Within 14 days of the finding, the Department shall notify the appropriate local health department of a finding that a groundwater monitoring well sample taken from a high–risk groundwater use area, as defined by the Department, contains: Methyl tertiary butyl ether at or in excess of 20 parts per billion; Benzene at or in excess of 5 parts per billion; or A combination of benzene, toluene, ethyl benzene, and xylene at or in excess of 100 parts per billion. Except as provided in paragraph (2) of this subsection, the Department shall notify each owner of property within one–half mile of the site from which the sample was taken. If the Department and the local health department agree, the local health department shall give the notice required under this section. The notification shall: Be mailed within 14 days of the receipt of a notice from the Department under subsection (a) of this section; Be mailed via certified mail; and Provide the property owner with information regarding the amount of contamination at the site. The person responsible for the release that resulted in the groundwater contamination shall reimburse the Department or the local health department for the costs associated with providing the notice required under subsection (b) of this section.