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Benjamin C. Whitehead, PE Benjamin J. Klayman, PhD, PE. Case Study: Commissioning New Rapid Sand Filters at Donald K. Shine Water Treatment Plant. Plant Flow Schematic. South Treatment Facility – Phase IB Expansion. Type of Filtration. Six New Conventional Rapid Sand Filters
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Benjamin C. Whitehead, PE Benjamin J. Klayman, PhD, PE Case Study: Commissioning New Rapid Sand Filters at Donald K. Shine Water Treatment Plant
Type of Filtration • Six New Conventional Rapid Sand Filters • Roberts Leotech Underdrain w/IMS Cap • 12-inches Sand • 24-inches Anthracite • Water and Air Scour Backwash • 1360 sq.ft. per Filter • 4 gpm / sq.ft.
New Filter Installation • Filter Underdrain • J-Tube Riser Air Scour Manifold
New Filter Installation • Grout Bed • Grout Infill
New Filter Installation • Completed Underdrain
Filter Backwash Equipment • Air Scour Blower • Gardner-Denver • Multi-stage Centrifugal • 300 Hp • 5440 scfm @ 6.2 psig • Backwash Pump • Perless Pump Company • Vertical Turbine Mixed Flow • 250 Hp • 32 MGD @ 17.5-feet TDH
Filter Backwash • Backwash Sequence • Drain filter to 6-inches above media • Initiate Air Scour 2 minutes • Add 4 gpm/sq.ft. Low Rate BW (8 MGD) until just below troughs • Stop Air Scour and continue Low Rate water only to top of trough • Initiate 17 gpm/sq.ft. High Rate BW (32 MGD) 4 minutes • Low rate BW (8 MGD) for 1 minute • 10 minute settling delay • Open effluent valve 2 minutes after filling starts • Backwash is reclaimed / returned to raw water influent of the plant
Backwash Backwash
MDNRE Requirements • 2 Consecutive 15 min. NTU > 1.0 • 2 Consecutive NTU > 0.5 first 4 hours • 2 Consecutive NTU > 1.0, 3 consecutive months • 2 Consecutive NTU > 2.0, 2 consecutive months • Maintain NTU < 0.3 (<0.1 normally) • < 0.1 NTU @ 7 MGD B&V / City of Wyoming Start-up Goals
Commissioning Plan How do we get there? • Careful Planning • Start Slowly • Filter to Rest • Monitor/Operate Closely • Flow • Turbidity • Headloss
Commissioning Pre-requisites • Media Washing/Screening • VOC testing • Chlorination • Instrumentation / Alarms • Monitoring / Trending • SCADA Control • Backwash Equipment • Backwash Sequence • Transfer Pumping
Commissioning Plan • Initial Start-up: • Initiate Filter Off-line (Filter-to-Waste) • 1 MGD, Filter-to-Waste until < 0.3 NTU • Filter On-line: 1 MGD • > 0.3 NTU, Initiate Settling-delay: 4 hours • Re-test: <0.1 NTU up to 3 MGD • Seasoning: • 2 weeks up to 3 MGD • 1 week off-line
Commissioning Plan Performance Test: • Run Filter Several minutes • Backwash • Place On-line, 1 to 3 MGD • Ramp 0.5 MGD @ 30 min intervals • > 0.2 NTU Initiates Continuous Monitoring • > 0.3 NTU Initiates Filter-to-Waste • Ramp to 7 MGD for 1 hour < 0.1NTU
Filter Performance (Results) • Filter Influent Turbidity: +/- 0.3 NTU • Filter Effluent Turbidity: < 0.1 NTU @ 7 MGD • Filter Effluent Turbidity: 0.02-0.07 after Initial Commissioning & Current Conditions • Filter Headloss: 1 to 7.5-feet • Run Time: 200 hours - New and Existing Filters • 4X longer after expansion • Previously 40-60 hours
Filter Performance • Meurer Research Inc. Plate Settling Equipment
Field Engineering Improvements • Reduced Washwater Quantity • Reduced High Rate Wash: 10 minutes to 4 minutes • Total Wash Volume = 75 gal / sq.ft. (100,000 gal) • Industry Standard = 150-180 gal / sq.ft. (250,000 gal) • Allows for 5 Consecutive Backwashes to Reclaim • Operator Adjustable Settling Delay • Washwater Launder Stabilization • Headloss Instrumentation Calibration • Air Distribution Optimization
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