The Canadian Geodetic Survey (CGS) is currently executing a 5-year project to densify the Canadian Active Control System (CACS) GNSS network with 22 stations of very high precision, high frequency and high reliability, which will contribute to the foundation for positioning standards in Canada. These stations provide positioning, navigation and timing (PNT) information, supporting a variety of essential services as well as geoscience applications. In addition to contributing to the realization of the International Reference Frame (ITRF) and being the basis for positioning in Canada, the Canadian Geodetic Survey uses these stations to create a velocity model used to describe the movement of the North American plate. Data from these stations contribute to space weather monitoring, sea-level rise studies, and early warning systems for natural hazards. This presentation will show the locations of these stations, the rational for choosing them, and the challenges we are facing in expanding this network. We are open to input on how future GNSS sites and geodetic infrastructure can best be located to maximize benefits for scientific purposes and we believe this forum could be a good opportunity for feedback.