Rawwater is commercialising its unique leak and defect sealing technologies. One of the remaining hurdles to commercialisation is control of material ingress through the repair site and into the system. For many applications, this is undesirable. NPL have a vast range of knowledge and access to equipment for Non-Destructive Testing (NDT). The proposed project would be to test NDT options for a limited number of 'typical' leaks repairs to assess whether NDT will be able to identify if there is any ingress. The reason that it is so crucial to achieve an NDT method is that the only other way of measuring is destructively which either involves changing the end state, potentially disrupting any ingress and therefore not providing accurate information or physically destroying each test piece, which is not a commercially or environmentally viable option. The target is to identify NDT options for laboratory analysis, to allow Rawwater to control parameters to reduce/remove ingress and explore the potential to use this in the field to provide customers with a post seal analysis to prove ingress has not occurred.