Second Five-Year Review to Begin - Lehigh Portland Cement Company Superfund Site, Mason City, Iowa
The U.S. Environmental Protection Agency conducts regular five-year reviews on Superfund sites where cleanups have been completed. These reviews are required by the Superfund law [42 U.S.C. Section 9621 (c)]. EPA Region 7 and the Iowa Department of Natural Resources have initiated their second five-year review of the Lehigh Portland Cement Co. site in Mason City, Iowa.
The site is at 700 25th St. on the north side of Mason City in Cerro Gordo County. It is bordered by 25th Street on the south, state Highway 65 on the east and northeast, and the Chicago Rock Island and Pacific railroads and Calmus Creek on the west. Calmus Creek flows to the Winnebago River, which is north and east of the site. Rural and agricultural areas lie to the east and west of the site. The Lime Creek Nature Center is to the northeast.
The Lehigh Portland Cement Co. has made cement since 1911. Cement making generates large quantities of kiln dust as the waste produced from heating raw materials. The cement kiln dust is alkaline. Disposal was in several on-site piles and in the Area C Pond.
Lehigh had installed an overflow control on the Blue Waters Pond. That allowed water from the pond to be discharged directly to Calmus Creek and eliminate possible equipment back-flooding. Problems were identified in 1981 when routine testing of the pond indicated alkaline waters.
A 1984 Iowa Department of Natural Resources investigation determined that an alkaline discharge from the pond had contaminated Calmus Creek. Lehigh retained a consultant in 1985 to conduct a hydrogeological study of the site. An EPA report in 1987 concluded that on-site contamination existed and that contaminants were migrating to ground water and Calmus Creek.
A remedial investigation/feasibility study was done by Lehigh in 1991. The adjacent Lime Creek Nature Center was investigated by Lehigh in the fall of 1990.
A Record of Decision signed in 1991 selected remedies for both the Lehigh Portland Cement Co. area and the Lime Creek Nature Center area.
The selected remedy for the Lehigh Portland Cement Co. area included digging up and moving cement kiln dust from the Blue Waters and Arch ponds to the Area C Pond. The remedy included constructing a clay cap over the Area C pond and the reclamation area. Pond waters were neutralized and surface and shallow ground waters were collected and treated before on-site discharge. Deed restrictions were placed on the property.
The remedy for the Lime Creek Nature Center area included building a dam across Quarry Pond and draining the western portion. Cement kiln dust dug up from Quarry Pond was combined with the cement kiln dust from all other areas and moved to an exhausted quarry east of the pond. A clay cap was built over the exhausted quarry. Quarry Pond was allowed to refill, and ground water and surface water are being monitored. The record of decision included cleanup goals for arsenic, lead, chromium, and alkalinity.
An administrative order was issued to Lehigh in 1992 to conduct the remedial design and remedial action. The remedial action began in 1994.
Five Year Review
EPA and the Iowa Department of Natural Resources will study site information during this second five-year review and inspect the site to determine if the remedial action continues to protect human health and the environment. EPA and the state encourage members of the community to ask questions and report any concerns about the site. A final report will be prepared at the end of the review and will be available at the site information repositories.Additional Information
The site administrative record is available at the following locations:
EPA Superfund Records Center
901 N. Fifth St.
Kansas City, Kan.
Mason City Public Library
225 Second St. SE
Mason City, Iowa
Questions or requests for information can be submitted to:
Community Involvement Coordinator
EPA Region 7
901 N. Fifth St.
Kansas City, KS 66101
Toll free: (800) 223-0425