At long last, after operating under the draft Vapor Intrusion Guidance of 2002 for almost 13 years, EPA finally issued final vapor intrusion guidances on June 11, 2015, a specific guidance for petroleum vapor intrusion at leaking underground storage tank sites, and a more general technical guide for assessing and mitigating the vapor intrusion pathway at chlorinated solvent sites. (Technical Guide). In response to criticism that EPA did not subject the guidances to the public scrutiny of the administrative rule-making process, EPA allowed for a longer public comment period than is customary for guidances. Additionally, both vapor intrusion guidances were the subject of extensive discussions between EPA, various sister agencies, private industry, environmentalists, and the White House.
The recently issued vapor intrusion guidances substantially change EPA processes and technical approaches with respect to potential indoor air exposures to volatile chemicals. Additionally, EPA has fundamentally changed its approach to vapor intrusion in non-residential buildings by abandoning its deference to OSHA cleanup levels reflected in EPA’s 2002 Vapor Intrusion Draft Guidance.
Prior to the publication of the Technical Guide, it was clear that the decision to use OSHA indoor air levels in the non-residential workplace settings was based on OSHA and RCRA statutory requirements, the 1990 EPA/OSHA Memorandum of Understanding, and public policy considerations. Recently, EPA decided to change all of that. In its recent Technical Guide, EPA decided without much legal analysis, if any, that EPA’s guidance-based risk levels and not OSHA’s regulatory indoor air levels would determine whether vapor intrusion was a concern in a non-residential building and whether remediation was necessary (Technical Guide, page 10).
In its Technical Guide, EPA is seeking to replace by guidance OSHA’s validly promulgated regulatory indoor air levels otherwise applicable in the workplace setting in violation of the rule-making procedures required for such change. And, OSHA is now more or less suggesting that OSHA’s indoor air levels are no longer protective, thereby implicitly supporting EPA’s position. But to date, OSHA has not initiated the necessary rule-making process to change OSHA’s regulatory indoor air levels. Therefore, the EPA/OSHA jurisdictional conflict previously addressed by this author remains unresolved. In fact, OSHA’s indoor air levels are still effective since OSHA has not changed its regulatory indoor air levels through the required rule-making. This author has maintained that until such rule-making change is made, OSHA levels should apply in the workplace setting at UST and chlorinated solvent sites.