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Anne Arundel County Department of Public Works Mayo Water Reclamation Facility Presented to West/Rhode River Keepers March 23, 2012.

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Presentation on theme: "Anne Arundel County Department of Public Works Mayo Water Reclamation Facility Presented to West/Rhode River Keepers March 23, 2012."— Presentation transcript:

1 Anne Arundel County Department of Public Works Mayo Water Reclamation Facility Presented to West/Rhode River Keepers March 23, 2012

2 Agenda  Project – Purpose and Need Statement  Plant Service Area  Septic Tank Effluent Pump (STEP) System  Flows  Treatment Facilities  Unit Processes  Performance  Plant Outfall  Operating Costs  Refurbish Existing Units  Plant Expansion Efforts  Design of Conventional Plant  Negotiations with MDE and FDA  Expansion Alternatives  Ongoing Plant Improvements  Phase 1 Improvements  Current Options Being Considered

3 Project Purpose and Need Expand Capacity – Lift Moratorium Current Permitted Capacity – mgd Current Allocated Flow – 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

4 Service Area Need service area figure from George  Septic tank effluent flows to pumping stations  Flow pumped to treatment plant  Solids Handling

5  Flows  Current  Average Daily Flow (ADF) = 0.56 mgd  Peak Flow = 2.18 mgd  Currently 3,615 EDUs  Projected  Build-out ADF = 1.14 mgd (uses 225 gallons per day per EDU)  Build-out Peak = 3.58 mgd (uses MD peaking curve)  Essentially Un-changed since Mayo inception Service Area continued Build-out Equivalent Dwelling Units (EDUs)

6 Treatment Facilities  Treatment Train  STEP – solids settle  Influent Pumping  Recirculating Sand Filters  Reduces solids (TSS), ammonia-N (NH3), Biological Oxygen Demand (BOD)  Small degree of pathogen reduction  Emergent Wetlands  Subsurface flow lined gravel beds supporting growth of bulrushes and cattails  Further reduces solids, (TSS), ammonia- N (NH3), Biological Oxygen Demand (BOD)  Small degree of pathogen reduction  Phosphorus Clarifier  Lime added to precipitate phosphorus

7 Treatment Facilities  Treatment Train, continued  Peat Wetlands  Drained, lined beds, with alternating layers of sand and peat with a grassy vegetative cover over which wastewater is sprayed  Effluent polishing (TSS removal)  Some pathogen reduction  UV Disinfection  Primary source of pathogen reduction  UV radiation penetrates pathogen DNA and precludes them from reproducing  Effluent Pumping

8 RHODE RIVER OFFSHORE WETLANDS EFFLUENT PUMPING STATION EFFLUENT UV DISINFECTION PEAT WETLANDS RAPID MIX CHEMICAL CLARIFIERS DISTRIBUTION BOX A MAIN INFLUENT PS RECIRCULATING SAND FILTERS EMERGENT WETLANDS INFLUENT SLUDGE STORAGE INFLUENT PEAT WETLAND PS FILTER PS FILTER PS 24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION TANKS 2 HOUR EMERGENCY SHELLFISH STORAGE PEAT WETLAND UV DISINFECTION Existing Mayo WRF

9 Operating Performance Annual Averages: 2011  Total Suspended Solids 2.0 mg/l  Total Nitrogen 18.6 mg/l  Total Phosphorus 0.76 mg/l  Fecal Coliform <2.0 MPN/100ML  BOD 1.0 mg/l  Permitted Operating levels are higher than other plants Example Monitoring Report

10  Discharges to a Shellfish Harvesting Area  Limited Capacity  Approved without Shellfish Closure Zone Plant Outfall Camp Wabanna

11 Operating Costs  Does not include CIP costs  Refurbish existing units when treatment effectiveness decreases (sand filters, emergent wetlands) Water Reclamation Facility 2012 Annual Operating Budget, $ Current Plant Flow, million gallons per day Unit Cost, $/1,000 gallons Cox Creek5,796, Annapolis4,753, Broadneck3,088, Patuxent3,347, Broadwater1,139, Maryland City1,307, Mayo1,091,

12 Plant Expansion Efforts  Planning started 1998  Design nearly complete 2002  Change in treatment process dictates changes to outfall  Negotiations with MDE and FDA required to determine if existing outfall could be used – Risk Analysis  Possible outfall modifications  New outfall location (abandon existing)  Establish shellfish harvesting closure zone around existing outfall  MDE requires new outfall location – no new closure zones  Growth moratorium in place until plant can be expanded

