EPA Response to Comments from Berks County
Dan Erdman of Keystone E-Sciences Group commented on the Exide Cleanup workplan on behalf of Berks County.
EPA’s Order requires Exide to investigate and remediate historical lead releases from their smelter operations. Over the last 20 years, EPA has found that exterior paint, particularly in homes built before 1978, can be a significant source of lead in soil. This impact is most typical along foundations and beneath the roof driplines. This lead does not originate from the Exide smelter. EPA cannot require Exide to conduct a cleanup unless the source of the lead is smelter emissions.
Given the age of the housing in the study area, EPA wanted to avoid the influence of painted surfaces on the characterization. EPA approved the protocol in the workplan to avoid any ambiguity in the sample results and to avoid disputes about Exide's obligation for cleanup.
EPA is relying on the large number of samples taken (over 12,500 sampling locations) to establish a well-defined area affected by the smelter emissions. EPA’s established action level of 650 parts per million (ppm) is a yard-wide average. Each property was sampled in at least two composite samples, front and back, even if the off-set limits applied. So no property was ignored simply because the sampling locations were within the specified set backs.
Modifications to the sampling procedures were made, as necessary, to meet the soil characterization objectives. These modifications required EPA’s approval prior to sampling. For those properties requiring remediation, offset areas will be included in the soil remediation.
EPA agrees with this comment and disapproved the garden exclusion proposed in the Exide work plan.
The County will not be afforded input into field decisions. Oversight will be carried out by EPA or EPA’s contractor, the US Army Corps of Engineers. Field notes and reports will be made available to the County, once reviewed by EPA.
EPA and PADEP Response:
At the August 22, 2007 meeting referenced in the comment, Paul Gotthold of EPA said that EPA will discuss the prospect of Act 2 relief with PADEP for remediated properties. EPA and DEP have held extensive discussions concerning PADEP Act 2 relief of liability (ROL).
PADEP has reviewed the risk assessment and concurs that 650 mg/kg is protective of human health and that 650 mg/kg would be acceptable under the Act 2 site-specific option for residential properties. However, PADEP does not plan to provide a general Act 2 release for properties cleaned up under the EPA Consent Order.
EPA will provide written confirmation to each property owner in the study area that the property has been remediated in compliance with the EPA Consent Order and that the post remediation soil lead levels are protective of residential use. Properties whose soil has been or will be remediated would be eligible to obtain a ROL by following all Act 2 requirements.
No sampling or remediation will be required beneath streets, sidewalks, building foundations, driveways or parking lots. Construction of most barriers, which requires the excavation of the top soil layer, has already removed the majority of the soil lead contamination. The lead levels in the soil beneath these barriers are substantially lower than the residential soil lead levels. EPA is confident that the risk of exposure to soils beneath permanent infrastructure is essentially zero. Given the average lead levels in the residential portions of the study area (537 ppm), replacement or repair of existing driveways, sidewalks are not expected to present an exposure risk to residents.
Remediated areas will include the exclusion zone/offset areas (drip zone, downspouts) as part of the cleanup. The EA square footage calculations will include the exclusion zone/offset areas.