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. 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

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)
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. 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

9. Operating Performance Annual Averages: 2011
Total Suspended Solids     mg/l
Total Nitrogen                  mg/l
Total Phosphorus             mg/l
Fecal Coliform               <2.0 MPN/100ML
BOD 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 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)

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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

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