Visual PFAS is a simple DOS executable program which reads various text input files, and then exports data to text output files, some of which may then be viewed as radial diagrams using Golden Surfer®.  When running Visual PFAS, the program reads a series of input files which define lists of: monitoring wells at the site, chemicals in the site database, monitoring events, and units of concentration or environmental properties with applicable conversion factors.  Visual CHEM also reads a file which defines various properties of the radial diagram plots to be created, as well as a database of analytical results for the site. Output files created by Visual CHEM include various layers associated with radial diagram maps including:

• radial diagram axes and tick marks at each well location (i.e. BLN file in Surfer);
• polygons representing chemical concentrations and/or environmental properties for each event or reference series (i.e. BLN files in Surfer); and
• symbols representing MCL exceedances or non-detect chemical concentrations (i.e. data file with symbol coordinates that may be “posted” in Surfer). 

Each of these layer files may be imported separately into Surfer, which allows them to be assigned different styles (e.g. colors, line types and weights).  Other files output by Visual CHEM include:

• “echo” files which mirror radial diagram properties and concentration/property results, which may be used to verify data used on figures, for error checking, or for preparing report tables;
• Polygon areas for evaluating Relative Redox Area (RRA), or a similar metric related to VOC changes with distance or time;
• Statistics such as minimum and maximum concentrations/properties at monitoring wells, to assist with defining axis minimum and maximum ranges; and
• Total parent and daughter product concentrations at each monitoring well, and the ratio of these two values for evaluating changes along a flow path which provide lines of evidence for the occurrence of reductive dichlorination processes.

User-defined properties which may vary with each individual axis of a radial diagram include:

• Chemical or property to be represented by each axis on the radial diagram;
• Axis angle (0o to 360o);
• Use of log or arithmetic scale;
• Number of tick marks between minimum and maximum axis concentrations (only applicable when axis is to be plotted using arithmetic scale);
• Concentration or property units (e.g. some axes may be in ug/L, others in mg/L) – Visual CHEM will calculate unit conversions if analytical input data are assigned different units than those to be used on a specific radial diagram axis;
• Minimum and maximum concentration ranges;
• Direction of increasing concentration – either towards or away from the origin of the radial diagram

Visual CHEM includes three options for plotting data series and symbols when the result for a chemical concentration is non-detect:

• At a value corresponding to the detection limit;
• At a value corresponding to one-half of the detection limit; or
• At the minimum concentration range on the axis.