EMB145 Captain experienced a number 2 bleed leak upon switching over from APU bleed to engine bleed at 10;000 FT. QRH procedures are complied with and flight returned to departure airport.

Narrative

While climbing through 10;000 FT we switched from the APU bleed to the engine bleed systems; which resulted in an immediate Bleed #2 Leak and a Master Warning. We followed the QRH procedures; which had us contain the leak by closing cross bleed valve and the associated bleed valve (No. 2) and the APU bleed valve. This contained the leak; and no icing conditions were present so the remainder of the check list though read through was acknowledged not applied. This checklist does not terminate nor does it give guidance towards continuation or termination at the nearest suitable airport; so between the concern that damage may have occurred from the bleed leak and the tight fuel condition we were dispatched under I made the decision to return.A critical system that allows both pneumatic and deicing systems to function at high altitudes (above FL250) had failed. I questioned whether damage could have occurred due to the release of superheated bleed air; so I felt an overweight landing was warranted in this situation. We were also inadequately fueled to fly to destination at such a low altitude; and would have needed to land to take on more fuel enroute as a result of the significantly higher burn we would have experienced at FL250 (as opposed to FL370 which we were planned for).