Homeowners in the 300 block of Ryan Drive have alerted Scott officials about a landslide on a property that abuts vacant land between Beth-El Congregation and Chatham Park.

Joe Woznicki, who lives in that block of Ryan, told officials July 14 that the slide began about six years ago and has continued to crack driveways, separate retaining walls, uproot trees, knock over fences and ruin vegetation.

He said it also is presenting a potential health and safety risk because utility poles and their guide wires are slanting dangerously.

"The total hill doesn't have a chance to survive without remediation," said Mr. Woznicki, a general contractor, engineer and real estate agent.

Mine subsidence has been ruled out, according to a report in May by a geologist from the U.S. Department of Interior Office of Surface Mining Reclamation and Enforcement. However, drainage from the approximately 40-year-old Chatham Park apartment complex has eroded the bottom of the hill and a large drainage pipe has become separated, Mr. Woznicki said.

"It's literally a river down there," he added.

All of the properties involved appear to be privately owned, including the residences on Ryan and the Chatham Park apartments. A triangular piece of wooded hillside leading from the apartment complex was purchased by Mt. Lebanon in August 1995 for $1 million, even though the land is in Scott.

Mr. Woznicki, who was on Scott's planning commission in the 1990s, thought a part of the nearly 25-acre parcel was to be retained by the township, but apparently all of it was sold to Mt. Lebanon. At the time, the two communities were working on developing joint recreational trails, he recalled.

Though board President Eileen Meyers was quick to point out that Chatham Park was contributing to the problem, Mr. Woznicki remains convinced that Scott has some responsibility, too.

"I still feel there's some culpability from Scott for not doing something about Chatham Park," he said after the meeting. He also fears the problem will escalate and involve more homes as well as eventually impact sanitary sewer lines.

Repair costs have been estimated at $35,000 to $50,000 per house, he said, adding that erecting a wall a little bit at a time would only stress the hillside further.

Commissioners are dealing with another landslide problem affecting five houses on Boroview Drive. A proposal for a retaining wall there was estimated at $750,000 four years ago.

Since that time, a controversy has developed over whether the site qualifies for a public grant. The homes are privately owned and their boundaries extend to a closed walking path that was erected by mill workers to reach the now-abandoned steel mill below.

In March 2007, Allegheny County Chief Executive Dan Onorato gave Scott $100,000 in grant money for a proposed retaining wall.

Officials recently approved an $18,460 expenditure for additional core borings on the hillside.