Changes to Act 2 Statewide Health Standards on the Horizon
This year may bring important revisions to the numeric cleanup standards established for many regulated substances under Pennsylvania's Land Recycling Program. The Pennsylvania Environmental Quality Board recently published a proposed rulemaking that would amend the regulations implementing the Pennsylvania Land Recycling and Environmental Remediation Standards Act ("Act 2") administered by the Pennsylvania Department of Environmental Protection ("PADEP"). The proposal was published in the March 6, 2010 Pennsylvania Bulletin, initiating a 30-day comment period ending on April 5.
The rulemaking's primary purpose is to update the medium-specific concentrations ("MSCs"), which are numeric standards developed by PADEP to implement the statewide health cleanup standards under Act 2 that remediators may attain at contaminated sites across the Commonwealth. The update incorporates current science into the numeric standards, which were first promulgated in 1997 and last formally revised in 2001. For example, as new toxicological data and information becomes available, that data and information can affect previously calculated MSCs. In addition, because some of the MSCs reflect maximum contaminant levels ("MCLs") promulgated by the U.S. Environmental Protection Agency ("EPA"), the proposed regulations include new MSCs that are already in use by virtue of previously finalized changes in the MCLs.
The proposed revisions to the MSCs, as currently drafted, will have a mixed impact on cleanups. In total, the MSCs will increase in 215 instances, including for various regulated substances with respect to the groundwater, soil direct contact, and/or soil-to-groundwater exposure pathways. Conversely, MSCs across these same pathways will decrease in 170 cases. Among commonly encountered regulated substances, the proposed revisions will impact soil and/or groundwater MSCs for benzene, benzo(a)pyrene and other polycyclic aromatic hydrocarbons, methyl ethyl ketone, various PCB aroclors, tetrachloroethylene ("PCE"), trimethylbenzene compounds, trichloroethylene ("TCE"), xylenes, arsenic and chromium VI. In addition, MSCs will be issued for 26 new regulated substances.
Notably, PADEP decided not to revise the used aquifer groundwater MSC for methyl tertiary butyl ether ("MTBE"), a prevalent gasoline-related contaminant. This standard was originally established using very conservative assumptions regarding toxicity. However, additional toxicity information has become available in recent years that would have resulted in a more lenient cleanup standard for MTBE using the scientific approaches prescribed in Act 2. Notwithstanding the availability of this information, PADEP decided not to alter the current MSCs for MTBE citing concerns over potential groundwater taste and odor impacts. The Cleanup Standards Scientific Advisory Board, an advisory committee that consults with PADEP on the Land Recycling Program, opposed PADEP's decision pertaining to the MSC for MTBE because it is based on aesthetic rather than health-based criteria.
Besides revising MSCs for specific substances, the proposed rulemaking will, among other things: set a three-year review cycle for future MSC table revisions; incorporate changes to MSC equations based on the current version of EPA's Risk Assessment Guidance for Superfund; clarify that MCLs and health advisory levels ("HALs") automatically become Act 2 MSCs upon promulgation; and clarify that remediators must address vapor intrusion when attaining the statewide health standard under Act 2.
The proposed changes to the MSCs could have a significant impact on parties remediating contaminated sites in Pennsylvania. Depending on the substances involved and whether the MSCs will increase or decrease, remediators may find it easier or more difficult to attain the statewide health standard. Parties currently in the midst of a cleanup should also review the proposal carefully to determine how it may affect an existing cleanup strategy.