The signs are weathered and rusting, and their warning is outdated.

"Caution," they read. "Waste containment site."

Yet no danger lurks beyond the signs and the forbidding barbed wire-topped, chain-link fence to which they're affixed — aside from the occasional skinned knee or elbow of a skateboarder.

Today, the handful of signs on the northern border of Rosewood Park is the only visual evidence of the unlined sludge pit where oil companies disposed of acidic waste for about 25 years.

Now, after 20 years of environmental cleanup, Salt Lake City government officials are transforming the formerly off-limits land into a place where Rose Park residents are encouraged to gather.

The Salt Lake City Council committed to more than $1 million in improvements to the park over the past year, including the construction of a skate park last summer.

New playground and exercise equipment has been installed, along with sidewalks and landscaping. A gravel driveway and parking lot now penetrate the park, providing easier access to baseball and soccer fields.

In the coming weeks, an off-leash dog area will open on nearly one acre of formerly contaminated land.

"It's a great example of reuse," said Carlton Christensen, the Salt Lake City councilman who represents Rose Park.

The U.S. Environmental Protection Agency agrees. A recent report of its Superfund Redevelopment Initiative highlights the former sludge pit site as a reuse success, calling the expansion of Rosewood Park "a beautiful addition to the Rose Park neighborhood for recreational use."

"It's a functioning part of the park now," said Dell Cook, Salt Lake City's landscape architect project manager. "Before, it was a no man's land."

The contaminated land covers five acres on the north side of Rosewood Park, 1200 W. 1300 North. Utah Oil and Refining Co. used it as a dumping area for acidic waste sludge from the 1930s until 1957, when Salt Lake City purchased the land, according to the EPA report.

In September 1983, the site was placed on the EPA's National Priorities List of environmentally contaminated areas, also called Superfund sites.

The Army Corps of Engineers began cleaning up the site in 1982. A slurry wall was built around the perimeter of the site, and the waste material was capped.

The work was designed to prevent exposure to the acid-waste sludge, eliminate potentially unhealthy odors and vapors and prevent the sludge from spreading off-site through surface water or groundwater.

The EPA and the Utah Department of Environmental Quality determined in 2003 that the cleanup was complete, and the site was taken off the Superfund list.