diff --git a/ckan/migration/versions/077_add_revisions_to_system_info.py b/ckan/migration/versions/077_add_revisions_to_system_info.py
index 9516a9127c0..daa979164a2 100644
--- a/ckan/migration/versions/077_add_revisions_to_system_info.py
+++ b/ckan/migration/versions/077_add_revisions_to_system_info.py
@@ -1,6 +1,6 @@
 # encoding: utf-8
 
-import vdm.sqlalchemy
+from ckan import model
 
 
 def upgrade(migrate_engine):
@@ -21,5 +21,5 @@ def upgrade(migrate_engine):
         ALTER TABLE system_info_revision
             DROP CONSTRAINT "system_info_revision_key_key";
 
-        '''.format(state=vdm.sqlalchemy.State.ACTIVE)
+        '''.format(state=model.State.ACTIVE)
     )
diff --git a/ckan/model/core.py b/ckan/model/core.py
index 4147f9c34c5..97af8cc831f 100644
--- a/ckan/model/core.py
+++ b/ckan/model/core.py
@@ -8,7 +8,9 @@
 from sqlalchemy import Column, DateTime, Text, Boolean
 
 
-__all__ = ['System', 'Revision', 'State', 'revision_table']
+__all__ = ['System', 'Revision', 'State', 'StatefulObjectMixin',
+           'revision_table']
+log = __import__('logging').getLogger(__name__)
 
 # VDM-specific tables
 revision_table = vdm.sqlalchemy.make_revision_table(meta.metadata)
@@ -31,8 +33,27 @@ def by_name(cls, name):
 
 
 # VDM-specific domain objects
-State = vdm.sqlalchemy.State
-State.all = [State.ACTIVE, State.DELETED]
+class State(object):
+    ACTIVE = u'active'
+    DELETED = u'deleted'
+    PENDING = u'pending'
+
+
+class StatefulObjectMixin(object):
+    __stateful__ = True
+
+    def delete(self):
+        log.debug('Running delete on %s', self)
+        self.state = State.DELETED
+
+    def undelete(self):
+        self.state = State.ACTIVE
+
+    def is_active(self):
+        # also support None in case this object is not yet refreshed ...
+        return self.state is None or self.state == State.ACTIVE
+
+
 Revision = vdm.sqlalchemy.make_Revision(meta.mapper, revision_table)
 
 
diff --git a/ckan/model/domain_object.py b/ckan/model/domain_object.py
index 9761042a553..c7b5ae1cf16 100644
--- a/ckan/model/domain_object.py
+++ b/ckan/model/domain_object.py
@@ -79,7 +79,7 @@ def remove(self):
 
     def delete(self):
         # stateful objects have this method overridden - see
-        # vmd.base.StatefulObjectMixin
+        # core.StatefulObjectMixin
         self.Session.delete(self)
 
     def purge(self):
diff --git a/ckan/model/group.py b/ckan/model/group.py
index 469d0669329..a27a00e1503 100644
--- a/ckan/model/group.py
+++ b/ckan/model/group.py
@@ -27,9 +27,11 @@
                      Column('capacity', types.UnicodeText,
                             nullable=False),
                      Column('group_id', types.UnicodeText,
-                            ForeignKey('group.id')),)
+                            ForeignKey('group.id')),
+                     Column('state', types.UnicodeText,
+                            default=core.State.ACTIVE),
+                     )
 
-vdm.sqlalchemy.make_table_stateful(member_table)
 member_revision_table = core.make_revisioned_table(member_table)
 
 group_table = Table('group', meta.metadata,
@@ -47,14 +49,17 @@
                            default=datetime.datetime.now),
                     Column('is_organization', types.Boolean, default=False),
                     Column('approval_status', types.UnicodeText,
-                           default=u"approved"))
+                           default=u"approved"),
+                    Column('state', types.UnicodeText,
+                           default=core.State.ACTIVE),
+                    )
+
 
