peaking factor, is defined as follows Sustained peaking factor, PF-/peak flowrate(eg, houry, daily average long-term flowrate The most common method of determining the peaking factor is from the analysis of flowrate data. Where flowrate records are available, at least 3 years of data should be analyzed to define the peak to average day 3-5 Analysis of Constituent Mass Loading Data The analysis of wastewater data involves the determination of the flowrate and mass loading variations The analysis may involve determining the concentrations of specific constituents, mass loadings, or sustained mass loadings, loadings that occur over a defined period of time From the standpoint of treatment processes. one of the most serious deficiencies results when the design of a treatment plant is based on average flowrates and average BOD and TSS loadings, with little or no can reach two or more ust also flowrates and BOD and TSS mass-loading rates do not occur at the same time Analysis of current records is the best method of arriving at appropriate peak and sustained mass loadings The principal factors responsible for loading variations are (1)the established habits of community esidents, which cause short-term(hourly, daily, and weekly) variations; (2) seasonal conditions, which usually cause longer-term variations; and(3)industrial activities, which cause both long- and short-term Wastewater Constituent Concentrations The physical, chemical, and biological characteristics of wastewater vary throughout the day. An adequate determination of the waste characteristics will result only if the sample tested is representative. Typically, omposite samples made up of portions of samples collected at regular intervals during a day are used. The amount of liquid used from each sample is proportional to the rate of flow at the time the sample was collected. Adequate characterization of wastewater is of fundamental importance in the design of treatment and disposal processes Quantity of Waste Discharged by Individuals in the United States. Typical data on the total quantities of waste discharged per person per day(dry weight basis) from individual residences are reported in Table 3-7. The data have been gathered from numerous sources (primarily the United States). The total number of pathogenic organisms discharged will depend on whether an individual is ill and is shedding pathogens. If one or more members of a family are ill and several orders of magnitude Tab. 3-7 Quantity of waste discharged by individual on a dry weight basis Range Typical without ground-up kitchen Typical with ground-up kitchen waste CODcr tkn as N Rgp as p 09-18 Composition of Wastewater in Collection Systems. Typical data on the composition of untreated domestic wastewater as found in wastewater-collection systems (in the United States)are reported in Table 3-8. The data presented in this table for medium-strength wastewater are based on an average flow of 460 L/capita.d and include constituents added by commercial, institutional, and industrial sources Typical concentrations for low-strength and high-strength wastewater, which reflect different amounts of infiltration, are also given. Be ere is no"typical"wastewater, it must be emphasized that the typical data presented in Table 3-8 should only be used as a guide. Tab. 3-8 Typical composition of untreated domestic wastewater Contaminants Low strengt High strength TDS 3-73-7 peaking factor, is defined as follows: Sustained peaking factor, PF=[peak flowrate(e.g., hourly, daily)]/(average long-term flowrate) The most common method of determining the peaking factor is from the analysis of flowrate data. Where flowrate records are available, at least 3 years of data should be analyzed to define the peak to average day peaking factor. 3-5 Analysis of Constituent Mass Loading Data The analysis of wastawater data involves the determination of the flowrate and mass loading variations. The analysis may involve determining the concentrations of specific constituents, mass loadings, or sustained mass loadings, loadings that occur over a defined period of time. From the standpoint of treatment processes, one of the most serious deficiencies results when the design of a treatment plant is based on average flowrates and average BOD and TSS loadings, with little or no recognition of peak conditions. In many communities, peak influent flowrates and BOD and TSS loadings can reach two or more times average values, it must also be emphasized that, in nearly all cases, peak flowrates and BOD and TSS mass-loading rates do not occur at the same time. Analysis of current records is the best method of arriving at appropriate peak and sustained mass loadings. The principal factors responsible for loading variations are (1) the established habits of community residents, which cause short-term (hourly, daily, and weekly) variations; (2) seasonal conditions, which usually cause longer-term variations; and (3) industrial activities, which cause both long- and short-term variations. Wastewater Constituent Concentrations The physical, chemical, and biological characteristics of wastewater vary throughout the day. An adequate determination of the waste characteristics will result only if the sample tested is representative. Typically, composite samples made up of portions of samples collected at regular intervals during a day are used. The amount of liquid used from each sample is proportional to the rate of flow at the time the sample was collected. Adequate characterization of wastewater is of fundamental importance in the design of treatment and disposal processes. Quantity of Waste Discharged by Individuals in the United States. Typical data on the total quantities of waste discharged per person per day (dry weight basis) from individual residences are reported in Table 3-7. The data have been gathered from numerous sources (primarily the United States). The total number of pathogenic organisms discharged will depend on whether an individual is ill and is shedding pathogens. If one or more members of a family are ill and shedding pathogens, the number of measured organisms can increase by several orders of magnitude. Tab. 3-7 Quantity of waste discharged by individual on a dry weight basis constituents Value,g/capita·d Range Typical without ground-up kitchen waste Typical with ground-up kitchen waste BOD5 50-120 80 100 CODcr 110-295 190 220 TSS 60-150 90 110 NH3 as N 5-12 7.6 8.4 Org N as N 4-10 5.4 5.9 TKN as N 9-21.7 13 14.3 Org P as P 0.9-1.8 1.2 1.3 Inorg P as P 1.8-2.7 2.0 2.2 TP 2.7-4.5 3.2 3.5 Oil and grease 10-40 30 34 Composition of Wastewater in Collection Systems. Typical data on the composition of untreated domestic wastewater as found in wastewater-collection systems (in the United States) are reported in Table 3-8. The data presented in this table for medium-strength wastewater are based on an average flow of 460 L/capita·d and include constituents added by commercial, institutional, and industrial sources. Typical concentrations for low-strength and high-strength wastewater, which reflect different amounts of infiltration, are also given. Because there is no "typical" wastewater, it must be emphasized that the typical data presented in Table 3-8 should only be used as a guide. Tab. 3-8 Typical composition of untreated domestic wastewater Contaminants Unit Concentration Low strength Medium strength High strength TS mg/L 390 720 1230 TDS Fixed mg/L 270 160 500 300 860 520