Index: Ringtoets/Common/src/Ringtoets.Common.Data/AssessmentSection/AssessmentSectionExtensions.cs
===================================================================
diff -u -r175cb39b49a146149811954e3800bebfc0819e3d -r83ad808e24b4781346cbf61955354127fd942a75
--- Ringtoets/Common/src/Ringtoets.Common.Data/AssessmentSection/AssessmentSectionExtensions.cs	(.../AssessmentSectionExtensions.cs)	(revision 175cb39b49a146149811954e3800bebfc0819e3d)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/AssessmentSection/AssessmentSectionExtensions.cs	(.../AssessmentSectionExtensions.cs)	(revision 83ad808e24b4781346cbf61955354127fd942a75)
@@ -21,6 +21,8 @@
 
 using System;
 using System.ComponentModel;
+using System.Linq;
+using Core.Common.Base;
 using Core.Common.Base.Data;
 using Ringtoets.Common.Data.Contribution;
 using Ringtoets.Common.Data.Hydraulics;
@@ -33,15 +35,17 @@
     public static class AssessmentSectionExtensions
     {
         /// <summary>
-        /// Gets the normative assessment level from a <see cref="HydraulicBoundaryLocation"/>.
+        /// Gets the normative assessment level for a <see cref="HydraulicBoundaryLocation"/>.
         /// </summary>
-        /// <param name="assessmentSection">The assessment section.</param>
+        /// <param name="assessmentSection">The assessment section to get the normative assessment
+        /// level from.</param>
         /// <param name="hydraulicBoundaryLocation">The hydraulic boundary location to get the normative
-        /// assessment level from.</param>
+        /// assessment level for.</param>
         /// <returns>The normative assessment level or <see cref="RoundedDouble.NaN"/> when:
         /// <list type="bullet">
         /// <item><paramref name="hydraulicBoundaryLocation"/> is <c>null</c>;</item>
-        /// <item><paramref name="hydraulicBoundaryLocation"/> contains no corresponding calculation output.</item>
+        /// <item><paramref name="hydraulicBoundaryLocation"/> is not part of <paramref name="assessmentSection"/>.</item>
+        /// <item><paramref name="assessmentSection"/> contains no corresponding calculation output.</item>
         /// </list>
         /// </returns>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="assessmentSection"/>
@@ -66,15 +70,23 @@
                                                        typeof(NormType));
             }
 
+            IObservableEnumerable<HydraulicBoundaryLocationCalculation> calculations;
+
             switch (normType)
             {
                 case NormType.Signaling:
-                    return hydraulicBoundaryLocation?.DesignWaterLevelCalculation2.Output?.Result ?? RoundedDouble.NaN;
+                    calculations = assessmentSection.WaterLevelCalculationsForSignalingNorm;
+                    break;
                 case NormType.LowerLimit:
-                    return hydraulicBoundaryLocation?.DesignWaterLevelCalculation3.Output?.Result ?? RoundedDouble.NaN;
+                    calculations = assessmentSection.WaterLevelCalculationsForLowerLimitNorm;
+                    break;
                 default:
                     throw new NotSupportedException();
             }
+
+            HydraulicBoundaryLocationCalculation calculation = calculations.FirstOrDefault(calc => ReferenceEquals(calc.HydraulicBoundaryLocation, hydraulicBoundaryLocation));
+
+            return calculation?.Output?.Result ?? RoundedDouble.NaN;
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/Common/test/Ringtoets.Common.Data.Test/AssessmentSection/AssessmentSectionExtensionsTest.cs
===================================================================
diff -u -r812934f2d315f3e88151a988cb621070cee72791 -r83ad808e24b4781346cbf61955354127fd942a75
--- Ringtoets/Common/test/Ringtoets.Common.Data.Test/AssessmentSection/AssessmentSectionExtensionsTest.cs	(.../AssessmentSectionExtensionsTest.cs)	(revision 812934f2d315f3e88151a988cb621070cee72791)
+++ Ringtoets/Common/test/Ringtoets.Common.Data.Test/AssessmentSection/AssessmentSectionExtensionsTest.cs	(.../AssessmentSectionExtensionsTest.cs)	(revision 83ad808e24b4781346cbf61955354127fd942a75)
@@ -22,6 +22,7 @@
 using System;
 using System.ComponentModel;
 using System.Linq;
+using Core.Common.Base;
 using Core.Common.Base.Data;
 using Core.Common.TestUtil;
 using NUnit.Framework;
@@ -70,57 +71,160 @@
             mocks.VerifyAll();
         }
 
