Bowery Bay Wastewater Treatment Plant Queens

FACILITY BASIC INFORMATION

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Plant Name	Bowery Bay Wastewater Treatment Plant (WRRF)
Location	Astoria, Queens, New York
Operating Authority	New York City Department of Environmental Protection (NYC DEP)
Design Capacity	150 MGD (Dry Weather)
Wet Weather Capacity	300 MGD (2x Design)
Population Served	~850,000 residents
Service Area	Northwest Queens (Astoria, Long Island City, Sunnyside)
Receiving Water Body	Upper East River / Riker’s Island Channel
SPDES Permit Number	NY0026158
Year Commissioned	1939

TARGET AUDIENCE

• Civil and environmental engineers designing urban wastewater retrofits.
• Municipal plant operators studying step-feed BNR configurations.
• Regulatory officials monitoring Long Island Sound nitrogen reduction compliance.
• Construction managers involved in dense urban infrastructure upgrades.

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1. INTRODUCTION

The Bowery Bay Wastewater Treatment Plant (WWTP) is a cornerstone of New York City’s environmental infrastructure, serving the densely populated residential and commercial hubs of Northwest Queens. Operated by the New York City Department of Environmental Protection (NYC DEP), the facility is designed to treat 150 million gallons per day (MGD) of dry weather flow, with a peak wet weather capacity of 300 MGD. Originally commissioned in 1939, Bowery Bay has evolved from a primary treatment facility into a sophisticated secondary treatment plant utilizing Step-Feed Biological Nutrient Removal (BNR) to meet stringent nitrogen limits for the Long Island Sound and East River.

Situated in Astoria near LaGuardia Airport, the plant manages wastewater for approximately 850,000 residents. It represents a critical case study in urban wastewater management, balancing the challenges of an aging collection system, combined sewer overflows (CSOs), and the necessity for continuous modernization without expanding the physical footprint. With recent capital investments exceeding $200 million focused on power reliability and main sewage pump rehabilitation, Bowery Bay remains a pivotal asset in NYC’s $87 billion “One Water” strategic plan.

2. FACILITY OVERVIEW

A. Service Area & Coverage

The Bowery Bay service area encompasses approximately 15,203 acres of Northwest Queens. This highly urbanized catchment includes the neighborhoods of Astoria, Long Island City, Sunnyside, Woodside, and parts of Jackson Heights. The collection system is primarily a Combined Sewer System (CSS), managing both sanitary sewage and stormwater runoff. The drainage basin is characterized by high impervious surface coverage, leading to rapid hydraulic loading during precipitation events.

B. Operational Capacity

The plant operates with a permitted dry weather design capacity of 150 MGD. However, due to the combined nature of the collection system, the facility is engineered to handle a peak wet weather flow of 300 MGD through primary treatment. Historical average daily flows typically range between 100 and 110 MGD, indicating a utilization rate of roughly 70-75%, providing a safety margin for population growth and intensification of land use in Long Island City.

C. Discharge & Compliance

Treated effluent is discharged into the Upper East River via a submerged outfall located in the turbulent waters of the Riker’s Island Channel. The facility operates under a State Pollutant Discharge Elimination System (SPDES) permit administered by the NYS DEC. A primary compliance driver for Bowery Bay is the Total Maximum Daily Load (TMDL) for nitrogen in the Long Island Sound. Consequently, the plant functions as a key component in the “Upper East River” aggregate limit, necessitating advanced nitrogen removal capabilities.

3. TREATMENT PROCESS

A. Preliminary Treatment

Incoming flow enters the plant through the Main Sewage Pump Station. Preliminary treatment is designed to protect downstream mechanical equipment:

• Screening: Mechanical bar screens remove large debris, rags, and plastics. The facility utilizes climber-type mechanical screens with automated cleaning cycles based on differential level control.
• Grit Removal: Following screening, flow enters aerated grit chambers. These reduce the velocity of the wastewater, allowing heavy inorganic solids (sand, gravel, coffee grounds) to settle while keeping lighter organic material in suspension.

B. Primary Treatment

Primary treatment occurs in rectangular settling tanks. These tanks utilize mechanical chain-and-flight sludge collectors to scrape settled solids to hopper sumps at the influent end, while skimmers remove fats, oils, and grease (FOG) from the surface. The hydraulic retention time (HRT) is designed to maximize Total Suspended Solids (TSS) removal—typically achieving 50-60% removal—reducing the organic load (BOD) sent to the secondary system.

C. Secondary Treatment (Step-Feed BNR)

The core of the Bowery Bay process is the Step-Feed Activated Sludge system, specifically configured for Biological Nutrient Removal (BNR).

• Step-Feed Configuration: Unlike plug-flow reactors where influent enters at the head of the tank, Bowery Bay splits primary effluent into four distinct “passes” or steps along the aeration tank. This allows the Return Activated Sludge (RAS) to be re-aerated in the first pass without food, maximizing the nitrification potential.
• Nitrogen Removal: By alternating anoxic and aerobic zones within the passes, the plant achieves nitrification (ammonia to nitrate) and denitrification (nitrate to nitrogen gas). Supplemental carbon (typically glycerol or methanol) is often added to the anoxic zones to drive denitrification, ensuring compliance with the stringent Nitrogen TMDL.
• Secondary Clarification: The mixed liquor flows to final settling tanks where the biological floc separates from the treated water. The clarified effluent overflows the weirs, while the settled sludge is either returned to the aeration tanks (RAS) or removed as waste activated sludge (WAS).

