§620.210. Class I: Potable Resource Groundwater

Except as provided in Sections 620.230, 620.240, or 620.250, Potable Resource Groundwater is:

 

a)         Groundwater located 10 feet or more below the land surface and within:

 

1)         The minimum setback zone of a well which serves as a potable water supply and to the bottom of such well;

 

2)         Unconsolidated sand, gravel or sand and gravel which is 5 feet or more in thickness and that contains 12 percent or less of fines (i.e., fines which pass through a No. 200 sieve tested according to ASTM Standard Practice D2487-06, incorporated by reference at Section 620.125);

 

3)         Sandstone which is 10 feet or more in thickness, or fractured carbonate which is 15 feet or more in thickness; or

 

4)         Any geologic material which is capable of a:

 

A)        Sustained groundwater yield, from up to a 12 inch borehole, of 150 gallons per day or more from a thickness of 15 feet or less; or

 

B)        Hydraulic conductivity of 1 x 10^-4 cm/sec or greater using one of the following test methods or its equivalent:

 

i)          Permeameter;

 

ii)         Slug test; or

 

iii)        Pump test.

 

b)         Any groundwater which is determined by the Board pursuant to petition procedures set forth in Section 620.260, to be capable of potable use.

 

            BOARD NOTE:  Any portion of the thickness associated with the geologic materials as described in subsections 620.210(a)(2), (a)(3) or (a)(4) should be designated as Class I:  Potable Resource Groundwater if located 10 feet or more below the land surface.

 

(Source:  Amended at 36 Ill. Reg. 15206, effective October 5, 2012)