Category: Sewer Sociology

World Trade Center
in 0by

World Trade Center

World Trade Center Attack

September 11, 2001 is a defining moment in U.S. history, and its memories and emotions echo through the words of the 9/11 Commission:

At 8:46 on morning of September 11, 2001, the United States became a nation transformed.  An airliner traveling at hundreds of miles per hour and carrying some 10,000 gallons of jet fuel plowed into the North Tower of the World Trade Center in Lower Manhattan.  At 9:03, a second airliner hit the South Tower.  Fire and smoke billowed upward.  Steel, glass, ash, and bodies fell below.  The Twin Towers, where up to 50,000 people worked each day, both collapsed less than 90 minutes later . . . More than 2,600 people died at the World Trade Center . . . [and] the death toll surpassed that at Pearl Harbor in December 1941.

This composite hydrograph offers a unique perspective on the events of September 11th as observed by a flow monitor located near the World Trade Center.

Note that this day started out like any normal day.  That all changed at 8:46 AM when terrorists flew American Airlines Flight 11 into the North Tower of the World Trade Center.  Much of Manhattan, including this area, was evacuated as rescue and recovery efforts began.  This clearly was not a normal or average day.  Instead, this flow monitor has documented its own account of a historic tragedy from a unique perspective.  Although the perspective is different, the story remains compelling.

References:

Acknowledgement:

Special thanks are extended to the New York City Department of Environmental Protection for contributing this flow monitoring data and authorizing its use for this purpose.

 
Hurricane Rita
in 0by

Hurricane Rita

Religious Observances

Certain religious practices can also be observed in sewer use patterns.  This composite hydrograph shows normal dry weather flow patterns from a flow monitor located in a region with a prominent Orthodox Jewish population.  The sewer use on Fridays is quite different from other weekdays.  The sewer use pattern observed on Friday, August 26, 2005 is shown for comparison.

The Jewish Sabbath, or Shabbat, begins at dusk on Friday evening.  However, preparations such as shopping, cooking, cleaning, and bathing start much earlier and must be completed by dusk.  The Jewish Sabbath is a time of worship, reflection, and rest, and other activities are limited during this period.  Preparation for the Sabbath and rest that follows are reflected in the sewer use pattern each Friday.  These patterns are repeatable from week to week.  However, peak flows do shift with changing sunset times.

References:

  • Klagsbrun, F. (1996).  Jewish Days — A Book of Jewish Life and Culture Around the Year, Farrar Straus Giroux; New York, NY.
 
Religious Observations
in 0by

Religious Observations

Religious Observances

Certain religious practices can also be observed in sewer use patterns.  This composite hydrograph shows normal dry weather flow patterns from a flow monitor located in a region with a prominent Orthodox Jewish population.  The sewer use on Fridays is quite different from other weekdays.  The sewer use pattern observed on Friday, August 26, 2005 is shown for comparison.

The Jewish Sabbath, or Shabbat, begins at dusk on Friday evening.  However, preparations such as shopping, cooking, cleaning, and bathing start much earlier and must be completed by dusk.  The Jewish Sabbath is a time of worship, reflection, and rest, and other activities are limited during this period.  Preparation for the Sabbath and rest that follows are reflected in the sewer use pattern each Friday.  These patterns are repeatable from week to week.  However, peak flows do shift with changing sunset times.

References:

  • Klagsbrun, F. (1996).  Jewish Days — A Book of Jewish Life and Culture Around the Year, Farrar Straus Giroux; New York, NY.
 
Holidays
in 0by

Holidays

Holidays

Holidays are welcomed diversions from everyday life and provide time to celebrate and relax with family and friends.  These diversions are reflected in sewer use patterns, as shown below.  Flow monitoring data from several familiar holidays are displayed in comparison with normal weekday and weekend sewer use patterns.  To a sewer sociologist, a holiday looks much like a weekend.  However, characteristic differences are observed that make each holiday unique.  See what differences you can find and how they compare with your holiday traditions.

