Index: Ringtoets/Common/src/Ringtoets.Common.IO/Structures/StructuresCharacteristicsCsvReader.cs
===================================================================
diff -u -r653c18f73b4404d9ac58d818845474d68e48635d -r50d02243937ff6a19020bf095c778252c1c47561
--- Ringtoets/Common/src/Ringtoets.Common.IO/Structures/StructuresCharacteristicsCsvReader.cs	(.../StructuresCharacteristicsCsvReader.cs)	(revision 653c18f73b4404d9ac58d818845474d68e48635d)
+++ Ringtoets/Common/src/Ringtoets.Common.IO/Structures/StructuresCharacteristicsCsvReader.cs	(.../StructuresCharacteristicsCsvReader.cs)	(revision 50d02243937ff6a19020bf095c778252c1c47561)
@@ -26,6 +26,7 @@
 using Core.Common.IO.Readers;
 using Core.Common.Utils;
 using Core.Common.Utils.Builders;
+using Ringtoets.Common.IO.Properties;
 using CoreCommonUtilsResources = Core.Common.Utils.Properties.Resources;
 
 namespace Ringtoets.Common.IO.Structures
@@ -43,7 +44,7 @@
         {
             "identificatie",
             "kunstwerken.identificatie",
-            "numeriekeWaarde",
+            "numeriekewaarde",
             "standarddeviatie.variance",
             "boolean"
         };
@@ -70,13 +71,14 @@
         /// Counts the number of parameter definitions found in the file.
         /// </summary>
         /// <returns>An integer greater than or equal to 0, being the number of parameter rows.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">File/directory cannot be found or 
+        /// <exception cref="CriticalFileReadException">File/directory cannot be found or 
         /// some other I/O related problem occurred or the header is not in the required format.</exception>
         public int GetLineCount()
         {
             using (var reader = StreamReaderHelper.InitializeStreamReader(filePath))
             {
-                ValidateHeader(reader, 1);
+                lineNumber = 1;
+                ValidateHeader(reader);
 
                 return CountNonEmptyLines(reader, 2);
             }
@@ -87,15 +89,15 @@
         /// </summary>
         /// <returns>The next <see cref="Ringtoets.Common.IO.Structures.StructuresParameterRow"/> based on the read file,
         /// or null when at the end of the file.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">
+        /// <exception cref="CriticalFileReadException">
         /// Thrown when either:
         /// <list type="bullet">
         /// <item>The file or directory cannot be found.</item>
         /// <item>The file is empty.</item>
         /// <item>Some I/O related problem occurred.</item>
         /// <item>The header is not in the required format.</item>
         /// </list></exception>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">Thrown when either:
+        /// <exception cref="LineParseException">Thrown when either:
         /// <list type="bullet">
         /// <item>The line does not contain the separator character.</item>
         /// <item>Location id field is empty or consists out of only white spaces.</item>
@@ -144,14 +146,13 @@
         /// Validates the header of the file.
         /// </summary>
         /// <param name="reader">The reader, which is currently at the header row.</param>
-        /// <param name="currentLine">Row index used in error messaging.</param>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">The header is not in the required format.</exception>
-        private void ValidateHeader(TextReader reader, int currentLine)
+        /// <exception cref="CriticalFileReadException">The header is not in the required format.</exception>
+        private void ValidateHeader(TextReader reader)
         {
             string[] tokenizedHeader = GetTokenizedHeader(reader);
             const int uninitializedValue = -999;
             int[] requiredHeaderColumnIndices = GetRequiredHeaderColumnIndices(uninitializedValue, tokenizedHeader);
-            ValidateRequiredColumnIndices(currentLine, requiredHeaderColumnIndices, uninitializedValue);
+            ValidateRequiredColumnIndices(requiredHeaderColumnIndices, uninitializedValue);
         }
 
         /// <summary>
@@ -160,7 +161,7 @@
         /// <param name="reader">The reader at the row from which counting should start.</param>
         /// <param name="currentLine">The current line, used for error messaging.</param>
         /// <returns>An integer greater than or equal to 0, being the number of parameter rows.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">An I/O exception occurred.</exception>
+        /// <exception cref="CriticalFileReadException">An I/O exception occurred.</exception>
         private int CountNonEmptyLines(TextReader reader, int currentLine)
         {
             int count = 0, lineNumberForMessage = currentLine;
@@ -182,7 +183,7 @@
         /// <param name="reader">The opened text file reader.</param>
         /// <param name="currentLine">Row number for error messaging.</param>
         /// <returns>The read line, or null when at the end of the file.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">An critical I/O exception occurred.</exception>
+        /// <exception cref="CriticalFileReadException">An critical I/O exception occurred.</exception>
         private string ReadLineAndHandleIOExceptions(TextReader reader, int currentLine)
         {
             try
@@ -195,7 +196,7 @@
             }
             catch (IOException e)
             {
-                string errorMessage = string.Format((string)CoreCommonUtilsResources.Error_General_IO_ErrorMessage_0_,
+                string errorMessage = string.Format((string) CoreCommonUtilsResources.Error_General_IO_ErrorMessage_0_,
                                                     e.Message);
                 var fullErrorMessage = new FileReaderErrorMessageBuilder(filePath).Build(errorMessage);
                 throw new CriticalFileReadException(fullErrorMessage, e);
@@ -206,15 +207,15 @@
         /// Reads the header and sets the internal indices of the required header columns.
         /// </summary>
         /// <param name="reader">The reader used to read the file.</param>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">The file is empty or some I/O exception
+        /// <exception cref="CriticalFileReadException">The file is empty or some I/O exception
         /// occurred or the header is not in the required format.</exception>
         private void IndexFile(TextReader reader)
         {
             string[] tokenizedHeader = GetTokenizedHeader(reader);
 
