Assesing the environmental impact of bentonite discharge on marine ecosystems: a 3D modelling approach in the vicinity of Tamaduste, El Hierro

Abstract

This Final Degree Project presents an analysis of the dispersion of a hypothetical bentonite discharge resulting from a horizontal directional drilling operation used for the cable connection between an offshore wind farm and the onshore power station, specifically in Tamaduste, El Hierro. The aim of the study is to evaluate the potential environmental impact of the bentonite discharge at the end of the drilling process. The methodology combines field data analysis, historical oceanographic data, seabed bathymetry and morphology assessment, and three- dimensional numerical modelling using MIKE 3 Flow Model FM and MUD Transport.The results show that, under certain environmental conditions, the suspended material exhibits limited dispersion behaviour in both concentration and spatial extent, remaining mainly confined near the discharge point without significant large-scale dispersion. This research contributes to a better understanding of the dispersion and dilution processes of bentonite discharges in marine environments, supporting sustainable offshore development through scientific evidence that facilitates environmental management and the implementation of monitoring plans.