diff --git a/pychunkedgraph/graph/attributes.py b/pychunkedgraph/graph/attributes.py
index ea03d2216..b58a6f0f8 100644
--- a/pychunkedgraph/graph/attributes.py
+++ b/pychunkedgraph/graph/attributes.py
@@ -106,7 +106,7 @@ class Connectivity:
 
     L2CrossChunkEdge = _AttributeArray(
         pattern=b"l2_cross_edge_%d",
-        family_id="3",
+        family_id="4",
         serializer=serializers.NumPyArray(
             dtype=basetypes.NODE_ID, shape=(-1, 2), compression_level=22
         ),
@@ -114,13 +114,13 @@ class Connectivity:
 
     FakeEdges = _Attribute(
         key=b"fake_edges",
-        family_id="3",
+        family_id="4",
         serializer=serializers.NumPyArray(dtype=basetypes.NODE_ID, shape=(-1, 2)),
     )
 
     CrossChunkEdge = _AttributeArray(
         pattern=b"atomic_cross_edges_%d",
-        family_id="4",
+        family_id="3",
         serializer=serializers.NumPyArray(
             dtype=basetypes.NODE_ID, shape=(-1, 2), compression_level=22
         ),
diff --git a/pychunkedgraph/graph/client/bigtable/client.py b/pychunkedgraph/graph/client/bigtable/client.py
index 486cbdd73..19a08b9a8 100644
--- a/pychunkedgraph/graph/client/bigtable/client.py
+++ b/pychunkedgraph/graph/client/bigtable/client.py
@@ -636,9 +636,9 @@ def _create_column_families(self):
         f.create()
         f = self._table.column_family("2")
         f.create()
-        f = self._table.column_family("3")
+        f = self._table.column_family("3", gc_rule=MaxAgeGCRule(datetime.timedelta(days=1)))
         f.create()
-        f = self._table.column_family("4", gc_rule=MaxAgeGCRule(datetime.timedelta(days=1)))
+        f = self._table.column_family("4")
         f.create()
 
     def _get_ids_range(self, key: bytes, size: int) -> typing.Tuple:
diff --git a/pychunkedgraph/ingest/create/atomic_layer.py b/pychunkedgraph/ingest/create/atomic_layer.py
index d87638b26..a59bc9f20 100644
--- a/pychunkedgraph/ingest/create/atomic_layer.py
+++ b/pychunkedgraph/ingest/create/atomic_layer.py
@@ -101,7 +101,13 @@ def _get_remapping(chunk_edges_d: dict):
 
 
 def _process_component(
-    cg, chunk_edges_d, parent_id, node_ids, sparse_indices, remapping, time_stamp,
+    cg,
+    chunk_edges_d,
+    parent_id,
+    node_ids,
+    sparse_indices,
+    remapping,
+    time_stamp,
 ):
     nodes = []
     chunk_out_edges = []  # out = between + cross
@@ -145,3 +151,49 @@ def _get_outgoing_edges(node_id, chunk_edges_d, sparse_indices, remapping):
             # edges that this node is part of
             chunk_out_edges = np.concatenate([chunk_out_edges, edges[row_ids]])
     return chunk_out_edges
+
+
+def postprocess_atomic_chunk(
+    cg: ChunkedGraph,
+    chunk_coord: np.ndarray,
+    time_stamp: Optional[datetime.datetime] = None,
+):
+    time_stamp = get_valid_timestamp(time_stamp)
+
+    chunk_id = cg.get_chunk_id(
+        layer=2, x=chunk_coord[0], y=chunk_coord[1], z=chunk_coord[2]
+    )
+
+    properties = [
+        attributes.Connectivity.CrossChunkEdge[l] for l in range(2, cg.meta.layer_count)
+    ]
+
+    chunk_rr = cg.range_read_chunk(
+        chunk_id, properties=properties, time_stamp=time_stamp
+    )
+
+    result = {}
+    for l2id, raw_cx_edges in chunk_rr.items():
+        try:
+            cx_edges = {
+                prop.index: val[0].value.copy() for prop, val in raw_cx_edges.items()
+            }
+            result[l2id] = cx_edges
+        except KeyError:
+            continue
+
+    nodes = []
+    val_dicts = []
+    for l2id, cx_edges in result.items():
+        val_dict = {}
+        for layer, edges in cx_edges.items():
+            l2_edges = np.zeros_like(edges)
+            l2_edges[:, 0] = l2id
+            l2_edges[:, 1] = cg.get_parents(edges[:, 1])
+            col = attributes.Connectivity.L2CrossChunkEdge[layer]
+            val_dict[col] = np.unique(l2_edges, axis=0)
+            val_dicts.append(val_dict)
+
+        r_key = serializers.serialize_uint64(l2id)
+        nodes.append(cg.client.mutate_row(r_key, val_dict, time_stamp=time_stamp))
+    cg.client.write(nodes)