Section 106.115. Additivity of dioxins and furans.

  The 2,3,7,8-TCDD toxicity equivalence concentration in effluent shall be used when developing waste load allocations and for purposes of establishing water quality based effluent limits.

(1)  For the chlorinated dibenzo-p-dioxins (CDDs) listed in Tables 8 and 9 in ch. NR 105 , the potential adverse additive effects of all dioxin (CDD) and chlorinated dibenzofuran (CDF) congeners in effluents shall be accounted for as specified in this section.

(2)  The Toxicity Equivalency Factor (TEF) in Table 1 and Bioaccumulation Equivalency Factor (BEF) in Table 2 shall be used when calculating a 2,3,7,8-TCDD toxicity equivalence concentration in effluent to be used when implementing both human health noncancer and cancer criteria. The chemical concentration of each CDD and CDF in effluent shall be converted to a 2,3,7,8-TCDD toxicity equivalence concentration in effluent by using the following equation:

(TEC) tcdd = S (C) x (TEF) x (BEF) x
where:

(TEC) tcdd = 2,3,7,8-TCDD toxicity equivalence
concentration in effluent

(C) x = concentration of total chemical x in effluent

(TEF) x = TCDD toxicity equivalency factor for x from table 1

(BEF) x = TCDD bioaccumulation equivalency factor for x from table 2

Table 1 — Toxicity Equivalency Factor for
CDDS and CDFs - See PDF for table

Table 2 — Bioaccumulation Equivalency Factor
for CDDs and CDFs - See PDF for table

Cr. Register, August, 1997, No. 500 , eff. 9-1-97; CR 03-050 : renum. from NR 106.16 Register February 2004 No. 578 , eff. 3-1-04; CR 09-123 : am. (1) Register July 2010 No. 655 , eff. 8-1-10; CR 15-085 : am. Table 1 (title), Table 2 (title) Register August 2016 No. 728 , eff. 9-1-16.