-vdm.sqlalchemy.make_table_stateful(group_table)
 group_revision_table = core.make_revisioned_table(group_table)
 
 
 class Member(vdm.sqlalchemy.RevisionedObjectMixin,
-             vdm.sqlalchemy.StatefulObjectMixin,
+             core.StatefulObjectMixin,
              domain_object.DomainObject):
     '''A Member object represents any other object being a 'member' of a
     particular Group.
@@ -112,7 +117,7 @@ def __unicode__(self):
 
 
 class Group(vdm.sqlalchemy.RevisionedObjectMixin,
-            vdm.sqlalchemy.StatefulObjectMixin,
+            core.StatefulObjectMixin,
             domain_object.DomainObject):
 
     def __init__(self, name=u'', title=u'', description=u'', image_url=u'',
diff --git a/ckan/model/group_extra.py b/ckan/model/group_extra.py
index 331c4c66d08..fd4fb9ba6ea 100644
--- a/ckan/model/group_extra.py
+++ b/ckan/model/group_extra.py
@@ -1,7 +1,6 @@
 # encoding: utf-8
 
 import vdm.sqlalchemy
-import vdm.sqlalchemy.stateful
 from sqlalchemy import orm, types, Column, Table, ForeignKey
 from six import text_type
 
@@ -19,15 +18,15 @@
     Column('group_id', types.UnicodeText, ForeignKey('group.id')),
     Column('key', types.UnicodeText),
     Column('value', types.UnicodeText),
+    Column('state', types.UnicodeText, default=core.State.ACTIVE),
 )
 
-vdm.sqlalchemy.make_table_stateful(group_extra_table)
 group_extra_revision_table = core.make_revisioned_table(group_extra_table)
 
 
 class GroupExtra(vdm.sqlalchemy.RevisionedObjectMixin,
-        vdm.sqlalchemy.StatefulObjectMixin,
-        domain_object.DomainObject):
+                 core.StatefulObjectMixin,
+                 domain_object.DomainObject):
     pass
 
 meta.mapper(GroupExtra, group_extra_table, properties={
diff --git a/ckan/model/package.py b/ckan/model/package.py
index e267d712f59..337b33ef460 100644
--- a/ckan/model/package.py
+++ b/ckan/model/package.py
@@ -52,18 +52,18 @@
         Column('metadata_created', types.DateTime, default=datetime.datetime.utcnow),
         Column('metadata_modified', types.DateTime, default=datetime.datetime.utcnow),
         Column('private', types.Boolean, default=False),
+        Column('state', types.UnicodeText, default=core.State.ACTIVE),
 )
 
 
-vdm.sqlalchemy.make_table_stateful(package_table)
 package_revision_table = core.make_revisioned_table(package_table)
 
 ## -------------------
 ## Mapped classes
 
 class Package(vdm.sqlalchemy.RevisionedObjectMixin,
-        vdm.sqlalchemy.StatefulObjectMixin,
-        domain_object.DomainObject):
+              core.StatefulObjectMixin,
+              domain_object.DomainObject):
 
     text_search_fields = ['name', 'title']
 
diff --git a/ckan/model/package_extra.py b/ckan/model/package_extra.py
index 55c5188ba2b..9d717779b33 100644
--- a/ckan/model/package_extra.py
+++ b/ckan/model/package_extra.py
@@ -23,13 +23,14 @@
     Column('package_id', types.UnicodeText, ForeignKey('package.id')),
     Column('key', types.UnicodeText),
     Column('value', types.UnicodeText),
+    Column('state', types.UnicodeText, default=core.State.ACTIVE),
 )
 
-vdm.sqlalchemy.make_table_stateful(package_extra_table)
+
 extra_revision_table= core.make_revisioned_table(package_extra_table)
 
 class PackageExtra(vdm.sqlalchemy.RevisionedObjectMixin,
-        vdm.sqlalchemy.StatefulObjectMixin,
+        core.StatefulObjectMixin,
         domain_object.DomainObject):
 
     def related_packages(self):
diff --git a/ckan/model/package_relationship.py b/ckan/model/package_relationship.py
index 5aaeea0e60c..fd28b11e0f6 100644
--- a/ckan/model/package_relationship.py
+++ b/ckan/model/package_relationship.py
@@ -27,13 +27,14 @@ def _(txt):
      Column('object_package_id', types.UnicodeText, ForeignKey('package.id')),
      Column('type', types.UnicodeText),
      Column('comment', types.UnicodeText),
+     Column('state', types.UnicodeText, default=core.State.ACTIVE),
      )
 
