Seasonal Variation Pattern of Monthly Wastewater Influent

Abstract

This study investigates the seasonal variation pattern of monthly wastewater influent data collected from the active treatment plants in Kuwait from 1999 to 2009. An attempt to examine the relationship with the population connected to the sanitary network is achieved indirectly by correlating monthly totaled influent data with climatological parameters of monthly averaged temperature and totaled rainfall. The periodograms of the influent, temperature, and rainfall data are also determined. The results reveal two significant periods in influent data of 12 and 6 months. The 12-month period is found in the two climatological data but the 6-month period exists only in rainfall data. The source of the 6-month period in the influent data has been related here to the illegal connection of storm sewers into the sanitary networks in many residential houses and to the typical variation of four seasons of the year during which the mode of people for watering activities or travel plans may change on average. The existing connection between residential stormwater and the sanitary networks may constitute a possible rainfall-harvesting system for arid countries as long as the wastewater plants have the capacity to handle the treatment process. The study concludes with the possibility of employing readily available climatological data to analyze the relationship between the seasonal wastewater influent and the population. The study also considers the detected periodicities to develop a time-series model that can be used to set a management plan for securing a nonconventional water supply for the country.