Ill. Admin. Code tit. 35, § 302.621 - Determining the Acute Aquatic Toxicity Criterion - Procedure for Combinations of Substances

An AATC for any combination of substances (including effluent mixtures) must be determined by the following toxicity testing procedures:

a) Not more than 50% of test organisms from the most sensitive species tested may exhibit mortality or immobility after a 48-hour test for invertebrates or a 96-hour test for fish.

b) Three resident or indigenous species of ecologically diverse taxa must be tested initially. If resident or indigenous species are not available for testing, non-resident species may be used if the non-resident species is of the same family or genus and has a similar habitat and environmental tolerance.

Notes

Ill. Admin. Code tit. 35, § 302.621

Added at 14 Ill. Reg. 2899, effective February 13, 1990

Amended at 47 Ill. Reg. 4437, effective 3/23/2023