Blueleaf Incorporated Pilot Report

City of PortsmouthWastewater Master Plan

Phase 2 Initial Piloting Technical MemorandumVolume Two September, 2012

preserve our community protect our environment manage our resources explore innovative solutions

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CITY OF PORTSMOUTH, NH PHASE 2 INITIAL PILOTING TECHNICAL MEMORANDUM

TABLE OF CONTENTS

Page

Letter of Transmittal ............................................................................................................................... i Table of Contents ................................................................................................................................. ii List of Attachments ............................................................................................................................... iii List of Figures ........................................................................................................................................iv List of Tables .........................................................................................................................................vi List of Abbreviations ........................................................................................................................... viii Acknowledgements ............................................................................................................................... x Volume One of Two EXECUTIVE SUMMARY

Section1- Introduction and Purpose ....................................................................................... ES-1

Introduction .............................................................................................................. ES-1 Purpose .................................................................................................................... ES-2 Consent Decree Requirements ................................................................................. ES-2

Section 2 - Pilot Process, Equipment, and Approach ............................................................. ES-2 Section 3 - Pilot Data Analysis............................................................................................... ES-2

Ability to Meet Study Effluent Goals .......................................................................... ES-3 Effluent Performance Comparison ............................................................................ ES-3 Vendor Constituent Loading Rate Validation and Potential to Reduce Technology Size .......................................................................................................................... ES-4 Hydraulic Stress Test Summary ................................................................................ ES-5

Section 4 - Wastewater Data and Revised Full scale Design Criteria ..................................... ES-6 Wastewater Characterization Program ...................................................................... ES-6 Revised Flows and Loads ......................................................................................... ES-6

Section 5 - Secondary Process Resizing and Comparison ..................................................... ES-7 Approach .................................................................................................................. ES-8 Capital Cost Comparison .......................................................................................... ES-8 Operations and Maintenance Comparison ................................................................ ES-9 Life Cycle Cost Comparison...................................................................................... ES-9

Section 6 - Non-Monetary Evaluation Factors Update ............................................................ ES-9 Technology Comparison and Ranking .................................................................... ES-10

Section 7 Pilot technical Memorandum Recommendations ............................................... ES-10 Secondary Treatment Facilities Design Capacity .................................................... ES-10 Design Recommendations ...................................................................................... ES-10

SECTION ONE INTRODUCTION AND PURPOSE

Background.............................................................................................................................. 1-1 WWMP Piloting Phase 1 Evaluation ..................................................................................... 1-1

Purpose ....................................................................................................................... 1-2 Consent Decree Requirements ................................................................................................ 1-3

SECTION TWO - PILOT PROCESSES, EQUIPMENT, AND APPROACH

Introduction .............................................................................................................................. 2-1 Overview of Piloted Technologies............................................................................................. 2-1 BAF ............................................................................................................................. 2-1

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Page

CAS with BioMag......................................................................................................... 2-1 MBBR with DAF .......................................................................................................... 2-2 Pilot Equipment ........................................................................................................................ 2-2 Primary Clarifier ........................................................................................................... 2-3

BAF ............................................................................................................................. 2-6 CAS with BioMag......................................................................................................... 2-7 MBBR with DAF .......................................................................................................... 2-8 Piloting Approach ................................................................................................................... 2-10

SECTION THREE PILOT DATA ANALYSIS

Introduction .............................................................................................................................. 3-1 Review of Pilot Testing ............................................................................................................. 3-1

Sample Pilot Loading vs. Constituent Removal Graph.................................................. 3-1 Biological Aerated Filter ........................................................................................................... 3-3

Experimental Plan Summary........................................................................................ 3-4 Data Presentation ........................................................................................................ 3-4 Ability to Meet Pilot Study Effluent Concentration Goals ............................................... 3-6 Load Rate Validation ................................................................................................... 3-6 Hydraulic Stress Testing Performance ....................................................................... 3-17 Concerns with Fats, Oils, and Grease ........................................................................ 3-23 Piloting Observations and Considerations for Full Scale Implementation ................... 3-23

Conventional Activated Sludge with BioMag ........................................................................... 3-25 Experimental Plan Summary...................................................................................... 3-26 Data Presentation ...................................................................................................... 3-26 Ability to Meet Pilot Study Effluent Concentration Goals ............................................. 3-26 Load Rate Validation ................................................................................................. 3-28 Hydraulic Stress Testing Performance ....................................................................... 3-43 Piloting Observations and Considerations for Full Scale Implementation .................... 3-47

Moving Bed Bioreactor with Dissolved Air Floatation .............................................................. 3-50 Experimental Plan Summary...................................................................................... 3-50 Data Presentation ...................................................................................................... 3-50 Ability to Meet Pilot Study Effluent Concentration Goals ............................................. 3-52 Load Rate Validation ................................................................................................. 3-53 Hydraulic Stress Testing Performance ....................................................................... 3-62 Piloting Observations and Considerations for Full Scale Implementation .................... 3-66

Pilot Data Analysis Summary ................................................................................................. 3-68 Experimental Plan Results and Ability to Meet the Treatment Goals ........................... 3-68 Comparison of Effluent Concentrations ...................................................................... 3-68 Vendor Constituent Loading Rate Validation and Potential to Reduce Technology Size ........................................................................................................................... 3-73 Hydraulic Stress Test Summary ................................................................................. 3-74

SECTION FOUR- WASTEWATER DATA AND REVISED FULL SCALE DESIGN CRITERIA

Introduction .............................................................................................................................. 4-1 Wastewater Characterization Program ..................................................................................... 4-1 Recalcitrant Dissolved Organic Nitrogen (rDON) ...................................................................... 4-2 Revised Flows and Loads ........................................................................................................ 4-3 Secondary Treatment Revised Flows Analysis ............................................................. 4-4 Secondary Treatment Revised Loads Analysis ............................................................ 4-5 Upgraded WWTF Effluent Treatment Requirements ................................................................. 4-6

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Page SECTION FIVE - SECONDARY PROCESS RESIZING AND COMPARISON

Introduction .............................................................................................................................. 5-1 Approach ................................................................................................................................. 5-1

Common Elements ...................................................................................................... 5-2 BAF Process ............................................................................................................................ 5-3 Conventional Activated Sludge with BioMag Process ............................................................... 5-5 MBBR with DAF Process ....................................................................................................... 5-12 Cost Comparison ................................................................................................................... 5-13

Capital Cost Comparison ........................................................................................... 5-13 Operation and Maintenance Cost Comparison ........................................................... 5-16 Life Cycle Cost Comparison....................................................................................... 5-16

SECTION SIX - NON-MONETARY EVALUATION FACTORS UPDATE

Introduction .............................................................................................................................. 6-1 Peirce Island WWTF Operators Questionnaire ......................................................................... 6-1 Revised Criteria Evaluation Matrix ............................................................................................ 6-2

Eliminated Phase 1 Evaluation Criteria ........................................................................ 6-2 Added Phase 2 Evaluation Criteria .............................................................................. 6-6 Unchanged Evaluation Criteria .................................................................................... 6-7 Phase 2 Evaluation Criteria ......................................................................................... 6-7

Technology Comparison and Ranking ...................................................................................... 6-7 SECTION SEVEN - DESIGN RECOMMENDATIONS

Secondary Treatment Facilities Design Capacity ...................................................................... 7-1 Design Recommendations ....................................................................................................... 7-1 Recommended next Steps ....................................................................................................... 7-1

LIST OF ATTACHMENTS

ATTACHMENT A PHASE 1 TECHNOLOGY EVALUATION AND FINAL TECHNICAL MEMORANDUM

Volume Two of Two ATTACHMENT B BLUELEAF INCORPORATED PILOT REPORT ATTACHMENT C REVISED FLOW AND LOADING TECHNICAL MEMORANDUM ATTACHMENT D FINAL WASTEWATER CHARACTERIZATION DATA ATTACHMENT E 2007 NPDES PERMIT ATTACHMENT F UPDATED EQUIPMENT/TECHNOLOGY SIZING COST PROPOSALS ATTACHMENT G OPINION OF COSTS ATTACHMENT H BLANK OPERATOR EVALUATION QUESTIONNAIRE ATTACHMENT I EPA JULY 31, 2012 LETTER

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LIST OF FIGURES Page

Figure ES-1. Box Plot of Effluent TSS for All Processes, All Experimental Plans ................................ ES-4 Figure ES-2. Box Plot of Effluent BOD for All Processes, All Experimental Plans ............................... ES-5 Figure ES-3. Box Plot of Effluent TN for All Processes, Experimental Plans-05/06 ............................. ES-6 Figure 2-1. Pilot Process Flow Schematic .......................................................................................... 2-4 Figure 2-2. Pilot Floor Plan ............................................................................................................... 2-5 Figure 2-3. Pilot Primary Clarifier ....................................................................................................... 2-3 Figure 2-4. BAF Pilot Units ................................................................................................................ 2-6 Figure 2-5. CAS with BioMag Aeration Tank ...................................................................................... 2-7 Figure 2-6. CAS with BioMag Clarifier ................................................................................................ 2-8 Figure 2-7. MBBR Aeration Tank ....................................................................................................... 2-9 Figure 2-8. MBBR DAF .................................................................................................................... 2-10 Figure 3-1. Sample Pilot Loading vs. Constituent Removal Graph ..................................................... 3-2 Figure 3-2A. BOD Loading Rate and Removal through Stage 1 BAF .................................................... 3-7 Figure 3-2B. Ammonia Loading Rate and Removal through Stage 1 BAF .......................................... 3-10 Figure 3-2C. Average Daily Effluent Ammonia Through BAF Process ................................................ 3-11 Figure 3-2D. Nitrate Loading Rate and Removal through Stage 2 BAF ............................................... 3-13 Figure 3-2E. Estimated Average Daily Effluent Total Nitrogen Through Stage 2 BAF ......................... 3-15 Figure 3-2F. Stage 1 BAF and Stage 2 BAF Average Daily Effluent TSS ........................................... 3-16 Figure 3-3A. BOD Volumetric Loading Rate and Removal through CAS-BioMag ................................ 3-29 Figure 3-3B. BOD Mass Loading Rate and Removal through CAS-BioMag ....................................... 3-30 Figure 3-3C. Ammonia Volumetric Loading Rate and Removal through CAS-BioMag ......................... 3-33 Figure 3-3D. Ammonia Mass Loading Rate and Removal through CAS-BioMag ................................ 3-34 Figure 3-3E. CAS-BioMag Average Daily Effluent Nitrogen Species ................................................... 3-36 Figure 3-3F. Solids Loading vs. CAS-BioMag Average Daily Clarifier Effluent TSS ............................ 3-39 Figure 3-3G. Surface Overflow Loading vs. CAS-BioMag Average Daily Clarifier Effluent TSS ........... 3-40 Figure 3-3H. CAS-BioMag Mixed Liquor Magnetite:VSS Ratio vs. SVI ............................................... 3-42 Figure 3-3I. CAS-BioMag Effect of Polymer on Settling Times of Mixed Liquor.................................. 3-44

