About 30 residents of Forward have sued the state, claiming that a January 2005 landslide of a fly-ash dump was not cleaned up properly, leaving them exposed to harmful levels of arsenic.

Members of families living along Rostosky Ridge and Rainbow Run roads will be heading to court Monday in their effort to seek an injunction to force the state Department of Environmental Protection to rid their neighborhood of fly ash.

They also are seeking reimbursement for costs involved in living with "the unlawful contamination of their neighborhood with toxic substances," the suit says.

Defendants include Allegheny Power, whose Mitchell Power Plant, the suit says, produced the fly ash decades ago; the Municipal Authority of Westmoreland County, whose broken waterline is blamed for creating the landslide; the state Department of Transportation, which is accused of using fly ash as an inadequate base for a portion of River Hill Road that collapsed in a later incident; and the state DEP.

The lawsuit focuses on an embankment constructed of fly ash near River Hill Road, Malerie Lane and Manown Road. The embankment collapsed Jan. 25, 2005 into the valley where the plaintiffs live.

They said the collapse occurred when fly ash corroded a waterline running through the dump near River Hill Road and caused it to break, precipitating the landslide that revealed the presence of a fly-ash dump, the suit said.

The result, plaintiffs said, has been 20 months of exposure to airborne fly ash that's accumulated on their lawns, inside their homes and in their bodies.

The suit claims residents have been exposed to three to seven times the legal limits of arsenic exposure. The toxic and hazardous substance has produced symptoms that include sore throats, skin irritation, rashes, gastric distress, nausea, vomiting, abnormal heart rhythm and pins-and-needles sensations in hands and feet, the suit says.

"That's what we're worried about now," said Barbara Diess, one of the plaintiffs. "We've had almost two years of exposure. Once there are heavy metals in the body, they stay there. They don't leave, and there are children here."

One child, the suit said, can no longer live at her home because of asthma attacks prompted by fly-ash exposure.

It also claims that visible fly ash on properties and throughout the neighborhood goes airborne during dry weather.

In the spring of 2005, the DEP hired Weavertown Environmental Group Inc. of Carnegie to do an initial cleanup.

The company, also a defendant in the case, returned several times to do additional work.

But the suit claims the cleanup failed to remove "substantial deposits of visible fly ash" in their neighborhood and streams.

It also claims that DEP officials said they have no funds for further cleanup, yet they haven't requested the U.S. Environmental Protection Agency to designate it as a Superfund site and conduct a cleanup.

Although the DEP spent money to shore up River Hill Road near the dump, it did not prevent it from collapsing, adding to the problems for residents, the suit says.

It also accuses the DEP of failing to take adequate remediation action to correct the problem or to take legal action against responsible parties.

DEP spokeswoman Helen Humphreys said she could not comment on the lawsuit because the department has yet to see the suit.

Although experts cited by plaintiffs show high arsenic levels in the neighborhood, Ms. Humphreys said the Allegheny County Health Department conducted a study showing arsenic levels similar to natural background levels.

She also said the department did significant work in the area, including rerouting a stream to prevent flooding, to help resolve problems for residents.

Jim Struzzi, PennDOT spokesman for District 12, said the department would not comment on current litigation.