§ 34-170. Limitations on toxic and hazardous pollutants.

No person shall discharge or cause to be discharged the following described substances, materials, waters or wastes except as authorized by an order of determination as issued by the public services director. The following numerical limitations were based on technical analysis of NPDES permit requirements, industrial loadings, sludge management practices and treatment process tolerance and efficiency as in place at the time of ordinance adoption and are intended to meet the objectives given in section 34-166. The technical support documentation for numerical limitations is on file as a part of the city's industrial pretreatment program. The director may set limitations lower than the limitations established below if in his or her review changing factors in the technical support documentation necessitate more stringent limitations in order to meet the objectives given in section 34-166. The director may establish numerical limitations for substances not specifically limited below in order to meet the objectives of section 34-166. The director may set, by an order of determination for individual dischargers, alternative or additional mass limitations provided adequate provision for flow metering and sampling are provided by the discharger.

(1)

These limitations shall be daily maximum limitations. Compliance or noncompliance may be determined by analysis of: Twenty-four-hour flow proportioned samples, twenty-four-hour composite samples, or one (1) or more grab samples averaged over a twenty-four-hour period as determined to be appropriate by the public services director for the discharge and parameters to be measured. No discharge to the city's wastewater system shall exceed the following limitations unless so authorized in an order of determination from the public services director which sets alternative mass limitations for the specific parameter:

1.0 mg/l Arsenic

0.1 mg/l Cadmium

2.7 mg/l Chromium (total)

2.0 mg/l Copper

0.6 mg/l Lead

1.0 mg/l Nickel

4.5 mg/l Zinc

0.0002 mg/l Mercury

0.07 mg/l Selenium

1.0 mg/l Silver

0.56 mg/l Cyanide (free)

1.0 mg/l Trichloroetheylene

No detectable discharge PCB's (total)

(2)

Specific limitations on compatible pollutants.

a.

These limitations shall be daily maximum limitations. Compliance or noncompliance is to be based on twenty-four-hour composite samples. No discharge to the city's wastewater system shall exceed the following limitations unless so authorized in an order of determination by the public services director pursuant to subsection b. below:

500 mg/l BOD-5 (or CBOD-5)

1000 mg/l Suspended solids

100 mg/l Total phosphorous

100 mg/l Ammonia

b.

The public services director may specify alternate mass and/or concentration limits for compatible pollutants for individual industrial users through issuance of an order of determination. Such alternate limitations shall be based on plant treatment capacity available for the user, treatability of the wastewater and determination that such discharges will not cause interference with the wastewater system. Such alternate limitations are subject to revocation or modification by the public services director due to changing conditions.

(3)

Any waters or wastes containing fats, wax, grease, petroleum oil, cutting oil or other oils, whether emulsified or not, in excess of one hundred (100) mg/l; or containing substances which may solidify or become viscous at temperatures between thirty-two (32) and one hundred fifty (150) degrees Fahrenheit;

(4)

Any liquid or vapor having a temperature higher than one hundred fifty (150) degrees Fahrenheit (sixty-six (66) degrees Celsius);

(5)

Any waters or wastes containing phenols or other taste and odor producing substances in such concentrations exceeding limits which may be established by the public services director to meet the objectives of section 34-166;

(6)

Any waters or wastes having a pH in excess of 9.5 unless specifically authorized in an order of determination issued by the public services director. The public services director may allow a higher discharge pH, not to exceed 11.0, upon determining that such discharge will not cause corrosion or interfere with the operation of the wastewater system;

(7)

Any waters or wastes which contain unusual concentrations of dissolved solids;

(8)

Waters or wastes containing substances which are not amenable to treatment or reduction by the wastewater treatment process employed, or are amenable to treatment only to such degree that the wastewater treatment plant effluent cannot meet the requirements of its NPDES permit or which may interfere with the sludge management practices.

(9)

Except where expressly authorized to do so by an applicable pretreatment standard or order of determination by the public services director, no industrial user shall increase the use of process water or dilute a discharge as a substitute for adequate treatment to achieve compliance with any pretreatment standard.

(Ord. No. 433, § 1(2.62), 6-3-85; Ord. No. 490, § 1, 4-20-92; Ord. No. 688, § 1, 11-5-07)