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Anne Arundel County Department of Public Works. Mayo Water Reclamation Facility. Presented to West Rhodes River Keepers March 23, 2012. Agenda. Project – Purpose and Need Statement Plant Service Area Septic Tank Effluent Pump (STEP) System Flows Treatment Facilities Unit Processes - PowerPoint PPT Presentation
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Anne Arundel CountyAnne Arundel County Department of Public WorksDepartment of Public Works
Mayo Water Reclamation Mayo Water Reclamation FacilityFacility
Presented to West Rhodes River KeepersPresented to West Rhodes River Keepers
March 23, 2012March 23, 2012
AgendaAgenda Project – Purpose and Need StatementProject – Purpose and Need Statement Plant Service AreaPlant Service Area
Septic Tank Effluent Pump (STEP) SystemSeptic Tank Effluent Pump (STEP) System FlowsFlows
Treatment FacilitiesTreatment Facilities Unit ProcessesUnit Processes PerformancePerformance Plant OutfallPlant Outfall Operating Costs Operating Costs Refurbish Existing UnitsRefurbish Existing Units
Plant Expansion EffortsPlant Expansion Efforts Design of Conventional PlantDesign of Conventional Plant Negotiations with MDE and FDANegotiations with MDE and FDA Expansion AlternativesExpansion Alternatives
Ongoing Plant ImprovementsOngoing Plant Improvements Phase 1 ImprovementsPhase 1 Improvements
Current Options Being ConsideredCurrent Options Being Considered
Project Purpose and NeedProject Purpose and Need
•Expand Capacity – Lift Moratorium•Current Permitted Capacity – 0.615 mgd
•Current Allocated Flow – 0.579 mgd
•Ultimate Projected Flow – 1.14 mgd
•Upgrade Treatment – Enhanced Nutrient Removal (ENR)
•Current Total Nitrogen – 18.6 mg/l
•Current Total Phosphorous – 0.76 mg/l
•ENR-Total Nitrogen – 3 mg/l
•ENR – Total Phosphorous – 0.3 mg/l
Service Service AreaArea
Need service area figure from George
Septic tank Septic tank effluent flows to effluent flows to pumping pumping stationsstations
Flow pumped Flow pumped to treatment to treatment plantplant
Solids HandlingSolids Handling
FlowsFlows CurrentCurrent
Average Daily Flow Average Daily Flow (ADF) = 0.56 mgd(ADF) = 0.56 mgd
Peak Flow = 2.18 mgdPeak Flow = 2.18 mgd Currently 3,615 EDUsCurrently 3,615 EDUs
ProjectedProjected Build-out ADF = 1.14 Build-out ADF = 1.14
mgd (uses 225 gallons mgd (uses 225 gallons per day per EDU)per day per EDU)
Build-out Peak = 3.58 Build-out Peak = 3.58 mgd (uses MD peaking mgd (uses MD peaking curve)curve)
Essentially Un-changed Essentially Un-changed since Mayo inceptionsince Mayo inception
Service Area Service Area continuedcontinued
Build-out Equivalent Dwelling Units (EDUs)
Treatment FacilitiesTreatment Facilities Treatment TrainTreatment Train
STEP – STEP – solids settlesolids settle Influent PumpingInfluent Pumping Recirculating Sand FiltersRecirculating Sand Filters
Reduces solids (TSS), ammonia-N Reduces solids (TSS), ammonia-N (NH3), Biological Oxygen Demand (BOD)(NH3), Biological Oxygen Demand (BOD)
Small degree of pathogen reductionSmall degree of pathogen reduction Emergent WetlandsEmergent Wetlands
Subsurface flow lined gravel beds Subsurface flow lined gravel beds supporting growth of bulrushes and supporting growth of bulrushes and cattailscattails
Further reduces solids, (TSS), ammonia-N Further reduces solids, (TSS), ammonia-N (NH3), Biological Oxygen Demand (BOD)(NH3), Biological Oxygen Demand (BOD)
