Tinley Park officials say a water main break at the former Tinley Park Mental Health Center has spilled more than 2 million gallons and there is concern about possible contamination of nearby wells.

The water is discharging into a storm sewer as well as the adjacent Midlothian Creek, according to the village, which said the leak was discovered late last week.

The property is northwest of Harlem Avenue and 183rd Street and prior testing has shown evidence of contaminated soil in some areas of the site.

“We’re incredibly concerned about the immediate health and safety risk this is posing,” Tinley Park Mayor Michael Glotz said in a news release. “There’s currently no means of fire suppression in the area of the main break should any disaster occur, and we’re concerned about the potential contamination this may cause to the nearby households that utilize well water.”

Officials were not available Monday for an update.

The hospital and adjacent Howe Developmental Center closed in 2012, and the village has cited the state for environmental issues such as the presence of asbestos on the property.

Tinley Park’s budget for the fiscal year that began May 1 includes $7.5 million set aside to buy and remediate the property for potential redevelopment, although an earlier cost estimate to clean the site and demolish structures put the bill at more than $12 million.

The state’s Rebuild Illinois capital program has also designated $15 million toward cleanup of the property.

In late 2019, the village sent letters to the Illinois Environmental Protection Agency and U.S. EPA stating the property is in such a deplorable state that it presents “an imminent and substantial endangerment” to the environment and public health.

The village asked the agency to rid the site of contaminants such as asbestos and secure the 280-acre property with a fence.

In a bid to gain greater control over how the site might be redeveloped, Tinley Park had, in 2015, planned to pay the state what was then an asking price of $4.16 million for the property but backed away from that idea.

One proposal included building more than 400 single-family homes described as active adult, age-restricted housing targeting buyers 55 and older, as well as a 200-unit luxury senior apartment building.

In early 2019, gears shifted to a $450 million development that included a harness racing track and casino as well as a restaurant, nightclub and luxury hotels on about 120 acres of the site.

However, in October 2019, Gov. J.B. Pritzker blocked a possible sale of the site after the Chicago Tribune reported on one of the racino developer’s long-standing business ties to a banking family with reputed mob connections.

Tinley Park’s November 2019 letter to the IEPA and U.S. EPA cites hazards on the property including fuel storage tanks, asbestos and containers of hazardous materials.

The village had previously estimated the cost of getting the site ready for development, including environmental cleanup and demolition of the dozens of buildings on the property, at $12.4 million.

Testing completed in 2014 revealed environmental issues such as an abandoned sewage treatment plant, leaking underground storage tanks holding gasoline and other petroleum products, drums containing chemicals and soil contaminated with mercury and lead.

mnolan@tribpub.com