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Page Figure 3-4A. BOD Loading Rate and Removal through MBBR BOD Reactor ...................................... 3-54 Figure 3-4B. Ammonia Loading Rate and Removal through MBBR N1 & N2 Reactors ....................... 3-56 Figure 3-4C. Average Daily Effluent Ammonia Through MBBR-DAF Processes ................................. 3-58 Figure 3-4D. Nitrate Loading Rate and Removal through MBBR DN1 & DN2 Reactors....................... 3-59 Figure 3-4E. MBBR-DAF Average Daily Effluent TSS ........................................................................ 3-61 Figure 3-5A. Sample Box Plot ............................................................................................................ 3-70 Figure 3-5B. Box Plot of Effluent TSS for All Processes, All Experimental Plans ................................. 3-72 Figure 3-5C. Box Plot of Effluent BOD for All Processes, All Experimental Plans ................................ 3-73 Figure 3-5D. Box Plot of Effluent TN for All Processes, Experimental Plans-05/06 .............................. 3-74 Figure 5-1. BAF Total Nitrogen < 8 mg/l Process Flow Schematic ...................................................... 5-6 Figure 5-2. BAF Total Nitrogen < 8 mg/l Site Layout .......................................................................... 5-7 Figure 5-3. CAS with BioMag Total Nitrogen < 8 mg/l Process Flow Schematic ................................. 5-9 Figure 5-4. CAS with BioMag Total Nitrogen < 8 mg/l Site Layout .................................................... 5-10 Figure 5-5. MBBR with DAF Total Nitrogen < 8 mg/l Process Flow Schematic ................................. 5-13 Figure 5-6. MBBR with DAF Total Nitrogen < 8 mg/l Site Layout ...................................................... 5-14

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LIST OF TABLES

Page Table ES-1. Projected Year 2032 Design Flows and Loads to Secondary..................................... ES-7 Table ES-2. Opinion of Capital Cost Summary ............................................................................. ES-8 Table ES-3. Estimated Annual Operation and Maintenance Costs Summary ................................ ES-9 Table ES-4. Estimated Life Cycle Costs Summary ($MM) ............................................................ ES-9 Table ES-5 Criteria Evaluation Matrix ........................................................................................ ES-11 Table ES-6 Option Evaluation Matrix ......................................................................................... ES-12 Table ES-7. Secondary Treatment Facilities Design Capacity .................................................... ES-13 Table 1-1. Consent Decree Modification Peirce Island WWTF Milestones and Dates .................... 1-3 Table 3-1. BAF Experimental Plan Summary ................................................................................ 3-4 Table 3-2. BAF Experimental Plan Data Result............................................................................. 3-5 Table 3-3. Maximum BOD Concentrations with Primary and Single Stage BAF Treatment To

Meet WWTF Permit Conditions. ................................................................................... 3-8 Table 3-4. BAF Hydraulic Stress Test Summary ......................................................................... 3-18 Table 3-5. CAS-Biomag Experimental Plan Summary................................................................. 3-26 Table 3-6. CAS-BioMag Experimental Plan Data Results ........................................................... 3-27 Table 3-7. Maximum BOD Concentrations with Primary and CAS-BioMag Treatment To Meet

WWTF Permit Conditions .......................................................................................... 3-32 Table 3-8. CAS-BioMaAg Hydraulic Stress Test Summary ......................................................... 3-46 Table 3-9. MBBR-DAF Experimental Plan Summary .................................................................. 3-50 Table 3-10. MBBR-DAF Experimental Plan Data Results ............................................................. 3-51 Table 3-11 Maximum BOD Concentrations with Primary and MBBR-DAF Treatment To Meet WWTF

Permit Conditions ...................................................................................................... 3-55 Table 3-12. MBBR-DAF Hydraulic Stress Test Summary .............................................................. 3-63 Table 3-13. Experimental Plan Summary...................................................................................... 3-69 Table 3-14. Ability to meet Pilot Study Effluent Concentration Goals ............................................. 3-68 Table 3-15. Pilot Technology Effluent TSS Concentration ANOVA Analysis .................................. 3-71 Table 3-16. Pilot Technology Effluent BOD Concentration ANOVA Analysis ................................ 3-71

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Page Table 3-17. Pilot Technology Effluent TN Concentration ANOVA Analysis .................................... 3-72 Table 3-18. Vendor Constituent Loading Rate Validation Summary ............................................. 3-75 Table 4-1. Sampling and Analysis Summary ................................................................................. 4-1 Table 4-2. Final Average Wastewater Characterization Results .................................................... 4-2 Table 4-3. Peirce Island Raw Wastewater rDON Test Data .......................................................... 4-3 Table 4-4. Secondary Treatment Process Design Flow Rates....................................................... 4-5 Table 4-5. Projected Year 2032 Design Flows and Loads to Secondary........................................ 4-6 Table 4-6. 2007 Peirce Island WWTF NPDES Permit Limits ......................................................... 4-7 Table 5-1. CAS-BioMag Bioreactor and Clarifier Dimensions ........................................................ 5-5 Table 5.2. MBBR Bioreactor Dimensions .................................................................................... 5-11 Table 5-3. Total Nitrogen < 8 mg/L Opinion of Capital Cost Summary ........................................ 5-15 Table 5-4. Estimated Annual Operation and Maintenance Costs Summary ................................. 5-15 Table 5-5. Estimated Life Cycle Costs Summary ($MM) ............................................................. 5-16 Table 6-1. Portsmouth WWTF Operator Pilot Evaluation ............................................................... 6-3 Table 6-2. Portsmouth WWTF Operator Pilot Evaluation by Category ........................................... 6-4 Table 6-3. Criteria Evaluation Matrix ............................................................................................. 6-9 Table 6-4. Option Evaluation Matrix ............................................................................................ 6-10 Table 7-1. Secondary Treatment Facilities Design Capacity .......................................................... 7-1

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LIST OF ABBREVIATIONS

ANOVA Analysis of Variance BAF Biologically Aerated Filter BDL Below Detection Limit BOD Biochemical Oxygen Demand C Celsius Cf Cubic Foot CaCO3 Calcium Carbonate CAS Conventional Activated Sludge CAS-BioMag Conventional Activated Sludge with BioMag CASB Conventional Activated Sludge with BioMag CEPT Chemically Enhanced Primary Treatment CSO Combine Sewer Overflow COD Chemical Oxygen Demand C/N Carbon and Nitrification Removal CWT Cambridge Water Technologies DAF Dissolved Air Floatation DN Denitrification DN1 Denitrification Reactor Tank 1 DN2 Denitrification Reactor Tank 2 DO Dissolved Oxygen DPE Diluted Strength, Peak Flow, Extended Duration Trial EP Experimental Plan EPA Environmental Protection Agency F/M Food to Microorganism Ratio FMS Full Strength, Mid Flow, Short Duration Trial FOG Fats, Oils, and Grease FPS Full Strength, Peak Flow, Short Duration Trial FPM Full Strength, Peak Flow, Medium Duration Trial Ft Feet FXM Full Strength, High-Peak Flow, Medium Duration Trial FXE Full Strength, High-Peak Flow, Extended Duration Trial gpm Gallons per Minute gpm/sf Gallons per Minute per Square Foot (of surface area) gpd Gallons per Day g Gram I&C Instrumentation and Control IR Internal Recycle Rate Hr Hour L Liter Lab Laboratory Lb Pound LTCP Long Term Control Plan MBBR Moving Bed Bioreactor mg Milligram MG Million Gallons MGD Million Gallons per Day

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mg/l Milligrams per liter (equivalent to ppm) min Minutes ML Mixed Liquor MLE Modified Ludzack-Ettinger MLSS Mixed Liquor Suspended Solids MLVSS Mixed Liquor Volatile Suspended Solids MBR Membrane Bioreactor MOR Monthly Operating Report mV Millivolt N Nitrogen N1 Nitrification Reactor Tank 1 N2 Nitrification Reactor Tank 2 NA Not Applicable NOx Nitrogen Oxides NO3 Nitrate NR1 Nitrification Reactor Tank 1 NR2 Nitrification Reactor Tank 1 NH3 Ammonia NHDES New Hampshire Department of Environmental Services

g/L Micrograms per liter (equivalent to ppb) N/A Not Available / Not Applicable ND Not Detected O&M Operation and Maintenance ORP Oxidation Reduction Potential PID Proportional Integral Derivative ppb Parts per Billion ppm Parts per Million R2 Coefficient of Determination RAS Return Activated Sludge rDOM Recalcitrant Dissolved Organic Nitrogen SALR Surface Area Loading Rate SARR Surface Area Removal Rate SBR Sequencing Batch Reactor Sf Square Foot SLR Solids Loading Rate SOR Surface Overflow Rate SRT Solids Retention Time SVI Sludge Volume Index TKN Total Kjehldahl Nitrogen TN Total Nitrogen TP Total Phosphorus PO4-P Phosphate TSS Total Suspended Solids uM Micrometer VSS Volatile Suspended Solids WAS Waste Activated Sludge WWMP Wastewater Master Plan WWTF Wastewater Treatment Facility

