Gwinnett County F Wayne Hill Water Resources Center Buford

1. INTRODUCTION

The F. Wayne Hill Water Resources Center (FWHWRC) represents the pinnacle of advanced wastewater treatment on the East Coast. As the flagship facility for the Gwinnett County Department of Water Resources, this 60-MGD plant serves a critical dual purpose: managing wastewater for the rapidly growing metropolitan Atlanta suburbs and returning ultra-high-quality effluent to Lake Sidney Lanier—the primary drinking water source for the region. This “pipe-to-lake” return loop makes the facility a model for indirect potable reuse (IPR) strategies in the United States.

Commissioned in 2000 and expanded significantly throughout the decade, the facility utilizes a sophisticated treatment train involving biological nutrient removal, chemical precipitation, ozone oxidation, and membrane ultrafiltration. The plant is renowned not only for its stringent effluent limits—particularly regarding phosphorus—but also for its onsite innovation hub, The Water Tower, and its sustainable energy generation systems which recover nutrients and power from biogas.

2. FACILITY OVERVIEW

A. Service Area & Coverage

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The FWHWRC serves the central and northern portions of Gwinnett County, a jurisdiction that has seen explosive growth over the last three decades. The collection system feeding the plant includes major interceptors traversing the Suwanee Creek, Richland Creek, and Sweetwater Creek basins. The service area is a dense mix of suburban residential developments, commercial corridors (including the Mall of Georgia area), and light industrial zones.

B. Operational Capacity

The plant has a permitted design capacity of 60 MGD. Historically, the plant was built in phases, starting at 20 MGD in 2000, expanding to 28 MGD, and finally reaching 60 MGD to accommodate regional growth. Current average daily flows typically range between 38 and 42 MGD, providing the utility with a crucial buffer for wet-weather events and future population influxes.

C. Discharge & Compliance

The facility’s discharge location is its defining engineering constraint. Effluent is discharged via a deep-water diffuser into Lake Lanier. Because the lake is a federally protected reservoir and a drinking water source, the NPDES permit limits are exceptionally strict. The plant effectively functions as a water reclamation factory, producing effluent that often exceeds the quality of the receiving raw water body. This high-level treatment allows Gwinnett County to return water to the basin, earning “return flow credits” that are vital for state water planning and inter-state water rights negotiations (the “Water Wars”).

3. TREATMENT PROCESS

The F. Wayne Hill WRC employs a complex, multi-barrier treatment train designed to achieve near-drinking water quality standards before discharge.

A. Preliminary Treatment

Raw wastewater enters the headworks where it passes through coarse and fine mechanical bar screens to remove large debris. Following screening, the flow enters vortex grit removal chambers where heavy inorganic solids (sand, gravel) are settled out to protect downstream pumps and clarifiers. The headworks is fully enclosed and ventilated through chemical scrubbers for odor control.

B. Primary Treatment

Flow moves to rectangular primary clarifiers. Here, settleable organic solids drop to the bottom as primary sludge, while fats, oils, and grease (FOG) are skimmed from the surface. The hydraulic retention time allows for a roughly 30-40% reduction in BOD and 50-60% reduction in TSS before biological treatment.

C. Secondary Treatment (Biological Nutrient Removal)

The heart of the plant is the biological system, which utilizes an enhanced activated sludge process configured for Biological Nutrient Removal (BNR). The basins are designed with anaerobic, anoxic, and aerobic zones to facilitate:

• Nitrification/Denitrification: Converting ammonia to nitrate, and then to nitrogen gas.

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• Biological Phosphorus Removal: Using Phosphorus Accumulating Organisms (PAOs) to uptake phosphorus.

Secondary clarification follows the aeration basins, separating the biomass from the treated water. The Waste Activated Sludge (WAS) is sent to the solids handling train.

D. Tertiary & Advanced Treatment

To meet the ultra-low regulatory limits for Lake Lanier, FWHWRC utilizes three distinct advanced technologies:

• Chemical Clarification: Alum or ferric salts are added to precipitate remaining dissolved phosphorus and flocculate fine solids.
• Ozonation: The plant utilizes a massive ozone generation system. Ozone is injected to oxidize organics, remove color and odor, and provide primary disinfection. This step is critical for breaking down emerging contaminants and ensuring the water is aesthetically indistinguishable from lake water.
• Membrane Ultrafiltration (UF): The facility operates one of the largest tertiary membrane systems in the U.S. (GE/Suez ZeeWeed cassette modules). These membranes provide a physical barrier against suspended solids, bacteria, and some viruses, producing a filtrate with turbidity consistently below 0.1 NTU.

E. Disinfection

While ozone provides significant disinfection, the final step utilizes Low-Pressure High-Output Ultraviolet (UV) light irradiation. This ensures the inactivation of Cryptosporidium and Giardia without creating chlorinated disinfection byproducts (DBPs) that could harm the lake’s aquatic life.

F. Solids Handling & Resource Recovery

The plant views waste as a resource. Primary sludge and WAS are thickened (via Rotary Drum Thickeners and Centrifuges) and sent to Anaerobic Digesters.

• Nutrient Recovery (Ostara): The plant features an Ostara Pearl® process that treats centrate (liquid from dewatering) rich in phosphorus and ammonia. It precipitates these nutrients into high-purity fertilizer pellets (Crystal Green®), preventing struvite scaling in pipes and recycling phosphorus.
• Cogeneration: Methane gas produced in the digesters powers onsite Combined Heat and Power (CHP) generators, offsetting a significant portion of the plant’s electrical demand.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The site spans over 700 acres, providing a substantial buffer zone against residential neighbors. The architecture emphasizes modern industrial aesthetics, with most processing equipment enclosed to contain noise and odors.

