Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Handlers/AssessmentSectionCompositionChangeHandler.cs
===================================================================
diff -u -r9cd70453e2e24e2a5896757edd13d36620e09dad -r8555639e4bd5abc568b3da0d8bd4f7c206bab337
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Handlers/AssessmentSectionCompositionChangeHandler.cs	(.../AssessmentSectionCompositionChangeHandler.cs)	(revision 9cd70453e2e24e2a5896757edd13d36620e09dad)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Handlers/AssessmentSectionCompositionChangeHandler.cs	(.../AssessmentSectionCompositionChangeHandler.cs)	(revision 8555639e4bd5abc568b3da0d8bd4f7c206bab337)
@@ -96,7 +96,7 @@
                 grassCoverErosionOutwardsFailureMechanism, duneErosionFailureMechanism);
             if (hydraulicBoundaryLocationAffected.Any())
             {
-                log.Info(Resources.FailureMechanismContributionNormChangeHandler_Waveheight_and_design_water_level_results_cleared);
+                log.Info(Resources.AssessmentSectionCompositionChangeHandler_Waveheight_and_design_water_level_results_cleared);
                 return new IObservable[]
                 {
                     grassCoverErosionOutwardsFailureMechanism.HydraulicBoundaryLocations,
Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.Designer.cs
===================================================================
diff -u -r3722e29f53ce7db0f11fb184cdc2a76d33078cf2 -r8555639e4bd5abc568b3da0d8bd4f7c206bab337
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 3722e29f53ce7db0f11fb184cdc2a76d33078cf2)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 8555639e4bd5abc568b3da0d8bd4f7c206bab337)
@@ -94,6 +94,16 @@
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Alle berekende resultaten voor alle hydraulische randvoorwaardenlocaties van grasbekleding erosie binnentalud en duinen zijn verwijderd..
+        /// </summary>
+        public static string AssessmentSectionCompositionChangeHandler_Waveheight_and_design_water_level_results_cleared {
+            get {
+                return ResourceManager.GetString("AssessmentSectionCompositionChangeHandler_Waveheight_and_design_water_level_resul" +
+                        "ts_cleared", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to De resultaten van {0} berekeningen zijn verwijderd..
         /// </summary>
         public static string ChangeHandler_Results_of_NumberOfCalculations_0_calculations_cleared {
Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.resx
===================================================================
diff -u -r3722e29f53ce7db0f11fb184cdc2a76d33078cf2 -r8555639e4bd5abc568b3da0d8bd4f7c206bab337
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.resx	(.../Resources.resx)	(revision 3722e29f53ce7db0f11fb184cdc2a76d33078cf2)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Properties/Resources.resx	(.../Resources.resx)	(revision 8555639e4bd5abc568b3da0d8bd4f7c206bab337)
@@ -166,4 +166,7 @@
   <data name="RingtoetsPlugin_BackgroundMapDataContext_Text" xml:space="preserve">
     <value>Achtergrondlaag</value>
   </data>
+  <data name="AssessmentSectionCompositionChangeHandler_Waveheight_and_design_water_level_results_cleared" xml:space="preserve">
+    <value>Alle berekende resultaten voor alle hydraulische randvoorwaardenlocaties van grasbekleding erosie binnentalud en duinen zijn verwijderd.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/Handlers/AssessmentSectionCompositionChangeHandlerTest.cs
===================================================================
diff -u -r9cd70453e2e24e2a5896757edd13d36620e09dad -r8555639e4bd5abc568b3da0d8bd4f7c206bab337
--- Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/Handlers/AssessmentSectionCompositionChangeHandlerTest.cs	(.../AssessmentSectionCompositionChangeHandlerTest.cs)	(revision 9cd70453e2e24e2a5896757edd13d36620e09dad)
+++ Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/Handlers/AssessmentSectionCompositionChangeHandlerTest.cs	(.../AssessmentSectionCompositionChangeHandlerTest.cs)	(revision 8555639e4bd5abc568b3da0d8bd4f7c206bab337)
@@ -196,7 +196,7 @@
             string[] expectedMessage =
             {
                 "De resultaten van 32 berekeningen zijn verwijderd.",
-                "Alle berekende resultaten voor alle hydraulische randvoorwaardenlocaties zijn verwijderd."
+                "Alle berekende resultaten voor alle hydraulische randvoorwaardenlocaties van grasbekleding erosie binnentalud en duinen zijn verwijderd."
             };
             TestHelper.AssertLogMessagesAreGenerated(call, expectedMessage, 2);
 
@@ -256,7 +256,7 @@
             Action call = () => affectedObjects = handler.ChangeComposition(assessmentSection, newComposition);
 
