Anne Arundel County Department of Public Works Mayo Water Reclamation Facility Presented to West/Rhode 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 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

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

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

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)

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) Phosphorus Clarifier Lime added to precipitate phosphorus

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

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

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

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

Operating Costs Does not include CIP costs Water Reclamation Facility 2012 Annual Operating Budget, $ Current Plant Flow, million gallons per day Unit Cost, $/1,000 gallons Cox Creek 5,796,000 11.327 1.40 Annapolis 4,753,000 8.561 1.52 Broadneck 3,088,500 5.131 1.65 Patuxent 3,347,500 5.317 1.72 Broadwater 1,139,200 1.078 2.90 Maryland City 1,307,800 1.054 3.40 Mayo 1,091,300 0.560 5.34 Does not include CIP costs Refurbish existing units when treatment effectiveness decreases (sand filters, emergent wetlands)

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

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)

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

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

Alternatives Comparison ENR Treatment (Y/N) Closure Zone Required Recommendation 1: ENR @Mayo-Ex. Outfall Y Drop 2: ENR @ Mayo – Deep Water Outfall Y/N Advance 3: Pump Mayo to Annapolis ENR N 4: ENR @ Mayo – pump to Annapolis Outfall 5: Hybrid: Pump Mayo to Annapolis ENR/ Retain Ex. Mayo treatment 6. ENR @ Mayo: recirculate thru Ex. Mayo treatment 7. Modular expansion at Mayo – Existing treatment/outfall

Initial Expansion Alternative 2: 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 ENR WWTP Upgrade at Mayo Typical Pump to new outfall

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

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

Initial Expansion Alternative 3: No WWTP Upgrade at Mayo Pump wastewater to Annapolis for treatment 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 4: Mayo WRF Proposed Forcemain Annapolis WRF N Existing Forcemain and Outfall (Abandoned) Annapolis WRF Outfall ENR WWTP Upgrade at Mayo Pump effluent to Annapolis Outfall

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

Alternatives Cost Comparison

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)

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.

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