Benchmarking the Energy Intensity of Small Water Resource Recovery Facilities

Area of Science:

• Environmental Engineering
• Energy Management
• Wastewater Treatment

Background:

• Small communities face challenges in assessing water resource recovery facility (WRRF) energy efficiency.
• Existing benchmarks often do not accurately reflect the operational scale and specific needs of smaller facilities.

Purpose of the Study:

• To develop multiple linear regression models for benchmarking energy intensity (kWh/m3) in small WRRFs.
• To identify key variables influencing energy consumption in small-scale wastewater treatment operations.

Main Methods:

• Utilized data from Nebraska and Pennsylvania to build regression models.
• Analyzed significant variables including facility type, sludge treatment energy, flow rates, and effluent/influent quality parameters (NH3-N, CBOD5).

Main Results:

• Energy use models for small WRRFs differ significantly from those for large facilities.
• Facility type, supplemental sludge treatment, flow dynamics, building size, and specific pollutant levels were key predictors of energy intensity.
• Operational changes, such as operator transitions, demonstrably impact energy efficiency.

Conclusions:

• The developed models provide a valuable reference benchmark for small WRRFs (serving <10,000 people).
• Operational decisions and regulatory contexts play a crucial role in the energy efficiency of small wastewater treatment facilities.
• State-specific data highlighted regional variations in energy use patterns.