2016 White Paper regarding the Callahan Site as prepared by the City of Wildwood

The concerns raised in the White Paper are unsubstantiated. Furthermore, they are false. Below I will cite scientific articles or studies to address each of the concerns listed within the White Paper.

Refer to the White Paper prepared by an unknown author for their comments. Rather than repeat what was stated, I will only provide my comments.

On March 4th, 2022 the City of Wildwood published a document suggesting the White Paper is based on data from the 2012 Mundell Report. This report was produced prior to the 2012 cleanup at the Callahan site and is therefore irrelevant to the current site conditions.

1a Geophysical testing was performed by Tetra Tech in June of 2012. All areas of anomalies were later excavated as part of the 2012 remedial action. (Tetra Tech 2012).

1b Composite sampling is performed to provide a better estimate of mean concentrations and increases the ability to detect hot spots by increasing the number of locations sampled (US NRC).

1c It is irrelevant what sample depths were used pre 2012. The site was thoroughly sampled before and after the remedial actions that were performed at the end of 2012. See the Removal Action Report for details.

1d See the Removal Action Report for results of the extensive testing that was performed. Dioxin was never detected on the site and is not of concern at the Callahan property. ( Removal Action Report)

2a “The bottom of the pit was excavated to bedrock; therefore, no post-excavation samples of the floor of the pit were collected.” (Tetra Tech Removal Action Report 2013 p6)

2b Composite sampling is performed to provide a better estimate of mean concentrations and increases the ability to detect hot spots by increasing the number of locations sampled. (US NRC).

2c Geophysical testing was performed by Tetra Tech in June of 2012. All areas of anomalies at the Callahan site were later excavated as part of the 2012 remedial action. (Tetra Tech 2012).

3a Groundwater assessments and monitoring were completed by MDNR. Three monitoring wells were installed at the Callahan site and additional wells were installed in the vicinity of the site. No contaminants of concern were attributed to the Callahan property. (Site Reassessment Report 2016 p15) and (2012 MDNR “Monitoring Well Installation Report)

3b There is no cause for concern for vapor intrusion from groundwater because the ground water does not contain contaminants of concern. Ground water monitoring wells were installed into bedrock and at depths of 98-168 feet. (Site Reassessment Report 2016 p15) and  (2012 MDNR “Monitoring Well Installation Report)

3c Ground water is much more homogenous than soil and therefore fewer samples are necessary to obtain accurate results. (Practical Guide for Ground-water Sampling)

3d Three ground water wells were installed at the Callahan Site. Additional wells were installed within the same aquifer at the Strecker Forest site. All contaminants of concern were analyzed including Dioxin and VOCs and others. (Site Reassessment Report 2016 p15)

3e Three monitoring wells were installed at the Callahan site. Monitoring well MW-C01 was installed down gradient from the drum removal area. No contaminants of concern were detected in this well. (Site Reassessment Report 2016)

3f “Six new monitoring wells were installed by MDNR between September 20 and October 3, 2011, to better determine groundwater flow patterns at the site and to further characterize shallow groundwater quality.” (Site Reassessment Report 2016 p10)

4a Discusses cancer risk levels. The 2015 Human Health Risk Assessment uses the Cancer Risk levels of 1×10^-6 as recommended by the White Paper. See page 4 of this HHRA.

4b The evaluation of the Callahan property was performed using January 2015 residential screening levels.

4c The 2015 Human Health Risk Assessment uses the Cancer Risk levels of 1×10^-6 as recommended by the White Paper. See page 4 of this HHRA.

4d The use of composite sampling is an approved industry standard practice used to protect human health. See this document.

Comments to address recommendations listed within the White Paper

1. Geophysical and electromagnetic surveys were performed by Tetra Tech in 2012. All areas of anomalies were excavated during the remedial action performed in late 2012. During this RA over 2000 tons of soil were removed and disposed offsite. Geotechnology (seems to be Wildwood’s preferred contractor) provided a cost estimate of $5,000 per day to perform a Magnetometer survey. They estimate it will take 15-20 days to complete the survey for an estimated cost of $75,000 – 100,000.  (Tetra Tech 2012) and (Removal Action Report 2013)
2. These areas were sampled as part of the remedial action performed in 2012. At that time they concluded no additional excavation or testing was necessary. TRC Companies, a nationwide environmental firm with a local office, outlined a cost estimate of a minimum of $100,000 to perform a survey of a limited area. Higher resolutions and a greater area will increase the cost. (Removal Action Report 2013)
3. The EPA and Missouri Department of Natural Resources concluded that no additional groundwater testing was needed onsite and historical testing wells were removed or capped. TRC Companies provided a cost estimate for installation and monitoring of the 5 – 7 wells as outlined in the White Paper as anywhere from $100,000 to $250,000. (Tetra Tech 2012) and (Removal Action Report 2013)