diff --git a/src/central/adapters/nws.py b/src/central/adapters/nws.py
index 4ba2819..8fa11c5 100644
--- a/src/central/adapters/nws.py
+++ b/src/central/adapters/nws.py
@@ -211,6 +211,7 @@ class NWSAdapter(SourceAdapter):
     requires_api_key = None
     wizard_order = 1
     default_cadence_s = 60
+    dedup_sweep_days = 8
 
     # Alerts cover forecast zones/counties (polygons), not a single point.
     enrichment_locations = []
@@ -393,42 +394,6 @@ class NWSAdapter(SourceAdapter):
         )
         self._db.commit()
 
-    def is_published(self, event_id: str) -> bool:
-        """Check if an event has already been published."""
-        if not self._db:
-            return False
-        cur = self._db.execute(
-            "SELECT 1 FROM published_ids WHERE adapter = ? AND event_id = ?",
-            (self.name, event_id)
-        )
-        return cur.fetchone() is not None
-
-    def mark_published(self, event_id: str) -> None:
-        """Mark an event as published."""
-        if not self._db:
-            return
-        self._db.execute(
-            """
-            INSERT INTO published_ids (adapter, event_id, first_seen, last_seen)
-            VALUES (?, ?, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
-            ON CONFLICT (adapter, event_id) DO UPDATE SET
-                last_seen = CURRENT_TIMESTAMP
-            """,
-            (self.name, event_id)
-        )
-        self._db.commit()
-
-    # TODO(v0.9.19.1): unscoped global DELETE -- clobbers other adapters' dedup rows; scope to adapter + move to base.
-    def sweep_old_ids(self) -> int:
-        """Remove published_ids older than 8 days. Returns count deleted."""
-        if not self._db:
-            return 0
-        cur = self._db.execute(
-            "DELETE FROM published_ids WHERE last_seen < datetime('now', '-8 days')"
-        )
-        self._db.commit()
-        return cur.rowcount
-
     @retry(
         stop=stop_after_attempt(5),
         wait=wait_exponential_jitter(initial=1, max=60),
diff --git a/tests/test_nws_normalization.py b/tests/test_nws_normalization.py
index 706ce1d..701b5be 100644
--- a/tests/test_nws_normalization.py
+++ b/tests/test_nws_normalization.py
@@ -2,6 +2,7 @@
 
 from datetime import datetime, timezone
 from pathlib import Path
+import sqlite3
 from unittest.mock import MagicMock
 
 import pytest
@@ -353,6 +354,36 @@ class TestDeduplication:
         assert event2 is not None
         assert event1.id == event2.id
 
+    def test_sweep_only_deletes_own_adapter_rows(
+        self, adapter: NWSAdapter, tmp_path: Path
+    ) -> None:
+        """Regression (v0.9.19.1): sweep_old_ids must be adapter-scoped.
+
+        NWS previously ran an unscoped global DELETE that purged *every*
+        adapter's published_ids older than 8 days; the inherited base method
+        scopes the delete to ``adapter = ?``.
+        """
+        adapter._db = sqlite3.connect(tmp_path / "dedup.db")
+        adapter._db.execute(
+            "CREATE TABLE published_ids (adapter TEXT, event_id TEXT, "
+            "first_seen TIMESTAMP DEFAULT CURRENT_TIMESTAMP, "
+            "last_seen TIMESTAMP DEFAULT CURRENT_TIMESTAMP, "
+            "PRIMARY KEY (adapter, event_id))"
+        )
+        for adp in ("nws", "eonet"):
+            adapter._db.execute(
+                "INSERT INTO published_ids (adapter, event_id, last_seen) "
+                "VALUES (?, 'old', datetime('now', '-9 days'))",
+                (adp,),
+            )
+        adapter._db.commit()
+        assert adapter.dedup_sweep_days == 8
+        assert adapter.sweep_old_ids() == 1  # only the nws row
+        survivors = {
+            r[0] for r in adapter._db.execute("SELECT adapter FROM published_ids")
+        }
+        assert survivors == {"eonet"}  # foreign adapter's row survives
+
 
 class TestGeometry:
     """Tests for geometry computation."""