The Morning Call of Allentown reports the material was found Jan. 7 when it arrived at the IESI Bethlehem Landfill in Lower Saucon Township.
Officials say the material contains radium 226 isotope and may be from a glow-in-the-dark World War II era device. Township official say the material was not considered a serious threat at the time.
But the state Department of Environmental Protection expressed a concern about it several months later.
Officials say the cleanup was completed Wednesday afternoon.
Information from: The Morning Call, http://www.mcall.com