Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/PlLinesCreator/SoilProfileValidator.cs
===================================================================
diff -u -r5835 -r5836
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/PlLinesCreator/SoilProfileValidator.cs	(.../SoilProfileValidator.cs)	(revision 5835)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/PlLinesCreator/SoilProfileValidator.cs	(.../SoilProfileValidator.cs)	(revision 5836)
@@ -99,9 +99,7 @@
             return;
         }
 
-        bool isValid = !SoilProfile2DHelper.IsAquitardPresentWithAquiferInnerLoop(SoilProfile2D);
-        isValid = isValid && !SoilProfile2DHelper.IsAtLeastOneIsolatedInBetweenAquiferPresent(SoilProfile2D);
-        if (!isValid)
+        if (SoilProfile2DHelper.IsAtLeastOneIsolatedInBetweenAquiferPresent(SoilProfile2D))
         {
             throw new PlLinesCreatorException(Resources.SoilProfileValidator_General
                                               + string.Format(Resources.SoilProfileValidator_DiscontinuousAquiferPresent, SoilProfile2D.Name));
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Common/SoilProfile2DHelper.cs
===================================================================
diff -u -r5835 -r5836
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Common/SoilProfile2DHelper.cs	(.../SoilProfile2DHelper.cs)	(revision 5835)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Common/SoilProfile2DHelper.cs	(.../SoilProfile2DHelper.cs)	(revision 5836)
@@ -68,8 +68,18 @@
         return count > 0;
     }
     
+    /// <summary>
+    /// Check if at least one isolated in-between aquifer is present.  
+    /// </summary>
+    /// <param name="soilProfile"></param>
+    /// <returns>True if an isolated in between aquifer is present, otherwise false.</returns>
     public static bool IsAtLeastOneIsolatedInBetweenAquiferPresent(SoilProfile2D soilProfile)
     {
+        if (IsAquitardPresentWithAquiferInnerLoop(soilProfile))
+        {
+            return true;
+        }
+        
         SoilProfile2D soilProfileWithoutInnerLoops = CreateSoilProfileWithoutInnerLoops(soilProfile);
         double[] xCoordinates = DetermineAllXCoordinatesOfSoilProfile(soilProfileWithoutInnerLoops);
         var previousCount = 0;
@@ -133,7 +143,7 @@
         return previousCount - currentCount == 1 && !currentCrossSection.Layers[0].IsAquifer;
     }
 
-    public static bool IsAquitardPresentWithAquiferInnerLoop(SoilProfile2D soilProfile2D)
+    private static bool IsAquitardPresentWithAquiferInnerLoop(SoilProfile2D soilProfile2D)
     {
         foreach (GeometrySurface surface in soilProfile2D.Geometry.Surfaces.Where(surface => surface.InnerLoops.Count > 0))
         {