B. Energy Systems

FWHWRC is a leader in energy neutrality efforts. The CHP system utilizes GE Jenbacher engines fueled by digester gas. Additionally, the plant has implemented rigorous energy optimization in its aeration blowers and membrane scour systems.

C. Odor Control

Given the proximity to high-value real estate, odor control is paramount. The facility uses a three-stage approach: containment (covers on tanks), extraction (negative pressure ductwork), and treatment (wet chemical scrubbers and biotrickling filters) at the headworks, primary clarifiers, and solids handling facilities.

5. RECENT UPGRADES & MAJOR PROJECTS

Membrane Technology Replacement (Ongoing/Recent)

Scope: As the original ZeeWeed 500 series membranes reached the end of their useful life, the facility has undertaken phased replacement programs to install newer generation membranes that offer higher permeability and lower fouling rates. This ensures the 60 MGD capacity is maintained without expanding the physical footprint.

The Water Tower – Global Innovation Hub (2019-2022)

• Project Scope: While technically a separate entity, The Water Tower represents a massive infrastructure integration on the FWHWRC campus. It includes field training centers, R&D labs, and demonstration areas fed by active plant flows.
• Significance: This allows technology vendors to test sensors, pumps, and treatment processes using real wastewater sidestreams from FWHWRC, bridging the gap between academic research and municipal application.

Ostara Nutrient Recovery Installation (Commissioned ~2015)

• Technology: Implementation of the WASSTRIP® and Pearl® process.
• Drivers: High costs of chemical phosphorus removal and maintenance issues caused by struvite (magnesium ammonium phosphate) buildup in pipes.
• Results: The system recovers over 80% of the phosphorus and 40% of the ammonia from the dewatering stream, creating a revenue-generating fertilizer product.

6. REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

A. Permit Requirements

The discharge to Lake Lanier requires adherence to some of the strictest limits in Georgia:

• Phosphorus: Typically < 0.08 mg/L (Monthly Avg) – The plant consistently achieves < 0.04 mg/L.
• Ammonia (NH3-N): < 0.5 mg/L (Summer).
• Turbidity: Must be near zero to ensure UV effectiveness.
• Fecal Coliform: Non-detect or < 23 CFU/100mL.

B. Compliance History

FWHWRC consistently wins the Platinum Award from the Georgia Association of Water Professionals (GAWP), signifying 100% permit compliance for consecutive years. The plant serves as a regulatory benchmark for how wastewater can be safely returned to drinking water reservoirs.

7. OPERATIONAL EXCELLENCE

The facility is staffed 24/7/365 by Georgia State Certified wastewater operators. The operational culture focuses on predictive maintenance and SCADA-driven optimization. The laboratory onsite is fully accredited, capable of running sophisticated nutrient analysis and biological profiling to manage the health of the BNR process.

8. CHALLENGES & FUTURE PLANNING

A. Challenges

• Membrane Fouling & Lifecycle: Operating a massive membrane plant requires rigorous chemical cleaning (CIP) schedules and expensive periodic replacements.
• Changing Influent Profile: As the county promotes water conservation, the influent wastewater becomes more concentrated (higher strength), placing higher loads on biological processes despite lower hydraulic flows.

B. Future Planning

Gwinnett County’s Master Plan envisions FWHWRC continuing as the workhorse of the system. Future considerations include testing for PFAS destruction (potentially leveraging the existing Ozone system) and further optimization of energy recovery to reach “Net Zero” energy goals.

9. COMMUNITY & REGIONAL IMPACT

The plant is pivotal to the “One Water” concept in Georgia. By returning high-quality water to Lake Lanier, Gwinnett County preserves the reservoir’s volume, securing the water supply for downstream users and the county itself. The facility also features an extensive trail system and environmental education center, actively engaging the public to destigmatize wastewater reuse.

10. TECHNICAL SPECIFICATIONS SUMMARY

11. RELATED FACILITIES

• Crooked Creek Water Reclamation Facility: A nearby 16 MGD facility that diverts flow to FWHWRC or processes flow within the central Gwinnett basin.
• Shoal Creek Filter Plant: The drinking water plant that withdraws water from Lake Lanier, completing the urban water cycle supported by FWHWRC’s discharge.
• The Water Tower: Non-profit innovation center located on the FWHWRC campus.

12. FAQ SECTION

Q: Is the water leaving F. Wayne Hill safe to drink?
A: While the effluent quality meets or exceeds many drinking water standards, it is discharged into Lake Lanier where it blends with natural water before being withdrawn and treated again at a drinking water plant. This is known as Indirect Potable Reuse.

Q: Why does the plant use Ozone?
A: Ozone is a powerful oxidant used to remove color, odor, and trace organic compounds that biological treatment might miss. It prepares the water for membrane filtration and provides high-level disinfection.

Q: What is the “Green Fertilizer” produced at the plant?
A: The plant recovers phosphorus and nitrogen to create “Crystal Green” fertilizer pellets. This prevents these nutrients from clogging plant pipes (struvite) and creates a sustainable agricultural product.

Q: How does the plant handle extreme rainfall?
A: The plant has equalization basins and robust hydraulic capacity. Its 60 MGD design capacity provides significant headroom over the current average flow of ~40 MGD.

Q: Can the public tour the facility?
A: Yes, Gwinnett County DWR offers scheduled tours for educational groups, universities, and industry professionals. The Water Tower also facilitates technical tours.