The state Department of Environmental Protection has ordered PPG Industries to collect and treat highly polluted water leaching from a mountainous 77-acre glass dump and lagoon into the Allegheny River just south of Ford City in Armstrong County.

Yesterday's administrative order also requires PPG to restrict access to the site and a stretch of the Allegheny River where the dump runoff has been measured as having a pH of 12 -- higher than ammonia. Fish cannot live in such water and it could cause skin burns to anyone contacting it.

The polluted runoff, which has killed much of the vegetation on a hillside between the dump and the river, also contains high levels of arsenic, lead, manganese and aluminum, according to a DEP sampling report.

The site, located 38 miles upriver from Pittsburgh, was used by PPG from 1949 through 1970 as a dump site for waste produced by its Ford City glass factory, once one of the biggest glass manufacturing operations in the world. In 1972, PPG sold the site for $1 to Ford City, which has established a park with ballfields on the northern part of the property.

The DEP issued its order after receiving water sampling findings late last year from the Allegheny River Stewardship Project, an environmental project initiated by the University of Pittsburgh's Graduate School of Public Health.

Jeremy Neuhart, a PPG spokesman, said several environmental assessments of the site since 1984 have concluded that no action by the company was necessary. He said the company was "surprised" by yesterday's order and has asked to review the data relied on by the department.

"PPG remains committed to fulfilling its environmental stewardship responsibilities," he said. "PPG also remains committed to working closely with Ford City to return this site to a condition that would be beneficial to the community."

The order requires PPG within 30 days to begin monitoring the quality and quantity of the seepage and the receiving streams and to submit to DEP an interim abatement plan for review and approval. Helen Humphreys, a DEP spokeswoman, said the monitoring order includes the ground water.