Third Five-Year Review to Begin, Northwestern States Portland Cement Co. 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 third five-year review of the Northwestern States Portland Cement Company site in Mason City, Iowa.
The site consists of a portion of the Holcim (U.S.) Inc. (formerly Northwestern States Portland Cement Company and Holnam Inc.) cement manufacturing facility located north of Mason City, Iowa, near the intersection of 25th St. and U.S. Highway 65.
The Holcim facility has made cement since 1908. Before the cleanup, a byproduct of the cement making process known as cement kiln dust (CKD) was disposed on the site. It caused visible sediment in the surface water of Calmus Creek as well as the high alkalinity and high level of dissolved solids found in the creek and in the area ground water.
An area referred to as the West Quarry was mined for limestone, a raw material for cement production, until 1950. In 1969, Holcim began using the West Quarry for the disposal of CKD. Disposal of CKD in the West Quarry ceased in 1985 and the open portion of the quarry filled with water.
Under EPA oversight, Holcim installed a system to dewater the West Quarry and treat the collected water. An engineered clay cap was placed over the area of the West Quarry filled with CKD. Access to the area is restricted. Holcim continues to maintain and operate the treatment system.
EPA and the Iowa Department of Natural Resources will study site information during this third five-year review and inspect the site to determine if the remedy 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 INFORMATIONThe site administrative record is available at the following locations during normal business hours:
EPA Region 7
901 N. Fifth St.
Kansas City, Kansas
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. 5th Street
Kansas City, KS 66101
Toll free: 1-800-223-0425