adj.
connected to utilities, such as sewers, electricity and water.
The earliest known attestation of this term is found in The New York Times dated 1924. This term is not currently most frequent in Canada (see Charts 1 & 2). Chart 2 suggests that the term serviced site in reference to campsites is much more frequent in Canada than in the US. However, camping as an activity may be more frequent in Canada, skewing the results.
See also COD-2, s.v. "serviced", which is marked "Cdn & Brit".
See also: supply teacher unserviced
Images:

Chart 1: Internet Domain Search, 21 Feb. 2013 
Chart 2: Internet Domain Search, 28 May 2013