Illinois Administrative Code › Title 35 - ENVIRONMENTAL PROTECTION › Part 817 - REQUIREMENTS FOR NEW STEEL AND FOUNDRY INDUSTRY WASTES LANDFILLS › Subpart D - NEW STEEL AND FOUNDRY INDUSTRY LOW RISK WASTE LANDFILLS › Section 817.415 - Groundwater Monitoring Programs

Current through Register Vol. 48, No. 28, July 12, 2024
a)
				Detection monitoring program:
Any use of the term "maximum allowable predicted
				  concentration" or "MAPC" in this Section is a reference to Section
				  817.414(c),
				  as defined in Section
				  811.102. The
				  operator shall implement a detection monitoring program in accordance with the
				  following requirements:
1) Monitoring
				schedule and frequency:
A) The monitoring
				period shall begin as soon as waste is placed into the unit of a new landfill
				or within one year after August 1, 1994 for an existing landfill. Monitoring
				shall continue for a minimum period of five years after closure or, in the case
				of landfills, other than those used exclusively for disposing waste generated
				at the site, a minimum of fifteen years after closure. The operator shall
				sample all monitoring points for all potential sources of contamination on a
				quarterly basis except as specified in subsection (a)(3) of this Section or may
				institute more frequent sampling throughout the time the source constitutes a
				threat to groundwater. For the purposes of this Section, the source shall be
				considered a threat to groundwater if the results of the monitoring indicate
				that the concentrations of any of the constituent monitored within the zone of
				attenuation are above the MAPC for that constituent.
B) Beginning five years after closure of the
				unit, or five years after all other potential sources of discharge no longer
				constitute a threat to groundwater, as defined in subsection (a)(1)(A) of this
				Section, the monitoring frequency may change on a well by well basis to an
				annual schedule if either of the conditions listed in subsection (a)(1)(B)(i)
				or (a)(1)(B)(ii) of this Section exist. However, monitoring shall return to a
				quarterly schedule at any well where a statistically significant increase is
				determined to have occurred in accordance with Section
				817.416(e),
				in the concentration of any constituent with respect to the previous sample.
i) All constituents monitored within the zone
				of attenuation have returned to a concentration less than or equal to ten
				percent of the MAPC; or
ii) All
				constituents monitored within the zone of attenuation are less than or equal to
				their MAPC for eight consecutive quarters.
C) Monitoring shall be continued for a
				minimum period of five years after closure or, in the case of landfills, other
				than those used exclusively for disposing waste generated at the site, a
				minimum period of fifteen years after closure. Monitoring, beyond the minimum
				period, may be discontinued under the following conditions:
i) No statistically significant increase is
				detected in the concentration of any constituent above that measured and
				recorded during the immediately preceding scheduled sampling for three
				consecutive years, after changing to an annual monitoring frequency;
				or
ii) Immediately after
				contaminated leachate is no longer generated by the unit.