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ACKNOWLEDGMENTS

We would like to acknowledge the invaluable assistance and cooperation of the staff of the Portsmouth Department of Public Works and the Peirce Island WWTF. In particular, we extend our thanks to Mr. David Allen, Assistant City Manager; Mr. Peter Rice, Deputy Director of Public Works; Mr. Terry Desmarais, City Engineer; Ms. Paula Anania, WWTF Chief Plant Operator; Mr. Michael Baker, WWTF Assistant Chief Plant Operator; Mr. David Lovely, Assistant Chief Plant Operator; and Ms. Roxanna Chomas, Plant Operator. This Technical Memorandum was prepared by Mr. Matthew Formica, Project Manager, and Mr. Jon Pearson Project Manager and Vice President, under the direction of Donald Chelton, Vice President. Technical review and guidance was Provided by Mr. Mark Laquidara, Vice President. The Cover Photos are used under Creative Commons Public License from Doug Kerr; and the project consulting team.

ATTACHMENT B

BLUELEAF INCORPORATED PILOT REPORT

PILOT STUDY REPORT WASTEWATER MASTER PLAN PILOTING EFFORT

PHASE 2 INITIAL PILOT PHASE

PORTSMOUTH NH PEIRCE ISLAND WASTEWATER TREATMENT FACILITY

SEPTEMBER 2012

Submitted by: Blueleaf, Inc.

57 Dresser Hill Road Charlton MA 01507

For: AECOM 701 Edgewater Drive

Wakefield, MA 01880

Date: September 14, 2012

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EXECUTIVESUMMARY

ThisPilotStudyReportdetailstheapproach,equipment,analyticalandexperimentalmethods,andresultsofapilotstudycompletedattheCityofPortsmouthsPeirceIslandWastewaterTreatmentFacilitybetweenAugust2011,andAugust2012.TheworkwascompletedunderthedirectionofAECOMaspartoftheWastewaterMasterPlanPhase2,InitialPilotingEvaluation.In2011,AECOMbeganawastewatercharacterizationstudy,completedadesktopevaluationofeightpotentialtreatmentprocesses,andselectedthreeprocessesforaninitialsixmonthpilotscaleevaluation.

Thethreewastewatertreatmentprocessesthatwerepilotedinparallelwere:BiologicalAeratedFilter(BAF),MovingBedBioreactor(MBBR)withDissolvedAirFlotation(DAF),andConventionalActivatedSludgewithaproprietaryballastedprocessmarketedasBioMag(CASB).TheintentionoftheinitialphaseofpilotinginPhase2wastodevelopdatatochooseoneofthethreeprocessesforfurtherpiloting,Vendorselection,orpreliminarydesign.AdditionalpilottestingmaybeundertakeninasecondpilotingphasetocomparecompetingVendorsofthetechnology,toallowtheselectionofaVendorfortheupgradeofthePeirceIslandWWTF,ortoprovideoperationalexperienceforthePortsmouthwastewatertreatmentplantoperators,buttheadditionaltestingisnotdescribedinthisdocument.

Thepilotscaletestingequipmentwasdesignedbasedonsizinginformationprovidedbytheprocessvendors,typicalengineeringpractice,theexperienceofthepilotoperators,andthelimitsofthebudgetandschedule.Thepilotequipmentconsistedofaprimaryclarifier,MovingBedBioreactor,andConventionalActivatedSludgereactiontankandclarifiers,andnecessaryappurtenantequipment,allconstructedonsite.TheDissolvedAirFlotationequipment,andBiologicalAeratedFilterswereprovidedbytheequipmentvendor,andappurtenantequipmentwasaddedtothefilteronsite.Thepilotequipmentoperatedeachprocessatbetween3gallonsperminuteand28gallonsperminute.

Onsitetestingfoundthattheinfluentorganicsconcentrationwashigherthanhadbeenexpected,andthattheinfluentnitrogenconcentrationwasslightlylowerthanexpected.Inmostcases,theflowratesintothepilotprocessesweredecreasedtohandletheincreasedorganicloadings,andsupplementalammoniawasaddedtotheinfluentstreamtomimicthedesignnitrogenloading.

Atotalof26plannedexperimentswereconductedontheprocesses.

Fiveoftheexperimentsfocusedonmeetingthesecondarytreatmentgoalof30mg/LBODand30mg/LofTSS.Twoofthefiveexperiments(ExperimentalPlan01)wereconductedatanaveragemonthloadcondition,andthree(ExperimentalPlan02)wereconductedunderamaximummonthloadcondition.AllthreeprocesseswereabletomeetthetreatmentgoalsforSecondaryTreatmentundertheappropriateorganicloading.

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Twoexperiments(ExperimentalPlan03)achievedTotalNitrogenremovaltobelow8mg/Lwiththeambientconcentrationofammoniaintherawwater.TheCASBandMBBR/DAFprocessesweresuccessfulinproducingeffluenttotalnitrogenconcentrationbelow8mg/L.TheBiologicalAeratedFilterwasnottestedwiththeambientnitrogenconcentration.

Threeexperiments(ExperimentalPlan05)evaluatedthethreeprocessesfortotalnitrogenremovaltobelow8mg/Lwithanincreasednitrogenconcentrationintheinfluentstream.TheBiologicalAeratedFiltereffluenttotalnitrogenaveraged4.9mg/L.TheConventionalActivatedSludgewithBioMagprocesseffluentTotalNitrogenconcentrationaveraged5.8mg/L,andtheMovingBedBioreactorandDAFprocesseffluentTotalNitrogenaveraged5.3mg/L.

Twoexperiments(ExperimentalPlan06)includedtheconversionoftheConventionalActivatedSludgewithBioMagprocessandtheMovingBedBioreactorprocessintoalternatelayoutsthatcouldachieveeffluenttotalnitrogenconcentrationsoflessthan3mg/L.TheconversionoftheBiologicalAeratedFilterwasnotnecessary,astheconfigurationfortotalnitrogenremovaltobelow3isthesameasthetotalnitrogentobelow8.Noneoftheprocessesreliablyproducedeffluenttotalnitrogenbelow3mg/L.TheBiologicalAeratedFiltereffluenttotalnitrogenaveraged4.9mg/L.TheConventionalActivatedSludgewithBioMagprocesseffluenttotalnitrogenconcentrationaveraged4.2mg/L,andtheMovingBedBioreactorandDAFprocesseffluentTotalNitrogenaveraged5.1mg/L.Additionaltimemayhavebeenrequiredtooptimizetheprocesses,ortoacclimatethemediaforlowereffluenttotalnitrogenconcentrations.

Fourteenexperiments(ExperimentalPlan04)wereconductedtoevaluatetheprocessesatavarietyofhighflowconditions.Thestresstestsweredesignedtomimichighfloweventsinthebiologicalprocesses,andtoevaluatetreatmentperformance,solidsretentionandrecoverytime.NoneofthehighstressconditionscausedtheConventionalActivatedSludgewithBioMagprocesseffluenttoexceedTSSof30mg/Lortotalnitrogenof8mg/L.BoththeBiologicalAeratedFilterandtheMovingBedBioreactorexceededtotalnitrogenlimitof8duringmostofthehighstressconditions,butgenerallyrecoveredwithinfourhoursaftertheflowconditionwasstopped.Itisdifficulttodirectlycomparetheresultsofthehydraulicstresstests,however,aseachprocessexperiencedadifferentflowcondition.Forinstance,theflowratethroughtheConventionalActivatedSludgewithBioMagprocesswasdoubledtoachievethepeakflowrates,whiletheflowratethroughtheBiologicalAeratedFilterwasincreasedbyafactorof3,andthen6.Noneoftheprocessesappearedtolosebiosolidsasaresultoftheincreasedflowrates.

Datawasalsocollectedthroughoutthepilottestingperiodtoevaluatetheloadingcapacityofeachprocess.Thepilotoperatorsalsomadecarefulobservationsonseveralfactorsofeachprocesstoprovideinformationontheoperability,robustness,advantagesanddisadvantagesofeachprocess,andondesignissuesthatshouldbeevaluatedforthefullscaledesign.

ThisPilotStudyReportdoesnotincludearecommendedprocessforfullscaleapplication.Insteaditisintendedtobeusedbythedesignengineertoevaluatetheperformanceandlimitationsofeachprocessthatwasevaluated.

