921.10 LIMITATIONS ON WASTEWATER STRENGTH.

   (a)   National Categorical Pretreatment Standards. National Categorical Pretreatment Standards as promulgated by the U.S. Environmental Protection Agency (U.S. EPA) pursuant to the Act shall be met by all dischargers of the regulated industrial categories. An application for modification of the national categorical pretreatment standards may be considered for submittal to the Approval Authority by the Service Director, when the City's wastewater treatment system achieves consistent removal of the pollutants as defined by 40 CFR 403.7.

   (b)   Right of Revision. The City reserves the right to amend this chapter to provide for more stringent limitations or requirements on discharges to the POTW where deemed necessary to comply with the objectives set forth in Section 921.01.

   (c)   Dilution. No discharger shall increase the use of potable or process water in any way, nor mix separate waste streams for the purpose of diluting a discharge as a partial or complete substitute for adequate treatment to achieve compliance with the standards set forth in this chapter.

(Ord. 95-147. Passed 9-19-95.)

   (d)   Supplementary Limitations. No discharger shall discharge wastewater containing concentrations of the following enumerated materials exceeding the following values:

(Ord. 97-124. Passed 9-16-97.)

Material	Concentration (mg/l)
Ag (silver)	0.23
Cd (cadmium)	0.05
CNT (total cyanide) Cn (free cyanide)	0.38
Cr+6 (hexavalent chromium)	0.91
Cr (total chromium)	3.28
Cu (copper)	1.47
Grease & Oil of Animal, Vegetable or Mineral Origin	100.0
Hg (mercury)	0.0005*
Ni (nickel)	0.73
Pb (lead)	0.59
Zn (zinc)	2.30

 

   * The limit for mercury will be one-half the PQL which is 0.0005 mg/L.

   (Ord. 2007-005. Passed 2-6-07.)