Books like Curse of the Broomstaff

A secret society of Janitors with wizard-like powers continue their battle, and now, the stakes are even higher. The Bureau of Educational Maintenance is after Alan Zumbro and this time they mean business - deadly business. Spencer, Daisy, and their little team of rebels must find the source of all magical Glop and destroy it before it can destroy the world as we know it. No small task with the BEM and their monster toxites at their heels. It's a wild and dangerous ride as they follow the trail of clues all the way to the hiding place of the mysterious aurans: guardians of a secret landfill. What they discover there will change the way Spencer sees himself, not to mention the fate of the rebels.