An existing backflow assessment must be looked at again when (a) any new cross-connection, or a device or system able to contaminate the water supply, is connected to the facility's water service, directly or indirectly; or (b) connections made before certification were judged not to need backflow prevention but a GMO not previously handled, whose risks differ from those of the GMOs assessed at certification, is about to be introduced.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.