East Coast P Removal Technology Performance Summary Charles B. Bott Hampton Roads Sanitation District NonReactive Phosphorus Workshop Spokane, Washington August 11 12, 2009
Acknowledgements Numerous slides provided by Sudhir Murthy Input from treatment plant managers Some data from WERF Study Evaluating the Performance of Nutrient Removal Treatment Processes
Municipal WWTP Point Source 483 Municipal WWTP s in watershed Treat an average of 1,600 MGD (dry weather) More than 3,500 MGD in wet weather From CBP-2009
Chesapeake Bay 2000 Agreement Goals Priority Area Reducing Pollution Agriculture Nitrogen 50 Agriculture Phosphorus 49 47%, 63%, 64% of Goals Achieved N P S -85-74 Agriculture Sediment Wastewater Nitrogen Wastewater Phosphorus Urban/Suburban Nitrogen Urban/Suburban Phosphorus 48 67 Note: Some jurisdictions may be underreporting existing stormwater management practices. 91-61 Urban/Suburban Sediment Air Nitrogen 9 Data and Methods: www.chesapeakebay.net/status_reducingpollution.aspx From CBP-2009
Wastewater Treatment Goals Relative Responsibility of Wastewater Loads Nitrogen 67% of Nitrogen Goal Achieved Wastewater Pollution Controls Percent of Goal Achieved 100 80 60 40 20 0-20 Controlling Nitrogen GOAL 1985 1990 1995 2000 2005 2010 Controlling Phosphorus Phosphorus 91% of Phosphorus Goal Achieved 100 80 60 40 20 GOAL 0 1985 1990 1995 2000 2005 2010 Accounting begins Data and Methods: www.chesapeakebay.net/status_wastewater.aspx From CBP-2009
How was this done: Phosphorus Detergent Ban Design Goals - effluent TP 1.0 mg/l) Specific plants with lower effluent TP limits Potomac River Standard = 0.18 mg/l TP Current effort - bay wide limits: - 0.3 mg/l TP (some much lower) - 3-8 mg/l TN (most 3-5 mg/l)
Arlington Co. AWTP 40 mgd Alexandria AWTP 54 mgd Noman Cole, Jr AWTP 67 mgd Blue Plains AWTP 370 mgd Piscataway AWTP 30 mgd H.L. Mooney AWTP 24 mgd
TN or TP Limits (mg/l) Permit Limits for Tidal Potomac Plants 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 3.0 4.2 3.0 4.0 3.0 3.0 0.18 0.18 0.18 0.18 0.18 0.18 Arlington Co. Blue Plains Alexandria Piscataway Noman Cole Mooney TN (future) TP (current)
TN or TP Limits (mg/l) 2006 Performance for Tidal Potomac Plants 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0.18 0.18 0.18 0.18 0.18 0.18 0.09 0.10 0.09 0.09 0.07 0.05 Arlington Co. Blue Plains Alexandria Piscataway Noman Cole Mooney TP (2006 annual average) TP (permit)
Arlington Plant Some Fe addition ahead of primary clarification (CEPT) Tertiary Clarification using Fe Granular Media Filters Additional Denitrification Filters
Blue Plains Plant Multipoint Fe CEPT using Fe Simultaneous Precipitation using Fe GMF
WSSC Piscataway Plant Simultaneous Precipitation using Al GMF From Grit Chamber Primary Clarifier Primary Sludge Train 1 Screw Pump Station Step-Feed Basins RAS Train 2 Step-Feed Basins Alum WAS Alum Flocculation Final Chambers Clarifier RAS WAS Final Clarifiers To Gravity Filters
Noman Cole Plant Some Bio P (step feed BNR) Tertiary Clarification with Fe Tertiary Sludge Recycling GMF Preliminary & Primary Treatment Secondary Treatment Equalization Ponds Tertiary Clarifiers Solids Processing & Incineration FeCl3 Filters
H. L. Mooney Plant Multipoint Fe CEPT using Fe Simultaneous Precipitation using Fe Denite Filters Preliminary & Primary Treatment FeCl 3 Secondary Treatment FeCl 3 Denitrification Filters Solids Processing & Incineration
