Section 302.530  Supplemental Mixing Provisions for Bioaccumulative Chemicals of Concern (BCCs)

The General Provisions of Section 302.102 (Allowed Mixing, Mixing Zones and ZIDs) apply within the Lake Michigan Basin except as otherwise provided herein for substances defined as BCCs in Section 302.501:

a)         No mixing shall be allowed for BCCs for new discharges commencing on or after December 24, 1997.

b)         Discharges of BCCs existing as of December 24, 1997 are eligible for mixing allowance consistent with Section 302.102 until March 23, 2007.  After March 23, 2007 mixing for BCCs will not be allowed except as provided in subsections (c) and (d) of this Section.

c)         Mixing allowance for a source in existence on December 24, 1997 may continue beyond March 23, 2007 where it can be demonstrated on a case by case basis that continuation of mixing allowance is necessary to achieve water conservation measures that result in overall reduction of BCC mass loading to the Lake Michigan Basin.

d)         Mixing allowance for a source in existence on December 24, 1997 shall only continue if necessitated by technical and economic factors. Any mixing allowance continued beyond March 23, 2007 based on technical and economic factors shall be limited to not more than one NPDES permit term, and shall reflect the maximum achievable BCC loading reduction within the identified technical and economic considerations necessitating the exception. Such continued mixing allowance shall not be renewed beyond that permit term unless a new determination of technical and economic necessity is made.

(Source:  Added at 22 Ill. Reg. 1356, effective December 24, 1997)