Anaerobic Digestion Optimization System Provides Exceptional Improvements

Faced with soaring ammonia loads—especially during race weekends when 250,000+ fans descend on the town—the Speedway, Indiana Wastewater Treatment Plant was in urgent need of a solution. In 2012, they became the first facility to install Thermal Process Systems’ ExCalibAer™-inspired SNDR system following their anaerobic digester. The result? A 98% reduction in ammonia concentrations in dewatering filtrate, solving a major cause of permit violations and plant disruption.

This aerobic/anoxic upgrade not only eliminated hydrogen sulfide odors, creating a safer and less corrosive environment, but also dramatically improved dewatering efficiency. The plant saw a 30% increase in volatile solids reduction (VSR), a 33% drop in polymer use, and reduced hauling costs by 30%—all without the need for costly liquid-stream expansion.

Originally a partial ExCalibAer™ installation, Speedway’s system has delivered long-term, consistent results while paving the way for broader innovation. The full ExCalibAer™ system now offers even greater benefits like biogas quality improvement, struvite prevention, and pH control—all without added chemicals. For Speedway, the project was a win across the board: cleaner air, better biosolids, and fewer costs, right in the shadow of the “Greatest Spectacle in Racing.”