Girard Point in Philadelphia is owned by Republic Services (RSG) and appears to be still operating. I don't know if they continue to use the Jezco system.
According to the article Minerva Enterprises is a landfill in Ohio owned by Environmental Waste Technology. The landfill is listed as a licensed facility by the Ohio Environmental Protection Agency. Environmental Waste Technology is a Massachusetts corporation and has not filed an annual report with Massachusetts since 4/30/02. (Sounds like WTCH)
The only other information I found is in regard to Minerva Landill. Its an article from January, 2004 and doesn't really relate to Jezco, just to the landfill operation.