Last month, an underground storage tank located at the gas station on 1201 N. Mattis Avenue was reported as the latest leaking tank in the City of Champaign.

Throughout Illinois there are over 73,000 underground storage tanks that are registered with the Office of the Illinois State Fire Marshal. These tanks are commonly used to store petroleum products, chemicals and hazardous substances below the ground, primarily at gas stations, industrial facilities and agricultural sites. 

But state records show these tanks have leaked nearly 31,000 times since 1984, with about 350 incidents reported each year since 2009.

The leaking tank on Mattis is used for gasoline and diesel products, records show.

The American Economic Association estimates that 60% of all underground storage tanks have experienced at least one leak.  

Across Champaign, underground storage tanks (UST) have quietly leaked hazardous substances into the soil and groundwater, posing significant environmental and public health concerns. Federal laws say these tanks are regulated due to their potential to contaminate drinking water sources and create long-term environmental hazards.

It is difficult to determine from state data the exact number of tanks that are actively leaking.

The Illinois Environmental Protection Agency maintains a database of reported leaking tank incidents, including contamination discovered at both active and abandoned tank sites. The state data shows at least 175 leaks have occurred in Champaign since 1984, but many entries are incomplete and don’t have a date showing when the leaking stopped, for example.

There are 121 tanks currently registered in Champaign on the state fire marshal website, but only 38 facilities are listed as currently using a tank. Overall, about 218 facilities in Champaign have removed at least one tank after the facility using it ceased operations. 

According to the U.S. Environmental Protection Agency (EPA), some of the main streets in Champaign where leaking underground storage tanks have been concentrated include South Neil Street, Edgebrook Drive, West Springfield and North Mattis Avenue. 

Federal laws say leaking underground storage tanks have been an issue in Illinois for decades.

Leaking tanks are particularly dangerous because contamination can spread undetected beneath the surface. The state agency reported threats to human safety caused by these leaks can include fire or explosion, inhalation of dangerous vapors, contamination of soil and contamination of drinking and ground water.

Kim Biggs, a spokesperson for the Illinois EPA said in an email, “With all of the entries in the database across the state, about 85% of them are closed.” 

Newer regulations have introduced stricter safety standards, including requirements for double-walled tanks, leak detection systems and corrosion-resistant materials. These updates aim to prevent new leaks, but aging infrastructure and past contamination continue to pose environmental challenges. A log of updates can be found on the Illinois EPA website.

Underground storage tanks that are regulated by the state must undergo inspections. 

“A regulated UST system is scheduled for a routine inspection every two years,” JC Fultz, spokesperson for the Illinois State Fire Marshal’s Office, said in an email. 

There are currently 19 storage tank safety specialists across the state who conduct on-site inspections to ensure compliance. During inspections, specialists evaluate tanks under a range of technical standards. 

“The inspectors will check a regulated UST system for compliance with requirements such as spill prevention, overfill prevention, corrosion protection and release detection, operator training, financial responsibility and walk through requirements,” Fultz said.

If a facility passes inspection with no violations, it receives a green decal that is valid for two years and must be displayed on site as evidence of compliance. If violations are found, the facility has 60 days to fix the issues. 

“If a facility does so within that time period, it is then issued a green decal,” Fultz said. “If it does not, it is issued a red tag prohibiting future fuel deposits until that facility has achieved full compliance.”

When a tank does leak, it’s reported to the Illinois Emergency Management Agency (IEMA), which forwards the reports to the Illinois EPA Office of Emergency Response.

The Illinois EPA says the median length of time to clean up a site is 72 months. 

The cost for clean up and remediation can vary anywhere from $20,000 to $1 million depending on the size of the tanks and how much clean up is needed. The state agency has a fund available for underground storage tank owners to be able to fix, clean up or remove their leaking tanks.