The event described here can be limited to specific settings and might not be encountered in every geothermal projects. More details about this topic are presented in a report that can be found on GEOENVI website.
Like any human activity, geothermal plants produce both liquid and solid waste, resulting from the construction, operation and maintenance of the plant, as well as household waste from the personnel. The nature of waste is very diverse, it ranges from household waste (paper, garbage, etc.), plastics from packaging, fuel and lubricant used for engines, steel, copper and scrap metals or hazardous waste from pipes, filters and other tools disposed from sites, chemical waste, unused material for building or road construction and waste-water, excavated earth and rocks resulting from the plant construction, waste timber, rubbery materials, filters and materials contaminated with lubricating oil.
Waste treatment is regulated by a European Directive (Water Framework Directive 2000/60/EC) and national legislation
The adverse environmental effects of surface waste production, which can be encountered in any other industrial activities, are limited in time and volumes for geothermal development. The direct consequences on humans, ecosystems and the atmosphere are almost inexistent, as waste is evacuated and recycled or treated. Research and innovation efforts are also improving applicability and use of recycled/secondary materials or waste in geothermal plants, favouring the integration of geothermal into the circular economy.
Only waste produced by surface operations are considered in this topic. See Liquid and solid effusions on surface or Degassing for waste of material from underground, such as drilling mud, cuttings, geothermal fluid waste.
The table here below provides an overview of this topic in term of risk and impact assessment i.e. its causes, consequences, the phases concerned, the influencing contexts or the principals monitoring and mitigation measures that can be adopted.