These composite hydrographs are interpreted by noting the differences between the average weekend curve and the holiday of interest.  Several interesting observations are noted:

  • Higher sewer flows are observed early on New Year’s Day as people celebrate the arrival of the New Year.  The morning rise also occurs later in the day as people recover from the night before.

  • Martin Luther King, Jr. Day and President’s Day are government holidays.  However, many businesses in the private sector remain open.  As a result, the morning rise occurs earlier than a typical weekend as a certain percentage of the people wake at their normal weekday time and prepare for work.

  • Memorial Day and Labor Day are quite similar, both with higher sewer flows during the late morning and early afternoon as people enjoy the holidays.

  • Lower sewer flows are observed during the evening on Independence Day as many people depart to watch local fireworks displays.

  • Thanksgiving Day provides the most noticeable deviation from typical weekday flows, with peak flows occuring around the time of the traditional Thanksgiving meal.

  • Peak flows on Christmas Day are less than those observed on Thanksgiving.  However, increases are observed around afternoon and evening meal times.  Note also the higher sewer flows observed during the early morning hours, a traditional time when Santa Claus is believed to be busy delivering gifts.
Northeast Blackout
in 0by

Northeast Blackout

Northeast Blackout

Millions of people were left without power on August 14, 2003 at 4:09 PM when the largest blackout in the history of North America occurred.  The blackout began when three transmission lines failed near Cleveland, Ohio.  Within minutues, over 100 power plants in the United States and Canada were overwhelmed and knocked offline.

The blackout affected several major metropolitan areas — including Detroit, Cleveland, Columbus, New York, Toronto, and Ottawa.  This composite hydrograph displays normal dry weather conditions from a flow monitoring located in Oakland County, Michigan during this period.  Flow monitoring data from August 14th are shown for comparison.

Note the dramatic drop in flow after the power failure.  The minimum flow during the blackout was well below the normal night-time flow.  This example illustrates how the disruption of one basic service can affect the use of another.

References:

  • Gibbs, N. (2003).  ‘Lights Out,’ Time, Volume 162, Issue 8, 30-39.

Acknowledgement:

Special thanks are extended to the Oakland County Drain Commissioner for contributing this flow monitoring data and authorizing its use for this purpose.

College Football
in 0by

College Football

College Football

College football games are big-time events in big-time college towns as students, alumni, and fans descend upon campus for a day of spirited festivities.  Flow monitoring data from Tallahassee, Florida — home to Florida State University (FSU) — are shown below and provide a glimpse into the world of college football.

This data was obtained during a portion of the 2005 football season at a monitoring location downstream from the Florida State University campus.  The FSU football schedule and the outcome of each regular season game are provided below for reference.

Flow rates at this location show a dramatic increase on three occassions which happen to correspond to three home football games at Doak Campbell Stadium.  The flow rates observed during these three games are compared to average dry day flows on the composite hydrographs shown below.

All three games began in the early afternoon, and as expected, sewer flows began to increase a few hours prior to kickoff.  During the Maryland and North Carolina State games, two distinct flow increases were observed that coincide with halftime and the end of the game.  Note, however, that the same pattern was not observed during the Wake Forest game.  A review of the final score reveals that Wake Forest was routed 41-24 by FSU.  The flow monitoring data reveal that fans began to depart the stadium early in the game.  The final scores from the other two games were much closer — resulting in on win and one loss for FSU.

Flow directly associated with the stadium are determined by subtracting each game day flow from the average weekend flow.  The Maryland and North Carolina State games generated an additional 304,000 gallons of flow.  With a stadium capacity 82,300, this results in a sewer use rate of 3.7 gallons/day/seat — comparable to the 4 gallons/day/seat sewer use estimates used for other stadium development projects.

References:

Acknowledgement:

Special thanks are extended to the City of Tallahassee for contributing this flow monitoring data and authorizing its use for this purpose.