Northeast Ohio Regional Sewer District Westerly Wastewater Treatment Plant Cleveland

FACILITY BASIC INFORMATION

Plant Name: Westerly Wastewater Treatment Center (WWTC)

Location: 5800 Cleveland Memorial Shoreway, Cleveland, Cuyahoga County, Ohio

Operating Authority: Northeast Ohio Regional Sewer District (NEORSD)

Design Average Capacity: 35 MGD

Peak Wet Weather Capacity: 400 MGD (Combined Plant & CSOTF)

Population Served: ~106,000 residents

Service Area: Cleveland (West Side), Brooklyn Heights, Cuyahoga Heights, Newburgh Heights

Receiving Water Body: Lake Erie

NPDES Permit Number: 3PF00002*PD

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Year Commissioned: 1922 (Major modernization in 1970s and 2010s)

1. INTRODUCTION

The Westerly Wastewater Treatment Center (WWTC) serves as a critical environmental bulwark for Cleveland’s Near West Side, operating directly adjacent to Edgewater Park and Lake Erie. As the oldest facility in the Northeast Ohio Regional Sewer District (NEORSD) portfolio, Westerly has evolved from a basic primary treatment plant commissioned in 1922 into a sophisticated wet-weather control hub. While its average daily flow is approximately 35 million gallons per day (MGD), the facility is engineered to handle massive hydraulic fluctuations, boasting a peak capacity of up to 400 MGD through its integrated Combined Sewer Overflow Treatment Facility (CSOTF).

Strategically located between a major urban thoroughfare and the Lake Erie shoreline, Westerly plays a pivotal role in the district’s “Project Clean Lake,” a $3 billion infrastructure investment program to reduce combined sewer overflows. Utilizing a unique Trickling Filter/Solids Contact (TF/SC) secondary treatment process—chosen for its ability to handle shock loads and spatial efficiency—Westerly demonstrates how legacy infrastructure can be adapted to meet modern nutrient limits and stringent bacteriological standards for protecting public bathing beaches.

2. FACILITY OVERVIEW

A. Service Area & Coverage

The Westerly WWTC serves a highly urbanized sewershed covering approximately 14 square miles. The service area encompasses the Near West Side of the City of Cleveland and the suburbs of Brooklyn Heights, Cuyahoga Heights, and Newburgh Heights. The collection system is largely combined, conveying both sanitary sewage and stormwater runoff, which dictates the facility’s heavy focus on wet-weather management. The service area is a mix of dense residential neighborhoods and legacy industrial zones, presenting a complex influent profile requiring robust pretreatment protocols.

B. Operational Capacity

Unlike conventional plants where peak flow is typically 2-3 times the average flow, Westerly functions as a dual-mode facility:

• Dry Weather/Conventional Mode: The plant treats an average of 30-35 MGD through full secondary and tertiary treatment.
• Wet Weather Mode: During heavy precipitation events, the facility activates the Combined Sewer Overflow Treatment Facility (CSOTF). This parallel treatment train allows the site to process up to 400 MGD. Flows exceeding the secondary capacity receive enhanced primary treatment and disinfection before discharge, significantly reducing untreated overflow volume into Lake Erie.

C. Discharge & Compliance

Treated effluent is discharged directly into Lake Erie via a submerged outfall. Given the proximity to Edgewater Beach—one of Cleveland’s most popular recreational assets—effluent quality is heavily scrutinized. The facility operates under a stringent Ohio EPA NPDES permit with strict limits on E. coli, suspended solids, and phosphorus. The plant consistently achieves high compliance rates, earning Peak Performance Awards from the National Association of Clean Water Agencies (NACWA).

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3. TREATMENT PROCESS

A. PRELIMINARY TREATMENT

Influent enters the headworks where it undergoes rigorous screening to protect downstream equipment. The system utilizes mechanically cleaned bar screens to remove large debris (rags, wood, plastics). Following screening, flow enters aerated grit tanks where velocity is controlled to allow inorganic grit (sand, gravel, coffee grounds) to settle while keeping organic matter in suspension. The removed grit and screenings are washed, compacted, and hauled to a landfill.

B. PRIMARY TREATMENT

Westerly utilizes rectangular primary clarifiers equipped with chain-and-flight sludge collectors. In this stage, approximately 60-70% of Total Suspended Solids (TSS) and 30-40% of Biochemical Oxygen Demand (BOD) are removed via gravity settling.
Wet Weather Optimization: During storm events, the primary treatment process is augmented with chemical addition (Chemically Enhanced Primary Treatment – CEPT). Ferric chloride and anionic polymers are injected to enhance coagulation and flocculation, allowing for rapid settling at high surface overflow rates in the CSOTF tanks.

