City of Morgan Hill Sewer System Master Plan 2017

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City of Morgan Hill
Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study
12-0248 AEG CofMorganHill FM Rpt.docx Page 21 of 46
Flow Monitoring: Average Dry Weather Flows
Weekday and weekend diurnal flow patterns differ and can be separated when establishing average
dry weather flow rates. Within weekdays, the average dry weather flow (ADWF) patterns for Friday
will vary from the Monday through Thursday patterns, particularly in the evening hours as people
prepare for the weekend. Similarly, Sunday flow patterns typically vary in the evenings from Saturday
flow patterns as people prepare for the work week. illustrates the varying flow patterns
within a work week (Site 7 shown). Graphs of the ADWF flow patterns for each site may be found in
Appendix A .
Figure 15. Sample ADWF Diurnal Flow Patterns (Site 7)
The overall average dry weather flow (ADWF) is calculated per the following equation:





 × +




 × +




 × +




 × = − 7
1
7
1
7
1
7
4
Sun Sat Fri Thu Mon ADWF ADWF ADWF ADWF ADWF ,
ists the average dry weather flow (ADWF) recorded during this study for the flow monitoring
sites. hows a schematic diagram of the average dry weather flows and flow levels.
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 00
Flow (mgd)
Hour
Mon-Thu Friday Saturday Sunday Site 7: Average Daily Flows