Overview

Lead-based paint was widely used throughout the United States until it was banned in 1978 due to toxicity concerns. Facility owners are still contending with how to manage lead-based paint impacts to the environment to this day, many decades after its ban. The Pennsylvania Department of Environmental Protection (PADEP) recognizes this, and has established a risk-based cleanup standard for lead in soil and groundwater.

We recently encountered elevated lead concentrations in soil surrounding a former water storage tank that had been built in the 1940s. Lead-based paint was likely applied then removed via sandblasting over the lifetime of the tank, and accumulated in shallow soil around the perimeter of the former tank. In order to mitigate the human-health risk of lead exposure and the associated liability for our client, the horizontal and vertical extent of lead impacts above the soil cleanup standard needed to be delineated.

We used a combination of field instrumentation and soil sample collection followed by laboratory analysis to detect and delineate the lead concentrations. An X-ray fluorescence (XRF) spectrometer was used to screen for lead concentrations in soil in the field, and to guide sample locations. Approximately 20 grab samples were collected. Samples were collected at six-inch depth intervals to determine the vertical distribution of lead in the soil column, and at four-foot radial intervals to determine the horizontal distribution. Half of the sample set exceeded the PADEP cleanup standard. Elevated lead concentrations were generally proximal to the former tank and present within the uppermost soil layers. Concentrations generally decreased at a depth of one foot below grade, but also extended to deeper soils in some locations. Therefore we recommended the removal of soil within an eight-foot radius of the former tank foundation to a depth of 18 inches, followed by the collection of post-excavation soil samples to demonstrate that the residual lead concentrations pose no adverse risk.

In Pennsylvania, commercial and private landowners may obtain a release of liability from the PADEP for contaminants pursuant to the requirements of the Land Recycling and Remediation Standards Act (commonly known as Act 2). Pursuit of liability protection from the PADEP is voluntary, but insulates the landowner from legal claims resulting from human exposure to the contaminant of concern.

Now that the site has been sampled and a plan developed, the site owner can remediate the site, protect future site inhabitants and groundwater from lead exposure, and protect themselves and future landowners from liability concerns.