Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/PlLinesCreator/SoilProfileValidatorTests.cs
===================================================================
diff -u -r5822 -r5835
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/PlLinesCreator/SoilProfileValidatorTests.cs	(.../SoilProfileValidatorTests.cs)	(revision 5822)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/PlLinesCreator/SoilProfileValidatorTests.cs	(.../SoilProfileValidatorTests.cs)	(revision 5835)
@@ -464,11 +464,11 @@
     /// </code>
     [Test]
     [SetUICulture("nl-NL")]
-    [TestCase(true, true)]
-    [TestCase(true, false)]
-    [TestCase(false, true)]
-    [TestCase(false, false)]
-    public void GivenSoilProfile2DWithInnerLoop_WhenValidating_ThenExpectedResultReturned(bool isOuterLoopAquifer, bool isInnerLoopAquifer)
+    [TestCase(true, true, true)]
+    [TestCase(true, false, true)]
+    [TestCase(false, true, false)]
+    [TestCase(false, false, true)]
+    public void GivenSoilProfile2DWithInnerLoop_WhenValidating_ThenExpectedResultReturned(bool isOuterLoopAquifer, bool isInnerLoopAquifer, bool isCombinationValid)
     {
         SurfaceLine2 surfaceLine = FactoryForSurfaceLines.CreateHorizontalSurfaceLine(8, leftCoordinate, rightCoordinate);
         var soilProfile = new SoilProfile2D
@@ -501,7 +501,7 @@
             SoilProfile2D = soilProfile,
             DikeEmbankmentMaterial = new Soil()
         };
-        if ((isInnerLoopAquifer && !isOuterLoopAquifer) || (!isInnerLoopAquifer && isOuterLoopAquifer))
+        if (!isCombinationValid)
         {
             Assert.That(() => soilProfileValidator.ValidateSoilProfileForPlLinesCreator(),
                         Throws.InstanceOf<Exception>().With.Message.EqualTo
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Common/SoilProfile2DHelper.cs
===================================================================
diff -u -r5438 -r5835
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Common/SoilProfile2DHelper.cs	(.../SoilProfile2DHelper.cs)	(revision 5438)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Common/SoilProfile2DHelper.cs	(.../SoilProfile2DHelper.cs)	(revision 5835)
@@ -70,12 +70,13 @@
     
     public static bool IsAtLeastOneIsolatedInBetweenAquiferPresent(SoilProfile2D soilProfile)
     {
-        double[] xCoordinates = DetermineAllXCoordinatesOfSoilProfile(soilProfile);
+        SoilProfile2D soilProfileWithoutInnerLoops = CreateSoilProfileWithoutInnerLoops(soilProfile);
+        double[] xCoordinates = DetermineAllXCoordinatesOfSoilProfile(soilProfileWithoutInnerLoops);
         var previousCount = 0;
         SoilProfile1D previousCrossSection = null;
         for (var i = 0; i < xCoordinates.Length; i++)
         {
-            SoilProfile1D crossSection = soilProfile.GetSoilProfile1D(xCoordinates[i]);
+            SoilProfile1D crossSection = soilProfileWithoutInnerLoops.GetSoilProfile1D(xCoordinates[i]);
             int currentCount = crossSection.GetInBetweenAquiferClusters?.Count ?? 0;
             
             if (i > 0 && (currentCount != previousCount) && IsAtLeastOneIsolatedInBetweenAquiferPresent(currentCount, previousCount, crossSection, previousCrossSection))
@@ -90,6 +91,23 @@
         return false;
     }
 
+    private static SoilProfile2D CreateSoilProfileWithoutInnerLoops(SoilProfile2D soilProfile)
+    {
+        SoilProfile2D soilProfileWithoutInnerLoops = soilProfile.Clone();
+
+        foreach (GeometrySurface geometrySurface in soilProfileWithoutInnerLoops.Geometry.Surfaces.Where(surface => surface.InnerLoops.Count > 0))
+        {
+            geometrySurface.InnerLoops.Clear();
+        }
+
+        foreach (SoilLayer2D surface in soilProfileWithoutInnerLoops.Surfaces.Where(surface => surface.GeometrySurface.InnerLoops.Count > 0))
+        {
+            surface.GeometrySurface.InnerLoops.Clear();
+        }
+
+        return soilProfileWithoutInnerLoops;
+    }
+
     private static bool IsAtLeastOneIsolatedInBetweenAquiferPresent(int currentCount, int previousCount, SoilProfile1D currentCrossSection, SoilProfile1D previousCrossSection)
     {
         // If more than one new or one less in-between aquifers are found, at least one is an isolated aquifer.
@@ -115,6 +133,28 @@
         return previousCount - currentCount == 1 && !currentCrossSection.Layers[0].IsAquifer;
     }
 
+    public static bool IsAquitardPresentWithAquiferInnerLoop(SoilProfile2D soilProfile2D)
+    {
+        foreach (GeometrySurface surface in soilProfile2D.Geometry.Surfaces.Where(surface => surface.InnerLoops.Count > 0))
+        {
+            SoilLayer2D soilLayerOfOuterLoop = soilProfile2D.Surfaces.First(s => s.GeometrySurface == surface);
+            if (!soilLayerOfOuterLoop.IsAquifer)
+            {
+                foreach (GeometryLoop innerLoop in surface.InnerLoops)
+                {
+                    GeometrySurface geometrySurfaceOfInnerLoop = soilProfile2D.Geometry.Surfaces.First(s => s.OuterLoop == innerLoop);
+                    SoilLayer2D soilLayerOfInnerLoop = soilProfile2D.Surfaces.First(s => s.GeometrySurface == geometrySurfaceOfInnerLoop);
+                    if (soilLayerOfInnerLoop.IsAquifer)
+                    {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        return false;
+    }
+
     /// <summary>
     /// Determines all the points of the layer boundary for the specified layer type:
     /// - For LayerType = BottomAquiferCluster, layerBoundaryTop is the top boundary of the bottom aquifer (= waternet line for PL3)
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/PlLinesCreator/SoilProfileValidator.cs
===================================================================
diff -u -r5456 -r5835
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/PlLinesCreator/SoilProfileValidator.cs	(.../SoilProfileValidator.cs)	(revision 5456)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/PlLinesCreator/SoilProfileValidator.cs	(.../SoilProfileValidator.cs)	(revision 5835)
@@ -99,7 +99,9 @@
             return;
         }
 
-        if (SoilProfile2DHelper.IsAtLeastOneIsolatedInBetweenAquiferPresent(SoilProfile2D))
+        bool isValid = !SoilProfile2DHelper.IsAquitardPresentWithAquiferInnerLoop(SoilProfile2D);
+        isValid = isValid && !SoilProfile2DHelper.IsAtLeastOneIsolatedInBetweenAquiferPresent(SoilProfile2D);
+        if (!isValid)
         {
             throw new PlLinesCreatorException(Resources.SoilProfileValidator_General
                                               + string.Format(Resources.SoilProfileValidator_DiscontinuousAquiferPresent, SoilProfile2D.Name));