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.
Leak due to surface installation is a typical risk in any operation of civil engineering and industrial activity. It consists of an accidental escape of fluids from tanks temporarily storing waste or from a hole or crack in the surface pipe circuits. The specificity of geothermal operation is the characteristics of the fluids encountered, since geothermal fluids can be highly mineralized, and of the produced material (cuttings, additives) (Gombert et al., 2017) that are treated in a specific chapter. A special case is the leak from the circuit of secondary fluids of binary geothermal plants, if these fluids are toxic, explosive or have a Global Warming Potential (GWP).
A leak is a risk and not an impact. Its gravity is limited with low consequences on the environment as it is generally detected before extensive damage occurs. However, from the beginning of the geothermal industry, no accident related to this risk was reported.
Temporary storage of waste and circulation of fluids are unavoidable in the geothermal surface operation, and environmental impact assessment enforces proper management to prevent and mitigate environmental adverse effects due to leaks.
Other accidental discharges at surface of fluids and solids beside leaks from tanks and pipes and a more detailed description of geothermal brine composition are described in Liquid and solid effusions on surface. For further information on other fluid waste, see Waste production from surface operations.
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 principal monitoring and mitigation measures that can be adopted.
