Good at the First Drop: Start-up of the Western Wake Regional WRF Meets Summer Permit Limits 95 TH Annual Conference | November 2015 | Raleigh Convention Center, Raleigh, NC Chris White, PE

Acknowledgements Town of Cary Damon Forney Greg Johnson Hazen and Sawyer Barry Bickerstaff Katya Bilyk Bob Difiore Ron Taylor David Wankmuller

Agenda Introduction Background Permit Facilities Process Model Sampling Start-up Results

Introduction New Influent and Effluent Lines New Plant Summer Limits Meet Permit on Day 1 Use Basin Capacity to Hold Flow

Background Western Wake Partners Town of Apex Town of Cary Town of Morrisville Interbasin Transfer Certificate Discharge to the Cape Fear River Basin Western Wake Regional Water Reclamation Facility – WWRWRF Wastewater Management Facilities – WWRWMF

Interbasin Transfer Cape Fear River Basin Neuse River Basin

Timeline 1992 Interbasin Transfer Certificate 2001 Interbasin Transfer Certificate With Conditions 2002 Planning Studies Began 2011 Construction Began 2014 Placed in Service

NPDES Permit Monthly Average Weekly Average BOD 5, mg/L April – October November – March TSS, mg/L Ammonia, mg/L April – October November – March TN (April – October), mg/L5.0 TP (April – October), mg/L0.75 TN Load (April – October)112,400 lbs/season TP Load (April – October)16,100 lbs/season

NPDES Permit Fecal Coliform, N/100 mL200 Monthly400 Weekly DO, mg/L6.0+ Daily Average pH6.0 – 9.0 Daily TKN, NO 3 -N + NO 2 -NWeekly Total Copper, Total Zinc, Conductivity,Monthly Chloride, Total CyanideMonthly Chronic Toxicity, Total MercuryQuarterly Pollutant ScanAnnual

Western Wake Regional Wastewater Management Facilities Influent Conveyance 2 major pump stations ~9 miles pipelines Wastewater Treatment New 18 MGD WRF Effluent Conveyance Pump station ~11 miles pipeline Outfall at Cape Fear River

Pump Stations / Conveyance West Cary Pump Station – Upgraded Beaver Creek Pump Station – New West Cary Force Main West Reedy Branch Gravity Sewer Beaver Creek Gravity Sewer Beaver Creek Force Main

Western Wake Regional WRF Headworks Switchyard Effluent Pump Station Solids Handling Biological Reactor Basins Odor Control Administration & Maintenance Generators Clarifiers Filters Disinfection Post Aeration Bulk Chemicals

Basin Configuration Four Biological Reactor Basins (BRBs) Nine Cells Mixers: Cells 1 – 4 Jet Aeration and Mixing: Cells 5 – 9

Splitter Box Sluice gates direct PTE to each of the four BRBs Scum pumping station collects and sends scum to the scum digester

Basin Flow Preliminary Treatment Effluent – Cells 1, 2, or 3 Return Activated Sludge – Cells 1, 2, or 3

Recycles Fermentation Recycle – Cell 2 to Cell 1 Anoxic Recycle (ARCY) – Cell 4 to Cell 2 Nitrified Recycle (NRCY) – Cell 7 to Cell 3 BRB Drain Pump Station – return to Splitter Box Fermentation Recycle BRB Drain Pump Station Anoxic Recycle Nitrified Recycle

Aeration Four High Speed Blowers Jet Aeration and Mixing – Cells 5 – 9 Coarse Bubble Diffusers – Effluent Channel Blower Room

Process Configuration PTE RAS Fermentation Recycle ARCY NRCY Fermenter Anaerobic Anoxic Aerobic Post Anoxic

Chemical Feed Points Supplemental Carbon Cells 3 and 8 (Anoxic zones – denitrification) Metal Salt Cell 9 and Effluent Channel Polymer Effluent Channel

Clarifiers Clarifier Influent Channel Clarifier Effluent Channel

Clarifiers Scum Pump Station RAS Pump Station WAS Pump Station

Process Model

1 Basin 0.75 MGD, Adequate nitrification / denitrification capacity Second basin before 2 nd flow step-up Seeding ~600 mg/L target Model degradation effects Supplemental carbon Model predicted glycerin addition helps heterotrophs, but may negatively impact AOBs and NOBs Flow step-up 0.75 MGD to 2.66 MGD would require second seeding Split step-up into two events to give biomass time to grow

Process Model Chemicals Caustic Glycerin Ferric Polymer Solids 52 days to wasting (2500 mg/L MLSS) Intermittent wasting would not improve biomass growth

Batch Testing Concurrent with seeding – July 21 – 25 Evaluate nitrification Expected performance Quantify degradation Confirm seeding needs

Batch Testing

Seeding 5 days – July 21 – 25 Flow Starts – July 28 Additional Seeding – July 30 Potential Seeding – Aug 1 mg NH3-N / g VSS / hr July July 25, pH July 25, pH July July 29, repeat2.4 July 317.5

Seeding

Influent Flow

Recirculation Pumps Fermentation ARCY NRCY RAS All off at first except RAS Maximize nitrification time

DO Control

Caustic Feed Alkalinity concerns Feed issues (Manual drip) Recycles to distribute

Caustic Feed

Total Nitrogen Limit Supplemental Carbon Start August 8 Feed points Both anoxic zones Cell 8 aeration stopped Reaeration Zone (Cell 9) – Anoxic Rely on Effluent Channel single drops

Total Nitrogen Limit

Nutrient Profiles Abbreviated profiles during Batch Tests Aug 2 Aug 7 Aug 9 Aug 10 Secondary Effluent Began Aug 12

Nutrient Profiles – Ammonia

Nutrient Profiles – Nitrate

Results

Timeline July 21 – 25Seeding July 28Flow Starts July 30Additional Seeding August 8 Supplemental Carbon Feed Starts August 12Secondary Effluent Starts

Results InfluentEffluent NO x <0.05 mg/L1.19 mg/L TKN30.4 mg/L0.831 mg/L TN30.4 mg/L2.02 mg/L TP4.17 mg/L<0.10 mg/L

Questions Chris White