35 Ill. Adm. Code 309.157
Permit Limits for Total Metals
Section 309
Section 309.157 Permit
Limits for Total Metals
a) The NPDES permit limits for metals must be expressed in total
metals form even though the water quality standards for metals specified in 35
Ill. Adm. Code 302.208(e), 302.504(a), and 304.105 are in their dissolved
form. The total metals permit limit is determined by multiplying the dissolved
metals concentration and the appropriate metals translator.
b) Site-specific metals translators must be determined according
to "The Metals Translator: Guidance for Calculating a Total Recoverable
Permit Limit from a Dissolved Criterion," incorporated by reference at 35
Ill. Adm. Code 301.106.
c) Except as otherwise specified in subsection (d), the
reciprocal of the conversion factor multiplier used for obtaining the dissolved
metals standards at 35 Ill. Adm. Code 302.208(e) and 302.504(a) becomes the
metals translator and the resulting total metals value becomes the NPDES permit
limit.
d) A permittee may request the Agency to calculate a total metals
permit limit based on a site-specific metals translator. Upon review and
approval of the information submitted by the permittee, the Agency must
calculate a total metals permit limit that is protective of the dissolved metals
water quality standard.