Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/DerivedPipingInputTest.cs
===================================================================
diff -u -rce31448a066c084f755439f3e7d453bfb042b291 -r0cdb24eee9b746ab5d21381ca51c6836dd460292
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/DerivedPipingInputTest.cs	(.../DerivedPipingInputTest.cs)	(revision ce31448a066c084f755439f3e7d453bfb042b291)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/DerivedPipingInputTest.cs	(.../DerivedPipingInputTest.cs)	(revision 0cdb24eee9b746ab5d21381ca51c6836dd460292)
@@ -713,7 +713,7 @@
         }
 
         [Test]
-        public void SaturatedVolumicWeightOfCoverageLayer_MultipleLayersEqualShiftAndStandardDeviation_ReturnsWithWeightedMean()
+        public void SaturatedVolumicWeightOfCoverageLayer_MultipleLayersEqualStandardDeviationAndShift_ReturnsWithWeightedMean()
         {
             // Setup
             var input = PipingCalculationFactory.CreateInputWithAquiferAndCoverageLayer();
@@ -753,6 +753,54 @@
         }
 
         [Test]
+        [TestCase(0.01, 0)]
+        [TestCase(0, 0.01)]
+        [TestCase(2, 1)]
+        [TestCase(3, -1)]
+        [TestCase(-0.01, 0)]
+        [TestCase(0, -0.01)]
+        [TestCase(-2, 1)]
+        [TestCase(-3, -1)]
+        public void SaturatedVolumicWeightOfCoverageLayer_MultipleLayersInequalStandardDeviationOrShift_ReturnsNaNValues(double deviationDelta, double shiftDelta)
+        {
+            // Setup
+            var input = PipingCalculationFactory.CreateInputWithAquiferAndCoverageLayer();
+            var derivedInput = new DerivedPipingInput(input);
+            var random = new Random(21);
+            var belowPhreaticLevelMeanA = random.NextDouble();
+            var belowPhreaticLevelMeanB = random.NextDouble();
+            double deviation = random.NextDouble();
+            double shift = random.NextDouble();
+            input.StochasticSoilProfile.SoilProfile = new PipingSoilProfile("", -2.0, new[]
+            {
+                new PipingSoilLayer(2.5)
+                {
+                    BelowPhreaticLevelDeviation = deviation,
+                    BelowPhreaticLevelShift = shift,
+                    BelowPhreaticLevelMean = belowPhreaticLevelMeanA
+                },
+                new PipingSoilLayer(-0.5)
+                {
+                    BelowPhreaticLevelDeviation = deviation + deviationDelta,
+                    BelowPhreaticLevelShift = shift + shiftDelta,
+                    BelowPhreaticLevelMean = belowPhreaticLevelMeanB
+                },
+                new PipingSoilLayer(-1.5)
+                {
+                    IsAquifer = true
+                }, 
+            }, SoilProfileType.SoilProfile1D, 0);
+
+            // Call
+            var result = derivedInput.SaturatedVolumicWeightOfCoverageLayer;
+
+            // Assert
+            Assert.IsNaN(result.Mean);
+            Assert.IsNaN(result.Shift);
+            Assert.IsNaN(result.StandardDeviation);
+        }
+
+        [Test]
         public void DarcyPermeability_NoSoilProfile_ReturnsNaNForParameters()
         {
             // Setup