History of the Hyperion Treatment Plant and other LA area treatment facilities

Trench backfill compaction underway, Atascadero, CA, early 1900s.

Source: Photo provided courtesy of the Atascadero (CA) Historical Society. Please contact the Atascadero Historical Society in advance for authorization to use said photo for any profit-making endeavor.

Road construction activities, Atascadero, CA, early 1900s.

Source: Photo provided courtesy of the Atascadero (CA) Historical Society. Please contact the Atascadero Historical Society in advance for authorization to use said photo for any profit-making endeavor.

Concrete pipe being made in the field, Atascadero, CA, early 1900s.

Source: Photo provided courtesy of the Atascadero (CA) Historical Society. Please contact the Atascadero Historical Society in advance for authorization to use said photo for any profit-making endeavor.

Map showing the locations of manholes and sewers as designed by George E. Waring, Jr., for San Diego in 1888. For more illustrations of the project, see full article.

Source: George E. Waring, Jr., "Chapter XVI: The Sewerage of San Diego," Sewerage and Land-Drainage, 3rd Edition (New York: D. Van Nostrand Co., 1891), plate.