PICfURE k. CONCRETE PIPELINE INSTALLATION 



S umps and Outlets 



Free-flowing outlets are necessary if water tables are to be 

 maintained at desired levels. Subsurface flow in most tile 

 drains is carried in various laterals to a main collector 

 line located at the low end of a tiled field, and drains 

 into an open ditch or a concrete collector reservoir (sump). 

 A typical tile system layout commonly found on the west side 

 of the Valley is shown in Figure 5. 



Sumps are constructed of 7-foot diameter concrete rings 

 which aj?e 3 feet high; when placed one above the other these 

 rings form a sizable reservoir for collection of wastewater. 

 Water levels are usually maintained below the tile outlets 

 by automatically controlled pumps. Tile drainage outlets 

 and level control devices are accessible through a manhole 

 located on top of the sump. A typical sump is shown in 

 Figure 6. 



Many tile drains in the northern and central areas have 

 "free" or "gravity" type outlets that empty into open 

 drainage ditches. A few smaller sumps constructed of 3-foot 

 diameter pipeline have been installed near Tracy and in the 

 Tulare Lake area. These pipes are usually placed underground 

 in a horizontal position. 



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