             // Assert
-            TestHelper.AssertLogMessageIsGenerated(call, "Alle berekende resultaten voor alle hydraulische randvoorwaardenlocaties zijn verwijderd.", 1);
+            TestHelper.AssertLogMessageIsGenerated(call, "Alle berekende resultaten voor alle hydraulische randvoorwaardenlocaties van grasbekleding erosie binnentalud en duinen zijn verwijderd.", 1);
 
             Assert.AreEqual(newComposition, assessmentSection.Composition);
             Assert.True(assessmentSection.GetFailureMechanisms().SelectMany(fm => fm.Calculations).All(c => !c.HasOutput));
Index: Ringtoets/Integration/test/Ringtoets.Integration.Service.Test/RingtoetsDataSynchronizationServiceTest.cs
===================================================================
diff -u -re7b22b417acc51a88beb210ba39fef0f75e2760e -r8555639e4bd5abc568b3da0d8bd4f7c206bab337
--- Ringtoets/Integration/test/Ringtoets.Integration.Service.Test/RingtoetsDataSynchronizationServiceTest.cs	(.../RingtoetsDataSynchronizationServiceTest.cs)	(revision e7b22b417acc51a88beb210ba39fef0f75e2760e)
+++ Ringtoets/Integration/test/Ringtoets.Integration.Service.Test/RingtoetsDataSynchronizationServiceTest.cs	(.../RingtoetsDataSynchronizationServiceTest.cs)	(revision 8555639e4bd5abc568b3da0d8bd4f7c206bab337)
@@ -53,6 +53,64 @@
     [TestFixture]
     public class RingtoetsDataSynchronizationServiceTest
     {
+        #region TestData
+
+        private static IEnumerable<TestCaseData> GrassAndDuneLocations
+        {
+            get
+            {
+                TestDuneLocation duneLocationOutput;
+                TestHydraulicBoundaryLocation grassBoundaryLocationOutput;
+
+                yield return new TestCaseData(
+                    new TestHydraulicBoundaryLocation(),
+                    new TestDuneLocation(),
+                    new IObservable[0]
+                    ).SetName("GrassAndDuneLocationNoOutput");
+                yield return new TestCaseData(
+                    grassBoundaryLocationOutput = new TestHydraulicBoundaryLocation
+                    {
+                        DesignWaterLevelOutput = new TestHydraulicBoundaryLocationOutput(0.5),
+                        WaveHeightOutput = new TestHydraulicBoundaryLocationOutput(0.6)
+                    },
+                    new TestDuneLocation(),
+                    new IObservable[]
+                    {
+                        grassBoundaryLocationOutput
+                    }
+                    ).SetName("GrassLocationWithOutput");
+                yield return new TestCaseData(
+                    new TestHydraulicBoundaryLocation(),
+                    duneLocationOutput = new TestDuneLocation
+                    {
+                        Output = new TestDuneLocationOutput()
+                    },
+                    new IObservable[]
+                    {
+                        duneLocationOutput
+                    }
+                    ).SetName("DuneLocationWithOutput");
+                yield return new TestCaseData(
+                    grassBoundaryLocationOutput = new TestHydraulicBoundaryLocation
+                    {
+                        DesignWaterLevelOutput = new TestHydraulicBoundaryLocationOutput(0.5),
+                        WaveHeightOutput = new TestHydraulicBoundaryLocationOutput(0.6)
+                    },
+                    duneLocationOutput = new TestDuneLocation
+                    {
+                        Output = new TestDuneLocationOutput()
+                    },
+                    new IObservable[]
+                    {
+                        grassBoundaryLocationOutput,
+                        duneLocationOutput
+                    }
+                    ).SetName("GrassAndDuneLocationWithOutput");
+            }
+        }
+
+        #endregion
+
         [Test]
         public void ClearFailureMechanismCalculationOutputs_WithoutAssessmentSection_ThrowsArgumentNullException()
         {
@@ -205,7 +263,7 @@
         }
 
         [Test]
-        public void ClearHydraulicBoundaryLocationOutput_grassCoverErosionOutwardsFailureMechanismNull_ThrowsArgumentNullException()
+        public void ClearHydraulicBoundaryLocationOutput_GrassCoverErosionOutwardsFailureMechanismNull_ThrowsArgumentNullException()
         {
             // Setup
             var hydraulicBoundaryDatabase = new HydraulicBoundaryDatabase();
@@ -239,6 +297,36 @@
         }
 
