a) In determining the appropriate extent of action to be taken at a given release, the IEPA shall first review the preliminary assessment to determine if immediate removal action is appropriate. Immediate removal action shall be deemed appropriate in those cases in which the IEPA determines that the initiation of immediate removal action will prevent or mitigate immediate and significant risk of harm to human life or health or to the environment from such situations as:

1. 1) Human, animal, or food chain exposure to acutely toxic substances;
2. 2) Contamination of a drinking water supply;
3. 3) Fire and/or explosion; or
4. 4) Similarly acute situations.

b) If the IEPA determines that immediate removal is appropriate, defensive actions should begin as soon as possible to prevent or mitigate danger to the public health, welfare, or the environment. Actions may include, but are not limited to:

1. 1) Collecting and analyzing samples to determine the source and dispersion of the hazardous substance and documenting those samples for possible evidentiary use;
2. 2) Providing alternative water supplies;
3. 3) Installing security fencing or other measures to limit access;
4. 4) Controlling the source of release;
5. 5) Measuring and sampling;
6. 6) Moving hazardous substances off-site for storage, destruction, treatment, or disposal provided that the substances are moved to a facility that is in compliance with Subtitle G of the Board's regulations (35 Ill. Adm. Code 700: Subtitle G, Chapter I) or Subtitle C of the Solid Waste Disposal Act, as amended by the Resource Conservation and Recovery Act, as amended (42 U.S.C. 6901 et seq.);
7. 7) Placing physical barriers to deter the spread of the release;
8. 8) Controlling the water discharge from an up-stream impoundment;
9. 9) Recommending to appropriate authorities the evacuation of threatened individuals;
10. 10) Using chemicals and other materials in accordance with Subpart E to restrain the spread of the substance and to mitigate its effects;
11. 11) Executing damage control or salvage operations.

d) Immediate removal action shall be terminated after $1 million has been obligated for the action or six months have elapsed from the date of initial response to a release or threatened release unless it is determined that:

1. 1) Continued response actions are immediately required to prevent, limit or mitigate an emergency;
2. 2) There is an immediate risk to public health or welfare or the environment; and
3. 3) Such assistance will not otherwise be provided on a timely basis.