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TABLEOFCONTENTSEXECUTIVESUMMARY...................................................................................................................................i

TABLEOFCONTENTS....................................................................................................................................iii

LISTOFTABLES.............................................................................................................................................vi

LISTOFFIGURES...........................................................................................................................................ix

LIMITATIONS...............................................................................................................................................xii

RESPONSIBILITIES........................................................................................................................................xiii

ABBREVIATIONS..........................................................................................................................................xv

1 INTRODUCTION.....................................................................................................................................1

2 METHODSANDMATERIALS..................................................................................................................3

2.1 PilotEquipmentdescription,General...........................................................................................3

2.1.1 CityWater.............................................................................................................................7

2.1.2 RawWaterSupply.................................................................................................................7

2.1.3 SiteBuiltTankConstructionforClarifiers,Bioreactors,andSumps....................................7

2.1.4 PrimaryClarifier....................................................................................................................8

2.2 PilotEquipmentDescription,BiologicalAeratedFilter...............................................................13

2.2.1 FullScaleBAFSystems........................................................................................................13

2.2.2 PilotScaleBAFSystem........................................................................................................14

2.3 PilotEquipmentdescription,ConventionalActivatedSludgewithBioMag...............................17

2.3.1 ProposedFullScaleCASBDesign........................................................................................17

2.3.2 PilotScaleCASBDesign.......................................................................................................18

2.4 PilotEquipmentDescription,MBBRandDAF.............................................................................26

2.4.1 MBBR...................................................................................................................................26

2.4.2 DAF......................................................................................................................................36

2.5 ChemicalAddition.......................................................................................................................41

2.6 StatisticalMethods.....................................................................................................................43

2.7 AnalyticalMethods.....................................................................................................................47

2.7.1 FieldAnalyticalMethods.....................................................................................................47

2.7.2 LaboratoryMethods...........................................................................................................50

2.7.3 QualityAssurance/QualityControl.....................................................................................50

2.8 ExperimentalPlans......................................................................................................................60

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3 RESULTS..............................................................................................................................................62

3.1 RawWaterQuality......................................................................................................................62

3.1.1 RawWaterQualityFieldData.............................................................................................62

3.1.2 PilotRawWaterQualityDatavs.MORDataforJanuaryAugust2012..............................72

3.1.3 ComparisonofMORRawWaterQualityDatafor2012vs.20082011..............................76

3.2 ChemicalFeedRatesforAlkalinityAdjustment..........................................................................78

3.3 PrimaryClarifierWaterQualityandRemovalRates...................................................................80

3.3.1 PrimaryEffluentWaterQualityData..................................................................................80

3.3.2 PrimaryClarifierPerformance............................................................................................89

3.4 WaterQualityCOD:BODRatios..................................................................................................96

3.4.1 RawWater(PilotPlantInfluent)COD:BODRatio...............................................................96

3.4.2 PilotPlantPrimaryEffluentCOD:BODRatio.......................................................................96

3.5 BiologicalAeratedFilterResults.................................................................................................99

3.5.1 ScheduleofBAFExperiments.............................................................................................99

3.5.2 Results...............................................................................................................................101

3.5.3 ExperimentalPlanResults.................................................................................................128

3.5.4 HydraulicStressResults,BAFExperimentalPlan04.........................................................135

3.5.5 BODRemovalRates..........................................................................................................182

3.5.6 AmmoniaRemovalCapacity.............................................................................................182

3.5.7 NitrateRemovalCapacity.................................................................................................182

3.6 ConventionalActivatedSludgewithBioMag............................................................................187

3.6.1 ScheduleofConventionalActivatedSludgewithBioMag(CASB)Experiments...............187

3.6.2 Results...............................................................................................................................190


3.6.4 StressTrialResults,ResultsofExperimentalTrial04.......................................................242

3.6.5 BODRemovalRates..........................................................................................................261



3.7 MBBRandDAFResults..............................................................................................................269

3.7.1 ScheduleofMBBRandDAFExperiments.........................................................................269

3.7.2 Results...............................................................................................................................272


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3.7.4 StressTrialResults,ResultsofExperimentalTrial04.......................................................323

3.7.5 MediaMassCalculations..................................................................................................354

3.7.6 BODRemovalCapacity......................................................................................................355



3.7.9 DAFOperationandPerformance......................................................................................359

4 Summary...........................................................................................................................................362

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LISTOFTABLESTable2.101:PrimaryClarifierDimensions................................................................................................11Table2.102:ProposedFullScaleBAFDesignParameters........................................................................13Table2.103:ProposedPilotScaleBAFOperatingParameters.................................................................14Table2.104:CASB(BioMag)BioreactorDesignParameters.....................................................................17Table2.105:CASBSecondaryClarifierDesignParameters.......................................................................18Table2.106:CASBProposedPilotScaleBioreactorDesignParameters...................................................23Table2.107:CASBProposedPilotScaleClarifierDesignParameters.......................................................23Table2.108:MBBRDesignParametersperWorldWaterWorks,for30/30TreatmentOption..............27Table2.109:MBBRDesignParametersperWorldWaterWorks,forTN

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Table3.509:BAFExperimentalPlan04FPMSummaryofANOVAResults..........................................152Table3.510a:WaterQualityResultsforBAFExperimentalPlan04FPM...............................................156Table3.510b:WaterQualityResultsforBAFExperimentalPlan04FPM...............................................157Table3.510b:WaterQualityResultsforBAFExperimentalPlan04FPM...............................................158Table3.511:BAFExperimentalPlan04DPESummaryofANOVAResults...........................................160Table3.512a:WaterQualityResultsforBAFExperimentalPlan04DPE................................................164Table3.512b:WaterQualityResultsforBAFExperimentalPlan04DPE................................................165Table3.512b:WaterQualityResultsforBAFExperimentalPlan04DPE................................................166Table3.513:BAFExperimentalPlan04FXMSummaryofANOVAResults..........................................167Table3.514a:WaterQualityResultsforBAFExperimentalPlan04FXM...............................................171Table3.514b:WaterQualityResultsforBAFExperimentalPlan04FXM...............................................172Table3.515:BAFExperimentalPlan04FXESummaryofANOVAResults...........................................176Table3.516a:WaterQualityResultsforBAFExperimentalPlan04FXE.................................................177Table3.516b:WaterQualityResultsforBAFExperimentalPlan04FXE................................................178Table3.516c:WaterQualityResultsforBAFExperimentalPlan04FXE.................................................179Table3.516d:WaterQualityResultsforBAFExperimentalPlan04FXE................................................180Table3.516e:WaterQualityResultsforBAFExperimentalPlan04FXE................................................181Table3.601:CASBTrialSchedule............................................................................................................187Table3.602:ConventionalActivatedSludgewithBioMagDataReport.................................................192Table3.603:ResultsforCASBExperimentalTrial01...............................................................................227Table3.604:ResultsforCASBExperimentalTrial02...............................................................................230Table3.605:ResultsforCASBExperimentalTrial03...............................................................................233Table3.606:LaboratoryResultsforDissolvedContaminantsfromCASBExperimentalTrial03...........235Table3.607:ResultsforCASBExperimentalTrial05...............................................................................237Table3.608:ResultsforCASBExperimentalTrial06...............................................................................240Table3.608CASBExperimentalPlan04FMSSummaryofANOVAResults.........................................243Table3.609:WaterQualityResultsforCASBExperimentalPlan04FMS...............................................246Table3.609CASBExperimentalPlan04FPSSummaryofANOVAResults..........................................247Table3.610a:WaterQualityResultsforCASBExperimentalPlan04FPS...............................................250Table3.610b:WaterQualityResultsforCASBExperimentalPlan04FPS..............................................251Table3.611CASBExperimentalPlan04FPMSummaryofANOVAResults.........................................252Table3.612a:WaterQualityResultsforCASBExperimentalPlan04FPM.............................................255Table3.612b:WaterQualityResultsforCASBExperimentalPlan04FPM.............................................256Table3.613CASBExperimentalPlan04DPESummaryofANOVAResults..........................................257Table3.614:WaterQualityResultsforCASBExperimentalPlan04DPE................................................260Table3.614:SettlingDataforConventionalActivatedSludgewithBioMag..........................................266Table3.701:MBBRandDAFTrialSchedule............................................................................................269Table3.702:MBBRandDAFDataReport................................................................................................275Table3.703:ResultsforExperimentalPlan01onMBBRandDAF..........................................................307Table3.704:ResultsforExperimentalTrial02onMBBRandDAF..........................................................312Table3.705:ResultsforExperimentalTrial03onMBBRandDAF..........................................................316Table3.706:LaboratoryResultsforMBBR/DAFExperimentalTrial03..................................................316

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Table3.707:ResultsforExperimentalTrial05onMBBRandDAF..........................................................319Table3.708:ResultsforExperimentalTrial06onMBBRandDAF..........................................................322Table3.709:MBBR/DAFExperimentalPlan04FMSSummaryofANOVAResults..............................324Table3.710a:WaterQualityResultsforMBBR/DAFExperimentalPlan04FMS....................................329Table3.710b:WaterQualityResultsforMBBR/DAFExperimentalPlan04FMS(continued)................330Table3.710c:WaterQualityResultsforMBBR/DAFExperimentalPlan04FMS(continued)................331Table3.711:MBBR/DAFExperimentalPlan04FPSSummaryofANOVAResults................................332Table3.712a:WaterQualityResultsforMBBR/DAFExperimentalPlan04FPS.....................................335Table3.712b:WaterQualityResultsforMBBR/DAFExperimentalPlan04FPS(continued).................336Table3.712c:WaterQualityResultsforMBBR/DAFExperimentalPlan04FPS(continued).................337Table3.712d:WaterQualityResultsforMBBR/DAFExperimentalPlan04FPS(continued).................338Table3.713:MBBR/DAFExperimentalPlan04FPMSummaryofANOVAResults..............................339Table3.714a:WaterQualityResultsforMBBR/DAFExperimentalPlan04FPM...................................342Table3.714b:WaterQualityResultsforMBBR/DAFExperimentalPlan04FPM(continued)...............343Table3.714c:WaterQualityResultsforMBBR/DAFExperimentalPlan04FPM(continued)................344Table3.715:MBBR/DAFExperimentalPlan04DPESummaryofANOVAResults...............................345Table3.716a:WaterQualityResultsforMBBR/DAFExperimentalPlan04DPE....................................349Table3.716b:WaterQualityResultsforMBBR/DAFExperimentalPlan04DPE(continued)................350Table3.716c:WaterQualityResultsforMBBR/DAFExperimentalPlan04DPE(continued).................351Table3.716d:WaterQualityResultsforMBBR/DAFExperimentalPlan04DPE(continued)................352Table3.716e:WaterQualityResultsforMBBR/DAFExperimentalPlan04DPE(continued)................353Table3.717:MediaMassResults............................................................................................................354Table3.718:MBBRDAFPolymerdoses..................................................................................................361

