diff --git a/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java b/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java
index 214ac9b544d285b16f7320d54a7f0cbde2cf252b..51377f378382efc25b5e2633cf8b5e5ce6ad7f09 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java
@@ -203,6 +203,14 @@ public final class CalcConfig {
      */
     public final Set<Double> vs30s;
 
+    /**
+     * Whether or not consider site-specific data that may accompany a model.
+     * Set to false to turn off deep basin scaling effects, for example.
+     *
+     * <p><b>Default:</b> true
+     */
+    public final boolean useSiteData;
+
     /**
      * Viscous damping ratio. The default value is consistent with that used in
      * {@link GroundMotionModel} most (GMM) development. Values other than 5%
@@ -225,6 +233,8 @@ public final class CalcConfig {
      * Whether or not {@link GroundMotionModel} (GMM) sigmas are also modified
      * according to the Rezaeian et al. (2014) model when applying damping
      * scaling factors (DSF).
+     *
+     * <p><b>Default:</b> false
      */
     public final boolean gmmDampingSigma;
 
@@ -257,6 +267,7 @@ public final class CalcConfig {
       this.tectonicSettings = b.tectonicSettings;
       this.sourceTypes = b.sourceTypes;
       this.vs30s = b.vs30s;
+      this.useSiteData = b.useSiteData;
       this.gmmDampingRatio = b.gmmDampingRatio;
       this.gmmDampingSigma = b.gmmDampingSigma;
       this.gmmSigmaScale = b.gmmSigmaScale;
@@ -300,6 +311,7 @@ public final class CalcConfig {
       Set<TectonicSetting> tectonicSettings;
       Set<SourceType> sourceTypes;
       Set<Double> vs30s;
+      Boolean useSiteData;
       Double gmmDampingRatio;
       Boolean gmmDampingSigma;
       Double gmmSigmaScale;
@@ -316,6 +328,7 @@ public final class CalcConfig {
         checkNotNull(tectonicSettings);
         checkNotNull(sourceTypes);
         checkNotNull(vs30s);
+        checkNotNull(useSiteData);
         checkNotNull(gmmDampingRatio);
         checkInRange(
             RezaeianDamping_2014.DAMPING_RATIO_RANGE,
@@ -339,6 +352,7 @@ public final class CalcConfig {
         this.tectonicSettings = that.tectonicSettings;
         this.sourceTypes = that.sourceTypes;
         this.vs30s = that.vs30s;
+        this.useSiteData = that.useSiteData;
         this.gmmDampingRatio = that.gmmDampingRatio;
         this.gmmDampingSigma = that.gmmDampingSigma;
         this.gmmSigmaScale = that.gmmSigmaScale;
@@ -365,6 +379,9 @@ public final class CalcConfig {
         if (that.vs30s != null) {
           this.vs30s = that.vs30s;
         }
+        if (that.useSiteData != null) {
+          this.useSiteData = that.useSiteData;
+        }
         if (that.gmmDampingRatio != null) {
           this.gmmDampingRatio = that.gmmDampingRatio;
         }
diff --git a/src/main/resources/calc/calc-config-defaults.json b/src/main/resources/calc/calc-config-defaults.json
index cdf195683c756bc3681a8b09ef86dca391c41397..5ce1beba5cfb9ee5531a783a49a12832bd29dfb9 100644
--- a/src/main/resources/calc/calc-config-defaults.json
+++ b/src/main/resources/calc/calc-config-defaults.json
@@ -12,6 +12,7 @@
     "tectonicSettings": [],
     "sourceTypes": [],
     "vs30s": [],
+    "useSiteData": true,
     "gmmDampingRatio": 0.05,
 	"gmmDampingSigma": false,
     "gmmSigmaScale": 1.0,
diff --git a/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java b/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java
index d844e0a93995463871efbb8a3e290a124e0c776b..68d7cf9415181d88f6d8dc5776131b5f26a3c94c 100644
--- a/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java
+++ b/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java
@@ -134,7 +134,8 @@ class CalcConfigTests {
     assertEquals(3.0, def.truncationLevel);
     assertEquals(IMTS, def.imts);
     assertEquals(EnumSet.noneOf(TectonicSetting.class), def.tectonicSettings);
-    assertEquals(EnumSet.noneOf(SourceType.class), def.tectonicSettings);
+    assertEquals(EnumSet.noneOf(SourceType.class), def.sourceTypes);
+    assertEquals(true, def.useSiteData);
     assertEquals(0.05, def.gmmDampingRatio);
     assertEquals(false, def.gmmDampingSigma);
     assertEquals(ValueFormat.ANNUAL_RATE, def.valueFormat);
@@ -257,6 +258,7 @@ class CalcConfigTests {
     assertEquals(EnumSet.of(ACTIVE_CRUST, SUBDUCTION), def.tectonicSettings);
     assertEquals(EnumSet.of(FAULT, ZONE, SLAB), def.sourceTypes);
     assertEquals(Set.of(260.0, 760.0), def.vs30s);
+    assertEquals(false, def.useSiteData);
     assertEquals(0.03, def.gmmDampingRatio);
     assertEquals(true, def.gmmDampingSigma);
     assertEquals(0.85, def.gmmSigmaScale);
@@ -273,6 +275,7 @@ class CalcConfigTests {
     assertEquals(EnumSet.noneOf(TectonicSetting.class), def.tectonicSettings);
     assertEquals(EnumSet.noneOf(SourceType.class), def.tectonicSettings);
     assertEquals(Set.of(), def.vs30s);
+    assertEquals(true, def.useSiteData);
     assertEquals(0.05, def.gmmDampingRatio);
     assertEquals(false, def.gmmDampingSigma);
     assertEquals(1.0, def.gmmSigmaScale);
diff --git a/src/test/resources/calc/calc-config-extends.json b/src/test/resources/calc/calc-config-extends.json
index e60f3e234f3664c3e81300b7f8ff534f939aa0b6..39989c7f9087e2aa3a6a35691199b57bf222056b 100644
--- a/src/test/resources/calc/calc-config-extends.json
+++ b/src/test/resources/calc/calc-config-extends.json
@@ -8,6 +8,7 @@
     "tectonicSettings": [ "ACTIVE_CRUST", "SUBDUCTION" ],
     "sourceTypes": [ "FAULT", "ZONE", "SLAB" ],
     "vs30s": [ 260, 760 ],
+    "useSiteData": false,
     "gmmDampingRatio": 0.03,
     "gmmDampingSigma": true,
     "gmmSigmaScale": 0.85,