Section 724.193  Hazardous Constituents

a)         The Agency must specify in the facility permit the hazardous constituents to which the groundwater protection standard of Section 724.192 applies.  Hazardous constituents are constituents identified in Appendix H of 35 Ill. Adm. Code 721 that have been detected in groundwater in the uppermost aquifer underlying a regulated unit and that are reasonably expected to be in or derived from waste contained in a regulated unit, unless the Agency has excluded them under subsection (b).

b)         The Agency must exclude a constituent in Appendix H of 35 Ill. Adm. Code 721 from the list of hazardous constituents specified in the facility permit if it finds that the constituent is not capable of posing a substantial present or potential hazard to human health or the environment.  In deciding whether to grant an exemption, the Agency must consider the following:

1)         Potential adverse effects on groundwater quality, considering the following:

A)        The physical and chemical characteristics of the waste in the regulated unit, including its potential for migration;

B)        The hydrogeological characteristics of the facility and surrounding land;

C)        The quantity of groundwater and the direction of groundwater flow;

D)        The proximity and withdrawal rates of groundwater users;

E)        The current and future uses of groundwater in the area;

F)         The existing quality of groundwater, including other sources of contamination, and their cumulative impact on the groundwater quality;

G)        The potential for health risks caused by human exposure to waste constituents;

H)        The potential damage to wildlife, crops, vegetation, and physical structures caused by exposure to waste constituents;

I)         The persistence and permanence of the potential adverse effects; and

2)         Potential adverse effects on hydraulically-connected surface water quality, considering the following:

A)        The volume and physical and chemical characteristics of the waste in the regulated unit;

B)        The hydrogeological characteristics of the facility and surrounding land;

C)        The quantity and quality of groundwater and the direction of groundwater flow;

D)        The patterns of rainfall in the region;

E)        The proximity of the regulated unit to surface waters;

F)         The current and future uses of surface waters in the area and any water quality standards established for those surface waters;

G)        The existing quality of surface water, including other sources of contamination, and the cumulative impact on surface water quality;

H)        The potential for health risks caused by human exposure to waste constituents;

I)         The potential damage to wildlife, crops, vegetation, and physical structures caused by exposure to waste constituents; and

J)         The persistence and permanence of the potential adverse effects.

c)         In making any determination under subsection (b) about the use of groundwater in the area around the facility, the Agency must consider any identification of underground sources of drinking water and exempted aquifers made under 35 Ill. Adm. Code 704.123.

d)         The Agency must make specific written findings in granting any exemptions under subsection (b).

(Source:  Amended at 42 Ill. Reg. 22614, effective November 19, 2018)