There is camping just past the TV station walking toward Monte do Gozo (it was closed last November), and more camping (see below) if you turn left just before Monte do Gozo (it looked like a year-round facility with a pool, but I do not know for sure; call them).
Camping Monte Do Gozo
Carretera del Aeropuerto
15891 Santiago de Compostela, Spain
981 563 142
Camping San marcos
Spain
Teléfono:: (0034) 981587917
Fax:: (0034) 981587430