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LISTOFFIGURESFigure2.101:PilotPlantPhysicalLayout.....................................................................................................5Figure2.102PilotPlantFlowSchematic......................................................................................................6Figure2.103:PrimaryClarifierPlanandSections........................................................................................9Figure2.104:BAFPilotSystemSchematic................................................................................................16Figure2.105:CASBBioreactorPlanandSections......................................................................................24Figure2.106:CASBBioreactorandClarifierSections................................................................................25Figure2.107:MBBRPlanandSections......................................................................................................39Figure2.108:MBBRSections,DAFPlanandSections...............................................................................40Figure2.701:ComparisonofLabandFieldAnalysesforTSS....................................................................52Figure2.702:ComparisonofFieldandLabBODResults...........................................................................55Figure2.703:ComparisonofFieldandLabAmmoniaResults..................................................................56Figure2.704:ComparisonofFieldandLabTotalNitrogenResults..........................................................58Figure2.705:AnalysisofNitrateStandardsbyFieldMethods..................................................................59Figure3.101:RawWaterQualityFieldDataforTSSandTotalBOD........................................................69Figure3.102:BoxplotofDifferencesforDirectlyAnalyzed5DayBODsvs.CalculatedBODs..................72Figure3.103:ComparisonofPilotDatatoMORDataJanAug2012,forRawWaterTSS........................73Figure3.104:ComparisonofPilotDatatoMORDataJanAug2012,forRawWaterTotalBOD.............74Figure3.105:RawWaterTSSfor2012vs.20082011fromMORData....................................................77Figure3.106:RawWaterTotalBODfor2012vs.20082011fromMORData.........................................77Figure3.201:SodaAshTitrationsforPrimaryEffluentAlkalinityControl................................................79Figure3.301:PrimaryTSSandTotalBODData.........................................................................................88Figure3.302:PilotPrimaryClarifierPerformance:InfluentTSSvs.EffluentTSS......................................90Figure3.303:PilotPrimaryClarifierPerformance:InfluentBOD(t)vs.EffluentBOD(t)...........................91Figure3.304:CEPTInfluentTSSvs.CEPTEffluentTSS..............................................................................93Figure3.305:CEPTInfluentBOD(t)vs.CEPTEffluentBOD(t)....................................................................93Figure3.306:PilotPrimaryEffluentvs.HistoricalCEPTEffluentforTSS..................................................94Figure3.307:PilotPrimaryEffluentvs.HistoricalCEPTEffluentforTotalBOD........................................95Figure3.401:RawWaterCOD(t)versusBOD(t)........................................................................................97Figure3.402:PrimaryEffluentCOD(t)versusBOD(t)................................................................................98Figure3.501:ResultsfromExperimentalTrial02BAFStage1.............................................................129Figure3.502:BoxplotofBAFExperimentalPlan02Results....................................................................130Figure3.503:ResultsfromExperimentalTrial05/06BAFStage#1......................................................132Figure3.504:ResultsfromExperimentalTrial05/06BAFStage#2......................................................133Figure3.505:BoxplotofBAFExperimentalPlan05/06Results..............................................................135Figure3.506:EffectofBAFStage#1RuntimeonEffluentTSS................................................................136Figure3.507:BAF#1FMS|2hour,MediumFlowStressTest................................................................137Figure3.508:BAF#2FMS|2hour,MediumFlowStressTest................................................................139Figure3.509:BoxPlotsBAFFMSStressTest,TSSandCOD.....................................................................145Figure3.510:BoxplotsBAFFMSStressTest,Ammonia,NOx,andTN....................................................145

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Figure3.511:BAF#1FPS|2hour,PeakFlowStressTest.......................................................................147Figure3.512:BAF#2FPS|2hour,PeakFlowStressTest.......................................................................148Figure3.513:BoxplotsforBAFFPSStressTest,TSSandCOD................................................................149Figure3.514:BoxplotsforBAFFPSStressTest,Ammonia,NOx,andTN...............................................149Figure3.515:BAF#1FPM|2hour,PeakFlowStressTest......................................................................153Figure3.516:BAF#2FPM|2hour,PeakFlowStressTest......................................................................154Figure3.517:BoxplotsforBAFFPMStressTest,TSSandCOD..............................................................155Figure3.518:BoxplotsforBAFFPMStressTest,....................................................................................155Figure3.519:BAF#1DPE|24hour,PeakFlowStressTest,Diluted.......................................................161Figure3.520:BAF#2DPE|24hour,PeakFlowStressTest,Diluted.......................................................162Figure3.521:BoxplotsforBAFDPEStressTest,TSSandCOD...............................................................163Figure3.522:BoxplotsforBAFFPSStressTest,Ammonia,NOx,andTN...............................................163Figure3.523:BAF#1FXM|6hour,HighPeakFlowStressTest.............................................................168Figure3.524:BAF#2FXM|6hour,HighPeakFlowStressTest.............................................................169Figure3.525:BoxplotsforBAFFXMStressTest,TSSandCOD..............................................................170Figure3.526:BoxplotsforBAFFXMStressTest,Ammonia...................................................................170Figure3.527:BAF#1FXE|24hour,HighPeakFlowStressTest.............................................................174Figure3.528:BAF#2FXE|24hour,HighPeakFlowStressTest.............................................................175Figure3.529:BoxplotsforBAFFXEStressTest,TSSandCOD................................................................176Figure3.530:BAFStage#1OperationatPeirceIslandPilotStudy.........................................................183Figure3.531:BODLoadingRatesandRemovalthroughBAFStage#1...................................................184Figure3.532:AmmoniaLoadingandRemovalthroughBAFStage#1....................................................185Figure3.533:NitrateLoadingandRemovalthroughBAFStage#2........................................................186Figure3.601:ResultsofCASBExperimentalTrial01...............................................................................228Figure3.602:BoxplotofCASBResultsforExperimentTrial01...............................................................229Figure3.603:ResultsofCASBExperimentalTrial02...............................................................................231Figure3.604:BoxplotofCASBExperimentalPlan02Results.................................................................232Figure3.605:ResultsofCASBExperimentalTrial03...............................................................................234Figure3.606:BoxplotofCASBExperimentalPlan03Results.................................................................235Figure3.607:ResultsofCASBExperimentalTrial05...............................................................................238Figure3.608:BoxplotofCASBExperimentalPlan05Results.................................................................239Figure3.609:ResultsofCASBExperimentalTrial06...............................................................................241Figure3.610:BoxplotofCASBExperimentalPlan06Results.................................................................242Figure3.611:CASBFMS|2hour,MediumFlowStressTest..................................................................244Figure3.612:BoxPlotsCASBFMSStressTest,TSSandCOD...................................................................245Figure3.613:BoxplotsCASBFMSStressTest,Ammonia,NOx,andTN..................................................245Figure3.614:CASBFPS|2hour,PeakFlowStressTest.........................................................................248Figure3.615:BoxPlotsCASBFPSStressTest,TSSandCOD....................................................................249Figure3.616:BoxplotsCASBFPSStressTest,Ammonia,NOx,andTN...................................................249Figure3.617:CASBFPM|6hour,PeakFlowStressTest.......................................................................253Figure3.618:BoxPlotsCASBFPMStressTest,TSSandCOD...................................................................254Figure3.619:BoxplotsCASBFPMStressTest,Ammonia,NOx,andTN..................................................254

