Land use within a particular area can impact the shape of the diurnal pattern. The examples below represent diurnal patterns from six different land use areas. The residential pattern is the most common. Combinations and variations of these patterns are often observed in mixed land use areas. Industrial patterns are industry specific and come in many varieties. The industrial example provided here is from a meat processing facility that perfoms cleaning operations during the third shift.
The Australian Open is held each year in Melbourne, Australia and is one of four Grand Slam tennis tournaments, attracting top-ranked professional and junior players from around the world. Flow monitoring data from the 2006 Australian Open are shown below and provide a recap of the tournament from a sewer’s perspective. Attendance figures for each day of the tournament are provided for comparison.
This data was obtained from a flow monitor located just downstream from Melbourne Park — home to the Australian Open. Melbourne Park provides a world-class venue for competitive tennis, and key features of the venue are summarized below:
The Australian Open encompassed a total of 631 matches contested on 17 different courts during 14 days of competition — including 12 day sessions, 11 night sessions, and two twilight sessions.
Sewer flow rates observed during several days of the tournament are compared to average dry day flows on the composite hydrographs shown below. Dry day flows were obtained after the tournament during February 2006 when no other events were scheduled at Melbourne Park. Flows directly associated with the Australian Open are determined by subtracting each tournament day flow from the average weekday of weekend flow. Note that peak sewer flows occur just before the start of major matches and are most pronounced for the men’s singles finals.
According to tournament officials, patrons consumed more than 37,247 buckets of hot chips, 37,305 barbeque sausages, 5,500 pounds of curry, 164,416 ice creams, 200,821 bottles of water, and 110,685 espresso coffees. According to the flow monitor, they also generated 2,204,000 gallons of wastewater. With a reported attendance of 550,500, this results in a sewer use rate of 4.0 gallons/day/person over the duration of the tournament — consistent with the sewer use rate observed at college football games in the United States.
References:
Sewers are an important part of our society. They serve to promote public health, protect the environment, and support economic growth within our communities. They also happen to provide a unique view into everyday life, and thus the connection between sewers and sociology. Sewer sociology is defined as:
“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.” Adapted from the Merriam-Webster Collegiate Dictionary, Eleventh Edition (2004). Merriam-Webster, Springfield, MA
Sewer Sociology has direct applications to sewer design, hydraulic modeling, and real-time control:
Forecasting sewer flow rates is an important part of sewer design, and these design assumptions are often based on published or regulated per capita values. A closer look reveals that the underlying assumptions are often limited and/or dated. Sewer Sociology offers the opportunity to confirm or update per capita sewer use for a variety of land use characteristics.
Modeling dry weather sewer performance requires knowledge of anticipated diurnal patters from various land use areas, and the information available to hydraulic modelers in this regard is often limited. Sewer Sociology offers the opportunity to develop a library of diurnal patters to sharpen the performance of hydraulic models.
Real-time alarming and real-time control of sewer systems requires knowledge of subtle shifts in dirunal patterns that naturally occur in sewer systems. It is a weekday or weekend? Is it a holiday? Are local schools in session or out for a break? All of these conditions result in unique signatures in sewer use patterns which can affect real-time alarming and real-time control.
April 29, 2011 was a big day for the British – the much-anticipated Royal Wedding of Prince William and Kate Middleton.
A Royal Wedding is the type of event that captivates a nation . . . and reveals itself in sewer flow data. Flow monitor data from a residential area near London are shown here. The wedding took place on a Friday – which was also designated as a Bank Holiday in the United Kingdom. To a sewer sociologist, a holiday looks much like a weekend, so the effect of the Royal Wedding on sewer use is determined by comparing the wedding day to a typical weekend.
Note that sewer flows began to depart from normal soon after the first guests arrived at Westminster Abbey, as many residents discontinued their normal routine and tuned in to television coverage. Residential flows returned to normal by 2:00 PM – about half an hour after the official Royal Kiss on the balcony at Buckingham Palace.
This hydrograph displays flow monitor data from a residential area recorded over a four week period during normal dry weather conditions. Note that a repeatable daily or diurnal pattern is observed.
