§ 41-33. National categorical pretreatment standards.

(a)

National pretreatment standards. The categorical pretreatment standards found in 40 CFR Chapter I, Subchapter N, Parts 405—471 are incorporated in this chapter for all purposes.

(b)

Mass concentration. Where a categorical pretreatment standard is expressed only in terms of either the mass or the concentration of a pollutant in wastewater, the director may impose equivalent concentration or mass limits in compliance with 40 CFR 403.6(c).

(c)

Combined waste stream formula. When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the director shall impose an alternate limit using the combined waste stream formula in 40 CFR 403.6(e).

(d)

Variance. A user may obtain a variance from a categorical pretreatment standard if the user can prove, pursuant to the procedural and substantive provisions in 40 CFR 403.13, that factors relating to its discharge are fundamentally different from the factors considered by EPA when developing the categorical pretreatment standard.

(e)

Gross adjustment. A user may obtain a net cross adjustment to a categorical standard in compliance with 40 CFR 403.15.

(f)

[Finding.] Upon a finding that a user meeting the criteria of an SIU has no reasonable potential for adversely affecting the POTW's operation, and/or for violating any pretreatment standard, or requirement, and is not subject to national categorical pretreatment standards, the city may at any time on its own initiative, or in response to a petition received from an user, determine that such user should not be considered a significant industrial user. This determination shall be made in compliance with procedures in 40 CFR 403.8(f)(6).

(Ord. No. 8140, § 1, 3-20-03)