California Code, Health and Safety Code - HSC § 79275

(a) The exposure assessment of any risk assessment prepared in conjunction with a response action taken or approved pursuant to this part shall include the development of reasonable maximum estimates of exposure for both current land use conditions and reasonably foreseeable future land use conditions at the site.

(b) The exposure assessment of any risk assessment prepared in conjunction with a response action taken or approved pursuant to this part shall include the development of reasonable maximum estimates of exposure to volatile organic compounds that may enter structures that are on the site or that are proposed to be constructed on the site and may cause exposure due to accumulation of those volatile organic compounds in the indoor air of those structures.