Anne Arundel County Department of Public Works

1. Anne Arundel CountyDepartment of Public Works Mayo Water Reclamation Facility Presented to West Rhodes 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 – 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

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

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

9. Operating PerformanceAnnual 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. Plant Outfall • Discharges to a Shellfish Harvesting Area • Limited Capacity • Approved without Shellfish Closure Zone Camp Wabanna

11. Operating Costs • Does not include CIP costs • Refurbish existing units when treatment effectiveness decreases (sand filters, emergent wetlands)

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 Alternatives 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

17. N Natural Oyster Bar (Typical) Possible New Closure Area New Outfall Mayo WRF Existing Forcemain (Reused) 1.0 mi Existing Forcemain and Outfall (Abandoned) New Forcemain Initial Expansion Alternative 2: • ENR WWTP Upgrade at Mayo • Typical • Pump to new outfall

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

19. Annapolis WRF Outfall N Annapolis WRF Existing Annapolis WRF Sewer Proposed Forcemain Mayo Raw SPS Existing Forcemain and Outfall (Abandoned) Initial Expansion Alternative 3: • No WWTP Upgrade at Mayo • Pump wastewater to Annapolis for treatment

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

21. Annapolis WRF Outfall N Annapolis WRF Proposed Forcemain Mayo WRF Existing Forcemain and Outfall (Abandoned) Initial Expansion Alternative 4: • ENR WWTP Upgrade at Mayo • Pump effluent to Annapolis Outfall

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

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