5 BYPASS DISPOSAL S NPW SUPPLY

14 SECONDARY 13 PRIMARY 7 AERATION CLARIFIER SCREEN GRIT BASIN #2 CLARIFIER RECYCLE 8 #2 #1 CHANNEL #2 1 INTERMEDIATE 11 TRICKLING CLARIFIER 10 WAS 2 3 FILTER CHANNEL #1 6

U.V. DISINFECTION PRIMARY SECONDARY SCREEN GRIT CLARIFIER 9 AERATION CLARIFIER BASIN #1 15 #2 #1

12 RAS INTERMEDIATE

16 DAF EFFLUENT 18

17

WAS DAFT THICKENER 23 ADS EFFLUENT BYPASS 4 19 20 THICKENED SLUDGE PRIMARY ANAEROBIC TRUCK LOADING PRIMARY DIGESTION STATION CLARIFIER SLUDGE 24 25

ROTARY SLUDGE SCREWPRESS DYSTOR DRUM 21 STORAGE 22 SLUDGE THICKENER STORAGE

DRYING BEDS PRIMARY ANEROBIC DIGESTION EFFLUENT THICKENED WAS DAF BYPASS RDT & SCREWPRESS SUPERNATE 26 City of Pasco Schematic Description

1. Influent Raw - 4.3 MGD average for December to June. 4.9 MGD average for July to November (industrial flow). 2. Headworks Filter Screens and Grit Removal- 2.15 MGD per channel. 3. Primary Clarifiers- 2.15 MGD per clarifier. 4. Primary Clarifier Sludge. 5. Trickling Filter Bypass- 0 to 100% bypass. Currently 50% bypass equals 2.15 MGD. 6. Trickling Filter- 7.9 MGD over filter. Primary effluent flow to the filter depends on the trickling filter bypass set point. Currently 2.15 MGD primary effluent plus 5.75 MGD recycle flow equals 7.9 MGD total flow. 7. Trickling Filter Recycle- Total recycle flow depends on primary effluent flow to trickling filter. Currently 5.75 MGD. Varies due to trickling filter bypass. 8. Intermediate Clarifier- Depends on trickling filter bypass flow. Currently 2.15 MGD. 9. Intermediate Clarifier Sludge. 10. Aeration Basin ()- 4.3 MGD influent plus 3.5 MGD RAS (depends on RAS Q) plus 60,000 gallons DAF effluent equals 7.86 MGD total flow (3.93 MGD per basin). 11. Secondary Clarifiers- 7.86 MGD influent flow minus 3.5 MGD RAS minus 60,000 gallons DAF equals 4.3 MGD (2.15 MGD per clarifier). 12. Return Activated Sludge Line- Flow depends on RAS set points. Currently 3.5 MGD. 13. Ultraviolet Disinfection- Influent flow of 4.3 MGD. Currently using one channel. 14. Non-potable Water Supply- 100,000 to 220,000 gallons per day. Varies due to water usage and demand. 15. Discharge to River- 4.3 MGD 16. Waste Activated Sludge Line- Flow varies due to wasting needs. Current average wasting is 110,000 gallons per day. WAS is normally pumped directly to DAFT but can be sent to Rotary Drum Thickener if the DAFT is out of service. 17. Tank- Flow depends on WAS flow rate plus DAFT pressurization pump. Currently WAS flow is 110,000 gallons per day plus 360,000 gallons per day equals 0.47 MGD flow into the DAFT. 18. DAFT Effluent- Effluent flow varies due to WAS flow rate. Current average is 60,000 gallons per day. 19. DAFT Thickened Sludge- Flow depends on WAS flow rate. Currently 50,000 GPD. DAFT thickened sludge is pumped to anaerobic digesters. 20. Primary Anaerobic Feed Sludge- Flow into digesters depends on primary clarifier sludge/scum flow and DAFT thickened sludge. Currently primary sludge/scum flow of 29,000 gallons per day plus DAFT thickened sludge of 50,000 gallons per day equals 79,000 gallons per day. 21. Primary Anaerobic Digesters- The primary digesters feed flow is automatically switched from primary digester #1 to primary digester #2 every three hours. Currently the primary sludge/scum flow of 29,000 gallons per day plus the DAFT thickened sludge of 50,000 gallons per day equals 79,000 gallons per day. Detention time is 18 to 24 days depending on flow. 22. Sludge Storage/Dystor- Primary anaerobic digested sludge is gravity fed to the sludge storage and/or Dystor tank. Currently only the Dystor is being used for sludge storage. 79,000 gallons per day average is sent to this tank. 23. Activated Digested Sludge Effluent (ADS)- ADS effluent can then be pumped directly to the rotating drum thickener, screw press, or drying beds. Currently 65,000 gallons per day for four days is sent to the rotating drum thickener. The screw press can handle 67,000 gallons per day and 316,000 gallons per day could be sent directly to the drying beds. 24. Rotary Drum Thickener (RDT)- The RDT is fed ADS at an average flow of 65,000 gallons per day for four days. The thickened sludge of 12,000 to 15,000 gallons per day is sent to the drying beds. If necessary, the thickened sludge could be sent to the screw press for further processing. The RDT is also plumbed to accept and thicken waste activated sludge then pump the thickened “WAS” to primary . 25. Screw Press- The screw press is fed from either the ADS effluent or from RDT thickened sludge. This process is currently in construction. 26. RDT and Screw Press Supernate- The RDT and screw press supernate is gravity fed to the Maitland Lift Station which ultimately is brought back to the Wastewater Treatment Plant. Currently only the RDT is being used with a supernate flow of 50,000 gallons per day.

* 4.3 MGD Effluent was used for the chart