Small degree of pathogen reductionSmall degree of pathogen reduction Phosphorus ClarifierPhosphorus Clarifier
Lime added to precipitate phosphorusLime added to precipitate phosphorus
Treatment FacilitiesTreatment Facilities Treatment Train, continuedTreatment Train, continued
Peat WetlandsPeat Wetlands Drained, lined beds, with alternating Drained, lined beds, with alternating
layers of sand and peat with a layers of sand and peat with a grassy vegetative cover over which grassy vegetative cover over which wastewater is sprayedwastewater is sprayed
Effluent polishing (TSS removal)Effluent polishing (TSS removal) Some pathogen reductionSome pathogen reduction
UV DisinfectionUV Disinfection Primary source of pathogen Primary source of pathogen
reductionreduction UV radiation penetrates pathogen UV radiation penetrates pathogen
DNA and precludes them from DNA and precludes them from reproducingreproducing
Effluent PumpingEffluent Pumping
RHODERIVER
OFFSHOREWETLANDS
EFFLUENTPUMPING STATION
EFFLUENTUV DISINFECTION
PEAT WETLANDS
RAPIDMIX
CHEMICALCLARIFIERS
DISTRIBUTIONBOX A
MAIN INFLUENTPS
RECIRCULATINGSAND FILTERS
EMERGENTWETLANDS
INFLUENTSLUDGE
STORAGE
INFLUENT
PEAT WETLANDPS
FILTER PS
FILTERPS
24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION
TANKS
2 HOUREMERGENCY
SHELLFISH STORAGE
PEAT WETLANDUV DISINFECTION
Existing Mayo WRFExisting Mayo WRF
Operating PerformanceOperating PerformanceAnnual Averages: 2011Annual Averages: 2011
Total Suspended Solids 2.0 mg/l Total Suspended Solids 2.0 mg/l Total Nitrogen 18.6 mg/lTotal Nitrogen 18.6 mg/l Total Phosphorus 0.76 mg/lTotal Phosphorus 0.76 mg/l Fecal Coliform <2.0 MPN/100MLFecal Coliform <2.0 MPN/100ML BOD 1.0 mg/lBOD 1.0 mg/l Permitted Operating levels are higher than other Permitted Operating levels are higher than other
plantsplantsExample Monitoring Report
Discharges to Discharges to a Shellfish a Shellfish Harvesting Harvesting AreaArea
Limited Limited CapacityCapacity
Approved Approved without without Shellfish Shellfish Closure ZoneClosure Zone
Plant OutfallPlant Outfall
Camp Wabanna
Operating CostsOperating Costs
Does not include CIP costsDoes not include CIP costs Refurbish existing units when treatment effectiveness decreases (sand filters, Refurbish existing units when treatment effectiveness decreases (sand filters,
emergent wetlands)emergent wetlands)
Water Reclamation
Facility
2012 Annual Operating Budget, $
Current Plant Flow, million
gallons per day Unit Cost, $/gallon
Cox Creek 5,796,000 11.327 0.51
Annapolis 4,753,000 8.561 0.56
Broadneck 3,088,500 5.131 0.60
Patuxent 3,347,500 5.317 0.63
Broadwater 1,139,200 1.078 1.06
Maryland City 1,307,800 1.054 1.24
Mayo 1,091,300 0.560 1.95
Plant Expansion EffortsPlant Expansion Efforts
Planning started 1998Planning started 1998 Design nearly complete 2002Design nearly complete 2002 Change in treatment process dictates changes to outfallChange in treatment process dictates changes to outfall Negotiations with MDE and FDA required to determine if Negotiations with MDE and FDA required to determine if
existing outfall could be used – Risk Analysisexisting outfall could be used – Risk Analysis Possible outfall modificationsPossible outfall modifications
New outfall location (abandon existing)New outfall location (abandon existing) Establish shellfish harvesting closure zone around existing outfallEstablish shellfish harvesting closure zone around existing outfall