+        private static FailureMechanismContribution CreateFailureMechanismContribution(NormType normType)
+        {
+            var random = new Random(21);
+            int otherContribution = random.Next(0, 100);
+            const double norm = 1.0 / 30000;
+
+            return new FailureMechanismContribution(Enumerable.Empty<IFailureMechanism>(),
+                                                    otherContribution,
+                                                    norm,
+                                                    norm)
+            {
+                NormativeNorm = normType
+            };
+        }
+
+        #region Norm type signaling
+
         [Test]
-        public void GetNormativeAssessmentLevel_HydraulicBoundaryLocationWithOutputAndNormTypeSignaling_ReturnsCorrespondingAssessmentLevel()
+        public void GetNormativeAssessmentLevel_AssessmentSectionWithOutputAndNormTypeSignaling_ReturnsCorrespondingAssessmentLevel()
         {
             // Setup
+            var hydraulicBoundaryLocation = new TestHydraulicBoundaryLocation();
+            double expectedNormativeAssessmentLevel = new Random(21).NextDouble();
+
             var mocks = new MockRepository();
             var assessmentSection = mocks.Stub<IAssessmentSection>();
             assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.Signaling));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForSignalingNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>
+            {
+                new HydraulicBoundaryLocationCalculation(new TestHydraulicBoundaryLocation()),
+                new HydraulicBoundaryLocationCalculation(hydraulicBoundaryLocation)
+                {
+                    Output = new TestHydraulicBoundaryLocationOutput(expectedNormativeAssessmentLevel)
+                },
+                new HydraulicBoundaryLocationCalculation(new TestHydraulicBoundaryLocation())
+            });
             mocks.ReplayAll();
 
-            HydraulicBoundaryLocation hydraulicBoundaryLocationWithOutput = CreateHydraulicBoundaryLocationWithOutput();
+            // Call
+            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(hydraulicBoundaryLocation);
 
+            // Assert
+            Assert.AreEqual(expectedNormativeAssessmentLevel, normativeAssessmentLevel, normativeAssessmentLevel.GetAccuracy());
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void GetNormativeAssessmentLevel_HydraulicBoundaryLocationNullAndNormTypeSignaling_ReturnsNaN()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.Stub<IAssessmentSection>();
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.Signaling));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForSignalingNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>());
+            mocks.ReplayAll();
+
             // Call
-            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(hydraulicBoundaryLocationWithOutput);
+            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(null);
 
             // Assert
-            Assert.AreEqual(hydraulicBoundaryLocationWithOutput.DesignWaterLevelCalculation2.Output.Result, normativeAssessmentLevel);
+            Assert.AreEqual(RoundedDouble.NaN, normativeAssessmentLevel);
 
             mocks.VerifyAll();
         }
 
         [Test]
-        public void GetNormativeAssessmentLevel_HydraulicBoundaryLocationWithOutputAndNormTypeLowerLimit_ReturnsCorrespondingAssessmentLevel()
+        public void GetNormativeAssessmentLevel_HydraulicBoundaryLocationNotPartOfAssessmentSectionAndNormTypeSignaling_ReturnsNaN()
         {
             // Setup
             var mocks = new MockRepository();
             var assessmentSection = mocks.Stub<IAssessmentSection>();
-            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.LowerLimit));
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.Signaling));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForSignalingNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>());
             mocks.ReplayAll();
 
-            HydraulicBoundaryLocation hydraulicBoundaryLocationWithOutput = CreateHydraulicBoundaryLocationWithOutput();
+            // Call
+            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(new TestHydraulicBoundaryLocation());
 
+            // Assert
+            Assert.AreEqual(RoundedDouble.NaN, normativeAssessmentLevel);
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void GetNormativeAssessmentLevel_AssessmentSectionWithoutOutputAndNormTypeSignaling_ReturnsNaN()
+        {
+            // Setup
+            var hydraulicBoundaryLocation = new TestHydraulicBoundaryLocation();
+
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.Stub<IAssessmentSection>();
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.Signaling));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForSignalingNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>
+            {
+                new HydraulicBoundaryLocationCalculation(hydraulicBoundaryLocation)
+            });
+            mocks.ReplayAll();
+
             // Call
-            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(hydraulicBoundaryLocationWithOutput);
+            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(hydraulicBoundaryLocation);
 
