Cook County is underway with the first phase of a project to demolish dozens of buildings at the former Oak Forest Hospital site, with a three-year plan to clear more than 50 buildings on the 153 acres.

In unincorporated Cook County next to Oak Forest, the hospital grounds are southeast of Cicero Avenue and 159th Street.

The property in the mid-19th century was the site of a poor farm for Chicago’s indigent and sanitarium for tuberculosis patients. A full-service hospital on the property closed in 2011.

The county had hoped to start demolition sometime in 2023, but said that the site required further study of the potential preservation or reuse of some buildings.

An initial phase includes abatement of hazardous materials, such as asbestos and lead, in 11 buildings spread throughout the campus.

That is supposed to wrap up by March 2026, followed by a second phase that will involve abatement and demolition of another 40 buildings.

The second phase is supposed to start in April 2026 and continue through March 2028, according to the county.

Work including demolition will generally take place between 7:30 a.m. and 4:30 p.m. Monday through Friday, officials said. No explosives will be used to take down structures, but instead hydraulic excavators will take apart buildings piece by piece.

Abatement is going to be a big part of the demolition process, according to the county.

Any hazardous materials will be removed before demolition starts and, during demolition, contractors will use water cannons to soak down structures in an effort to minimize dust.

Officials said air-monitoring equipment will be used during the demolition.

Long-term plans call for redevelopment, and the county said it will seek community feedback on potential uses.

Officials said parts of the campus are priorities for preservation, including old-growth oak savanna at the northwest corner, closest to the intersection of 159th and Cicero, with trees estimated to be more than two centuries old.

Elsewhere, a team of arborists has worked to identify trees that should be saved, with demolition plans designed to remove a minimal number, according to the county.

Places of worship on the campus that catered to staff and the ill, such as Sacred Heart Chapel, shuttered in fall 2018, will be preserved. The chapel is surrounded by structures slated for demolition, and work will ensure the demolition doesn’t affect the chapel, according to the county.

In advance of abatement and demolition, the county’ archives and records office has completed extensive work to remove and preserve artifacts, documents and other important materials, officials said.

There is also a burial site that includes remains of victims of the 1918 flu pandemic, and that area won’t be touched, officials said.

The property opened in 1853 a poor farm for Chicago’s indigent and sanitarium for tuberculosis patients, then later a full-service hospital.

The campus was home to the 600-bed Oak Forest Hospital, which not only provided inpatient care in the south suburbs but was a training ground for health care workers.

Cook County’s Health and Hospitals System, after Oak Forest Hospital closed, continued to offer outpatient services at the campus, which moved to Blue Island in June 2020.

The Oak Forest campus is bordered by the Cook County Forest Preserve District’s 455-acre Midlothian Meadows on the north side of 159th and east of Cicero, as well as the district’s Oak Forest Heritage Preserve to the east. The district purchased the 176-acre site for $15 million in 2010.

A 1916 map of the Heritage Preserve property shows locations of cow and hog barns, poultry house and a hog hospital, an aged couples home, baseball fields, tennis courts, a crematory, casket manufacturer and Protestant and Catholic chapels.

There is also evidence of a Native American settlement, possibly dating to the 1600s, with archaeological surveys in the late 1950s uncovering eight houses and an entire Native American village, according to the forest preserve district. Among the findings were hundreds of prehistoric artifacts, primarily stone tools or byproducts of stone tool making.

Using logs kept from 1910 to 1971, Cook County officials were able to verify that more than 91,000 people were buried on property who may have lived at the poor farm or a tuberculosis sanitarium the county established at the site.

mnolan@southtownstar.com