Sannem continued to make waves for the longhorns in the NCAA. At the NCAA Championships in Austin, Sannem was a member of the third place 200 free relay team. He also swam in the prelims for the 400 medley relay and 400 free relay teams, but was not a member of the lineups in the event finals. Individually, he finished 12th in the 200 free (1:32.56) and 26th in the 100 free (42.45).
2017-2018 (Southern California)
As a freshman, Sannem made an immediate impact at USC. He was a member of the fourth place 800 free relay at the Pac-12 Championships, and individually finished ninth in the 200 free (1:34.94), 15th in the 500 free (4:20.80) and 19th in the 100 free (44.09).
At the NCAA Championships, Sannem was part of the 12th place 800 free relay. After the completion of his freshman season, Sannem transferred from USC to Texas.