Section 620.240  Class IV: Other Groundwater

Except as provided in Section 620.250, Other Groundwater is:

a)         Groundwater within the zone of attenuation as provided in 35 Ill. Adm. Code 811 and 814;

b)         Groundwater within a point of compliance as provided in 35 Ill. Adm. Code 724, but not to exceed a distance of 200 feet from a potential primary or secondary source.

c)         Groundwater that naturally contains more than 10,000 mg/L of total dissolved solids;

d)         Groundwater which has been designated by the Board as an exempt aquifer pursuant to 35 Ill. Adm. Code 730.104; or

e)         Groundwater which underlies a potential primary or secondary source, in which contaminants may be present from a release, if the owner or operator of such source notifies the Agency in writing and the following conditions are met:

1)         The outermost edge is the closest practicable distance from such source, but does not exceed:

A)        A lateral distance of 25 feet from the edge of such potential source or the property boundary, whichever is less, and

B)        A depth of 15 feet from the bottom of such potential source or the land surface, whichever is greater;

2)         The source of any release of contaminants to groundwater has been controlled;

3)         Migration of contaminants within the site resulting from a release to groundwater has been minimized;

4)         Any on-site release of contaminants to groundwater has been managed to prevent migration off-site; and

5)         No potable water well exists within the outermost edge as provided in subsection (e)(1).

f)         Groundwater which underlies a coal mine refuse disposal area not contained within an area from which overburden has been removed, a coal combustion waste disposal area at a surface coal mine authorized under Section 21(s) of the Act, or an impoundment that contains sludge, slurry, or precipitated process material at a coal preparation plant, in which contaminants may be present, if such area or impoundment was placed into operation after February 1, 1983, if the owner and operator notifies the Agency in writing, and if the following conditions are met:

1)         The outermost edge is the closest practicable distance, but does not exceed:

A)        A lateral distance of 25 feet from the edge of such area or impoundment, or the property boundary, whichever is less; and

B)        A depth of 15 feet from the bottom of such area or impoundment, or the land surface, whichever is greater;

2)         The source of any release of contaminants to groundwater has been controlled;

3)         Migration of contaminants within the site resulting from a release to groundwater has been minimized;

4)         Any on-site release of contaminants to groundwater has been managed to prevent migration off-site; and

5)         No potable water well exists within the outermost edge as provided in subsection (e)(1).

g)         Groundwater within a previously mined area, unless monitoring demonstrates that the groundwater is capable of consistently meeting the standards of Sections 620.410 or 620.420.   If such capability is determined, groundwater within the previously mined area shall not be Class IV.