             const int uninitializedValue = -999;
             int[] requiredHeaderColumnIndices = GetRequiredHeaderColumnIndices(uninitializedValue, tokenizedHeader);
-            ValidateRequiredColumnIndices(lineNumber, requiredHeaderColumnIndices, uninitializedValue);
+            ValidateRequiredColumnIndices(requiredHeaderColumnIndices, uninitializedValue);
 
             SetColumnIndices(requiredHeaderColumnIndices);
         }
@@ -224,7 +225,7 @@
         /// </summary>
         /// <param name="reader">The reader used to read the file.</param>
         /// <returns>The header split based on <see cref="separator"/>.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">The file is empty or some I/O exception
+        /// <exception cref="CriticalFileReadException">The file is empty or some I/O exception
         /// occurred.</exception>
         private string[] GetTokenizedHeader(TextReader reader)
         {
@@ -249,26 +250,33 @@
                 int index = Array.IndexOf(requiredHeaderColumns, columnName);
                 if (index != -1)
                 {
-                    // TODO: same column multiple times!
-                    requiredHeaderColumnIndices[index] = columnIndex;
+                    if (requiredHeaderColumnIndices[index] == initialColumnIndexValue)
+                    {
+                        requiredHeaderColumnIndices[index] = columnIndex;
+                    }
+                    else
+                    {
+                        string message = string.Format(Resources.StructuresCharacteristicsCsvReader_Column_0_must_be_defined_only_once, columnName);
+                        throw CreateCriticalFileReadException(lineNumber, message);
+                    }
                 }
             }
             return requiredHeaderColumnIndices;
         }
 
         /// <summary>
-        /// 
+        /// Checks if all required header columns have been matched.
         /// </summary>
-        /// <param name="currentLine"></param>
-        /// <param name="requiredHeaderColumnIndices"></param>
-        /// <param name="uninitializedValue"></param>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">The header is not in the required format.</exception>
-        private void ValidateRequiredColumnIndices(int currentLine, int[] requiredHeaderColumnIndices, int uninitializedValue)
+        /// <param name="requiredHeaderColumnIndices">The array of matched column indices.</param>
+        /// <param name="uninitializedValue">The initial index value put in <paramref name="requiredHeaderColumnIndices"/>.</param>
+        /// <exception cref="CriticalFileReadException">The header is not in the required format.</exception>
+        private void ValidateRequiredColumnIndices(int[] requiredHeaderColumnIndices, int uninitializedValue)
         {
             if (requiredHeaderColumnIndices.Any(i => i == uninitializedValue))
             {
-                throw CreateCriticalFileReadException(currentLine, string.Format("Het bestand is niet geschikt om kunstwerken parameters uit te lezen (Verwachte koptekst moet de volgende kolommen bevatten: {0}.",
-                                                                                 string.Join(", ", requiredHeaderColumns)));
+                string message = string.Format(Resources.StructuresCharacteristicsCsvReader_ValidateRequiredColumnIndices_Invalid_header_Must_have_columns_0_,
+                                               string.Join(", ", requiredHeaderColumns));
+                throw CreateCriticalFileReadException(lineNumber, message);
             }
         }
 
