<http://schema.org/about>
"The file includes the design and calculation table for a storm sewer system and sanitary sewage or, to a small area. The file includes a map of stabilization ponds, with standard measures defined by talus slopes."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.bibliocad.com/library/maps-of-storm-and-sanitary-sewerage_42004>