The Agency's determination must be based on the credible, scientific information available to it, and the Agency is not required to perform additional investigations or studies beyond those required by applicable federal or State laws.
For notices required under subparagraph (B) of paragraph (2) of subsection (a), the Agency shall (i) within 2 days after determining that groundwater contamination poses a threat of exposure to the public above the Class I groundwater quality standards, provide notice of the determination by issuing a press release and posting the press release on the Agency's website and (ii) within 5 days after the determination, provide the owner and operator of the community water system and the owners and operators of all connected community water systems with a notice printed on Agency letterhead that identifies the contaminant posing the threat, the level of contamination found, and possible human health effects associated with exposure to the contaminant. Within 5 business days after receiving a notice from the Agency under this paragraph, the owner or operator of the community water system must send, to all residents and owners of premises connected to the affected community water system: (i) a copy of the notice by first-class mail or by e-mail; or (ii) notification, in a form approved by the Agency, via first-class postcard, text message, or telephone; except that notices to institutional residents, including, but not limited to, residents of school dormitories, nursing homes, and assisted care facilities, may be made to the owners and operators of those institutions, and the owner or operator of those institutions shall notify their residents in the same manner as prescribed in this subsection for owners and operators of community water systems. If the manner for notice selected by the owner or operator of the community water system does not include a written copy of the notice provided by the Agency, the owner or operator shall include a written copy of the notice provided by the Agency in the next water bill sent to the residents and owners of the premises; provided, however, if the water bill is sent on a postcard, no written copy of the notice provided by the Agency is required if the postcard includes the Internet address for the notice posted on the Agency's website. The front of the envelope or postcard in which any such notice is sent to residents and owners of premises connected to the affected community water system shall carry the following text in at least 18 point font: PUBLIC HEALTH NOTICE - READ IMMEDIATELY. For a postcard, text message, or telephonic communication, the Agency shall specify the minimum information that the owner or operator must include in such methods of notice. Within 7 days after the owner or operator of the community water system sends the notices to residents and owners of premises connected to the community water system, the owner or operator shall provide the Agency with proof that the notices have been sent. The notices required under subparagraph (B) of paragraph (2) of subsection (a) shall be provided whether or not the threat of exposure has been eliminated.
415 ILCS 5/25d-3