Ready, Set, and Go: Deer Valley WTP East Basins Performance Testing, Start-Up, and Commissioning Toby Teegerstrom Brian Watson

Transcription

1 Ready, Set, and Go: Deer Valley WTP East Basins Performance Testing, Start-Up, and Commissioning Toby Teegerstrom Brian Watson January 25, 2011

2 Presentation Outline Background Process Overview Start-Up and Performance Testing Commissioning Acknowledgements Questions 2

3 Background 1 of 6 Surface WTP Owned by COP City Decided to Demolish and Rebuild Due to Soil Settling Issues East Basins Reconstruction Project in Commissioning R E S E R V O I R S SBF PSB GAC FILTERS WWEQ # 2 N 3

4 Process Overview Ferric Chloride Pre-Sedimentation Basins Tank Drain Pump Station Rapid Mix Sand Ballasted Flocculation Sand Silo Polymer Feed Facilities Chlorine Dioxide Feed System Granular Activated Carbon (GAC) Filter Adsorbers Wash Water Equalization Basin 4

5 Ferric Chloride City of Phoenix Decided to Change the Primary Coagulant from Alum to Ferric Included a New Feed System and Associated Feed Piping Ferric Dosage Dependent on Raw Water Quality 5

6 Pre-Sedimentation Basins N PRE-SEDIMENTATION BASINS 6

7 Pre-Sedimentation Basins Two (2) Trains with Three (3) Basins Each Modes of Operation Parallel Series By-Pass (One or Both) Sluice Gates Used to Divert Flow Blowdown System with Rake Mechanism Cathodic Protection Detention Time Approximately 40 minutes 7

8 Rapid Mix Basins Primary Ferric Feed Point Isolation Valves for Feed Control Four (4) 42 MGD Each VFD Drives for Mixers ph and Turbidity Meters Sample Pumps Level Sensors for Each Basin 8

9 Sand Ballasted Flocculation Inlet Gates on Pre- Sedimentation Basins 4 28 MGD, Each Train has Coagulation Tank Injection Tank Maturation Tank Settling Tank Polymer Can be Fed at Multiple Locations 6 Poly Skids in Chemical Building Carrier Water Added to Neat Polymer 9

10 Sand Ballasted Flocculation Sand Recirculation Pumps Two (2) Pumps and Four (4) Hydrocyclones per Train PLC and CCS Controls ph, Turbidity, and Flow Meters VFD Drives for Settling Tank Scraper and Maturation Tank Mixer Tank Drain System 10

11 Sand Silo Sand Loss Up to 25 LBS/MG Treated Manual Operation Daily Monitoring from Hydrocyclones to Determine Sand Concentrations (Suggested Concentration 4-6 g/l) Feed Rate Constant Speed Silica Sand Loading with Dust Collector Sand (#80, 114 Microns) Silo Holds 42 Tons 11

12 GAC Filter Adsorbers Eighteen (18) 7.3 MGD Each (For a EBCT of 10 Minutes) Calgon FILTRASORB 820(1.1 mm particle size) Virgin Media Fines Pumps Tank Drain Pumps Backwash Pump Station Hydropnuematic System Inclusive of Seal Well Pumps 12

13 GAC Filters Cont.. Backwash (East-West Basins) Common Channel to WWEQ Basin Turbidity, Media Depth, Flow, Pressure Differential, TOC Analyzers, and Channel Level Meters North and South Channels for Isolation 13

14 Washwater EQ Basin Additional WWEQ Basin with Pump Station No Additional Solids Facilities Modifications were Necessary 14

15 Start-Up and Performance Testing Performance Testing of SBF Basins 9/27/2010 to 10/04/ MGD Returned to West Basin Pre-Sedimentation Basins Performance Testing of GAC Filter Adsorbers 10/4/2010 to 10/15/ Filters- 2 Hour Run Times with <.1 NTU West Basin Filter Backwashes moved to nights Plant Shut Down 10/18/2010 Till 11/9/2010 For Final Tie-Ins 15

16 SBF Testing - Flow Pattern N WEST BASINS PRE-SEDIMENTATION BASINS RAPID MIX BASINS SBF BASINS GAC FINES PUMP STATION GAC FILTER ADSORBERS WWEQ BASINS 16

17 SBF Performance Testing East/West Plant Split Flow Controlled by Inlet Gates at East and West Basins Pre-Sedimentation Basins By-passed One Rapid Mix Basin One SBF Train On-line for Testing at Any Given Time Polymer Feed Rates Set Between 0.2ppm - 0.8ppm Sand Concentrations Varied Between 5-8 g/l 17

18 GAC Testing - Flow Pattern N WEST BASINS PRE-SEDIMENTATION BASINS SBF BASINS RAPID MIX BASINS GAC FINES PUMP STATION GAC FILTER ADSORBERS WWEQ BASINS 18

19 GAC Underdrain Testing Each Filter Required an Underdrain Test with Backwash Air Scour 0.12MG Volume per Filter Fill Water 6 Above Underdrain Block, Drain and Inspect Perform a Full Backwash, Drain and Inspect 2 nd Full Backwash, Drain and Inspect Spray Walls of Filter with 200ppm Cl2 for Disinfection 3 rd Full Backwash with Chlorinated Water Added to the End of the Run. Filter Filled and Chlorinated Water Held and Tested for a Cl2 Residual of 20-30ppm. Filter Held with Cl2 water for 12 Hours and Maintain 15ppm residual. De-Chlorinate Filter <5ppm and Take Bac-T Disposal and Re-use of Testing Water 19

