Record of Decision System (RODS)
RITARI POST & POLE
|Site Name:||RITARI POST & POLE|
|City & State:||SEBEKA MN 56477|
|NPL Status:||Currently on the Final NPL|
|ROD Type:||Record of Decision|
|Contaminant:||PCP, polychlorinated dibenzo-p-dioxin-equivalent (TCDD-eq|
Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by the EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.
The Ritari Post and Pole site is located approximately 3.5 miles northeast of the town of Sebeka, Minnesota. The site is in a predominantly wooded area with limited agricultural operations. The affected area occupies 10.25 acres of a 212-acre tract of land owned by Mrs. Hazel Ritari. The site is bounded by Country Road 143 on the south, pasture on the west, woods to the north and and pasture to east.
Mr. Melvin Ritari began wood treatment operations sometime between 1995 and 1957. The initial operation consisted of dipping wood into holding tanks containing creosote, and stacking the treated wood on the ground to dry. In 1959, the treatment process changed to using a heavy oil-based pentachlorophenol (PCP) mixture. The heavy oil was mixed with PCP in the PCP measuring tank and heated prior to being pumped into pressure tanks. Before 1973, treated wood was allowed to drip onto the ground before being stacked for drying. In 1973, treated wood was allowed to dry overnight in the pressure tank before being stacked on the ground. In 1979, the treatment process was modified to use a water-based PCP mixture. The treatment process included the bulk receipt of the product, which was transferred into 55-gallon drums prior to use. A vegetable oil was substituted for the heavy oil carrier in the water-based PCP solution. Mixing and treatment operations were similar for both oil and water-based mixtures. Mr. Ritari, the site owner and operator, died in May 1983, and his son Glenn took over the business. Wood treatment operations ceased in 1991, although the sale of treated wood continues to date. PCP sludge was generated from the mixing and treatment operations. Approximately 150 gallons of oil-based PCP sludge were estimated to have been generated each year. Water-based PCP sludge has been generated at a rate of 30 gallons or less per year. Sludge was removed from the tank once or twice per year and spread on the ground to dry. According to Glenn Ritari, some of the sludge was sold or given to farmers as a wood treating solution.
In 1976, the Minnesota Pollution Control Agency (MPCA) inspected the site and cited it for improper storage and disposal of sludge. In 1979, a complaint was filed with the MPCA by Mr. Thurman Ratcliff regarding the potential PCP contamination of his well. In 1980, MPCA determined the source of PCP in the Ratcliff well was probably due to the Ritari operation. Because of concern that soil contamination resulting from the treatment operations could impact area ground water, EPA inspected and evaluated the site and in 1985 placed it on the National Priorities List. Due to lack of financial resources, the MPCA issued a Determination of Inadequate Response on April 22, 1986, to allow the use of Superfund monies for a site investigation and remediation. Glenn Ritari was informed by EPA on March 24, 1987 of his responsibility for soil and ground water contamination at the site. On the 5-acre site, about 1,800 cubic yards of soil have dioxin contamination and about 5,000 cubic yards of soil have PCP contamination. The ground water directly below the contaminated soils has elevated levels of PCP and dioxin. The amount of ground water adversely impacted by the PCP and dioxin is unknown at this time.
This ROD discusses the potential detrimental health effects from site soil contaminants. These contaminants exceed health criteria and were also found in shallow ground water at the site. The contaminants of concern for soil and ground water are PCP and polychlorinated dibenzo-p-dioxin-equivalent (TCDD-eq). Remedial Action Objectives (RAOs) are proposed to protect human health and the environment from the contaminants at the site and are developed for site-specific conditions. Excavation and treatment will be the primary remedies for this site for the principal threats in the soil and ground water.
|Remedy:||The selected remedial action includes: decontaminating, dismantling or demolishing, and disposing of buildings and wood treating equipment; excavating and treating approximately 1,800 cubic yards of dioxin-contaminated soil using incineration; bioremediating 5,000 cubic yards of PCP-contaminated soil in an on-site treatment cell; implementing institutional controls including deed restrictions; installing a deep aquifer well for the on-site residents; restricting public access to the working area; and monitoring ground water to ensure an off-site migration of contaminants.|
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