13 Initial Expansion Alternatives  Seven Expansion Alternatives developed for discussions with MDE  MDE Criteria  Change in treatment process requires shellfish harvesting closure zone –or- new outfall location  State policy prohibits establishing new shellfish harvesting closure zones  ENR treatment requires change in treatment process  No choice: new outfall location  County Selection Criteria  No Shellfish Closure Zone  Includes Enhanced Nutrient Removal (ENR)

14 Conceptual Aternatives Considered  Alt 1: ENR Upgrade at Mayo – Existing Ouftall  Alt 2: ENR Upgrade at Mayo – New Deep Water Outfall  Alt 3: Pump Mayo Wastewater to Annapolis WRF (ENR treatment)  Alt 4: ENR Upgrade at Mayo – Pump treated effluent to Annapolis WRF Outfall  Alt 5: Pump Expanded flow (.525 mgd) to Annapolis WRF via Woodland Beach; Retain Mayo treatment for existing flow (.615 mgd)  Alt 6: ENR Upgrade at Mayo – Re-circulate effluent thru existing treatment process – Existing Outfall  Alt 7: Expand Mayo using existing treatment process – Existing Outfall

15 Initial Expansion Alternatives, cont.  Alternatives that maintain existing treatment were deleted  Alternatives that keep the existing outfall were deleted  Alternatives that meet criteria: 2, 3 and 4  For feasible alternatives, Cost Analysis showed  Alternative 2 (new outfall) is the most expensive  Alternative 3 (pump STEP flow wastewater to Annapolis) is the least expensive

16 Alternatives Comparison Alternative ENR Treatment (Y/N) Closure Zone Required (Y/N)Recommendation 1: OutfallYYDrop 2: Mayo – Deep Water Outfall YY/NAdvance 3: Pump Mayo to Annapolis ENR YNAdvance 4: Mayo – pump to Annapolis Outfall YNAdvance 5: Hybrid: Pump Mayo to Annapolis ENR/ Retain Ex. Mayo treatment NNDrop 6. Mayo: recirculate thru Ex. Mayo treatment NNDrop 7. Modular expansion at Mayo – Existing treatment/outfall NNDrop

17 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

18 MAYO INFLUENT DENITRIFICATION FILTERS MAIN INFLUENT PUMPING STATION FLOW DISTRIBUTION BOX AERATION BASINS UV DISINFECTION POST- AERATION 24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION TANKS CLARIFIERS CHESAPEAKE BAY DEEP WATER OUTFALL EFFLUENT PUMPING STATION 2 HOUR EMERGENCY SHELLFISH STORAGE Initial Expansion Alternative 2: ENR WWTP Upgrade at Mayo Pump to new outfall ENR UPGRADE

19 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

20 MAIN INFLUENT PUMPING STATION MAYO INFLUENT 24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION TANKS PUMP TO ANNAPOLIS WRF 2 HOUR EMERGENCY SHELLFISH STORAGE Initial Expansion Alternative 3: No WWTP Upgrade at Mayo Pump wastewater to Annapolis for treatment

21 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

22 DENITRIFICATION FILTERS MAIN INFLUENT PUMPING STATION MAYO INFLUENT FLOW DISTRIBUTION BOX AERATION BASINS UV DISINFECTION POST- AERATION 24 HOUR EMERGENCY SHELLFISH STORAGE / FLOW EQUALIZATION TANKS CLARIFIERS PUMP TO ANNAPOLIS WRF OUTFALL 2 HOUR EMERGENCY SHELLFISH STORAGE Initial Expansion Alternative 4: ENR WWTP Upgrade at Mayo Pump effluent to Annapolis Outfall ENR UPGRADE

23 Alternatives Cost Comparison

24 Phase 1 Improvements  Accelerate replacement of limited operational components given delays to Expansion/ENR Project.  No Expansion Related Upgrades – Moratorium remains in place  Phase 1 Upgrade – needed for systems near the end of useful life  Main Pump Station – pump replacements  Two covered flow equalization tanks  Ultra-Violet Disinfection System replacement  Upgrade Electrical Distribution System  Emergency Back-up Power  Upgrade System Controls (SCADA)

25 Next Steps  Pursue Phase 1 Upgrade Contract  Refine Scopes and Costs for Alternatives 2, 3 and 4  Develop and Evaluate Non-cost criteria  Re-convene Mayo CAC  Recommend and Pursue Preferred Alternative.

26 Questions & Answers


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