Highlights

• 1st Multi-sensor fugitive methane investigation in the western hemisphere
• 1st Dual-phase digestion microaeration pilot reduces hydrogen sulfide
• 6M Gallons increased capacity
• 6MW Cogeneration facility supplies up to 50% of power
• 91% Fugitive methane sources mitigated
• $200M+ federal funding

Innovative fugitive methane mitigation can mean big payoffs in sustainability and bioenergy programs — if done right. That’s exactly what the City of Columbus accomplished safely and successfully with its visionary Southerly Water Reclamation Plant (WRP) Bioenergy Facility.

The city’s project represents a first of firsts, leading the way to a brighter future for its growing community of 1.36 million residents by both significantly reducing methane, a greenhouse gas, and capturing the biogas for beneficial use in its Bioenergy Program to power the plant.

Midwest Biosolids Conference: Meet the team behind these pioneering solutions at the Midwest Biosolids Association’s 2nd Annual Conference.

To help the city reach its goals, Brown and Caldwell (BC) performed a novel fugitive methane mitigation alternatives evaluation (based on its measurement campaign) that attempted to composite all known methodologies to reduce fugitive methane and include many pioneering and emerging technologies. BC also conducted the first multi-sensor fugitive methane investigation in the Western Hemisphere to determine sources.

One key insight: Improving digestion design and performance is critical to reducing overall plant methane emissions. That concept was centered on modernizing design to reduce emissions from the digester and to increase effective digestion-reducing residual methane emissions downstream.

Another breakthrough included the design for a high-pressure digestion system to reduce leaks from the pressure relief valves. BC developed a greenhouse gas inventory and selected the most cost-effective solutions to be implemented in the Bioenergy Program design. The fugitive methane mitigation solutions included fixed concrete digester covers, rerouting biosolids handling air to a vapor combustion unit, and improved mixing and the digester designs.

The result? This project alone will reduce fugitive emissions by 91 percent and total GHG emissions at Southerly WRP by 80 percent by 2050 (not including nitrous oxide) while also increasing capacity and powering the plant up to 50% with bioenergy.

Together, these innovations have also enabled the city to secure federal funding and maximize the financial returns of their bioenergy program by $200+ million in eligible expenses.

“The Bioenergy project will help the Southerly facility reduce GHG emissions by 80% and help Columbus Water and Power make large strides toward meeting Columbus’ Climate Action Plan goals. This project would not have been possible without the partnership and contributions of Brown and Caldwell and the design team.”
Tyler Schweinfurth, Project Manager, Columbus Water and Power