         [Test]
+        public void ClearHydraulicBoundaryLocationOutput_TwoArgumentsGrassCoverErosionOutwardsFailureMechanismNull_ThrowsArgumentNullException()
+        {
+            // Setup
+            var duneErosionFailureMechanism = new DuneErosionFailureMechanism();
+
+            // Call
+            TestDelegate test = () => RingtoetsDataSynchronizationService.ClearHydraulicBoundaryLocationOutput(null,
+                                                                                                               duneErosionFailureMechanism);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("grassCoverErosionOutwardsFailureMechanism", exception.ParamName);
+        }
+
+        [Test]
+        public void ClearHydraulicBoundaryLocationOutput_TwoArgumentsDuneErosionFailureMechanismNull_ThrowsArgumentNullException()
+        {
+            // Setup
+            var grassCoverErosionOutwardsFailureMechanism = new GrassCoverErosionOutwardsFailureMechanism();
+
+            // Call
+            TestDelegate test = () => RingtoetsDataSynchronizationService.ClearHydraulicBoundaryLocationOutput(grassCoverErosionOutwardsFailureMechanism,
+                                                                                                               null);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("duneErosionFailureMechanism", exception.ParamName);
+        }
+
+        [Test]
         [TestCase(1.0, 3.0)]
         [TestCase(3.8, double.NaN)]
         [TestCase(double.NaN, 6.9)]
@@ -274,9 +362,9 @@
             Assert.AreEqual(CalculationConvergence.NotCalculated, hydraulicBoundaryLocation.WaveHeightCalculationConvergence);
 
             CollectionAssert.AreEqual(new[]
-                                      {
-                                          hydraulicBoundaryLocation
-                                      }, affectedObjects);
+            {
+                hydraulicBoundaryLocation
+            }, affectedObjects);
             mockRepository.VerifyAll();
         }
 
@@ -368,9 +456,9 @@
             Assert.AreEqual(CalculationConvergence.NotCalculated, grassCoverErosionOutwardsHydraulicBoundaryLocation.WaveHeightCalculationConvergence);
 
             CollectionAssert.AreEqual(new[]
-                                      {
-                                          grassCoverErosionOutwardsHydraulicBoundaryLocation
-                                      }, affectedObjects);
+            {
+                grassCoverErosionOutwardsHydraulicBoundaryLocation
+            }, affectedObjects);
         }
 
         [Test]
@@ -464,14 +552,42 @@
             Assert.AreEqual(CalculationConvergence.NotCalculated, grassCoverErosionOutwardsHydraulicBoundaryLocation.WaveHeightCalculationConvergence);
 
             CollectionAssert.AreEquivalent(new[]
-                                           {
-                                               grassCoverErosionOutwardsHydraulicBoundaryLocation,
-                                               hydraulicBoundaryLocation
-                                           }, affectedObjects);
+            {
+                grassCoverErosionOutwardsHydraulicBoundaryLocation,
+                hydraulicBoundaryLocation
+            }, affectedObjects);
             mockRepository.VerifyAll();
         }
 
         [Test]
+        [TestCaseSource(nameof(GrassAndDuneLocations))]
+        public void ClearHydraulicBoundaryLocationOutput_GrassCoverErosionOutwardsAndDuneLocations_ClearDataAndReturnAffectedHydraulicBoundaryLocations(HydraulicBoundaryLocation grassBoundaryLocation,
+                                                                                                                                                        DuneLocation duneLocation,
+                                                                                                                                                        IEnumerable<IObservable> expectedAffectedItems)
+        {
+            // Setup
+            var grassCoverErosionOutwardsFailureMechanism = new GrassCoverErosionOutwardsFailureMechanism();
+
+            var duneErosionFailureMechanism = new DuneErosionFailureMechanism();
+            duneErosionFailureMechanism.DuneLocations.Add(duneLocation);
+
+            grassCoverErosionOutwardsFailureMechanism.HydraulicBoundaryLocations.Add(grassBoundaryLocation);
+
+            // Call
+            IEnumerable<IObservable> affectedObjects = RingtoetsDataSynchronizationService.ClearHydraulicBoundaryLocationOutput(
+                grassCoverErosionOutwardsFailureMechanism,
+                duneErosionFailureMechanism);
+
+            // Assert
+            // Note: To make sure the clear is performed regardless of what is done with
+            // the return result, no ToArray() should be called before these assertions:
+            CollectionAssert.AreEquivalent(expectedAffectedItems, affectedObjects);
+            Assert.IsNull(duneLocation.Output);
+            Assert.IsNull(grassBoundaryLocation.DesignWaterLevelOutput);
+            Assert.IsNull(grassBoundaryLocation.WaveHeightOutput);
+        }
+
+        [Test]
         public void ClearReferenceLine_AssessmentSectionNull_ThrowArgumentNullException()
         {
             // Call