             // Assert
-            Assert.AreEqual(hydraulicBoundaryLocationWithOutput.DesignWaterLevelCalculation3.Output.Result, normativeAssessmentLevel);
+            Assert.AreEqual(RoundedDouble.NaN, normativeAssessmentLevel);
 
             mocks.VerifyAll();
         }
 
-        [TestCase(NormType.Signaling)]
-        [TestCase(NormType.LowerLimit)]
-        public void GetNormativeAssessmentLevel_HydraulicBoundaryLocationNull_ReturnsNaN(NormType normType)
+        #endregion
+
+        #region Norm type lower limit
+
+        [Test]
+        public void GetNormativeAssessmentLevel_AssessmentSectionWithOutputAndNormTypeLowerLimit_ReturnsCorrespondingAssessmentLevel()
         {
             // Setup
+            var hydraulicBoundaryLocation = new TestHydraulicBoundaryLocation();
+            double expectedNormativeAssessmentLevel = new Random(21).NextDouble();
+
             var mocks = new MockRepository();
             var assessmentSection = mocks.Stub<IAssessmentSection>();
-            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(normType));
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.LowerLimit));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForLowerLimitNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>
+            {
+                new HydraulicBoundaryLocationCalculation(new TestHydraulicBoundaryLocation()),
+                new HydraulicBoundaryLocationCalculation(hydraulicBoundaryLocation)
+                {
+                    Output = new TestHydraulicBoundaryLocationOutput(expectedNormativeAssessmentLevel)
+                },
+                new HydraulicBoundaryLocationCalculation(new TestHydraulicBoundaryLocation())
+            });
             mocks.ReplayAll();
 
             // Call
+            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(hydraulicBoundaryLocation);
+
+            // Assert
+            Assert.AreEqual(expectedNormativeAssessmentLevel, normativeAssessmentLevel, normativeAssessmentLevel.GetAccuracy());
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void GetNormativeAssessmentLevel_HydraulicBoundaryLocationNullAndNormTypeLowerLimit_ReturnsNaN()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.Stub<IAssessmentSection>();
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.LowerLimit));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForLowerLimitNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>());
+            mocks.ReplayAll();
+
+            // Call
             RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(null);
 
             // Assert
@@ -129,14 +233,14 @@
             mocks.VerifyAll();
         }
 
-        [TestCase(NormType.Signaling)]
-        [TestCase(NormType.LowerLimit)]
-        public void GetNormativeAssessmentLevel_NoCorrespondingAssessmentLevelOutput_ReturnsNaN(NormType normType)
+        [Test]
+        public void GetNormativeAssessmentLevel_HydraulicBoundaryLocationNotPartOfAssessmentSectionAndNormTypeLowerLimit_ReturnsNaN()
         {
             // Setup
             var mocks = new MockRepository();
             var assessmentSection = mocks.Stub<IAssessmentSection>();
-            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(normType));
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.LowerLimit));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForLowerLimitNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>());
             mocks.ReplayAll();
 
             // Call
@@ -148,36 +252,30 @@
             mocks.VerifyAll();
         }
 
-        private static FailureMechanismContribution CreateFailureMechanismContribution(NormType normType)
+        [Test]
+        public void GetNormativeAssessmentLevel_AssessmentSectionWithoutOutputAndNormTypeLowerLimit_ReturnsNaN()
         {
-            var random = new Random(21);
-            int otherContribution = random.Next(0, 100);
-            const double norm = 1.0 / 30000;
+            // Setup
+            var hydraulicBoundaryLocation = new TestHydraulicBoundaryLocation();
 
-            return new FailureMechanismContribution(Enumerable.Empty<IFailureMechanism>(),
-                                                    otherContribution,
-                                                    norm,
-                                                    norm)
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.Stub<IAssessmentSection>();
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(CreateFailureMechanismContribution(NormType.LowerLimit));
+            assessmentSection.Stub(a => a.WaterLevelCalculationsForLowerLimitNorm).Return(new ObservableList<HydraulicBoundaryLocationCalculation>
             {
-                NormativeNorm = normType
-            };
-        }
+                new HydraulicBoundaryLocationCalculation(hydraulicBoundaryLocation)
+            });
+            mocks.ReplayAll();
 
-        private static HydraulicBoundaryLocation CreateHydraulicBoundaryLocationWithOutput()
-        {
-            var random = new Random(32);
+            // Call
+            RoundedDouble normativeAssessmentLevel = assessmentSection.GetNormativeAssessmentLevel(hydraulicBoundaryLocation);
 
-            return new TestHydraulicBoundaryLocation
-            {
-                DesignWaterLevelCalculation2 =
-                {
-                    Output = new TestHydraulicBoundaryLocationOutput(random.NextDouble())
-                },
-                DesignWaterLevelCalculation3 =
-                {
-                    Output = new TestHydraulicBoundaryLocationOutput(random.NextDouble())
-                }
-            };
+            // Assert
+            Assert.AreEqual(RoundedDouble.NaN, normativeAssessmentLevel);
+
+            mocks.VerifyAll();
         }
+
+        #endregion
     }
 }
\ No newline at end of file