CO2 pipelines pose a risk to local population and the environment as the presence of water and other impurities within CO2 may lead to operational problems related to corrosion, gas hydrate, and ice formation, and thus accidental release of CO2. The exact levels of impurities will vary depending on the source and capture process. Therefore, apart from dehydration, gas treatment is required. The level of impurities that can be tolerated will depend on the storage method (or enduse) and the transportation method. Other challenges to CO2 transport through pipelines consist in pipeline design and maintaining the CO2 in supercritical phase. 152