July 2008, Vol. 20, No.7

Sewer Sociology

Sewer Sociology

Mystery Flow: Part 3

Kevin L. Enfinger and Patrick L. Stevens

sew´•ẽr sō•ci•ol´ō•gy, the science of society, social institutions, and social relationships viewed through the eyes of a sewer; specifically, the systematic study of the development, structure, interaction, and collective sewer use of organized groups of human beings. 

Most sewer flows are characterized by repeatable diurnal patterns that vary across weekdays, weekends, and holidays. Differences in land use are also apparent. During the past 2 months, we have put your sewer sociology skills to the test with mystery land-use patterns. The challenge continues this month with a new mystery.

A composite hydrograph of flow monitor data from a location in the western United States is provided in Figure 1. The data were obtained during winter months, and the wastewater flow on weekdays is about the same as the wastewater flow on the weekends. Weekdays are shown in green, and weekends are shown in light blue.


Figure 1. Mystery Flow: Part 3
Click figure for larger view 

Based on this information, which of the following do you think this mystery land-use pattern is?
a) A ski resort.
b) A school.
c) A campground.
d) A theme park.

Think you know the answer? To enter our contest, click here and select the answer you think best describes this month’s mystery flow. Responses will be accepted until Aug. 1. The winner, who will be drawn at random from correct responses, will receive a WE&T prize pack. Good luck!

Kevin L. Enfinger is senior project engineer, and Patrick L. Stevens is vice president of engineering at ADS Environmental Services, a division of ADS LLC (Huntsville, Ala.).


Mystery Flow: Part 2 Revealed

Last month’s mystery land-use pattern was obtained from a prison. Two composite hydrographs are shown here, one from a common residential area and one from a prison. Wastewater flows from a prison are nearly identical on weekdays and weekends — a telling account of life behind bars.
Click figure for larger view 

Mystery Flow: Part 1 Winner

Congratulations to Michael Drinkwater, City of Reno, Nev., who correctly identified the land-use pattern in Mystery Flow: Part 1 as a shopping mall.