Our Year in Review
December 18, 2024
This year McFadden Engineering has been busy with several sustainable projects. Our focus on providing innovative solutions for water and wastewater clients includes multiple projects. Our team chose to highlight two projects that demonstrate our commitment to sustainable engineering and helping our clients achieve their ESG goals in 2024.
J.F. Shields High School Lagoon System Upgrade Project
Background
In 2022, McFadden Engineering submitted a funding application under the American Recovery Plan Act (ARPA) to upgrade the wastewater treatment system at J.F. Shields High School. While the existing lagoon system was a low-maintenance and effective method of wastewater treatment, persistent algal blooms were causing elevated pH levels and low dissolved oxygen (DO) concentrations in the effluent.
The Problem
The upgrade was necessary due to insufficient flow and loading in the lagoon system, which led to inefficient treatment and the inability to consistently meet effluent water quality standards. The three-cell lagoon system was effective in reducing carbonaceous biological oxygen demand (CBOD), particularly in the first cell, and ammonia concentrations in the effluent were consistently below 1 mg/L. However, the system struggled to meet regulatory pH and DO requirements, highlighting the need for improvement.
McFadden’s Sustainable Solution
Our team designed a solution to enhance the lagoon system’s efficiency while minimizing changes to the existing structure. Key improvements included:
- Leaving the first and largest lagoon cell intact, with the addition of a single Ares aerator near the discharge to the second cell.
- Installing two Ares aerators in the second cell and a fourth in the third cell, which also serves as a backup for maintenance needs.
- Using Ares aerators to provide fine-bubble aeration and coarse-bubble mixing, improving overall treatment efficiency and reducing algae through mixing.
A portion of the third cell was covered with a polyethylene cover to limit algae growth, and baffles were added to allow settling before discharge. The final effluent is disinfected and aerated before being released into a nearby creek.
These upgrades, completed in September 2024, have significantly improved system performance, maintaining compliance with regulatory requirements since implementation.
Roanoke Utilities Pipeline Expansion Environmental Evaluation
Background
McFadden Engineering conducted an environmental evaluation as part of a due diligence process for the replacement of approximately 2.18 miles (11,500 feet) of high-risk, leak-prone cast iron pipes. The project involves installing a 6-inch MDPE plastic pipe between two regulator stations: one located on Old U.S. Highway 431, 0.6 miles North of the State Highway 22 intersection, and the other on County Road 61, 0.56 miles north of U.S. Highway 431.
The Challenge
The Roanoke Utilities Board’s natural gas distribution system contains a significant proportion of high-risk cast iron pipes. Additionally, the project area is regulated by Section 4(f) properties, requiring careful consideration of environmental and community impacts.
McFadden’s Sustainable Solution
The McFadden Engineering team performed a comprehensive review of environmental data and conducted detailed evaluations of:
- Air quality and greenhouse gas emissions
- Water resources
- Hazardous materials and waste sites
- Biological and cultural resources
- U.S. Federal Highway Administration Section 4(f) properties, land use and transportation
- Noise and vibration impacts sensitive areas
- Environmental justice concerns, with special attention to minority and low-income populations
The evaluation concluded that no significant environmental risks were present, and mitigation measures were outlined for potential concerns during construction. This proactive approach ensured compliance with environmental standards while supporting the replacement of outdated infrastructure.
Looking Ahead to 2025
In 2025 our team will continue our efforts to meet the needs of the environmental community. We look forward to serving our clients. Contact our team today to see how we can help you achieve your sustainability goals in the new year.