Both transport systems and storage reservoirs will need to include measurement and monitoring equipment to provide quantities of captured, compressed, transported and stored CO 2 , and account for any potential leaks in the process. Ultimately, determination of all carbon accounting for DACCS rests on the reliability of MRV tools, beginning with the initial measurements. Innovative forms of long term monitoring of subsurface storage may be able to provide either more detailed surveillance or lower costs, but may need to be included as infrastructure is built, rather than after the fact.