Section 415 ILCS 5/13.1 - Groundwater monitoring network(b) The Agency shall establish a Statewide groundwater monitoring network. Such network shall include a sufficient number of testing wells to assess the current levels of contamination in the groundwaters of the State and to detect any future degradation of groundwater resources. The monitoring network shall give special emphasis to critical groundwater areas and to locations near hazardous waste disposal facilities. To the extent possible, the network shall utilize existing publicly or privately operated drinking water or monitoring wells.P.A. 89-445, eff. 2/7/1996; 92-574, eff. 6/26/2002.