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Figure3.620:CASBDPE|24hour,PeakFlowStressTest,Diluted.........................................................258Figure3.621:BoxPlotsCASBDPEStressTest,TSSandCOD....................................................................259Figure3.622:BoxplotsCASBDPEStressTest,Ammonia,NOx,andTN..................................................259Figure3.623:BODLoadingRatesandRemovalthroughCASB...............................................................262Figure3.624:AmmoniaLoadingandRemovalthroughCASB.................................................................263Figure3.625:SDNRRemovalthroughCASB............................................................................................264Figure3.625:EffectofPolymeronSettlingTimesofMixedLiquor........................................................267Figure3.626:RelationshipbetweenSVIandMagnetiteConcentration.................................................268Figure3.701:ResultsfromExperimentalTrial01MBBRandDAF.......................................................308Figure3.702:BoxplotofExperimentalPlan01Results,MBBRandDAF................................................309Figure3.703:ResultsfromExperimentalTrial02MBBRandDAF........................................................311Figure3.704:AccumulatedSolidsinDAFEffluentPipingonMarch28,2012........................................312Figure3.705:BoxplotofExperimentalPlan02Results,MBBRandDAF................................................313Figure3.706:ResultsfromExperimentalTrial03MBBRandDAF........................................................315Figure3.707:BoxplotofExperimentalPlan03Results,MBBRandDAF................................................317Figure3.708:ResultsfromExperimentalTrial05MBBRandDAF........................................................318Figure3.709:BoxplotofExperimentalPlan05Results,MBBRandDAF................................................320Figure3.710:ResultsfromExperimentalTrial06MBBRandDAF........................................................321Figure3.711:BoxplotofExperimentalPlan06Results,MBBRandDAF................................................322Figure3.712:ResultsfromExperimentalTrial02MBBRandDAF........................................................326Figure3.713:BoxplotofMBBRandDAFExperimentalPlan04FMSResults,TSSandCOD...................327Figure3.714:BoxplotofMBBR/DAFExperimentalPlan04FMSResults,Ammonia,NOxadndTNandNOx...........................................................................................................................................................328Figure3.715:MBBRFPS|2Hour,PeakFlowStressTest.......................................................................333Figure3.716:BoxplotofMBBR/DAFExperimentalPlan04FPSResults,TSSandCOD...........................334Figure3.717:BoxplotofMBBR/DAFExperimentalPlan04FPSResults,Ammonia,TNandNOx..........334Figure3.718:MBBRFPM|6Hour,PeakFlowStressTest......................................................................340Figure3.719:BoxplotofMBBR/DAFExperimentalPlan04FPMResults,TSSandCOD.........................341Figure3.720:BoxplotofMBBR/DAFExperimentalPlan04FPMResults,Ammonia,NOx,andTN........341Figure3.721:MBBRDPE|24hour,PeakFlow,DilutedInfluent............................................................347Figure3.722:BoxplotofMBBR/DAFExperimentalPlan04DPEResults,TSSandCOD..........................348Figure3.723:BoxplotofMBBR/DAFExperimentalPlan04DPEResults,Ammonia,NOx,andTN.........348Figure3.724:MediaMassontheMBBRMedia......................................................................................354Figure3.725:BODRemovalthroughMBBRBODReactor.......................................................................356Figure3.726:AmmoniaRemovalthroughMBBRNR1&NR2Reactor......................................................357Figure3.727:NitrateRemovalthroughMBBRDN1&DN2Reactors.......................................................358Figure4.101:FrequencyDistributionforRawWaterBODEstimates....................................................363Figure4.102:BoxplotofEffluentTSSLaboratoryResultsforAllProcesses,AllExperimentalPlans......365Figure4.102:BoxplotofEffluentBODLaboratoryResultsforAllProcesses,AllExperimentalPlans....366Figure4.104:BoxplotofEffluentTNLaboratoryResultsforAllProcesses,AllExperimentalPlans.......368

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LIMITATIONSThispilottestreportwaspreparedforAECOMandtheCityofPortsmouth,forthepurposeofevaluatingtreatmenttechnologiesforremovingtotalnitrogenfromwastewateratthePeirceIslandWastewaterTreatmentFacilityinPortsmouth,NH.Thefindingsprovidedinthisreportarebasedsolelyontheinformationcontainedandreferencedherein.AlltheoriginalfielddataandlaboratorydatathatarepresentedhereinasResultswerecollectedduringonsiteinvestigations.Allfieldoperations,fieldanalyses,datacompilationandreporting,dataanalysisandreportingwerecompletedinafairandimpartialmannerandareintendedtobeanaccuraterepresentationoftreatmentperformance.Additionalquantitativeinformationregardingtherawwastewater,orothertreatmentgoalsandconcernsthatwerenotavailabletoBlueleaf,Inc.atthetimeofthepilotstudymayresultinmodificationofthestatedfindings.Notethatpilotscalestudiesmaynotidentifyissuesarisingfromlongtermchangestorawwaterquality,norpredictlongtermperformanceofthetreatmentprocessestested.

Thisreporthasbeenpreparedandsubmittedinconfidenceandistobeusedsolelyforthepurposeforwhichitisfurnished.Thisdocumentandsuchinformationisnottobereproduced,transmitted,disclosedorusedotherwiseinwholeorinpartwithoutthewrittenauthorizationofBlueleafIncorporated.

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RESPONSIBILITIESCityofPortsmouthDepartmentofPublicWorks680PeverlyHillRoad,Portsmouth,NH03801Maintainsthemunicipalinfrastructurethatincludesallstreets,parks,municipalbuildings,thewatersystem,andthesanitarysewercollectionandtreatmentsystem. PeterRice,P.E.,DeputyDirector (603)4271530 TerryDesmarais,P.E.,CityEngineerCityofPortsmouthDPWSewerDivision200PeirceIslandRoad,Portsmouth,NH03801OperatesthePeirceIslandandPeaseWastewaterTreatmentFacilities PaulaAnania,ChiefPlantOperator (603)4271553 MichaelBaker,AssistantChiefPlantOperator DavidLovely,AssistantChiefPlantOperator RoxannaChomas,PeasePlantOperator (603)8177611AECOM701EdgewaterDrive,Wakefield,MA01880ConsultingEngineerfortheCityofPortsmouth. DonChelton,P.E.,VPandPrincipalInCharge (781)2465200 JonPearson,P.E.VPandProjectManager MathewFormica,P.E.,PilotingServices MarkLaquidara,PhD,P.E.,WastewaterProcessAdvisor BeverlyStinson,PhD,NutrientRemovalAdvisorBlueleafIncorporated57DresserHillRoad,CharltonMA01507ContractedbyAECOMtoconstructandconductpilotstudyandproducePilotStudyReport. ErikGrotton,P.E.,President (508)2487094 GeorgeSwedberg,PilotEngineer (508)3407952 AaronDavis,ProjectManager (774)2008029 RussellHauver,PilotEngineer (508)8686734 MarioRogriguez,PilotEngineer (508)2487094EasternAnalytical25ChenellDrive,Concord,NH03301CertifiedLaboratoryServices. MichaelBecker,ClientServices (800)2870525

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I.Krueger,Inc.401HarrisonOaksBlvd.,Suite100,Cary,NC27513VendoroftheBIOSTYRBiologicalAeratedFiltration(BAF)System. DavidFoster,ProcessManager (919)6778310 LouisOrtenzio,ProcessEngineer JohnHe,ProcessEngineerSiemensIndustry,Inc.41HutchinsDrive,Portland,ME04102VendoroftheBiomagTMSystem. SteveWoodard,ChiefTechnicalOfficer (207)2218225 AndyBishop,EngineeringManager MattVarieka,PilotEngineerWorldWaterWorks,Inc.4061NW3rdStreet,OklahomaCity,OK73107VendoroftheMovingBedBioreactor(MBBR)System. ChandlerJohnson,ChiefTechnologyOfficer (800)6077873 KyleBooth,ExecutiveVicePresidentButterfieldEnvironmentalCorp.3OberyStreet,Plymouth,MA02360 LocalrepresentativeforAriesChemical.Providedpolymerproductsforthepilotstudy. NateButterfield,President (508)8300410

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ABBREVIATIONSANOVA AnalysisofVarianceBAF BiologicallyAeratedFilterBDL BelowDetectionLimitBOD BiochemicalOxygenDemandCaCO3 CalciumCarbonateCASB ConventionalActivatedSludgewithBioMagCOD ChemicalOxygenDemandC/N CarbonandNitrificationRemovalCWT CambridgeWaterTechnologiesDAF DissolvedAirFloatationDN DenitrificationDN1 DenitrificationReactorTank1DN1 DenitrificationReactorTank2DO DissolvedOxygenDPE DilutedStrength,PeakFlow,ExtendedDurationTrialF/M FoodtoMicroorganismRatioFMS FullStrength,MidFlow,ShortDurationTrialFPS FullStrength,PeakFlow,ShortDurationTrialFPM FullStrength,PeakFlow,MediumDurationTrialFXM FullStrength,HighPeakFlow,MediumDurationTrialFXE FullStrength,HighPeakFlow,ExtendedDurationTrialgpm GallonsperMinutegpm/sf GallonsperMinuteperSquareFoot(ofsurfacearea)gpd GallonsperDaygr GramIR InternalRecycleRateL LiterMBBR MovingBedBioreactormg MilligramMG MillionGallonsMGD MillionGallonsperDaymg/L MilligramsperLiter(equivalenttoppm)min MinutesML MixedLiquorMLE ModifiedLudzackEttingerMLSS MixedLiquorSuspendedSolidsMLVSS MixedLiquorVolatileSuspendedSolidsmV MillivoltN Nitrogen

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NOx NitrogenOxidesNR1 NitrificationReactorTank1NR2 NitrificationReactorTank1NH3 Ammoniag/L MicrogramsperLliter(equivalenttoppb)N/A NotAvailable/NotApplicableND NotDetectedORP OxidationReductionPotentialPID ProportionalIntegralDerivativeppb PartsperBillionppm PartsperMillionRAS ReturnActivatedSludgeSALR SurfaceAreaLoadingRateSARR SurfaceAreaRemovalRateSRT SolidsRetentionTimeTKN TotalKjehldahlNitrogenTN TotalNitrogenTSS TotalSuspendedSolidsVSS VolatileSuspendedSolidsWAS WasteActivatedSludgeWWTF WasteWaterTreatmentFacility

PeirceIslandPilotStudyReport

September2012 1

1 INTRODUCTIONTheCityofPortsmouthNHhasbeenissuedaConsentDecreebytheUSEnvironmentalProtectionAgency(EPA)toupgradetheexistingPeirceIslandWWTFtoprovidesecondarytreatment.ThisPilotStudywasconductedaspartoftheplanningprocessundertakenbytheCityinmeetingtherequirementsoftheConsentDecree.AWastewaterMasterPlanandLongTermControlPlan(WMP/LTCP)wascompletedbyWeston&SampsonEngineersandBrown&Caldwellin2010,withDraftssubmittedtotheEPAinMarchandJune,andaFinalSupplementsubmittedinNovember.TheMasterPlanrecommendationwastoconstructupgradestotheSandFilterBuildingatPeirceIslandWWTFtotreatapproximately5MGDAverageDailyFlow,and7.5MGDMaximumMonthlyFlowtoSecondaryTreatmentStandards.

