The owners of a Beaver County demolition company could go to prison in connection with an illegal dump as deep as a three-story building, state authorities said Tuesday.

Joan Unis, 71, of Aliquippa, Beaver County, and her son, Ralph Unis, 48, of Shadyside, are charged with storing construction and demolition waste on their property without a permit. The dump is so large that it has spilled down a hillside onto the property of St. George Byzantine Catholic Church.

"The days of being allowed to just take something out back and dump it in a hole in the ground are long gone," said Nils Frederiksen, a spokesman for state Attorney General Tom Corbett. "The rules and regulations that we have in place are there to protect everybody -- to protect the environment, the water supply, wildlife and neighbors."

The Unises own at least four demolition companies -- Unis Demolition Co., Beaver Valley Demolition Inc., Demolition Services Inc. and R. Unis Demolition Inc. -- all headquartered at the site of the dump in Aliquippa, which is Joan Unis' home. The dump is about 400 feet long by 300 feet wide and is up to 25 feet deep in some places, Frederiksen said.

Construction and demolition debris are among the items most commonly found in illegal dumps, said Shannon Reiter, president of PA CleanWays, a nonprofit that helps people fight illegal dumping.

"Contractors will charge a disposal fee but won't properly dispose of the items," Reiter said.

Ralph and Joan Unis each are charged with illegal waste disposal, illegal operation of a waste facility and creating a public nuisance -- each punishable by up to one year in prison and fines of $25,000 a day. The Attorney General's Environmental Crimes Section expects to prosecute the case in January.