Stage of Clean-up: Design Underway
Conditions at Proposal (January 18, 1994): Mason City Coal Gasification Plant covers approximately 2.3 acres in central Maso n City, a north-central Iowa community with a population of appro ximately 29,000 people. The plant operated from 1900 to 1951 and was demolished in 1952. An electrical substation and small stor age building currently occupy the southwest corner of the site. The remainder of the site is idle. Land use in the immediate vic inity consists of commercial and residential areas. The site is bounded to the east by South Pennsylvania Avenue, to the south by 5th Street Southeast, to the west by South Delaware Avenue, and to the north by a retaining wall along Willow Creek. During excavation activities for installation of a sewer lin e in 1984, oily sludges were encountered in subsurface soils at the site. Subsequent investigations conducted by the site owner, Interstate Power Co. (IPW), revealed the presence of three underg round storage structures containing oily sludge. The three struc tures and their contents were excavated, along with contaminated soil from around the structures. The excavated material was stoc kpiled directly onto the ground near the southeast corner of the site, and is covered with a membrane cap. This waste pile is one of two sources of hazardous substances at the site. Contaminate d soil is also present in the north-central portion of the site. More...