Ill. Admin. Code tit. 35, § 391.503
a) It is recommended that the following parameters be analyzed according to the referenced sections in Standard Methods for Examination of Water and Wastewater (14th ed), or as approved in 40 CFR 136. Other analyses or methodologies are acceptable provided equivalent results are obtainable. The permittee or applicant shall demonstrate that equivalent results are obtainable based on the nature of the test methodology, the nature of the parameter and the level of statistical accuracy.
b) Heavy Metals
1) Metals Other Than Mercury
2) Mercury: Tentative procedure
Analyze three separate portions according to USEPA procedure "Mercury in Sediment".