HIGH RATE TREATMENT AS PART OF THE SOLUTION FOR WET WEATHER FLOWS JUNE

Transcription

1 City of Newark, Ohio HIGH RATE TREATMENT AS PART OF THE SOLUTION FOR WET WEATHER FLOWS JUNE 22, 2011 High Rate Treatment Tanks/UV Wet Weather Screen Building JC2/Wet Weather Pump Station Wet Weather Control Building Wet Weather Grit Tanks Chemical Storage and Feed Room Final Clarifiers Presented By: Joe Jacobs, P.E.

2 PROJECT BACKGROUND Long Term Control (LTC) Plan Development o Recommended conveyance of wet weather flows to treatment plant site o Recommended construction of physical/chemical high rate treatment facilities NPDES Permit Compliance Schedule: o Submit permit-to-install application: August 2008 o Complete construction: December 2010 Planning/Basis of Design Report in 2007 Detail Design/Bid in 2008 Construction began in March of 2009 Facility Started-up in March/April 2011

3 COLLECTION SYSTEM RACCOON CREEK EXISTING RACOON CREEK INTERCEPTOR SEWER SOUTH FORK LIFT STATION CSO-1014B CSO-1014A CSO NORTH FORK INTERCEPTOR SEWER CSO-1006 ELIMINATED AND NEW 48 INTERCEPTOR REPLACED EXISITNG 30- INCH SEWER WET WEATHER PUMP STATION JUNCTION CHAMBER 1 54 LICKING RIVER INTERCEPTOR N 36 TO WET WEATHER SYSTEM CSO MAIN STEM INTERCEPTOR 42 TO WWTP CSO-1012 JUNCTION CHAMBER 2 CSO-1015 NEW RACCOON CREEK INTERCEPTOR SEWER EXISTING SEPARATE SEWER NEW/PROPOSED SEPARATE SEWER EXISTING COMBINED SEWER NEW COMBINED SEWER

4 HIGH RATE TREATMENT GOALS Limit 6 Upstream CSOs to 4 to 6 events per year No effluent permit limits in proposed draft permit. Permit provides for effluent monitoring only. Basis of Design Assumed: Minimum of 80 Percent of TSS No limit for CBOD No limit for NH 3 -N Disinfection required during summer months o E. Coli: o E. Coli: 284/100 ml on weekly basis 126/100 ml on a monthly basis No limit for dissolved oxygen

5 SWMM MODEL DEVELOPMENT The SWMM model was developed as part of Long Term Control Plan Model included all planned improvements to the collection system o 54-inch Licking River Interceptor (Completed) o CSO-1007 Separation (Completed) o CSO-1006 Elimination (Recently completed) o CSO-1013 Underflow (Recently completed) o 48-inch Raccoon Creek Interceptor (Under Design) o CSO-1030 Separation (Under Design) Model run with actual 2005 annual rainfall data

6 INFLUENT HYDROGRAPH SWMM Model Results WWTP Secondary Treatment Capacity EXTENDED STORM EVENT WITH MULTIPLE RAINFALL EVENTS RESULTS IN MULTIPLE PEAKS AT WWTP

7 SWMM MODEL CONCLUSIONS The existing 42-inch and 54-inch interceptors convey approximately 51-mgd before overflowing at CSO separate overflow events per year were identified where High Rate Treatment or Equalization would be required 6 events were identified where CSO-1008 would have activated with High Rate Treatment Use of existing Equalization could reduce the number of times High Rate Treatment is used by half

8 BASIS OF DESIGN WWTP Flow Rates: 8-mgd Average Dry Day 20-mgd Peak Secondary WWTP Influent Pumping & Grit Removal WWTP Screening Primary Clarifiers High Rate Treatment System: 28-mgd sustained 32-mgd intermittent peak Administration Building Equalization Aeration Total Wet Weather Capacity 48-mgd sustained 52-mgd intermittent peak Construction Cost: $15.3 Million ARRA Funding: $5.0 Million JC2/Wet Weather Pump Station Wet Weather Screen Building Final Clarifiers High Rate Treatment Tanks Wet Weather Control Building

9 PROCESS OVERVIEW Junction Chamber No. 2 Wet Weather Pump Station Wet Weather Screening Wet Weather Grit Removal Equalization High Rate Treatment o Microsand Recirculation Circuit o Bulk Sand Feed System o Coagulant Feed System o Polymer Feed System o Defoamer Feed System Wet Weather Disinfection

10 JUNCTION CHAMBER 2 Purpose: Provides flow splitting between Wastewater Treatment Plant and Wet Weather Treatment Facility Provides preferential diversion of separate sanitary sewer flows to Wastewater Treatment Plant Provides preferential diversion of combined sewer flows to Wet Weather Treatment System Wet Weather Pump Station 54 Licking River Interceptor (Combined) Wet Weather Pumps 36 HRT Force Main 42 WWTP Influent N 24 Secondary Effluent Wet Weather Pump Station 42 Main Stem (Separate) Junction Chamber 2 JC2 Control Gate Junction Chamber 2 Flow Meter Chamber

11 WET WEATHER PUMPING Purpose: Convey flow to wet weather process and control hydraulic grade in upstream sewers Basis of Design: Firm Pumping Capacity: 34 mgd Number of Pumps Five (4 duty, 1 standby) Type Submersible Centrifugal Pump Capacity 6, ft Drive Type: Variable Speed Submersible Wet Weather Pumps Wet Weather Pump Station and Junction Chamber 2 Section View