Alexandria Plant Some Fe Addition - CEPT Simultaneous Precipitation using Fe Tertiary Clarifiers with Al (including good rapid mix and flocculation) GMF Raw Wastewater Ferric Chloride Polymer Sodium VFAor Hydroxide Methanol Ferric Polymer Chloride Coarse Screens Recyclefrom PlantDrain Raw Wastewater Pumps Fine Screens VortexGrit Chambers ToLandfill Flow Measurement Primary Settling Tank Primary Effluent Pumps Sludgeto Gravity Thickeners Sodium Hypochlorite RAS AnoxicZone AerobicZone Biological Secondary Reactor Settling Internal Recycle MLR Basins Tanks Pumps WASto Thickening Centrifuges RAS Pumps Sodium Hydroxide Alum BackwashWastewater Intermediate Pumps RapidMixand FlocculationTanks Sludgeto Thickening Centrifuges Tertiary Settling Tanks GravityFilters Sodium Hydroxide PlantEffluent tooutfall UVDisinfection Post-Aeration
TN or TP Limits (mg/l) 2006 Performance for Tidal Potomac Plants 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0.18 0.18 0.18 0.18 0.18 0.18 0.09 0.10 0.09 0.09 0.07 0.05 Arlington Co. Blue Plains Alexandria Piscataway Noman Cole Mooney TP (2006 annual average) TP (permit)
Overall Molar Ratios Plant Dose (mg/l) Me/TP inf (molar) Notes: Blue Plains Fe 8 0.94 Fe; CEPT ASA Fe 6; Al 2 0.77 Fe & Al Piscataway Al 2 0.60 Al; Ca; BPR? Noman Cole Fe 7 0.57 Fe; BPR
Molar Ratios at Final Step Plant Me/OP Notes: Blue Plains 3.3 Simultaneous Precipitation Noman Cole 4.8 Tertiary Clarification
TP or OP (mg P/L) Alexandria - 30-Day Rolling Avg 1 Weekly Avg TP Limit = 0.27 mg/l Monthly Avg TP Limit = 0.18 mg/l 0.1 Median TP (50%) = 0.051 mg/l Median OP (50%) = 0.025 mg/l TP OP 0.01 Nov-04 May-05 Dec-05 Jul-06 Jan-07 Aug-07 Feb-08 19
Alexandria Plant 1 TP OP Ln-Normal Values TP or OP (mg P/L) 0.1 0.01 0.01 0.1 1 10 30 50 70 90 99 99.9 99.99 % of Values Less Than or Equal to Indicated Value 20
TP or OP (mg/l) 3.84 Percentile 50 th Percentile 90 th Percentile 95 th Percentile 99 th Percentile Alexandria Probability Summary 0.18 Daily Data 0.16 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0.00 TP OP 21
Effluent Policy Requirement Occoquan Reservoir and Dulles Corridor Discharge Limits: COD (mg/l) - 10.0 Suspended solids (mg/l) - 1.0 Nitrogen (mg/l) - 1.0 (as TKN) Phosphorus (mg/l) - 0.10 MBAS (mg/l) - 0.1 Turbidity (NTU) - 0.5 Coliform per 100 ml Sample - less than 2.0
Two Virginia Plants Included Upper Occoquan Sanitation Authority (UOSA) Loudoun County Broad Run WWTP
UOSA Treatment Process (54 MGD)
Broad Run WWTP MBR + GAC Al addition ahead of primary clarifiers (just starting this) - CEPT Simultaneous Precipitation using Al (relatively high dose) Bio-P process in MBR Membrane filtration Zenon hollow fiber GAC (Canham et al, 2009)
Broad Run WWTP MBR + GAC Design 11 MGD Operating now at 3.3 MGD without all units in service (Canham et al, 2009) April 2009 Avg: TP = 0.048 mg/l OP = 0.040 mg/l
HRSD VIP Plant 40 MGD Bio-P using VIP process Operating ~32 MGD Rare Fe Addition 2 mg/l annual TP limit Year-round nitrification No filtration Avg TP = 0.47 mg/l ( 04-08)
VIP Process
Summary All plants have filters Most plants use simultaneous precipitation Half of the plants use tertiary clarifiers Chemical removal in primary is not always possible Plants use iron or aluminum Bio P can reduce chemical dose
Questions?