35 Ill. Adm. Code 620.305
Preventive Notification Procedures
Section 620
Section 620.305Â Preventive
Notification Procedures
a)Â Â Â Â Â Â Â Â For groundwater quality monitoring under Section 620.302, a
preventive notification must occur whenever a contaminant:
1)Â Â Â Â Â Â Â Â Specified in Section 620.310(a)(3)(A) is detected (except due
to natural causes) in Class I groundwater;
2)Â Â Â Â Â Â Â Â Denoted as a carcinogen under Section 620.410(b) is detected in
Class I groundwater; or
3)Â Â Â Â Â Â Â Â Subject to a standard under Section 620.430 is detected
(except due to natural causes) in Class III groundwater.
b)Â Â Â Â Â Â Â Â When a preventive notification is required for groundwater that
is monitored by a regulated entity for the subject contaminant, the owner or
operator of the site must:
1)Â Â Â Â Â Â Â Â Confirm the detection by resampling the monitoring well within
30 days after the date on which the first sample analyses are received; and
2)Â Â Â Â Â Â Â Â Provide a preventive notification to the appropriate
regulatory agency of the results of the resampling analysis within 30 days after
the date on which the sample analyses are received, but no later than 90 days
after the results of the first samples were received.
c)Â Â Â Â Â Â Â Â When a preventive notification is required for groundwater that
is monitored by a regulatory agency, the agency must notify the owner or
operator of the site where the detection has occurred. The owner or operator must:
1)Â Â Â Â Â Â Â Â Confirm the detection by resampling within 30 days after the
date of the notice by the regulatory agency; and
2)Â Â Â Â Â Â Â Â Provide preventive notification to the regulatory agency of
the results of the resampling analysis within 30 days after the date on which
the sample analyses are received, but no later than 90 days after the results
of the first samples were received.
d)Â Â Â Â Â Â Â Â When a preventive notification of a confirmed detection has
been provided by an owner or operator under this Section, additional detections
of the same contaminant do not require further notice if the groundwater
quality conditions are substantially unchanged or that preventive response is
underway for the contaminant.