diff --git a/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java b/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java
index b54668199f1745ef42b6b2ac17a116fb8efb7ec7..9d9087042cfb6043df301e903a6f9dd2a9f4f6b8 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java
@@ -52,6 +52,7 @@ import gov.usgs.earthquake.nshmp.data.XySequence;
 import gov.usgs.earthquake.nshmp.gmm.Imt;
 import gov.usgs.earthquake.nshmp.internal.Logging;
 import gov.usgs.earthquake.nshmp.model.HazardModel;
+import gov.usgs.earthquake.nshmp.model.SiteData;
 
 /**
  * Disaggregate probabilistic seismic hazard at a return period of interest or
@@ -165,7 +166,10 @@ public class DisaggCalc {
           : OptionalDouble.empty();
 
       /* Sites */
-      List<Site> sites = Sites.fromCsv(siteFile, model.siteData(), vs30);
+      SiteData siteData = config.hazard.useSiteData
+          ? model.siteData()
+          : SiteData.EMPTY;
+      List<Site> sites = Sites.fromCsv(siteFile, siteData, vs30);
       log.info("Sites: " + sites.size());
 
       Set<Imt> modelImts = model.config().hazard.imts;
@@ -288,7 +292,8 @@ public class DisaggCalc {
 
     log.info(PROGRAM + " (return period): calculating ...");
 
-    HazardExport handler = HazardExport.create(model, config, sites, out);
+    boolean namedSites = sites.get(0).name() != Site.NO_NAME;
+    HazardExport handler = HazardExport.create(model, config, namedSites, out);
     Path disaggDir = out.resolve("disagg");
     Files.createDirectory(disaggDir);
 
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/HazardCalc.java b/src/main/java/gov/usgs/earthquake/nshmp/HazardCalc.java
index d893b3a1cde014bdef1c675e5de203311111e237..6b26713efa45c0f9ef41397843d231e1237b7396 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/HazardCalc.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/HazardCalc.java
@@ -110,10 +110,13 @@ public class HazardCalc {
       log.info("");
 
       Path out = createOutputDir(config.output.directory);
+      SiteData siteData = config.hazard.useSiteData
+          ? model.siteData()
+          : SiteData.EMPTY;
 
       if (config.hazard.vs30s.isEmpty()) {
 
-        List<Site> sites = readSites(args[1], model.siteData(), OptionalDouble.empty(), log);
+        List<Site> sites = readSites(args[1], siteData, OptionalDouble.empty(), log);
         log.info("Sites: " + Sites.toString(sites));
         calc(model, config, sites, out, log);
 
@@ -121,7 +124,7 @@ public class HazardCalc {
 
         for (double vs30 : config.hazard.vs30s) {
           log.info("Vs30 batch: " + vs30);
-          List<Site> sites = readSites(args[1], model.siteData(), OptionalDouble.of(vs30), log);
+          List<Site> sites = readSites(args[1], siteData, OptionalDouble.of(vs30), log);
           log.info("Sites: " + Sites.toString(sites));
           Path vs30dir = out.resolve("vs30-" + ((int) vs30));
           Files.createDirectory(vs30dir);
@@ -183,7 +186,8 @@ public class HazardCalc {
     log.info("Threads: " + ((ThreadPoolExecutor) exec).getCorePoolSize());
     log.info(PROGRAM + ": calculating ...");
 
-    HazardExport handler = HazardExport.create(model, config, sites, out);
+    boolean namedSites = sites.get(0).name() != Site.NO_NAME;
+    HazardExport handler = HazardExport.create(model, config, namedSites, out);
     Stopwatch stopwatch = Stopwatch.createStarted();
     int logInterval = sites.size() < 100 ? 1 : sites.size() < 1000 ? 10 : 100;