The primary function of bibliographic citations is to assist the reader in finding the sources used in the writing of a work. To these basic citations, the annotated bibliography adds descriptive and evaluative comments (i.e., an annotation), assessing the nature and value of the cited works. The addition of commentary provides the future reader or researcher essential critical information and a foundation for further research.
French drain. A French drain or weeping tile (also blind drain, rubble drain, rock drain, drain tile, perimeter drain, land drain, French ditch, sub-surface drain, sub-soil drain or agricultural drain) is a trench filled with gravel or rock or containing a perforated pipe that redirects surface water and groundwater away from an area.
A typical septic drain field (see Figure 1), also known as a leach field, is a series of perforated pipes that are set in trenches and buried with aggregates (Â½- to 2Â½-inch gravel or Â½- to 4-inch rubber chips) and soil.These drain lines are at a minimum depth of 6 inches and are typically 18 to 36 inches wide.The individual drain lines will usually be 8Â½ to 10 feet apart (see Figure 2). It is important to note here that each drain field system will vary from the next.hese drain lines are at a minimum depth of 6 inches and are typically 18 to 36 inches wide. The individual drain lines will usually be 8Â½ to 10 feet apart (see Figure 2). It is important to note here that each drain field system will vary from the next.