Significant Changes Coming to Act 2 Cleanup Standards and Management of Fill Policy
The Pennsylvania Department of Environmental Protection (PADEP) and the Cleanup Standards Scientific Advisory Board (CSSAB) are working on several significant changes to the Act 2 Cleanup Standards, which are expected to be finalized and take effect sometime in 2022. Because the numeric values on which the residential cleanup standards for soils under Act 2 are incorporated by reference in PADEP’s Management of Fill Policy, these changes will also have significant impacts on construction and redevelopment projects outside of the Act 2 program.
The first significant change is a modification to the toxicological model and risk thresholds that are used to quantify exposures to lead in soils. Lead is a unique contaminant in that specific models have been developed by EPA to quantify health risks in adults and children from exposure to lead from a variety of sources. PADEP is proposing to use the updated IEUBK model with a CDC-recommended target blood lead level to calculate a new cleanup standard for lead in soils at residential sites (in the range of 200 mg/kg, which is a significant decrease from the current standard of 450 mg/kg). Use of the IEUBK model will likely necessitate changes to the characterization and attainment sampling procedures required by the Act 2 regulations because the input concentrations for the model are based on average concentrations of lead. Because of the critical importance of these issues, PADEP published in the Pennsylvania Bulletin an advance notice of proposed rulemaking on October 30, 2021, seeking information regarding appropriate models to use, target blood lead levels to use and appropriate attainment methods to implement. The comment period closes on January 28, 2022.
The second significant change is an update to the toxicological values used to calculate cleanup standards for polycyclic aromatic hydrocarbons (PAHs). The cancer potency of many PAHs has been assessed relative to the toxicity of benzo[a]pyrene, a PAH reference compound that has been studied extensively. EPA updated the consensus toxicity values for benzo[a]pyrene in 2017, and PADEP incorporated this change into the updated regulations under Act 2 that were published on November 20, 2021, resulting in significantly less stringent cleanup standards for benzo[a]pyrene. However, the cancer potencies of other PAH compounds have not been adjusted relative to the new benzo[a]pyrene values. Therefore, it is expected that several other PAH toxicity values will undergo similar adjustments, potentially resulting in less stringent cleanup standards and clean fill concentration limits for these ubiquitous contaminants.
The final and perhaps most significant change is an expected increase to the cleanup standards for vanadium. The toxicity values previously used by PADEP have resulted in cleanup standards that are often below naturally-occurring background concentrations of vanadium in soils in Pennsylvania, resulting in costly site cleanup and fill management decisions to address vanadium concentrations that are not the result of a spill or release. However, PADEP and CSSAB have identified alternative toxicity values that are currently in use by EPA and other states. A rulemaking effort is underway to incorporate an alternative toxicity value recommended by CSSAB, which will relieve these issues in the Act 2 program once the new standards are approved and published. The changes that are proposed are expected to be considered by the Environmental Quality Board in the form of a proposed rule in the near future.
Separately, PADEP is considering policies that will address the exceedingly low clean fill standards for vanadium under the Management of Fill Policy. These policies may provide relief on an interim basis while the rulemaking process under Act 2 to amend cleanup standards for vanadium is completed.