WE&T Magazine

Sept08CoverWater Environment & Technology (WE&T) is the premier magazine for the water quality field. WE&T provides information on what professionals demand: cutting-edge technologies, innovative solutions, operations and maintenance, regulatory and legislative impacts, and professional development.


September 2008, Vol. 20, No.9

Sewer Sociology Contest

Mystery Flow: Part 5

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 4 months, we have put your sewer sociology skills to the test with mystery land-use patterns. The challenge continues this month with our fifth installment. 

A composite hydrograph of flow monitor data from a location in the northwestern United States is provided in the figure (below). Weekdays are shown in green, and weekends are shown in light blue. Weekday flows show more pronounced activity than weekday flows — beginning around 4 a.m. and ending around 2 p.m.

Mystery Land Use Area
Click figure for larger view>

Based on this information, which of the following do you think this mystery land-use pattern is?

a) A high school.
b) An automobile assembly plant.
c) A mental health hospital.
d) A government administration building.

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 Sept. 30. The winner, who will be drawn at random from correct responses, will receive a WE&T prize pack. For the solution to last month’s Mystery Flow, see below.

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 4 Revealed

Last month’s mystery land-use pattern was obtained downstream from a “big box” retail store in Alabama. This facility is open 24 hours a day, 7 days a week, and the observed pattern is governed by shopping habits of its customers.

Click figure for larger view

Mystery Flow: Part 3 Winner

Congratulations to Les Nemeth of Kelowna, British Columbia,
who correctly identified the land-use pattern in
Mystery Flow: Part 3 as a ski lift.