AdditionalengineeringserviceswerebegunbyAECOMintheSpringof2011toevaluateandselectsmallfootprinttreatmentprocessesforimplementationatPeirceIslandWWTF.Thiseffortconsideredtheabilityoftheprocessestoprovidesecondarytreatmentandtoreduceeffluenttotalnitrogen.TotalnitrogenperformancewasconsideredinpartduetoareviewoftheecologicalhealthofGreatBaythatsuggestednitrogenfrompointandnonpointsourcesarecontributingtoseasonalanoxicconditionswithintheestuary.Inaddition,othercommunitiesaroundGreatBayhadreceiveddraftNPDESpermitslimitingeffluentnitrogenconcentrationintheirtreatedwastewatereffluent.ThoughnitrogenlimitswerenotoriginallyincludedinthetreatmentrequirementsforthePeirceIslandWWTF,basedondiscussionswiththeEPA,theCitybelievedthatanitrogenlimitmightbeimplementedinthefuture,andwantedtobepreparedtoincludereasonableprovisionsinanycapitalimprovementstoincludenitrogenremoval.Atthetimethatthepilotplanningbegan,therewaslittleinformationavailabletoguidetheCityontheeventuallimitthatmightbeimposed.Sincethetimeframeforapotentialtotalnitrogenpermitlimitandthetreatmentlevelwasunknown,totalnitrogenremovalwasnotinitiallytheprimaryfocusofthispilot.Achievingresultsforsecondarytreatmentwasthefirstpriorityandoperationofpilotunitstoachievetotalnitrogenremovalwastobecompletedasthescheduleandbudgetallow.

AspartofPhase1ofthepilotingproject,AECOMcompletedaTechnologyEvaluationFinalTechnicalMemoranduminSeptember2011,inwhichthreeprocesseswereselectedforaninitial6monthpilotscaleevaluation.Thethreeprocesseswere:BiologicallyActivatedFiltration(BAF),MovingBedBioreactor(MBBR),andConventionalActivatedSludgewithaproprietaryballastedmarketedasBioMag(CASB).TheintentionoftheinitialphaseofpilotinginPhase2wastodevelopdatatochooseoneofthethreeprocessesforfurtherpiloting,Vendorselection,orpreliminarydesign.TheinitialpilottestingisthesubjectofthisPilotTestingProtocol.AdditionalpilottestingmaybeundertakeninasecondpilotingphasetocomparecompetingVendorsofthetechnology,toallowtheselectionofaVendorfortheupgradeofthePeirceIslandWWTF,ortoprovideoperationalexperienceforthePortsmouthwastewatertreatmentplantoperators,buttheadditionaltestingisnotdescribedinthisdocument.

ThisPilotStudyReportdetailstheapproach,methods,resultsandconclusionsofthepilotstudycompletedbetweenAugust2011,andAugust2012.Thepilotsystemwasdesigned,constructed,andoperatedbyBlueleafIncorporated,andthedatawasanalyzed,andthereportwaswrittenbyBlueleaf


September2012 2

operatorsandengineerswhoconductedthefieldworkonthepilot.Blueleafisanindependentandimpartialfirm,withnocontractualrelationshipwithanyoftheprospectivevendors.

Thepilotstudyreportisseparatedintothreesectionstopromoteimpartialityintheevaluationofthethreeprocessesincludedinthepilotstudy.

TheMethodsandMaterialsSectiondescribesthepilotequipment,fieldtestingproceduresandExperimentalTrialsindetail.

TheResultssectioncontainsthedataproducedduringthepilotstudywithoutobservationsorsubjectivecommentary.Theintentistoallowthereadertoconsiderthedatawithouttheopinionoftheauthorsofthisreport.

TheSummarysectionincludesacomparisonofthethreeprocesses,observations,commentsonpotentialissueswiththefullscaleapplicationofthethreeprocesses,andismoresubjectivethantheresultssection.TheSummarySectionisintendedtodocumenttheexperienceandobservationsofthepilotoperatorsforitspotentialuseaspartoftheprocessselectionprocedure.

ThisPilotStudyReportdoesnotincludearecommendationforprocessselection.Processselectionmustincludedesigndecisionsincludingsizing,capitalandoperatingcosts,andanumberofotherfactorsthatwerenotdirectlyincludedinthisphaseoftheStudy.ThisPilotReportisintendedtoprovidesomeofthedatathatwillaidtheCityinprocessselection.


September2012 3

2 METHODSANDMATERIALS

2.1 PILOTEQUIPMENTDESCRIPTION,GENERALFigure2.101showsthegeneralphysicallayoutofthepilotplant,andFigure2.102showsaschematicflowdiagramofthepilotplant.ThepilotplantwassituatedinsidethenorthwestcorneroftheperimeterfenceofthePeirceIslandWWTF,adjacenttotheentrygate.ThepilotplantwasconstructedfromOctobertoDecember2011.Maincomponentsofthepilotplantarelistedbelow.

1. Primaryclarifierandeffluentsump.2. BAF:BiologicalAeratedFiltrationconsistingofBODremoval/nitrification(stage1)anddenitrification

(stage2).3. CASB:ConventionalActivatedSludgewithBioMag(biologicalreactorwithmagnetiteballast)

followedbytwoparallelsedimentationclarifiers.4. MBBR/DAF:MixedBedBiologicalReactor,followedbyDissolvedAirFlotationforclarification.

Miscellaneousequipmentincludedarawwatersupplypump,aerationblower,aircompressor,chemicalfeedpumpsanddaytanks,feedpumpstorepumpprimaryeffluenttosecondaryprocesses,varioustanks,cleanwatersupply,andwastedrainagelines.Therewasamobilelaboratoryandofficeforperformingfieldanalysesandmonitoringprocessesviaonlinemetersandprobes.

Therewereseveralpremanufacturedpilotunits:

5. TheDAFwasaportablepilotscaleunitwithappurtenantequipment,providedbytheMBBRvendorWorldWaterWorks(WWW).

6. ThetwoBAFstageswerelargemobileunitsprovidedbythevendor,Kruger,anddeliveredtothesitewithanassociatedcontrolshed.ThetwoBAFunitsandcontrolshedweresetupadjacenttotheprimaryclarifier.TheBAFtowersandthreeappurtenanttankswereweatherprotectedwithclearplasticshrinkwrapping.

Pilotcomponentsthatwerebuiltonsiteincluded:

7. Primaryclarifierandprimaryeffluentsump.8. MBBRbioreactor.9. CASBbioreactor(BioMag)10. TwoCASBsecondaryclarifiers.

Thesitebuiltcomponentswereall4ftwidex8ftdeeptanksofvariouslengths.Thetopsofthetankswereopenatapproximately8ftto9ftabovegrade.Thetankswereadjoinedbydecksthatprovidedaccesstothetopsofthetanks,theinternalcomponents,andthewatervolumesinside.Thespaceunderthedeckswasenclosedandweatherized.Thisspacewasusedtohousemiscellaneousequipmentincluding:

DAFandappurtenances


September2012 4

Aerationblower Aircompressorandpressuretank FeedpumpsforMBBRandCASB ReturnActivatedSludge(RAS)pumpsforCASB Chemicalfeedpumpsanddaytanks WasteActivatedSludge(WAS)tankforDAFresiduals Pilotwastereturndrainlinesforeffluentstreamsandresiduals.


September2012 7

2.1.1 CityWaterCitywaterwassuppliedtothepilotfromahosecockatthegritbuilding,viaapproximately300ftofgardenhose,forusesincludingthelaboratorysink,makeupwaterforchemicalfeeds,andhosesforwashdown.

Citywaterwasalsosuppliedfromayardhydrantadjacenttothesludgethickener,viaapproximately300ftof3pipefordilutionwaterduringhydraulicstresstesting.Dilutionwaterflowswerecontrolledbya1PVCballvalve,andmonitoredbya50gpmrotameter.

2.1.2 RawWaterSupplyRawwaterwassuppliedtothepilotbya100gpmsubmersiblegrinderpumpplacedintheinfluentchanneltotheaerationchambers,upstreamofanychemicalinjectionpoint.Rawwaterwasconveyedfromthepumptotheprimaryclarifierviaapproximately350ftof4PVCpipe,againstapproximately15ftofelevationhead.Theflowratewascontrolledbya3PVCballvalveatthepilotprimaryclarifier.Theflowratewasmonitoredbyamagneticflowmeter,andrawwaterflowwascontinuouslyloggedbyadatalogger.

2.1.3 SiteBuiltTankConstructionforClarifiers,Bioreactors,andSumpsAseriesoftankswereconstructedonsitetoserveaspilotscaleclarifiersandbioreactors.Thelocationforthesitebuilttankswasgradedandalayerof1stonewasplaced.Thetanksweresupportedon8x8railroadtimbersthatwereplacedoverthestonelayerandleveled.Structuralsteelchannelsandanglesformedacribstructuretosupportthetankfloor,andcontainthewallsagainsthydraulicpressure.Steelangleswereinstalledacrossthewidthofeachtankat3ftintervals,toresisttheoutwardhydraulicpressure.Theseanglesalsoprovidedaframeworkthatsupportedvariouscomponentsandplatformsdirectlyabovethewatersurfaces.Thetankwallsandfloorswereconstructedofstructuralgradelumberandthickexteriorplywoodpanels.Theinteriorsofthetankswerewaterproofedwithrubberliners.

Therewerefourtankstructuresasfollows:

1. Primaryclarifierandeffluentstoragesump;2. MBBRbiologicalreactortanks;3. CASBbiologicalreactortanks;4. TwosecondaryclarifiersforCASBprocess.

