Removal of $PGDATA/base files that existed before streaming replication (v9.2.4)

Dear pgsql-admin,

I set up streaming replication using the rsync base backup described in the
wiki: http://wiki.postgresql.org/wiki/Binary_Replication_Tutorial

However, before starting replication I had previously loaded some databases
on the "Secondary" server for testing. Folders for those db's are still in
base/ and are consuming a lot of disk space. du reports that the base on my
Secondary is twice as large as on the Primary.

Do I have safe options for removing this unused data, beyond clearing the
Secondary's $PGDATA folder and re-doing the synchronization?

Cheers,
--
Dana Rea
Infrastructure Team Lead
Informatics Department
Biodiversity Institute of Ontario
University of Guelph
Guelph Ontario Canada N1G2W1
(519) 824-4120 x52872