Wastewater Plant Criteria
City of Fresno, Dept. of Public Utilities, Wastewater Division
Fresno/Clovis Regional Wastewater Reclamation Facility Design Criteria
Plant Capacity
Flow, mgd
Average day maximum month ........ 88
Average annual ................................ 80
Peak hour ....................................... 160
BOD 5 and suspended solids
Average concentration, mg/L ....... 240
Average loading 1,000 lb/day ...... 184
Headworks/Preliminary Treatment
Influent pumps
Number/capacity, mgd ......... 2 @ 32.4
................................................. 4 @ 46.1
Total capacity, mgd ....................... 203
Mechanical bar screens
Number ............................................... 4
Width, ft ............................................... 7
Bar spacing, in ..................................75
Grit basins
Diameter, ft.........................................24
Number ................................................4
Peak capacity (each), mgd ..............70
Total capacity, mgd .........................210
Grit pumps
Number .................................................6
Capacity, gpm .................................360
Parshall flumes
Number ................................................2
Width, ft ..............................................10
Total capacity, mgd ........................220
Primary Clarifiers
Number ............................................... 6
Diameter, ft .....................................140
Sidewater depth, ft .......................... 10
Overflow rates, gpd/sf ................ 1,010
Detention time, hrs ....................... 1.78
Weir loading, gpd/lf .................. 35,200
Primary Sludge Pump Stations Nos. 1 and 2
Primary sludge pumps - air diaphragm type
Number ............................................. 16
Capacity (each), gpm .................... 140
Primary scum pumps - air diaphragm type
Number ............................................... 4
Capacity (each), gpm .................... 140
Dewatering pumps - vertical non-clog centrifugal
Number ............................................... 2
Capacity (each), gpm ................. 1,300
Aeration Basins
Number ............................................... 8
Process design flow, mgd ............... 80
Volumetric loading, lb BOD 5/1,000 ft/day
........................................................48-58
Volume per basin, MG .................... 2.7
Sidewater depth, ft ...................... 15-17
Mixed liquor suspended solids,mg/L
............................................. 2,000-3,000
Carbonaceous oxygen requirements
lbs O2/lbs BOD ............................ 1.125
Aeration Air Blowers
Air blowers/capacity, cfm
.................................................4@27,000
.................................................3@18,400
Secondary Sedimentation Basins
Number ..............................................13
Process design flow, mgd ...............80
Sidewater depth, ft ......................13-14
Overflow rate, gpd/day/ft 2 .....532-577
Weir overflow, gpd/lf .........3,000-4,000
Effluent Disposal
Pond area, acres .........................1,400
Disposal pond freeboard, ft ................2
Average pond water depth, ft ........ 4-5
Sludge Thickening
Dissolved air flotation thickeners
Number .............................................. 2
Solids loading, lb/ft 2/day ................24
Diameter, ft .......................................40
Gravity belt thickeners
Width, meters..................................... 2
Number ...............................................2
Hydraulic loading, gpm ..................500
Anaerobic Digesters
Number .............................................12
Diameter, ft ...............................75-105
Volatile solids loading, lbs/ft^3/day... 0.12
Min. hydraulic retention time, days ...... 20
Sidewater depth, ft .....................26-29
Pumping mixing
Pump number ...................................16
Capacity (each), gpm ................5,000
Sludge Dewatering
Belt filter presses
Number ..............................................7
Width, meters ....................................2
Hydraulic loading, gpm .................180
Feed solids concentration, % ...... 2-3
Cake solids concentration, % .. 18-20
Sludge Storage Silos
Number ................................................1
Volume, cy .......................................430
Solids storage time, hrs ...................24
Plant Utilities
Steam boiler - horizontal fire tube
Number ...............................................1
Capacity, hp ...................................400
Air compressors - two-stage reciprocating type
Number ..............................................3
Size, scfm ......................................540+
Discharge pressure, psig ............125