Vapor Intrusion: Resolving lia...

Vapor Intrusion: Resolving liability for contaminated sites just got a little scarier

By Bret A. Stone

Environmental lawyers are adept at pointing fingers and ultimately settling liability for contaminated sites based on certain projected costs. Vapor intrusion, which has been a part of the risk analysis for more than a decade, is now making a bigger impact. While new guidance for vapor intrusion at Superfund and Resource Conservation and Recovery Act (“RCRA”) sites is expected, the bigger news is that EPA and state agencies are starting to reopen sites where no vapor intrusion analysis was considered in earlier remedial decisions. The reopening of closed sites will put potentially responsible parties who thought their work was done at risk for more remedial work at these sites as well as third party claims based on alleged exposure to vapors under the citizen suit provision of RCRA or traditional common law theories, including nuisance and trespass.

Case and point, a Superfund site in Mountain View that was the subject of a consent decree for cleanup in 1992 just added a vapor intrusion remedy. See United States v. Intel Corp. and Raytheon Co., 91-CV-20275 (N.D. Cal.) (Dkt. 74). The site at issue involved several industrial companies manufacturing semiconductors, electronics, and other products during the 1960s and 1970s that released volatile organic compounds (“VOCs”) into the environment, primarily trichloroethylene (“TCE”), which commingled with similar releases from nearby U.S. Navy and NASA contaminant sources.

There are many engineering and institutional controls that may be implemented to respond to vapor intrusion, all of which carry significant costs. For existing buildings, the remedies include installation, operation, maintenance, and monitoring of appropriate-sized sub-slab/sub-membrane ventilation systems, where determined as necessary through indoor air and other evidence. Existing non-residential buildings can utilize the building’s indoor air mechanical ventilation systems as the remedy if the building owner agrees to use, operate, and allow for monitoring of the system. For future buildings, the remedies include installation of vapor barriers and passive sub-slab ventilation systems with the ability to make such systems active, except where the evidence shows there is no potential for vapor intrusion above the appropriate site indoor air cleanup levels.

The institutional controls include city planning and permitting requirements to require the appropriate vapor intrusion control measures in new building construction at the site and to require that EPA approve any new construction plans. The controls also include recording of covenants with owners to provide notice to future building owners of the vapor intrusion remedy and requirements; access for sampling, remedy operation and maintenance, and monitoring; and notice to EPA and the parties implementing the remedy when there are changes in ownership.

The projected costs of the vapor intrusion remedy in Mountain View? They could be as much as $24 million. Now that is scary!