Dewey Avenue (McShares) Site

Site Background

The Dewey Avenue (McShares) site (Site) is located at 1835 East North Street, Salina, Saline County, Kansas. McShares, Inc., operates a facility that consists of three main buildings used for packaging and warehouse operations, business offices, food additive production, and benzoyl peroxide flour bleach production. Facility operations began at the Site in 1958, including grain storage; and the manufacture, formulation, storage, handling, and distribution of pesticides, chlorinated solvent blends, and fumigants used in grain and food industries.

In 1994 and 1995 KDHE completed a Preliminary Assessment and a Screening Site Inspection to assess the potential soil and groundwater contamination. Carbon tetrachloride and other volatile organic compounds (VOCs) used in grain fumigant products were detected in area groundwater. The McShares, Inc. (a division of Research Products) grain fumigant formulating facility was identified as the source.

In November 1996 McShares entered into a Consent Order with the Kansas Department of Health and Environment (KDHE) to conduct a site investigation and evaluate remedial alternatives.

Contaminants of concern (COCs) are primarily VOCs used in grain fumigant products, including carbon tetrachloride, 1,2-dichloroethane, and ethylene dibromide. A Comprehensive Investigation, conducted in several phases beginning in 1998 and ending in 2007, identified contamination in soil and groundwater originating from three primary release areas across the Site. Source areas were identified as the former chemical storage tanks area north of McShares Building A, an area where chemicals were transferred from railcars to tanks, and an area in the northeast corner of the facility property. The 1995 property assessment, as well as site investigation activities from 1995 to 2007, provided data for the following Interim Remedial Measures (IRMs) and pilot tests:

  • Removal of Above-ground Storage Tanks (ASTs) and Underground Piping: McShares removed all ASTs and underground piping associated with the ASTs in 1995 to address concerns raised during the property assessment the same year.
  • Source Area Accelerated Bioremediation: An accelerated bioremediation pilot test initiated in June of 2008 evaluated the effectiveness of injecting a bioremediation product into the subsurface to reduce groundwater contaminant concentrations. The pilot test results found that accelerated bioremediation was feasible for reducing VOCs in source area groundwater. Based on the results, the IRM was expanded in 2010 to include additional injection locations on the McShares property.
  • Soil Vapor Extraction (SVE) System: In February 2010 a pilot test was initiated to evaluate the efficacy of SVE Technology to address source area contaminated soils identified near the former storage tanks. The results of the pilot test found that SVE was an effective technology in the 15 to 27 feet below ground surface (bgs) subsurface soils, but that in the upper 0 to 15-foot interval SVE was unlikely to be effective due to the presence of low permeability soils. Based on the results of the pilot test, a total of five SVE wells were installed in September 2010 with system startup occurring in November 2010. The SVE system remained in operation until September 2015, at which time the system was shut down due to blower equipment failure. A replacement SVE system and expansion of the remedial system is scheduled to be completed following issuance of the Final CAD.
  • Residential Water Supply Activities: Groundwater contamination was identified in private wells downgradient of the McShares property at levels above KDHE Tier 2 risk-based standards. In response, McShares, Inc., implemented one or more of the following IRMs at each impacted residential property: connection to rural water district supply, installation of carbon filtration system on the well, and/or provide bottled water.

KDHE held a public comment period between March 11, 2019 and April 9, 2019 to solicit public comments regarding a proposal to address environmental contamination at the Site. A Draft Corrective Action Decision (CAD) document that outlined the proposal for cleanup was available for public review at the KDHE offices in Topeka and at the Salina Public Library. The Draft CAD and other pertinent information are electronically available at the links below.

No public comments were received during the public comment period. No significant changes to the Draft CAD were made. The Final CAD was signed by KDHE on May 16, 2019. Remediation activities outlined in the Final CAD will begin following negotiations between KDHE and McShares Inc.

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KDHE Site Documents