The Midwest was a powerhouse of manufacturing for a large part of the 20th century, and neighborhoods in Indianapolis are still dealing with the industrial pollution left behind.
In West Indianapolis, the owner of the former Reilly Tar & Chemical Corp. is trying to sell the prominent westside property on South Tibbs Avenue. A few prospective buyers have shown interest.
Efforts to cleanse the land, though, remain ongoing. The owner, a subsidiary of the Indianapolis-based Aurorium international chemical manufacturing company called 1500 South Tibbs LLC, is preparing to clean up the remaining harmful chemicals.
The plant opened in 1930 and made chemicals used for a variety of products, such as dandruff shampoos, herbicides and pharmaceuticals.
It changed hands over the years before it shut down in 2024, but chemical production and other activities at the site polluted the ground there and at nearby residential areas. The pollution became so bad that it was added to the National Priorities List, a federal inventory of the highest priority hazardous waste sites in the nation, in 1984.
Since then, the U.S. Environmental Protection Agency has been overseeing the cleanup of the site by the companies legally responsible for it.
Much of the pollution that was found at the site has been removed, but groundwater monitors are still detecting high levels of some dangerous chemicals.
So what’s the risk to nearby neighborhoods, and what happens to the cleanup if the site changes ownership? Here’s what you need to know.
The contaminants present
Groundwater monitors along South Tibbs Avenue and South Moreland Avenue have detected levels of benzene, pyridines and ammonia above the maximums allowed in the site’s cleanup agreement.
Breathing in benzene can cause drowsiness, dizziness, headaches and respiratory tract irritation. Long-term exposure to benzene has been linked with a higher risk of cancer, particularly leukemia and other cancers of blood cells.
Pyridines can affect your neurological system and kidneys, and ammonia, which is used to make pyridines, can hurt your skin, eyes, throat, and lungs and cause coughing and burns.
The chemicals are trapped at least 25 feet underground, but there is a small chance they could make their way above ground in a process called vapor intrusion.
“We don’t anticipate that vapor intrusion is going to be an issue here because of the concentrations that are in the groundwater right now, which are way lower than they were 20-30 years ago,” said EPA remedial project manager Dion Novak. “ We don’t anticipate it’s going to be a problem, but obviously we have the monitoring in place for that.”
If monitors detect the presence of chemicals at levels that could cause vapor intrusion, they will contact homeowners likely to be affected by the intrusion and ask permission to test their homes. If those chemicals are found, the EPA will arrange a way to mitigate the intrusion.
The cleanup plan
To clean up the land, contractors for 1500 South Tibbs LLC will use a chemical treatment strategy called biosparging.
It involves injecting air into the aquifer where the contaminated groundwater is located in order to accelerate the growth of bacteria, which will then break down the chemicals over time.
“It oxygenates the aquifer, which increases the degradation of the organic contamination that’s already there. Mother Nature already does that. This just enhances that,” Novak said.
It will take between 15 and 20 years to break down the contaminants.
To facilitate the biosparging, crews have dug 103 wells and will dig trenches along the South Tibbs Avenue property line to install piping for the air injection.
Crews have also installed dozens of groundwater and soil gas monitors to track the contamination in the future.
The final piece of the biosparging system will be two compressed air containers. They are modified shipping containers packed with air compressor equipment and equipment to regulate the makeup of the air used for biosparging.
They are expected to arrive in September.
Planning for a site sale
According to Aurorium site representative Dave Wilkes, the site is up for sale and there have been at least two prospective buyers. It’s unclear how they propose to use the property.
Aurorium wouldn’t identify the interested buyers, but the cleanup will still continue if a sale happens. The entity responsible for the cleanup will depend on the details of the sale.
“It’s going to be the same work regardless of who the site owner is,” Novak said.
1500 South Tibbs LLC signed a consent decree with the U.S. Department of Justice in 2024 that set the terms of the cleanup. As part of the deal, the company agreed to set up $4.7 million in financial assurance to ensure the cleanup would continue even if the company did not exist in the future.
That financial assurance, in the form of a trust fund and letter of credit, will be used to complete the cleanup even if there is a change in ownership, although the financial responsibility could ultimately change hands along with the site.
To contact the EPA
For more information about the Reilly Tar & Chemical Corp. Superfund site, check out the EPA’s dedicated website.
Residents living near the site can also contact EPA site staff for more information about vapor intrusion and other information.
EPA community involvement coordinator Francisco Arcaute can be contacted at 312-886-7613 or arcaute.francisco@epa.gov, and remedial project manager Dion Novak can be reached at 312-886-4737 or via email at novak.dion@epa.gov.
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Mirror Indy reporter Enrique Saenz covers west Indianapolis. Contact him at 317-983-4203 or enrique.saenz@mirrorindy.org. Follow him on Bluesky at @enriquesaenz.bsky.social.
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