Section 615.207  Sampling Frequency

a)         The owner or operator must determine whether groundwater standards have been exceeded at each monitoring well at least quarterly during the compliance period, except as provided otherwise in subsection (b) or (c) or Section 615.209(b).

b)         The owner or operator of a unit subject to Subpart I for the storage and handling of pesticides or Subpart J for the storage and handling of fertilizer may substitute the quarterly determination of subsection (a) with a determination at least semi-annually if all of the following conditions are met:

1)         The unit is in compliance with the containment requirements of 8 Ill. Adm. Code 255;

2)         There have been no detections within the preceding two years in any of the monitoring wells of any contaminant stored or handled at the facility or of any contaminant attributable to operation of the unit; and

3)         No reportable agrichemical spills, as defined in 8 Ill. Adm. Code 255, have occurred at the facility within the previous two years.

c)         The owner or operator of a unit subject to Subpart K for the storage and handling of road oils or Subpart L for the storage and handling of de-icing agents must determine whether groundwater standards have been exceeded at each monitoring well at least annually during the compliance period, except as provided at Section 615.209(b).

(Source:  Amended at 47 Ill. Reg. 7581, effective May 16, 2023)