Sludge Processing Facilities
Sludge Processing Facilities | 1995 | 2015 |
Primary Sludge (lb/d) | ||
Average | 28,400 | 38,300 |
Maximum-Month | 44,000 | 58,200 |
Maximum 3-Day | 62,100 | 83,500 |
Secondary Sludge (lb/d) | ||
Average | 15,700 | 21,800 |
Maximum-Month | 28,700 | 38,500 |
Maximum 3-Day | 36,700 | 48,600 |
Skimmings (lb/d) | 1,600 | 1,800 |
Total Sludge & Skimmings (lb/d) | ||
Average | 45,700 | 61,900 |
Maximum-Month | 74,300 | 98,500 |
Maximum 3-Day | 100,400 | 133,900 |
Gravity Thickeners (Primary Sludge) | ||
No. of Units | 3 | 4 |
Diameter, ft | 40 | 4.0 |
Sidewater depth, ft | 10 | 10 |
Percent Feed Solids | 0.2-1.0 | 0.2-1.0 |
Average | 7.5 | 7.4 |
Maximum-Month | 11.7 | 11.6 |
Maximum 3-Day | 16.5 | 16.6 |
Hydraulic Loading Rate, gpd/sf | 600 | 600 |
Thickened Solids % | 5.0-6.0 | 5.0-6.0 |
Solids Capture % | 90 | 90 |
Gravity Belt Thickeners(Secondary Sludge) | ||
Number (including one standby) | 4 | 4 |
Size of Units, meters | 2 | 2 |
Percent Feed Solids | 0.5 | 0.5 |
Solids Loading Rate, gpm/m | 438 | 438 |
Hydraulic Loading Rate, gpm/m | 175 | 175 |
No. of Units Operating | 3 | 3 |
Operating Schedule: | ||
Days/Week | 7 | 7 |
Hours/Day | ||
Average | 6.0 | 8.2 |
Maximum-Month | 11.0 | 14.7 |
Maximum 3-Day | 14.0 | 18.5 |
Thickened Solids, % | 5.0 | 5.0 |
Solids Capture, % | 95 | 95 |
Polymer Usage, lb/dry ton | 5.0-7.0 | 5.0-7.0 |
Sludge Blending/Storage Tanks | ||
Number | 6 | 6 |
Volume per tank (cu ft) | 12,700 | 12,700 |
Available Storage (days) | ||
Average | 5.7 | 4.4 |
Maximum | 3.5 | 2.6 |
Mixing Blowers | ||
Type | Rotary Positive Displacement | |
Number of Blowers | 5 | 5 |
Capacity (cfm) | 480 | 480 |
Horsepower | 30 | 30 |
Centrifuges | ||
No. of Units | 4 | 4 |
Percent Feed Solids | 5 | 5 |
Solids Loading Rate lb/hr/unit | 3,000 | 3,000 |
Hydraulic Loading Rate, gpm per unit | 120 | 120 |
Operating Schedule | ||
Day/Week | 5 | 5 |
Hours/Day | ||
Average | 6.5 | 9 |
Maximum-Month | 11 | 14 |
Maximum 3-Day | 14 | 19 |
Cake Solids, % | 28-30 | 28-30 |
Solids Capture, % | 95 | 95 |
Polymer Usage, lb/dry ton | 8.5 | 8-15 |
Sludge Hauling | ||
Dewatered Sludge Conc., % | 28-30 | 28-30 |
Sludge Volume (5 days/wk) | ||
Average (cu yd/d) | 116 | 162 |
Maximum-Month (cu yd/d) | 242 | 322 |
Hours of Operation (5 days/wk) | ||
Average (hrs/day) | 7 | 7 |
Maximum-Month (hrs/day) | 7 | 7 |
Truck Round Trips per day, 5 days/wk (20 cy truck) | ||
Average | 6 | 8 |
Maximum-Month | 12 | 16 |
- Includes solids processing sidestreams
- High groundwater season
- For Maximum-Month Loadings during high groundwater season