At what age can I safely neuter my beagle pup?

Bruce is 11 weeks old and starting to get out of control. So far I've been okay just to pen him in his domain when I leave the house, but he's a problem solver and has since figured out multiple escape routes. Every time I come home, now, I find him roaming about downstairs. He also seems to be peeing all the time; no matter how often I take him outside, he's always got some saved up to wet on the floor at least two or three more times when I get him in, and he's done so a number of times while lifting his leg. Finally, his biting is getting worse and worse, both in frequency and strength. He gets all the attention and exercise he needs, so I can't figure out what else the problem may be.