Today, Sensor Network Query Processors (SNQPs) are being integrated with Data Stream Management Systems (DSMSs). Due to the query capabilities of SNQPs, query processing can be extended from the DSMS into the sensor network. The problem then is to decide which operators should be allocated to the SNQP rather than being processed in the DSMS. This paper presents a first solution to this problem. Operators are classified as movable or not movable. Next, a QoS-based rating model, a two-stage neighborhood function browsing through the set of possible operator allocations, and an optimization algorithm using heuristics are introduced. Finally, it is shown how the operator allocation process fits into the Borealis optimization.