12 WET WEATHER SCREENING Purpose: Floatables control, mitigate plugging of downstream equipment (hydrocyclones) Basis of Design: Number of Screens: Two Type: Automatic Self Cleaning Filter Element Size: 6 mm Compactor: Screw conveyor w/press Two Parkson Aqua Guard Type Screens Conveyor Discharge Chute Continuous Conveyor Screen

13 WET WEATHER GRIT REMOVAL Purpose: Remove 95 percent of grit 100 microns and larger, essential for Actiflo process No grit dewatering or classifying equipment provided to simplify operation; grit returned to wastewater treatment plant influent Basis of Design No. of grit tanks: Two Type: Vortex tray settler No. of trays per tank: Eight 12 ft diameter Grit Underflow Valve Multiple Tray Vortex Settler Screen Channel and Grit Tank Section View

14 EQUALIZATION Purpose: Store volume from low intensity short duration storm events Basis of Design: Convert existing equalization to wet weather operation Volume: 1,000,000 gallons Existing Equalization Basins at Newark New Equalization Junction Chamber

15 HIGH RATE TREATMENT Purpose: Treat and discharge wet weather flows from high intensity long duration storm events Provide enhanced primary treatment of wet weather flows Basis of Design No. of Trains Two Type Ballasted flocculation process Manufacturer Actiflo process by Kruger Capacity 14 mgd per train sustained 16 mgd per train intermittent peak Overflow rate 60 gpm/sf sustained 66 gpm/sf intermittent peak

16 MICROSAND Purpose: Microsand serves as the seed for floc formation and ballast (weight) to aid with settling Basis of Design: Sand Concentration 3,000 to 6,000 mg/l Initial Sand Feed 800 lbs/mgd 14 MGD = 11,200 lbs per HRT tank Sand Loss 2 to 3 mg/l per MG treated 16 to 25 lbs per MG treated

17 MICROSAND CIRCUIT Purpose: Separate settled solids from microsand and return microsand to the injection tank. Settled solids are conveyed to the wastewater treatment plant Basis of Design Microsand Pumps o Purpose: Recirculation of microsand and settled solids o No. of pumps: 3 per train (2 duty, 1 standby) o Capacity: 310 gpm each at 76 ft TDH Hydrocyclones o Purpose: Separate microsand from settled solids o Hydrocyclones: 3 per train (2 duty, 1 standby) o Capacity: 310 gpm at 22 psig Underflow: 60 gpm to injection tank Overflow: 250 gm to 0.1 to 0.5 percent solids Microsand Pumps Train 1 Hydrocyclones and Sample Sink

18 BULK SAND FEED SYSTEM Monorail & Hoist Major Components 1 Ton Mini Sack Bulk Bag Unloader Unloading Bin Volumetric Feeder: (2,000 lb/hr) Unloading Bin Wetting Cone Eductor Nozzle Volumetric Feeder Booster Pump Booster Pump Eductor Nozzle Wetting Cone Bulk Sand Feed System

19 COAGULANT FEED SYSTEM Purpose: Destabilize suspended solids and colloidal matter in raw water Basis of Design: Coagulant: Aluminum Chlorohydrate (ACH) Feed Pumps: 4 each (2 duty, 2 standby) Type: Peristaltic (Hose) Pumps Dosage 10 to 50 mg/l (Based on ACH) Feed Range 2.4 to 130 gph 6,000 Gallon Coagulant Storage Tank Coagulant Induction Units Coagulant Feed Pumps

20 High Rate Treatment Coagulant Process Flow Schematic

21 POLYMER FEED SYSTEM Purpose: Flocculent aid for coagulated water Basis of Design Polymer Type: Anionic Emulsion Blending Units: 4 each (2 duty, 2 standby) Polymer Dosage: 1 to 3 mg/l Feed Range: 0.5 to 10 gph Feed Points Between the coagulation tank and the injection tank Between the injection tank and the maturation tank Mid-point of the maturation tank Polymer Blending Unit

22 High Rate Treatment Polymer Process Flow Schematic

23 DEFOAMER FEED SYSTEM Purpose: Mitigate foaming in HRT Effluent Basis of Design: Defoamer Agent: TRAMFLOC Feed Pumps: 2 each (1 duty, 1 standby) Dosage: 1 to 5 mg/l Feed Range 1.2 to 6 gph Feed Points HRT Effluent Channel Downstream of UV System Defoamer Feed System HRT Effluent Channel Foam at Start-up

24 WET WEATHER DISINFECTION Purpose: Provide disinfection of wet weather flows prior to discharge Basis of Design: Type: Manufacturer: Sustained Capacity: Intermittent Peak: Total No. of lamps: UV Transmittance: Medium Pressure Trojan Technologies 28 mgd 32 mgd 128 each 50 percent Trojan UV4000 Plus UV Disinfection System Influent and Effluent Automatic Samplers

25 QUESTIONS? Joe Jacobs, P.E. Malcolm Pirnie, Inc Polaris Parkway, Suite 200 Columbus, Ohio Wet Weather Treatment Facility West Elevation Wet Weather Treatment Facility East Elevation