Anne Arundel County Department of Public Works

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


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


• No WWTP Upgrade at Mayo

• Pump wastewater to Annapolis for treatment

Mayo Raw SPS

Proposed Forcemain

Annapolis WRF

N


(Abandoned)

Annapolis WRF Outfall

Existing Annapolis WRF

Sewer


MAYO INFLUENT


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


• ENR WWTP Upgrade at Mayo

• Pump effluent to Annapolis Outfall

Mayo WRF Proposed Forcemain

Annapolis WRF

N


(Abandoned)

Annapolis WRF Outfall

DENITRIFICATIONFILTERS


MAYO INFLUENT

FLOWDISTRIBUTION

BOX

AERATIONBASINS

UV DISINFECTION

POST-AERATION


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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AnswersAnswers

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Anne Arundel County Department of Public Works