MDE requires new outfall location – no new closure zonesMDE requires new outfall location – no new closure zones Growth moratorium in place until plant can be expandedGrowth moratorium in place until plant can be expanded
Initial Expansion AlternativesInitial Expansion Alternatives Seven Expansion Alternatives developed for Seven Expansion Alternatives developed for
discussions with MDEdiscussions with MDE MDE CriteriaMDE Criteria
Change in treatment process requires shellfish harvesting Change in treatment process requires shellfish harvesting closure zone –or- new outfall locationclosure zone –or- new outfall location
State policy prohibits establishing new shellfish harvesting State policy prohibits establishing new shellfish harvesting closure zonesclosure zones
ENR treatment requires change in treatment processENR treatment requires change in treatment process No choice: new outfall locationNo choice: new outfall location
County Selection CriteriaCounty Selection Criteria No Shellfish Closure ZoneNo Shellfish Closure Zone Includes Enhanced Nutrient Removal (ENR)Includes Enhanced Nutrient Removal (ENR)
Conceptual Alternatives ConsideredConceptual Alternatives Considered
Alt 1Alt 1: ENR Upgrade at Mayo – Existing Ouftall: ENR Upgrade at Mayo – Existing Ouftall
Alt 2Alt 2: ENR Upgrade at Mayo – New Deep Water Outfall: ENR Upgrade at Mayo – New Deep Water Outfall
Alt 3Alt 3: Pump Mayo Wastewater to Annapolis WRF (ENR treatment): Pump Mayo Wastewater to Annapolis WRF (ENR treatment)
Alt 4Alt 4: ENR Upgrade at Mayo – Pump treated effluent to Annapolis : ENR Upgrade at Mayo – Pump treated effluent to Annapolis WRF OutfallWRF Outfall
Alt 5Alt 5: Pump Expanded flow (.525 mgd) to Annapolis WRF via : Pump Expanded flow (.525 mgd) to Annapolis WRF via Woodland Beach; Retain Mayo treatment for existing flow (.615 Woodland Beach; Retain Mayo treatment for existing flow (.615 mgd)mgd)
Alt 6Alt 6: ENR Upgrade at Mayo – Re-circulate effluent thru existing : ENR Upgrade at Mayo – Re-circulate effluent thru existing treatment process – Existing Outfalltreatment process – Existing Outfall
Alt 7Alt 7: Expand Mayo using existing treatment process – Existing : Expand Mayo using existing treatment process – Existing OutfallOutfall
Initial Expansion Alternatives, Initial Expansion Alternatives, cont.cont.
Alternatives that maintain existing treatment Alternatives that maintain existing treatment were deletedwere deleted
Alternatives that keep the existing outfall were Alternatives that keep the existing outfall were deleteddeleted
Alternatives that meet criteria: 2, 3 and 4 Alternatives that meet criteria: 2, 3 and 4
For feasible alternatives, Cost Analysis showed For feasible alternatives, Cost Analysis showed Alternative 2 (new outfall) is the most expensiveAlternative 2 (new outfall) is the most expensive Alternative 3 (pump STEP flow wastewater to Alternative 3 (pump STEP flow wastewater to
Annapolis) is the least expensiveAnnapolis) is the least expensive
Alternatives ComparisonAlternatives Comparison
Alternative
ENR Treatment
(Y/N)
Closure Zone Required
(Y/N) Recommendation
1: ENR @Mayo-Ex. Outfall Y Y Drop
2: ENR @ Mayo – Deep Water Outfall
Y Y/N Advance
3: Pump Mayo to Annapolis ENR
Y N Advance
4: ENR @ Mayo – pump to Annapolis Outfall
Y N Advance
5: Hybrid: Pump Mayo to Annapolis ENR/ Retain Ex. Mayo treatment
N N Drop
6. ENR @ Mayo: recirculate thru Ex. Mayo treatment