D. Disinfection

Disinfection is achieved via chlorination using sodium hypochlorite. The effluent passes through Chlorine Contact Tanks (CCTs) designed to provide sufficient contact time (typically 15-30 minutes at peak flow) to ensure pathogen inactivation (specifically Fecal Coliform). Following disinfection, the effluent is dechlorinated (if required by seasonal permit limits) before discharge to the East River.

E. Solids Handling

Bowery Bay is a sludge processing hub with comprehensive on-site solids handling capabilities:

• Thickening: Primary sludge is thickened using gravity thickeners. Waste Activated Sludge (WAS) is typically thickened using centrifuges or gravity belt thickeners to reduce hydraulic volume.
• Anaerobic Digestion: Thickened sludge is pumped to anaerobic digesters. These heated, enclosed tanks break down volatile solids, reducing sludge volume and pathogen content while producing biogas (methane).
• Dewatering: Digested sludge is chemically conditioned with polymer and dewatered using high-solids centrifuges. The resulting biosolids “cake” is collected and transported off-site for beneficial reuse (land application) or landfill disposal.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The facility occupies a constrained urban footprint, necessitating vertical integration and compact process layouts. The site includes the Main Building (housing administrative offices and the central laboratory), the Main Sewage Pump Station, the Dewatering Building, and the extensive tankage for primary and secondary treatment. The architecture reflects the utilitarian municipal style of the late 1930s, with modern industrial additions.

B. Energy Systems

Energy reliability is paramount. The plant is served by high-voltage feeds from Con Edison. Significant investments have been made in emergency power generation to ensure continuous operation during grid failures. The anaerobic digesters produce biogas, a portion of which is utilized in boilers to heat the digesters and facility buildings, contributing to a circular energy loop.

C. Odor Control

Given the proximity to the Steinway and Astoria residential neighborhoods, Bowery Bay employs extensive odor control systems. This includes covering primary settling tanks and utilizing activated carbon adsorption vessels and chemical wet scrubbers at the headworks, dewatering building, and thickener complex to treat foul air before release.

5. RECENT UPGRADES & MAJOR PROJECTS

6. REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

A. Nitrogen Reduction (Long Island Sound)

Bowery Bay is a signatory to the Nitrogen Consent Judgment. The plant is part of the Upper East River aggregate, which imposes a collective pound-per-day limit on nitrogen discharge across four facilities (Bowery Bay, Hunts Point, Tallman Island, Wards Island). The implementation of Step-Feed BNR has been instrumental in meeting these aggregate limits.

B. Combined Sewer Overflows (CSO)

The facility is governed by the City-wide Long Term Control Plan (LTCP). During intense rain events, flow exceeding 300 MGD in the collection system may bypass the plant at upstream regulator structures. NYC DEP is currently implementing Green Infrastructure (bioswales, rain gardens) within the Bowery Bay catchment to reduce stormwater runoff volume and frequency of CSO events.

7. OPERATIONAL EXCELLENCE

Bowery Bay is staffed by NYS DEC-certified wastewater operators (Grades 1-4). The facility utilizes a robust SCADA (Supervisory Control and Data Acquisition) system for real-time process monitoring. A key operational focus is the “Carbon-to-Nitrogen Ratio” management in the BNR process. Operators constantly adjust the supplemental carbon feed rates based on influent ammonia loads and temperature to maintain optimal denitrification rates without wasting expensive chemicals or causing “bleed-through” of BOD.

8. CHALLENGES & FUTURE PLANNING

Climate Resiliency: Following Superstorm Sandy, Bowery Bay was identified as vulnerable to storm surge. Future planning includes the installation of flood barriers for critical equipment and the elevation of sensitive electrical switchgear above the 100-year flood plain plus freeboard.

Aging Infrastructure: Much of the concrete tankage dates to 1939/1950. Concrete rehabilitation and structural reinforcement of the aeration tanks and digesters are ongoing maintenance priorities to extend the asset life.

10. TECHNICAL SPECIFICATIONS SUMMARY

11. RELATED FACILITIES

The Bowery Bay plant operates in conjunction with several critical remote facilities:

• Remote Pump Stations: A network of pump stations in low-lying areas of Queens lifts sewage into the interceptors feeding Bowery Bay.
• Upper East River Plants: Bowery Bay coordinates operationally with the Tallman Island WRRF and Hunts Point WRRF to manage the aggregate nitrogen discharge load into the East River.

12. FAQ

Technical/Professional Questions

1. Does Bowery Bay utilize external carbon sources for BNR?
Yes, the facility utilizes glycerol (and historically methanol) injection to provide the necessary soluble BOD to drive denitrification in the anoxic zones of the step-feed process.

2. What is the wet weather protocol for Bowery Bay?
The plant is designed to treat 2x Design Dry Weather Flow (300 MGD) through primary and secondary treatment. Flows exceeding hydraulic capacity at the headworks trigger upstream regulator bypasses (CSO events).

3. How are biosolids managed?
Sludge is thickened, anaerobically digested, and dewatered on-site using centrifuges. The resulting cake is transported by truck or rail for beneficial reuse or disposal.

Public Interest Questions

4. Does the plant smell?
While wastewater treatment inherently generates odors, Bowery Bay employs extensive odor control scrubbers and carbon filters. Occasional odors may occur during maintenance events or extreme weather, but they are tightly regulated.

5. Can the public tour the facility?
NYC DEP occasionally offers tours for educational groups and during special events like “Open House New York.” Public access is otherwise restricted for security reasons.