Table 2 GRID analysis applied to a URG project. For each indicator its evaluation is shown along with the corresponding score and its justification when necessary, based on representative cases

Seismic hazard concern

 Depth of the reservoir

 > 3 km

2

3 to 5 km depth

 Cumulative injection volume during stimulation

 > 10,000 m³

2

Soultz 2000 stimulation 23400m³ (Cuenot et al. 2008)

 Daily injection or extraction volume during operation

1–10,000 m³/day

1

Soultz 2000 stimulation up to 50 L/s (Cuenot et al. 2008)

 Rock type

within 500 m from the crystalline basement

1

 Separation between background and induced seismicity

Seismic zone 2 in SIA

1

correspondence with global seismic hazard map

 Fluid injection pressure

0.3–10 MPa

1

mandatory upper limit of 10 MPa

 Distance to known and potentially active faults with length greater than 3 km

 < 2 km

2

reservoir is a fault zone

Total

10

Concern about secondary hazards, exposure and vulnerability (within a radius of 5 km)

 Local site amplification

No building or infrastructure on soft soil

0

 Exposed population

Urban (≥ 20,000 inhabitants)

2

 Industrial or commercial activity

High activity

2

 Importance of buildings and infrastructure

No building or infrastructure of class II or III

0

 Infrastructure with considerable environmental risk

non concern

0

 Unreinforced cultural heritage

 < 5% buildings listed as important local, regional or national heritage sites

0

 Susceptibility to secondary hazard

very low

0

Total

4

Social concern

 Potential for concern in the  general population

Exist

1

 Vulnerable or strongly opposing stakeholders

Exist

1

 Negative experiences with similar projects

Exist

1

Basel case

 Lack of trusts in the project operators or authorities

Exist

1

 Benefits to the local community

Direct benefits with or without local compensation

0

Total

4