@@ -286,7 +294,7 @@
         /// </summary>
         /// <returns>The next line which is not a white line, or <c>null</c> when no non-white
         /// line could be found before the end of file.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.CriticalFileReadException">An critical I/O exception occurred.</exception>
+        /// <exception cref="CriticalFileReadException">An critical I/O exception occurred.</exception>
         private string ReadNextNonEmptyLine(StreamReader reader)
         {
             string readText;
@@ -309,7 +317,7 @@
         /// </summary>
         /// <param name="readText">The read text.</param>
         /// <returns></returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">Thrown when either:
+        /// <exception cref="LineParseException">Thrown when either:
         /// <list type="bullet">
         /// <item><paramref name="readText"/> does not contain the separator character.</item>
         /// <item>Location id field is empty or consists out of only white spaces.</item>
@@ -345,7 +353,7 @@
         /// </summary>
         /// <param name="readText">The text.</param>
         /// <returns>The tokenized parts.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException"><paramref name="readText"/> lacks separator character.</exception>
+        /// <exception cref="LineParseException"><paramref name="readText"/> lacks separator character.</exception>
         private string[] TokenizeString(string readText)
         {
             if (!readText.Contains(separator))
@@ -363,7 +371,7 @@
         /// </summary>
         /// <param name="tokenizedText">The tokenized text.</param>
         /// <returns>The location ID.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">Location ID field is empty or only has whitespaces.</exception>
+        /// <exception cref="LineParseException">Location ID field is empty or only has whitespaces.</exception>
         private string ParseLocationId(string[] tokenizedText)
         {
             string locationId = tokenizedText[locationIdIndex];
@@ -380,7 +388,7 @@
         /// <param name="tokenizedText">The tokenized text.</param>
         /// <returns></returns>
         /// <returns>The parameter ID.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">Parameter ID field is empty or only has whitespaces.</exception>
+        /// <exception cref="LineParseException">Parameter ID field is empty or only has whitespaces.</exception>
         private string ParseParameterId(string[] tokenizedText)
         {
             string parameterId = tokenizedText[parameterIdIndex];
@@ -396,7 +404,7 @@
         /// </summary>
         /// <param name="tokenizedText">The tokenized text.</param>
         /// <returns>The numeric value (can be <see cref="double.NaN"/>).</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">When the numeric value field is not a number
+        /// <exception cref="LineParseException">When the numeric value field is not a number
         /// or when it's too large or too small to be represented as <see cref="double"/>.</exception>
         private double ParseNumericValue(string[] tokenizedText)
         {
@@ -409,7 +417,7 @@
         /// </summary>
         /// <param name="tokenizedText">The tokenized text.</param>
         /// <returns>The standard deviation or coefficient of variation value (can be <see cref="double.NaN"/>).</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">When the standard deviation or coefficient
+        /// <exception cref="LineParseException">When the standard deviation or coefficient
         /// of variation value field is not a number or when it's too large or too small
         /// to be represented as <see cref="double"/>.</exception>
         private double ParseVarianceValue(string[] tokenizedText)
@@ -425,7 +433,7 @@
         /// <param name="parameterName">Name of the parameter.</param>
         /// <returns><see cref="double.NaN"/> when <paramref name="doubleValueText"/> is null
         /// or only whitespaces; otherwise the parsed number.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">When <paramref name="doubleValueText"/> is
+        /// <exception cref="LineParseException">When <paramref name="doubleValueText"/> is
         /// not a number or when it's too large or too small to be represented as <see cref="double"/>.</exception>
         private double ParseDoubleValue(string doubleValueText, string parameterName)
         {
@@ -454,7 +462,7 @@
         /// </summary>
         /// <param name="tokenizedText">The tokenized text.</param>
         /// <returns>The <see cref="Ringtoets.Common.IO.Structures.VarianceType"/> based on the text in the file.</returns>
-        /// <exception cref="Core.Common.IO.Exceptions.LineParseException">When the 'boolean' field is not a valid value.</exception>
+        /// <exception cref="LineParseException">When the 'boolean' field is not a valid value.</exception>
         private VarianceType ParseVarianceType(string[] tokenizedText)
         {
             string varianceTypeText = tokenizedText[varianceTypeIndex];
@@ -486,12 +494,12 @@
         }
 
         /// <summary>
-        /// Throws a configured instance of <see cref="Core.Common.IO.Exceptions.LineParseException"/>.
+        /// Throws a configured instance of <see cref="LineParseException"/>.
         /// </summary>
         /// <param name="currentLine">The line number being read.</param>
         /// <param name="lineParseErrorMessage">The critical error message.</param>
         /// <param name="innerException">Optional: exception that caused this exception to be thrown.</param>
-        /// <returns>New <see cref="Core.Common.IO.Exceptions.LineParseException"/> with message set.</returns>
+        /// <returns>New <see cref="LineParseException"/> with message set.</returns>
         private LineParseException CreateLineParseException(int currentLine, string lineParseErrorMessage, Exception innerException = null)
         {
             string locationDescription = string.Format(CoreCommonUtilsResources.TextFile_On_LineNumber_0_, currentLine);
@@ -501,12 +509,12 @@
         }
 
         /// <summary>
-        /// Throws a configured instance of <see cref="Core.Common.IO.Exceptions.CriticalFileReadException"/>.
+        /// Throws a configured instance of <see cref="CriticalFileReadException"/>.
         /// </summary>
         /// <param name="currentLine">The line number being read.</param>
         /// <param name="criticalErrorMessage">The critical error message.</param>
         /// <param name="innerException">Optional: exception that caused this exception to be thrown.</param>
-        /// <returns>New <see cref="Core.Common.IO.Exceptions.CriticalFileReadException"/> with message and inner exception set.</returns>
+        /// <returns>New <see cref="CriticalFileReadException"/> with message and inner exception set.</returns>
         private CriticalFileReadException CreateCriticalFileReadException(int currentLine, string criticalErrorMessage, Exception innerException = null)
         {
             string locationDescription = string.Format(CoreCommonUtilsResources.TextFile_On_LineNumber_0_,