Allofthesitebuilttanksmeasured4ftwidex8ftdeep.Eachofthefourtankstructureslistedabovewassubdividedintosmallertanksofvariouslengthsbyinternaldividingwalls.Dividingwallsbetweentanksinserieswereeither:

a. Bulkheadwalls,whichwereconstructedoflumberandplywoodandwaterproofedwithrubberliners;

b. Bafflewalls,whichwereconstructedofpolyethylenesheetsfastenedbetweenthesidewallsofalargertanktoformaninternaldivision,withcircularorrectangularholestoallowflowtopassthrough.


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Therewerenumerouspenetrationsforsolidpipingthroughthesidewallsbelowwaterlineforthevarioustanks.PVCbulkheadfittingswereusedforpenetrations,oftenwiththeadditionofsiliconeorwaterstopcaulkingtopreventleakage.Bulkheadfittingsvariedinsizefrom1to4diameter.

Othercomponentsofthevarioustankswerespecifictotheprocesses.Theseincludedpiping,inlet/outletstructures,drains,pumps,mixers,etc.Thesearedescribedintheappropriatesections.

2.1.4 PrimaryClarifierFigure2.103showsascaledplanandsectionsoftheprimaryclarifier,showingdetailsofitsconfigurationandfunction.

Primaryclarificationwasnotpilotedfordesignpurposes,butrathertoproducenonCEPTprimaryeffluentforthesecondaryprocessesbeingpiloted.ThefullscaleWWTFproducedonlyCEPTeffluent.Theobjectivewasforthepilotprimaryclarifiertoproduceeffluentrepresentativeoffullscaleperformancewithouttheuseofcoagulantforenhancedprimarytreatment.TherewasnocorrespondingnonCEPTwaterqualitydatafromthefullscaleWWTFtoattempttoduplicateatthepilotscale.Instead,thepilotprimaryclarifierwassizedtooperateatsurfacehydraulicloadingratessimilartothefullscaleWWTFclarifierswithbothprimaryclarifiersinservice.

Rawwaterinfluentwassuppliedfromtherawwaterpump.Acontinuouslyloggedmagneticflowmeterwasinstalledupstreamoftheclarifier.Thefeedlinewasreducedfrom4PVCto3PVC,andtheinfluentflowratewascontrolledbya3PVCballvalve.

Theinletstructurewasimmediatelydownstreamfromthe3ballvalve.Theinletstructureconsistedoftwoparallel3diameterpipesthatextendedverticallybelowthewatersurfaceoftheclarifier.Eachinfluentpipewascappedatthebottom,andhadaseriesof1.5holesthatdispersedflowbelowthesurface.

Theprimaryclarifiermeasured4widex8deepx26long.Therewas2offreeboardabovethewatersurface.Theflooroftheclarifierwasslopedacrossthewidth(the4dimension)tocausesettledsludgetoflowtowardsludgedrainsinstalledalongthelengthoftheclarifier.Thewaterdepthwas6atthelowsideoftheslopedfloor(deepestpoint),and310atthehighside.Thewatervolumeoftheclarifierwas3950gallons(528cubicfeet).


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Therewereaseriesof5sludgedrainsalongthelowsideoftheslopedfloor.Eachdrainconsistedofa5ftlongslotted2diameterpiperunningalongtheflooroftheclarifieratthedeepestpoint,6ftbelowthesurface.Thesludgedrainpipeswerearrangedendtoendalongthelengthoftheclarifier.Theendsofeachslottedsludgedrainpipewerecapped.Eachhadateeatthemidpointwitha2branchthatpenetratedthesidewalloftheclarifierviaa2bulkheadfitting.Ontheoutsideoftheclarifier,eachsludgedrainwascontrolledbya2PVCballvalve,andtherewasalengthofclear2PVCdownstreamofeachvalvetoserveasasightglasstoobserveflow.Each2drainemptiedintoanopentop4standpipe,andthestandpipewasconnectedtoateeina4wasteline.ThewastelinereturnedtotheWWTFgritchamber.

Clarifiedeffluentexitedtheprimaryclarifieratthesurfaceoveravnotchweir.Therewasanunderflowbaffleimmediatelyupstreamoftheeffluentweir,toblockfloatingmaterials.Theunderflowbaffleextendedacrossthewidthoftheclarifiertoadepthof12.

Theeffluentpassedoverthevnotchweirintoaneffluenttrough,whichmeasured4ftwidex1ftlongx8deep.Theeffluenttroughextendedacrossthewidthoftheclarifier,andhadvnotchesalongboth4ftlengths.Thetotallengthoftheweirwas8ft,andeffluentflowedintothetroughfrombothsides.Theelevationoftheweirwasadjustable.Theweirelevationcontrolledthewaterlevelintheclarifier.Effluentflowedoutoftheweirthrougha4diameterflexiblepipe,toa4bulkheadfittingthatpenetratedthesidewalloftheclarifier,anddroppedtoa4diametermanifoldfordistribution.

Therewasa4diameteractuatedbutterflyvalveontheeffluentlinethatwascontrolledbyatimerpanel.Thetimerpanelhadtwotimers,onetocontroltheopenvalvetime,andonetocontroltheclosedvalvetime.Thepurposewastoallowforautomatedscumremovalcycles,byperiodicallyclosingtheeffluentvalveforshortperiods,whichwouldcausetheprimaryclarifierwaterleveltoriseandoverflowthescumtrough.Inpractice,thevalvewasnotusedforautomatedscumremoval.ThetimerpanelhadaHAND/OPEN/OFFswitchthatwastypicallysettoHAND(open).

Theeffluentmanifoldhadfourbranches:primaryeffluentsump;MBBRfeedpump;CASBfeedpump;andBAFfeedpump.EachofthethreesecondaryfeedpumpbrancheshadaPVCballvalvetoshutoffflowasnecessary.Theprimaryeffluentmanifoldwashorizontal,andthecenterlinewasapproximately10abovetheflooroftheprimaryclarifierandprimaryeffluentsump.Therewasapproximately5ftofheadabovethemanifoldcenterlineduringnormaloperatingconditionswithforwardflowthroughtheprimaryclarifier.Whentheflowofeffluentfromtheprimaryclarifierwasshutoff(forexample,duringsludgedraining)theprimaryeffluentsumpsuppliedflowtothemanifold.

Theprimaryeffluentsumpstoredavolumeofapproximately360gallons.Approximately300gallonswasavailabletothesecondaryprocessfeedpumps,andtheremainderwasbelowtheinvertoftheprimaryeffluentmanifold.Inflowenteredthesumpthrougha4diameterbulkheadfittingwithaninvert8abovethesumpfloor.Effluentflowedoutofthesumpthrougha4diameterverticalstandpipe.Thestandpipemaintainedthewaterdepthat4ft,whichwas2ftbelowtheleveloftheprimaryclarifier.


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Outflowfromthesump,andfromtheprimaryclarifiersludgedrains,ranintoa4PVCgravitydrainpipethatranthelengthofthegallerybetweentheprimaryclarifier/sumpandtheMBBRtanks.The4drainflowedintoa6pilotdrainpipethatreturnedtotheWWTFgritchamber.

Theprimaryclarifieroperatedataflowrategreaterthanthecombinedflowratesofthesecondaryprocesses.Theexcessflowmaintainedacontinuousflowthroughtheeffluentsump,sotherewasconstantturnoverofthestoredvolume.Thewaterlevelinthesump(definedbythetopofthedrainpipe)was2ftlowerthantheprimaryclarifierwaterlevel.The2ftheadwasenoughtomaintainanoverflowconditionatthevnotchweirforflowsupto95gpm,whichwasthemaximumflowratefortherawwatersupplypump.

Table2.101summarizesthedimensionsofthepilotprimaryclarifier.

Table2.101:PrimaryClarifierDimensionsWidth 4ft

Depth 6.0ft3.8ft(5.1ftavg.depth)

Length 26ft

SurfaceArea 104ft2

Volume 3950gal

2.1.4.1 OperationsandMaintenanceofthePrimaryClarifierTheprimaryclarifiertypicallyoperatedatflowratesof25gpmto50gpm.Theflowratewascontrolledbya3PVCballvalveimmediatelyupstreamoftheprimaryclarifierinletdistributionstructure.Theflowratewasmonitoredbyamagneticflowmeterwithcontinuousdatalogging.

Surfacescumremovalwastypicallyadailymaintenanceprocedure.Afractionoftheprimaryclarifierflowdrainedcontinuouslyintothescumtroughtoremovesurfacescumandfloatingobjects.Whenaccumulationsofsurfacescumwerepresent,theyweremanuallyremovedbysweepingintothescumscupper.Ifnecessary,theprimaryeffluentactuatedvalvewasputintheOFF(closed)positionwhilesweeping,toincreasetheclarifierwaterlevelandaidscumremoval.

SettledSludgeremovalwasadailymaintenanceprocedure.Thesludgedrainvalveswereopenedinsuccessiontoremovesettledsolids.Eachdrainwasusuallyopened515minutes,andtheentireprocessusuallytook3060minutes.Whilethesludgewasbeingdrained,theslopedflooroftheclarifierwassweptusinga16squeegeewitha12fttelescopinghandle,inordertopushsettledsolidstowardthedrains.Drainingloweredthewaterleveloftheclarifierbelowtheeffluentweir,whichpreventedsolidsstirredupbysweepingfromfoulingtheeffluent,butalsoshutofftheeffluentflowforthedurationofdraining.Theprimaryeffluentsumpstored360gallonsprovidedapproximately360gallonsofstoredeffluenttothesecondaryprocesses


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2.1.4.2 ModificationstoPrimaryClarifierTherewasinitiallyaninfluentscreentopreventlargerobjectsfromenteringtheprimaryclarifier.Thescreenstypicallycloggedwithinhours,andwereremoved

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