In 2024, the Coatesville, Pennsylvania Wastewater Treatment Plant (operated by Pennsylvania American Water) upgraded the blower systems serving its two digester processes—a traditional aerobic digester and a modern M-TAD system. Each process required blowers capable of handling a wide operating window, from large turndown to varying pressures, while still maintaining high efficiency at every operating point.

Only a handful of blower technologies can reliably meet such broad performance requirements, and even fewer can do so while also offering low maintenance, SCADA-ready controls, and start-stop durability. After evaluating available options, Coatesville selected Inovair geared centrifugal blowers, which delivered the unique combination of efficiency, robustness, and operational flexibility required for these parallel digester processes.

Coatesville WWTP underwent a major facility modernization in 2010, increasing capacity to 7 MGD with plans to scale to a 21 MGD surge capacity. As part of its long-term upgrade strategy, the digester systems—critical to solids stabilization—required blower technology that could serve two very different process trains simultaneously.

The aerobic digester and the M-TAD system each operate across broad flow and pressure ranges, with varying aeration demands throughout the day. As flows increased and treatment requirements evolved, the plant needed a blower solution capable of delivering reliable aeration across a broad dynamic range without increasing maintenance or operational complexity.

During the evaluation process, Coatesville and PAW outlined several critical requirements—driven largely by the broad operating envelope of the two digester systems:

1. High Efficiency Across a Broad Operating Range

 
The blowers needed to operate efficiently at flows between 850–1,900 SCFM and pressures ranging from 5.0–10.3 PSIG. Few blower technologies can maintain high efficiency at both low-flow/low-pressure and high-flow/high-pressure conditions—making this the plant’s most important requirement.

2. Reduced Maintenance Time and Cost

 
Plant personnel wanted equipment that they could maintain themselves, avoiding high-cost service contracts and minimizing downtime.

3. Seamless SCADA Integration

 
The new blowers needed to integrate easily with the facility’s existing Supervisory Control and Data Acquisition (SCADA) system to maintain operational visibility and control.

4. Locally Sourced Components

 
The utility prioritized systems built with readily available U.S.-sourced components, ensuring long-term serviceability, faster parts acquisition, and reduced lifecycle costs.

5. High Start-Stop Durability

 
Power outages were a concern, requiring frequent blower start-stop cycles. Durability under this operating profile was critical.

To meet the performance requirements of both digester systems, Coatesville installed 10 Inovair geared centrifugal blowers supported by a flexible, SCADA-integrated controls architecture designed for efficiency and reliability.

Installed Equipment

• Five (5) IM-20 blower packages with one Master Control Panel
• Five (5) IM-30 blower packages, including two stacked configurations and one single unit
• Two (2) total Master Control Panels, providing coordinated system control and sequencing

This combination allows Coatesville to deliver precise aeration across a wide range of flows and pressures, providing the flexibility needed to operate two different digester processes in parallel.

Controls & Process Integration

The blower system was integrated seamlessly into the plant’s existing SCADA framework with advanced process-control features, including:

• Dissolved Oxygen (DO) control
• Oxidation–Reduction Potential (ORP) monitoring
• pH monitoring for added process stability

This controls approach maximizes efficiency, stabilizes digester performance, and supports frequent start-stop cycling driven by operational conditions.

Following installation, the Coatesville wastewater plant (WWTP) reported significant operational improvements, including benefits beyond what they planned:

Reliable, High-Performing Blowers with Start-Stop Durability

The blowers handle varying liquid levels, operate within a wide range of discharge pressures (1.5 – 18 PSIG), and handle frequent cycling with ease, providing consistent performance across all operating conditions. Inovair’s optimized aerodynamics and flexible controls easily met the plant’s energy-performance and duty cycle expectations. Fully-floating journal bearings, drive components, and thermal management allow frequent cycling and long-term durability.

Lower Maintenance Burden

Plant personnel now perform routine upkeep quickly and in-house. Maintenance hours and associated costs dropped significantly. This is because the Inovair blowers are designed for quick, straightforward, DIY maintenance—no costly service contracts required—with standard, off-the-shelf parts.

Better System Integration

SCADA integration was seamless, giving operators clear visibility and precise control of blower performance. Inovair packages include flexible, open-architecture controls that integrate smoothly with existing plant systems.

Assured Part Availability

With locally sourced components and U.S.-based manufacturing, Inovair blower package parts and support are accessible, predictable, and cost-effective.

Savings From Reduced Solids Hauling Costs

The digesters, both the new M-TAD and the traditional aerobic digester, are more efficient and optimized thanks to the varying pressures and flows of the Inovair blowers. This has reduced the amount of solids hauled away, thus further reducing operating costs.

Lower Heat and Noise Levels

Compared to the previous technology blowers, the Inovair blowers produce much lower heat and noise levels, which significantly improved the safety and comfort for operators inside the facility.