CHALLENGE
A telecommunications company planned to close about a dozen utility pole storage areas throughout New England. Utility poles are preserved with oil containing pentachlorophenol. This liquid drips off the poles when it is warm and contaminates the underlying soil. To make matters worse, pentachlorophenol has historically contained dioxin, a highly toxic chemical with very low cleanup standards. The analysis a one soil sample for dioxin can cost $750. St.Germain was tasked with assessing the soil at each storage site in a cost-effective manner to determine if remediation was necessary.
RESPONSE
First, St.Germain utilized an immunoassay method for dioxin analysis at one-third the cost of conventional analysis. Although some regulatory agencies would not accept this method, it allowed the more expensive analysis to be used as a confirmatory tool.
Next, after several pole yards had been remediated, St.Germain concluded that the contamination was rarely deeper than 2 feet and only within about 4 feet laterally from the poles. Therefore, rather than sample the soil to determine the extent of contamination and then excavate the soil, St.Germain began the process by excavating the soil first and then completing confirmatory sampling of the excavation bottom and sidewalls. This approach eliminated the costs associated with pre-excavation sampling. These surfaces were gridded and confirmatory samples were collected from each grid cell, allowing areas that had not achieved the cleanup standard to be easily identified.
Regulatory agencies in three different states approved this approach.