On November 6, 2013, ASTM International issued its revised Phase I Environmental Assessment Standard, E1527-13, “Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process.” Perhaps the most significant change to the previous E1527-05 standard is the addition of subsurface vapor migration to the definition of “migration.” This change will require a new layer of risk analysis by environmental professionals (“EPs”) conducting Phase I environmental site assessments in accordance with the revised standard. We anticipate that the inclusion of vapor migration in the E1527-13 standard will result in an increased awareness of, and a heightened sensitivity to, the risks associated with conditions identified in Phase I reports.

Vapor Migration -

E1527-13 expands the E1527-05 definition of “migration” by adding “the movement of . . . vapor in the subsurface.” The new standard requires EPs to consider the potential for vapor migration in connection with any release to soil or groundwater, and requires vapor migration to be identified as a Recognized Environmental Condition (“REC”) unless an EP determines that no vapor migration can occur. This represents an increased analytical burden for EPs, particularly as vapor migration is often more difficult to identify than soil or groundwater contamination.