Green Energy

There are AFAIK two main risk with using geothermal energy:

1. risk of inducing (minor) earthquakes during drilling. I think this risk is slightly elevated with these new fracking like techniques the OP text mentions
2. creating mud geysers, which is very low risk but if it happens can be a major calamity.

Both these risks are during the development of new wells, and once things are completed there is basically no other problems other than that geothermal energy is not infinite and the hot aquifers lower their temperature after some decades. This can make the system too inefficient to be worth continuing operation.