20 GAC Filter Media Loading A 3 ft. Lift of GAC Media is Installed with Water Being Added to Just Above Media Level. Filter Media is Soaked for 12hrs Before the 2 nd Lift is Added. Water is Again Filled to Above Media and Left to Soak for a Minimum of 24hrs Backwash Water from the Fines Backwash Water Pump Station was Pumped to Head of the Plant Periodic Maintenance Backwashes 20

21 Performance Testing - Lessons Learned Filter Aid Filter Effluent Turbidity Levels with E38 Polymer Alone Did Not Meet Specification Requirements Use of Post Coagulation Filter Aid Suggested Dose of 1ppm - 3ppm Results Indicated Better Filter Turbidities ph Requirements Time Constraints Coordination Required with West Plant Operations Project Schedule Upcoming Shutdown Coordination with Contractor Schedule Includes Multiple Activities Like I&C Checkout, Filter Underdrain Testing, Filter Disinfection, and Media Loading 21

22 GAC Media Challenges High ph (Ash)-7% Longer run times necessary for achieving turbidity levels TOC removal Chlorine residuals in Backwash water <0.2ppm Zeta Potentials from SBF effluent 22

23 Commissioning Pre-Sedimentation Basins Rapid Mix Basins SBF Basins GAC Filter Adsorbers 23

24 Pre-Sedimentation Basins Commissioning Actuated Gates and Control Functions Blowdown Rake Mechanism Cathodic Protection Blowdown Vaults and Schedule Set Points Tank Drain Pump Station 24

25 Rapid Mix Commissioning Ferric Feed System Ferric Isolation Feed Valves Instrumentation Inlet Turbidity Inlet ph Outlet ph Level Sensors Sample Pumps Rapid Mixers and VFD s 25

26 SBF Commissioning One (1) SBF Train On-line 15MGD Flow (Spilt Flow at 30MGD) Balance Ferric with Polymer and Sand to Optimize Settling. Effluent Turbidity <2 NTU Chemical Doses: Ferric Chloride: 25ppm - 40ppm Polymer (E38): 0.2ppm - 0.8ppm Sand Concentration: 4g/L - 6g/L 26

27 GAC Filters Commissioning Three (3) Filters On-line 5MGD) Filter Aid Ferric 2ppm-3ppm Effluent Turbidity <0.1NTU Finished Water to Distribution System Maintenance Backwashes of Idle Filters Coordination to Maintain West Plant Operations 27

28 Turbidity Commissioning - Challenges EPDS Turbidity Levels due to Manganese/Iron precipitant needed to be monitored ph Requirements Raw Water Source Polymer Dosing Strategies Polymer Feed Control in Manual Plant Production Rates Changed with Returned Water Filter Aid Dosing Issues Ferric Chloride Metering Pump Issues 28

29 Back to the Drawing Board! City Strongly Preferred not to Have Any Filter Aid Team Decided to Perform Bench Scale Testing Using Various Polymers for the SBF Process During Performance Testing Team Noticed Changes in Zeta Potentials Raw Water Zeta SBF Treated Water Zeta Team Decided to Change Dosage Location of Chlorine Dioxide as a Pre-Oxidant at Rapid Mix Basins 29

30 30 Polymer Bench Scale Testing

31 Polymer Bench Scale Testing Goal was to Narrow Down the Polymers Suitable for SBF Process Simulation of GAC Filter Column Tests not Representative High Turbidity Bench Scale Tests were Inconclusive Results were Inconclusive Team Decided to Proceed with a Full Scale Testing with Available Polymers 31

32 Polymer Full Scale Testing Flow Limited to 10MGD Discharge to Sewer Restricted Flow During 12:00pm to 8:00am Plant Operated between 12:00pm and 8:00pm Each Polymer Tested for Two (2) Days Polymers Tested Consisted of E38 C6210 C6220 C6240 C6260 Raw Water Source Verde River Water 32

33 33 Polymer Full Scale Testing - Results

34 Full Scale Testing-Recommendations Recommended C6220 For SBF Process Recommended E38 Polymer With Post Ferric Feed For High Raw Water Turbidity Events Continuing Commissioning With C6220 Polymer Phase I Commissioning Schedule Jan 5-21, MGD From Jan 5-13, MGD From Jan 13-20, MGD From Jan 20-21, 2011 Phase 2 Commissioning Schedule Feb 7-20,

35 Operations Lessons Learned Maintain Hydraulic Level at Filter Beds Trim Filter Effluent Flow rate to maintain a more constant hydraulic level Polymer Flow Pacing - MAG Meters Vs Mass Meters ph Reduction Needed Approximately 20hr Runtime Water Temperatures Affected Polymer Dose Necessary for Treatment Performance Differences Between Polymer Totes Visual Confirmation Of Chemical Change in Maturation Tank Filter Run Times Increasing From 8 Hours to 20 Hours Over Time 35

36 Acknowledgements City of Phoenix Engineering Plant Staff Water Production Lab Staff McCarthy Building Companies & Subs Wilson Engineers Team 36

37 Questions??? What s for Lunch? 37