-vdm.sqlalchemy.make_table_stateful(package_relationship_table)
+
 package_relationship_revision_table = core.make_revisioned_table(package_relationship_table)
 
 class PackageRelationship(vdm.sqlalchemy.RevisionedObjectMixin,
-                          vdm.sqlalchemy.StatefulObjectMixin,
+                          core.StatefulObjectMixin,
                           domain_object.DomainObject):
     '''The rule with PackageRelationships is that they are stored in the model
     always as the "forward" relationship - i.e. "child_of" but never
diff --git a/ckan/model/resource.py b/ckan/model/resource.py
index effcd135b30..52bdaaf31f0 100644
--- a/ckan/model/resource.py
+++ b/ckan/model/resource.py
@@ -55,14 +55,15 @@
     Column('cache_last_updated', types.DateTime),
     Column('url_type', types.UnicodeText),
     Column('extras', _types.JsonDictType),
+    Column('state', types.UnicodeText, default=core.State.ACTIVE),
 )
 
-vdm.sqlalchemy.make_table_stateful(resource_table)
+
 resource_revision_table = core.make_revisioned_table(resource_table)
 
 
 class Resource(vdm.sqlalchemy.RevisionedObjectMixin,
-               vdm.sqlalchemy.StatefulObjectMixin,
+               core.StatefulObjectMixin,
                domain_object.DomainObject):
     extra_columns = None
 
diff --git a/ckan/model/system_info.py b/ckan/model/system_info.py
index 5ccf852dd16..365e452257b 100644
--- a/ckan/model/system_info.py
+++ b/ckan/model/system_info.py
@@ -23,14 +23,14 @@
     Column('id', types.Integer(),  primary_key=True, nullable=False),
     Column('key', types.Unicode(100), unique=True, nullable=False),
     Column('value', types.UnicodeText),
+    Column('state', types.UnicodeText, default=core.State.ACTIVE),
 )
 
-vdm.sqlalchemy.make_table_stateful(system_info_table)
 system_info_revision_table = core.make_revisioned_table(system_info_table)
 
 
 class SystemInfo(vdm.sqlalchemy.RevisionedObjectMixin,
-                 vdm.sqlalchemy.StatefulObjectMixin,
+                 core.StatefulObjectMixin,
                  domain_object.DomainObject):
 
     def __init__(self, key, value):
diff --git a/ckan/model/tag.py b/ckan/model/tag.py
index c1be31eb2c3..ab240cf0bd4 100644
--- a/ckan/model/tag.py
+++ b/ckan/model/tag.py
@@ -35,9 +35,9 @@
         Column('id', types.UnicodeText, primary_key=True, default=_types.make_uuid),
         Column('package_id', types.UnicodeText, ForeignKey('package.id')),
         Column('tag_id', types.UnicodeText, ForeignKey('tag.id')),
+        Column('state', types.UnicodeText, default=core.State.ACTIVE),
         )
 
-vdm.sqlalchemy.make_table_stateful(package_tag_table)
 # TODO: this has a composite primary key ...
 package_tag_revision_table = core.make_revisioned_table(package_tag_table)
 
@@ -218,8 +218,8 @@ def __repr__(self):
         return '<Tag %s>' % self.name
 
 class PackageTag(vdm.sqlalchemy.RevisionedObjectMixin,
-        vdm.sqlalchemy.StatefulObjectMixin,
-        domain_object.DomainObject):
+                 core.StatefulObjectMixin,
+                 domain_object.DomainObject):
     def __init__(self, package=None, tag=None, state=None, **kwargs):
         self.package = package
         self.tag = tag
diff --git a/ckan/model/user.py b/ckan/model/user.py
index fb1b36e61a4..e524355a34f 100644
--- a/ckan/model/user.py
+++ b/ckan/model/user.py
@@ -11,7 +11,6 @@
 from sqlalchemy.orm import synonym
 from sqlalchemy import types, Column, Table, func
 from six import text_type
-import vdm.sqlalchemy
 
 import meta
 import core
@@ -33,12 +32,11 @@
         Column('activity_streams_email_notifications', types.Boolean,
             default=False),
         Column('sysadmin', types.Boolean, default=False),
+        Column('state', types.UnicodeText, default=core.State.ACTIVE),
         )
 
-vdm.sqlalchemy.make_table_stateful(user_table)
 
-
-class User(vdm.sqlalchemy.StatefulObjectMixin,
+class User(core.StatefulObjectMixin,
            domain_object.DomainObject):
 
     VALID_NAME = re.compile(r"^[a-zA-Z0-9_\-]{3,255}$")