Index: Ringtoets/Piping/src/Ringtoets.Piping.Primitives/RingtoetsPipingSurfaceLine.cs
===================================================================
diff -u -ra940166534b3dd6e778de2e7c8e7e5241f3d3381 -rb8976a5e3cf525e419227e409e44ac69a430711a
--- Ringtoets/Piping/src/Ringtoets.Piping.Primitives/RingtoetsPipingSurfaceLine.cs	(.../RingtoetsPipingSurfaceLine.cs)	(revision a940166534b3dd6e778de2e7c8e7e5241f3d3381)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Primitives/RingtoetsPipingSurfaceLine.cs	(.../RingtoetsPipingSurfaceLine.cs)	(revision b8976a5e3cf525e419227e409e44ac69a430711a)
@@ -39,7 +39,7 @@
     public class RingtoetsPipingSurfaceLine : Observable, IMechanismSurfaceLine
     {
         private const int numberOfDecimalPlaces = 2;
-        private Point2D[] localGeometry;
+        private RoundedPoint2DCollection localGeometry;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="RingtoetsPipingSurfaceLine"/> class.
@@ -48,7 +48,7 @@
         {
             Name = string.Empty;
             Points = new Point3D[0];
-            localGeometry = new Point2D[0];
+            localGeometry = new RoundedPoint2DCollection(2, new Point2D[0]);
         }
 
         /// <summary>
@@ -109,7 +109,7 @@
         /// <summary>
         /// Gets the 2D points describing the local geometry of the surface line.
         /// </summary>
-        public IEnumerable<Point2D> LocalGeometry
+        public RoundedPoint2DCollection LocalGeometry
         {
             get
             {
@@ -141,7 +141,7 @@
                 EndingWorldPoint = Points[Points.Length - 1];
             }
 
-            localGeometry = ProjectGeometryToLZ().ToArray();
+            localGeometry = new RoundedPoint2DCollection(numberOfDecimalPlaces, Points.ProjectToLZ().ToArray());
         }
 
         /// <summary>
@@ -269,9 +269,9 @@
             }
 
             var segments = new Collection<Segment2D>();
-            for (var i = 1; i < localGeometry.Length; i++)
+            for (var i = 1; i < localGeometry.Count(); i++)
             {
-                segments.Add(new Segment2D(localGeometry[i - 1], localGeometry[i]));
+                segments.Add(new Segment2D(localGeometry.ElementAt(i - 1), localGeometry.ElementAt(i)));
             }
 
             IEnumerable<Point2D> intersectionPoints = Math2D.SegmentsIntersectionWithVerticalLine(segments, l).OrderBy(p => p.Y).ToArray();
@@ -289,34 +289,6 @@
         }
 
         /// <summary>
-        /// Projects the points in <see cref="Points"/> to localized coordinate (LZ-plane) system.
-        /// Z-values are retained, and the first point is put a L=0.
-        /// </summary>
-        /// <returns>Collection of 2D points in the LZ-plane.</returns>
-        public RoundedPoint2DCollection ProjectGeometryToLZ()
-        {
-            int count = Points.Length;
-            if (count == 0)
-            {
-                return new RoundedPoint2DCollection(numberOfDecimalPlaces, Enumerable.Empty<Point2D>());
-            }
-
-            Point3D first = Points.First();
-            if (count == 1)
-            {
-                return new RoundedPoint2DCollection(numberOfDecimalPlaces, new[]
-                {
-                    new Point2D(0.0, first.Z)
-                });
-            }
-
-            Point3D last = Points.Last();
-            var firstPoint = new Point2D(first.X, first.Y);
-            var lastPoint = new Point2D(last.X, last.Y);
-            return new RoundedPoint2DCollection(numberOfDecimalPlaces, Points.Select(p => p.ProjectIntoLocalCoordinates(firstPoint, lastPoint)));
-        }
-
-        /// <summary>
         /// Checks whether <paramref name="localCoordinateL"/> is in range of the geometry projected in local coordinate system 
         /// where the points are ordered on the L-coordinate being monotonically non-decreasing.
         /// </summary>