Speedway disputes reporting on Indianapolis 500 wastewater impacts

Speedway officials refute recent media reports suggesting that Indianapolis 500 crowds cause wastewater permit violations, emphasizing that their treatment plant remains compliant and that ongoing upgrades are part of routine modernization efforts.

May 20, 2026

2 min read

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Officials in the Town of Speedway are disputing recent media reports that linked Indianapolis 500 race-day crowds to wastewater treatment permit exceedances and sewer system strain, pushing back on claims published by local outlets ahead of this year’s race weekend.

A recent article from WISH-TV and Mirror Indy examined how the annual influx of more than 350,000 visitors during the Indianapolis 500 affects operations at the town’s wastewater treatment plant. The reports stated that elevated ammonia concentrations and other pollutant exceedances tied to race-related wastewater flows contributed to violations cited by the Indiana Department of Environmental Management (IDEM), prompting a planned $14 million treatment plant modernization project.

According to the articles, the Speedway Wastewater Treatment Plant is designed to treat an average daily flow of 7.5 million gallons, with the ability to manage peak wet-weather flows of up to 8.9 MGD. Town officials acknowledged that the facility has recorded periodic permit exceedances during Indianapolis 500 festivities in recent years, particularly for ammonia levels. Officials attributed those spikes to the temporary surge in wastewater strength and volume generated by hundreds of thousands of race attendees using restrooms and temporary sanitation facilities over race weekend.

Race week wastewater management plan

During Indianapolis 500 race week, wastewater handling is split between two systems to reduce strain on the Town of Speedway treatment infrastructure. Portable restroom waste generated at the speedway is diverted to Citizens Energy Group’s Belmont Advanced Wastewater Treatment Plant in Indianapolis rather than being sent to the Speedway Wastewater Treatment Plant.

At the same time, Speedway officials coordinate with Merrell Bros., Inc. to temporarily suspend deliveries of certain industrial waste streams that can contain elevated concentrations of ammonia, phosphorus, carbonaceous biochemical oxygen demand (CBOD) and total suspended solids. The town also increases available plant capacity ahead of race week and temporarily pauses some discharge operations during peak event activity to help maintain stable treatment performance.

In response, the Town of Speedway issued a formal statement requesting corrections from WISH-TV and Mirror Indy, arguing the reports inaccurately characterized the town’s wastewater infrastructure and regulatory standing.

The town stated that race-day wastewater flows do not overwhelm the treatment plant’s hydraulic capacity and said the facility remains compliant with all federal and state requirements for flow management. Officials also disputed suggestions that untreated sewage was being discharged because of Indianapolis 500 crowds, emphasizing that planned upgrades are part of ongoing infrastructure modernization and wet-weather management efforts.

The dispute comes as Speedway moves forward with treatment plant improvements tied to an agreed order with IDEM, including expanded wet-weather storage and upgrades to disinfection systems intended to improve long-term permit compliance.