorization.
One of the biggest challenges is the uncertainty associated with excavation, as surprises can arise, such as buried waste, fuel deposits, hazardous materials, among others. These situations require a quick and effective response to prevent any environmental damage. Thorough planning before excavation begins is crucial, and then constant vigilance must be maintained to address these unforeseen events immediately.
The DAO’s responsibility is ultimately to identify, manage and mitigate environmental risks that may arise from excavation and earthmoving on potentially contaminated plots of land since contaminants may be released into the environment during these activities if not properly managed.
The DAO’s responsibility is ultimately to identify, manage and mitigate environmental risks that may arise from excavation and earthmoving on potentially contaminated plots of land since contaminants may be released into the environment during these activities if not properly managed.
Before beginning to remove soil where there is evidence of contamination, an Excavation Plan is submitted to the waste regulator. How is it established and what elements does it include?
Prior to the drafting of the Excavation Plan it is necessary to evaluate the previous information that exists on the site, proceeding to a historical analysis of previous activities on the plot to identify areas with potential sources of potentially contaminated soils. If necessary, the information is completed with a characterization of the subsoil of the site, as well as a characterization of the soil as waste and its hazardousness, in order to evaluate management alternatives as established in the current regulatory framework.
Subsequently, the most appropriate management method is selected based on the characteristics of the waste and the needs of the project.
What is the difference between contaminated soil and waste?
A contaminated soil is one that contains hazardous substances in concentrations that represent an unacceptable risk, while a waste is any material that is intended to be disposed of. At Litoclean we perform detailed analyses to identify and quantify the contaminants present in the soil and then classify them and evaluate suitable treatment alternatives, always ensuring compliance with waste management regulations.
What kind of management is given to the land?
The characterization of the soil as a waste includes the evaluation of its composition and includes the evaluation of its hazardousness as it is a waste with a mirror code. If the final management pathway is a controlled deposit, it must also include the evaluation of the criteria for admission to deposit of inert, non-hazardous or hazardous waste. If the waste is not classified as hazardous and the final management route is not a controlled deposit, the acceptance criteria of the management company and its treatment possibilities defined in the environmental authorization of said company must be taken into account.
We recommend the recovery of waste to avoid unnecessary overfilling of landfills and to be able to give another use to these wastes, it is a very positive circular economy measure. In many cases, the treatment plants also classify the soils according to the classification to controlled deposit, although as mentioned above, the admission criteria will be defined by each plant depending on the treatment of the waste.
Once the plan has been drawn up, the excavation phase is next. How is a correct segregation of the extracted soils and residues carried out?
During excavation, we implement constant environmental monitoring, allowing us to detect and handle any contaminated material or unexpected debris immediately. This approach allows us to ensure that the project is executed safely and in compliance with regulations.
The presence of technical personnel with expertise in contaminated soils is essential to evaluate the excavation front that can be segregated both on the basis of organoleptic observations and by means of on-site analysis with specific technology.
When is the DAO terminated?
The DAO at site scale is considered completed once the bottom of the excavation is reached and the remaining soil samples are taken from both the base and the walls of the excavation vessel. This is unless the vessel is subsequently backfilled, in which case it will be necessary to control the input soils, both for their origin and to ensure their correct analytical status.
Based on the analytical results obtained from the remaining soils, a report is prepared detailing the evolution of the excavation, measurements taken, as well as any unexpected findings that may have been detected, previously unknown areas affected, the presence of tanks, drums, etc. This report includes the total amount of waste managed, as well as all the documents associated with its management.
In the event that the results of the remaining soils show concentrations above the reference standard, it is necessary to carry out a residual risk analysis to verify that they pose an acceptable risk to the health of future receptors that may be present at the site, and in some cases, the establishment of a control and monitoring network to verify that they are maintained over time.
Finally, this report is submitted to the competent regulatory body.
Environmental site management is essential to ensure that earthworks on potentially contaminated plots are carried out properly, safely and in compliance with current regulations. Marc Medina and the rest of the Litoclean team are clear that the ability to respond quickly to unforeseen situations is particularly important in these works, minimizing delays and cost overruns, and therefore work to ensure that the entire structure is prepared to act with determination, always based on expert knowledge.
