Hi Cristina, If you are using PPM 7.xx, this version does not allow you to delete resource pools which are already created. The only option so far is to disable them. Enhancement requests have already been filed with HP to see this functionality in their future versions. Thanks, Alex.
This is a known feature (issue). Since once a resource pool is created, different entities get attached to it and the data may be referred by the other entities as well, for historical purposes or current or future use. For example, resources, staffing profile, etc. entities tied to it. Unfortunately, even if the resource pool is entirely empty, i.e. never used, then also there's no way to delete it currently. Hopefully HP will come up with some solution for that in the future releases.