C. SECONDARY TREATMENT

Westerly is unique among NEORSD plants for utilizing a Trickling Filter / Solids Contact (TF/SC) process rather than conventional activated sludge. This selection was driven by the site’s limited footprint and the process’s resilience to shock loads.

• Trickling Filters: Primary effluent is pumped over plastic media towers. A zoogleal film (biomass) on the media metabolizes dissolved organics. The roughing filters reduce the majority of the soluble BOD.
• Solids Contact Tanks: Effluent from the trickling filters enters aerated solids contact tanks. Here, suspended growth microorganisms flocculate the remaining fine solids and polish the effluent. This stage improves the settleability of the solids before final clarification.
• Secondary Clarifiers: The mixed liquor settles in circular clarifiers. The clear supernatant proceeds to tertiary treatment, while settled biomass is either returned to the solids contact tanks (RAS) or wasted (WAS).

D. TERTIARY TREATMENT

To meet strict effluent limits, particularly for suspended solids and phosphorus, Westerly employs tertiary filtration. The facility utilizes gravity sand filters (or similar deep-bed media filtration) to capture remaining particulate matter. This step is crucial for ensuring the effectiveness of the subsequent UV or chlorination disinfection processes by increasing transmittance.

E. DISINFECTION

Disinfection is achieved using sodium hypochlorite (liquid chlorine). The chlorinated effluent passes through contact tanks to ensure adequate pathogen inactivation (kill time). Prior to discharge into Lake Erie, the water is dechlorinated using sodium bisulfite to protect aquatic life from chlorine toxicity. The effectiveness is continuously monitored via residual chlorine analyzers and daily bacteriological sampling.

F. SOLIDS HANDLING

Historically, Westerly operated on-site multiple-hearth incinerators. However, NEORSD has shifted toward regionalization of solids handling.
Primary and waste activated sludge is thickened (often using gravity thickeners for primary and dissolved air flotation or centrifuges for secondary). The thickened sludge is then pumped via the Inter-Plant Sludge Line to the Southerly Wastewater Treatment Center. At Southerly, the biosolids are processed in the Renewable Energy Facility (REF), where they are incinerated to generate electricity, significantly reducing the district’s carbon footprint.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The Westerly site is highly constrained, sandwiched between the Cleveland Memorial Shoreway (Route 2) and the Lake Erie shoreline. This geographical limitation has necessitated vertical construction (trickling filter towers) and compact process selection (TF/SC). The site includes an administration building, maintenance shops, and a fully equipped process control laboratory.

B. Odor Control

Due to its location adjacent to the affluent Edgewater neighborhood and a public beach, odor control is a paramount operational priority. The facility employs a multi-stage odor control strategy including:

• Covering of primary tanks and sludge processing areas.
• Collection of foul air via fiberglass ductwork.
• Treatment through chemical scrubbers (wet scrubbers using hypochlorite/caustic) and activated carbon adsorption units.

C. Combined Sewer Overflow Treatment Facility (CSOTF)

A distinct feature of the site is the CSOTF. While integrated with the main plant, it acts as a high-rate treatment system capable of screening, settling, and disinfecting vast volumes of dilute stormwater/sewage mix that would otherwise bypass treatment. This facility is essential for keeping Edgewater Beach open for swimming after rain events.

5. RECENT UPGRADES & MAJOR PROJECTS

As part of NEORSD’s “Project Clean Lake,” a 25-year consent decree program, Westerly has seen significant investment.

Westerly Tunneled Interceptor Capital Improvement

In conjunction with the storage tunnel, upgrades were made to the interceptor network delivering flow to the plant. This included gate structures and consolidation sewers to direct flow into the new WST.

Chemically Enhanced High Rate Treatment (CEHRT) Optimization

Recent operational upgrades have focused on optimizing the chemical dosing regimes for the CSOTF. By refining the polymer and coagulant ratios, the plant has improved settling velocities during peak wet weather events, ensuring that even during high-flow bypass scenarios, the discharged water meets primary treatment standards for TSS removal.

6. REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

A. Permit Requirements

Westerly operates under National Pollutant Discharge Elimination System (NPDES) Permit No. 3PF00002*PD issued by the Ohio EPA. Key parameters include:

• CBOD5: Weekly and monthly average concentration limits (typically < 15 mg/L).
• TSS: Strict removal efficiency requirements (85% removal minimum).
• E. coli: Seasonal limits (May-October) to protect recreational water usage.
• Total Phosphorus: 1.0 mg/L monthly average limit (Great Lakes protocol).
• Mercury: Low-level mercury monitoring due to Great Lakes operational standards.

B. Environmental Stewardship

The facility is a cornerstone of the health of Lake Erie’s Central Basin. The reduction of CSOs via the Westerly Storage Tunnel has had a direct correlation with the increased number of “green flag” days at Edgewater Beach. NEORSD monitors water quality daily during recreation season, providing real-time data to the public.

7. OPERATIONAL EXCELLENCE

Staffing: The facility is staffed 24/7/365. Operations are managed by Ohio EPA certified wastewater operators (Class III and IV). The maintenance team includes industrial electricians, millwrights, and instrumentation technicians specializing in the complex pumps and SCADA systems required for the dual-mode operation.

Automation: Westerly utilizes a Rockwell Automation / Allen-Bradley based SCADA system. This allows for automated transitions between dry-weather and wet-weather modes—a critical function when storm flows can cause influent rates to rise by 300% in under an hour.

8. CHALLENGES & FUTURE PLANNING

Current Challenges

• Aging Infrastructure: While the tunnel is new, much of the plant’s core concrete structures date back to the 1970s expansion or earlier. Concrete rehabilitation is an ongoing maintenance capital cost.
• Lake Levels & Erosion: Record high water levels in Lake Erie in recent years have threatened shoreline integrity. Revetment reinforcement is necessary to protect the northern boundary of the plant.
• Emerging Contaminants: Like all Great Lakes facilities, Westerly is preparing for potential future regulations regarding PFAS (Per- and polyfluoroalkyl substances).

Future Planning

Future CIP (Capital Improvement Plan) projects focus on energy efficiency and further CSO reductions. NEORSD is evaluating the long-term viability of the trickling filter media, which may require replacement or upgrades to newer, high-surface-area synthetic media to improve nitrification performance.

9. COMMUNITY & REGIONAL IMPACT

Westerly is more than a utility; it is a neighbor to one of Cleveland’s most vibrant communities (Gordon Square Arts District) and its premier beach. The District maintains a “Good Neighbor” policy, prioritizing odor control and architectural aesthetics (screening walls, landscaping). The facility’s performance is directly tied to the regional tourism economy; a clean Edgewater Beach draws hundreds of thousands of visitors annually, supporting local businesses.

10. TECHNICAL SPECIFICATIONS SUMMARY

11. FAQ SECTION

Technical Questions

Q: Why does Westerly use Trickling Filters instead of Activated Sludge?
A: The Trickling Filter/Solids Contact process requires less physical footprint than conventional aeration basins, which is critical for Westerly’s constrained site. It also handles the “shock loading” of high-strength industrial waste or sudden storm flows better than conventional activated sludge.

Q: How does the Westerly Storage Tunnel interact with the plant?
A: The tunnel acts as a flow equalization basin. During storms, excess flow fills the tunnel rather than overflowing to the lake. Once the storm passes, the plant pumps the stored water out of the tunnel and treats it through the full facility process.

Q: Does Westerly perform nutrient removal?
A: Yes. Phosphorus is removed via chemical precipitation (ferric chloride) and tertiary filtration. The biological process also achieves some nitrogen reduction, though the primary focus is BOD and TSS.

Public Interest Questions

Q: Is the steam coming from the plant smoke?
A: Generally, no. During colder months, warm water vapor from the treatment tanks or heating systems may be visible. However, Westerly no longer incinerates sludge on-site (it is pumped to Southerly), so there are no incineration stack emissions from this site.

Q: How does the plant protect Edgewater Beach?
A: By treating wastewater and controlling CSOs, the plant prevents bacteria (E. coli) from entering the lake. The District tests the water at Edgewater daily during the summer and posts advisories if bacteria levels are high.

Q: Can I tour the facility?
A: NEORSD occasionally offers public tours, particularly during their annual Open House events (often at the Southerly plant, but sometimes Westerly). Educational tours for schools or professional groups can sometimes be arranged by contacting the District’s outreach department.

Disclaimer: This page is a technical resource compiled for informational purposes. All operational figures and specifications are based on publicly available data, regulatory filings, and NEORSD reports as of 2023-2024. For official inquiries, please contact the Northeast Ohio Regional Sewer District directly.