LITOCLEAN exceeds targets in soil and water remediation project

Limited space was one of the obstacles that the professionals had to overcome to achieve the success of the work.

In any remediation project, it is important to know how to adapt to the circumstances and have the capacity to pursue the objectives set despite the difficulties. Under this maxim, Litoclean managed to remediate more than 37,000 m3 of affected land and more than 124,000 m3 of water, a figure well above the initial objectives, in an industrial port where activities in the food and textile sector had been developed. The land to be investigated detected the presence of hydrocarbons and chlorinated compounds that had to be treated, according to the Quantitative Risk Analysis.

At one point, the client needed to act quickly due to works to be carried out in a part of the plot, so Litoclean readapted the plans to quickly resolve the first phase, always responding to the planned objectives, as Joan Varias, environmental manager of the project explains: “the initial project foresaw a groundwater pumping through wells but it would have taken more time so we chose, in this phase, to eliminate the free phase, which allowed us to respond to the urgency of the client and meet the objectives”.

In the second phase, the complexity came from a question of space. It was necessary to work within the same plot, where there was not much room for it, so it was decided to separate the land into four sections and work separately in each of them. In each section, a selective excavation was carried out, separating the most contaminated, slightly contaminated and clean soils by means of in situ analyses with laboratory contrasts and, from there, each of them was treated appropriately. “The clean ones were taken to a soil stockpile that the client needed for future works, the slightly contaminated ones were treated by turning and aeration to volatilize the compounds and promote bioremediation until the objectives were reached and the most contaminated ones were treated by 500 m3 batches in a platform specially prepared for the execution of a landfarming with forced aeration, causing a more intensive and faster treatment,” explains Varias. This was repeated with each of the sections, taking into account that the walls separating one section from the other had to be waterproofed to prevent the treatment section from being affected.

Parallel to the action on the land, there was a groundwater treatment system. “We excavated up to 1.5 meters below the water table, the most affected section detected, and proceeded to pump and treat the water, which was then infiltrated back into the excavation vessel itself, it was a closed circuit,” says the project’s environmental director. This avoided discharge into the sewage system, which would have made the process more difficult. In addition, in all the areas where the earth was stockpiled, collection chambers were installed to collect the water (leachate from the excavated soils or rainwater), which was pumped to the treatment system and then infiltrated into the excavation vessels.

The final result was a complete success, since the objectives were met in terms of land and even exceeded in the case of groundwater, despite the reduced space that forced the project to be carried out in different sections and stages. All this in a fairly short execution time, considering the volumes of the project.

Litoclean’s ability to adapt to each case and its circumstances made it possible to remediate the area despite its complexity and meet the objectives set within the deadline. The TEMA LITOCLEAN Group has a long history of working on soil investigation and decontamination projects and as an environmental and safety consultant and applies its extensive knowledge and experience in each case.