In Vectorworks 2013 there was a change to the line styles. Now they are called Line Types, and they are more more graphic than they have every been.
This allows you to create line types that include the works SS for Sanitary Sewer, or SW for Stormwater. You can even make a line type that looks like footprints.
Download the file for Vectorworks 2013, then add it to your User folder or Workgroup folder. There are no files for older versions of Vectorworks, since they do not use Line types like this.