• MASON CITY COAL GASIFICATION PLANT, CERRO GORDO County, IA

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...

The soil, on-site waste pile, bedrock, and groundwater are contaminated with POLYNUCLEAR AROMATIC HYDROCARBONS (PAHS). Soil samples collected indicate that the soil is contaminated to a depth of 13 1/2 feet. A series of investigations between 1986 and 1993 by IPW identified high concentrations of PAHS in samples of groundwater taken from the uppermost aquifer and in samples of Willow Creek sediment downstream from the site. Ingesting or coming into direct contact with contaminated soil or groundwater could pose a public health threat.

Contaminants Detected
	Ground Water	Surface Water	Air	Soil	Other
ANTHRACENE	X	X
BENZ(A)ANTHRACENE	X	X
BENZENE	X
BENZO(A)PYRENE	X	X
CHRYSENE	X	X
ETHYLBENZENE	X
FLUORANTHENE	X	X
FLUORENE	X	X
NAPHTHALENE	X	X
PHENANTHRENE	X	X
PYRENE		X
TOLUENE	X

Groundwater and Drinking Water
Were drinking water wells shut down due to contamination?	No data
Are drinking water wells potentially threatened?	No data

EPA Hazard Ranking System scores for MASON CITY COAL GASIFICATION PLANT:

Less Hazard

National Average

More Hazard

0%					50%					100%

Overall site:

Surface water migration:

Ground water migration:

Rank Superfund sites in the U.S., IOWA, or in CERRO GORDO County by EPA Hazard Ranking Scores.

*Note: EPA's Hazard Ranking System is designed to screen and prioritize sites for the Superfund program, based on limited data available at time of listing. These scores are not based on a comprehensive risk assessment of the site and do not reflect conditions after initiation of cleanup work.

Number of PRPs currently associated with this site:

0

EPA Site Information

• NPL Fact Sheet
• Government Accounting Office (GAO) assessment
• Agency for Toxic Substances and Disease Registry Public Health Assessment
• Agency for Toxic Substances and Disease Registry (ATSDR) Public Health Assessment
• NPL Site 5 Year Reviews
• Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) Hazardous Waste Site Information
• Superfund Hazardous Waste Site Advanced Query Form

Scorecard reports for CERRO GORDO County on:

• Potential Sources of Land Contamination
• Criteria Air Pollutants
• Hazardous Air Pollutants