N N Drop
7. Modular expansion at Mayo – Existing treatment/outfall
N N Drop
Initial Expansion Alternative 2:Initial Expansion Alternative 2:
• ENR WWTP Upgrade at Mayo
• Typical
• Pump to new outfall
Mayo WRF New Outfall
Existing Forcemain and Outfall
(Abandoned)
Natural Oyster Bar(Typical)
N
New Forcemain
Existing Forcemain(Reused)
1.0
mi
Possible New Closure Area
MAYO INFLUENT
DENITRIFICATIONFILTERS
MAININFLUENT PUMPING STATION
FLOWDISTRIBUTION
BOX
AERATIONBASINS
UV DISINFECTION
POST-AERATION
24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION
TANKS
CLARIFIERS
CHESAPEAKE BAY
DEEP WATER OUTFALL
EFFLUENTPUMPING STATION
2 HOUREMERGENCY
SHELLFISH STORAGE
Initial Expansion Alternative 2:Initial Expansion Alternative 2:• ENR WWTP Upgrade at Mayo
• Pump to new outfall
ENR UPGRADE
Initial Expansion Alternative 3:Initial Expansion Alternative 3:
• No WWTP Upgrade at Mayo
• Pump wastewater to Annapolis for treatment
Mayo Raw SPS
Proposed Forcemain
Annapolis WRF
N
Existing Forcemain and Outfall
(Abandoned)
Annapolis WRF Outfall
Existing Annapolis WRF
Sewer
MAININFLUENT PUMPING STATION
MAYO INFLUENT
24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION
TANKS
PUMP TO ANNAPOLIS
WRF
2 HOUREMERGENCY
SHELLFISH STORAGE
Initial Expansion Alternative 3:Initial Expansion Alternative 3:• No WWTP Upgrade at Mayo
• Pump wastewater to Annapolis for treatment
Initial Expansion Alternative 4:Initial Expansion Alternative 4:
• ENR WWTP Upgrade at Mayo
• Pump effluent to Annapolis Outfall
Mayo WRF Proposed Forcemain
Annapolis WRF
N
Existing Forcemain and Outfall
(Abandoned)
Annapolis WRF Outfall
DENITRIFICATIONFILTERS
MAININFLUENT PUMPING STATION
MAYO INFLUENT
FLOWDISTRIBUTION
BOX
AERATIONBASINS
UV DISINFECTION
POST-AERATION
24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION
TANKS
CLARIFIERS
PUMP TO ANNAPOLIS
WRF OUTFALL
2 HOUREMERGENCY
SHELLFISH STORAGE
Initial Expansion Alternative 4:Initial Expansion Alternative 4:• ENR WWTP Upgrade at Mayo
• Pump effluent to Annapolis Outfall
ENR UPGRADE
Alternatives Cost ComparisonAlternatives Cost Comparison
Phase 1 ImprovementsPhase 1 Improvements
Accelerate replacement of limited operational components Accelerate replacement of limited operational components given delays to Expansion/ENR Project.given delays to Expansion/ENR Project.
No Expansion Related Upgrades – Moratorium remains in No Expansion Related Upgrades – Moratorium remains in placeplace
Phase 1 UpgradePhase 1 Upgrade – needed for systems near the end of – needed for systems near the end of useful lifeuseful life
Main Pump Station – pump replacementsMain Pump Station – pump replacements Two covered flow equalization tanksTwo covered flow equalization tanks Ultra-Violet Disinfection System replacementUltra-Violet Disinfection System replacement Upgrade Electrical Distribution SystemUpgrade Electrical Distribution System Emergency Back-up PowerEmergency Back-up Power Upgrade System Controls (SCADA)Upgrade System Controls (SCADA)
Next StepsNext Steps
Pursue Phase 1 Upgrade ContractPursue Phase 1 Upgrade Contract
Refine Scopes and Costs for Alternatives Refine Scopes and Costs for Alternatives 2, 3 and 42, 3 and 4
Develop and Evaluate Non-cost criteriaDevelop and Evaluate Non-cost criteria
Re-convene Mayo CACRe-convene Mayo CAC
Recommend and Pursue Preferred Recommend and Pursue Preferred Alternative.Alternative.
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