Underground geological storage is the engineering solution currently followed in most countries for the permanent disposal of hazardous waste such as nuclear waste or the minimisation of the impact of carbon emissions. The success of these operations rely on the isolation of the stored waste. Microseismic monitoring provides a unique tool for monitoring the stability of the rock mass and the risk of fracturing and creation of paths for fluid and waste migration; ExGeo personnel has been involved in the monitoring of research and final repository facilities in Canada, Sweden, Finland, Belgium and France.