
Biosolids Facility TBL Analysis
Overview
For decades, the Germantown and Salemtown neighborhoods in Nashville suffered from persistent challenges associated with sewage waste management—heavy truck traffic, pervasive odors, and significant community disruption. Nashville Metro Water Services responded with a bold $136 million investment in a cutting-edge Biosolids Facility that would fundamentally reimagine urban waste processing.
Prior to this innovative facility, raw sewage sludge was transported long distances, often facing disposal challenges that resulted in backups, odors, and increased municipal liability. Due to the facility’s decision to invest upfront in a better design, the long-term economic, social, and environmental benefits will prove transformative.
Wilmot’s Role
Wilmot conducted a Triple Bottom Line analysis to evaluate the impact of the Biosolids Facility, revealing a remarkable $493 million in total benefits. Our team's assessment went beyond traditional infrastructure evaluation, demonstrating the project's multifaceted value.
Key benefits identified included:
Environmental Improvements
Significant reductions in greenhouse gas emissions
Mitigation of criteria air pollutants
Reduction of nitrogen runoff
Potential for future biogas reuse
Economic Advantages
Substantial operations and maintenance savings
Sludge disposal cost reductions
Revenue generation from biosolid pellet production
Savings to the agricultural industry
Increased property values
Avoided legal liabilities
The facility now processes sewage sludge into fertilizer pellets, creating a valuable soil amendment used in agriculture, erosion control, and landscaping. By transforming a problematic waste stream into a resource, Nashville demonstrated how innovative infrastructure can simultaneously address environmental, economic, and community challenges.
Results
$493M Triple Bottom Line benefits over 20 years
Benefit-cost ratio of 1.77
Client
Metro Water Services
Location
Nashville, TN
Markets
Municipal
Water/Wastewater
Services
Triple Bottom Line Cost Benefit Analysis
Economic Impact Analysis
Geospatial Analysis
What is Wilmot’s Triple Bottom Line analysis?
A full-cost accounting of environmental, social, and economic impacts, providing a dollar value cost or benefit for each aspect your project is considering.