§ 90-83. General sewerage discharge prohibitions.

(a)

Nonpolluted water. No person shall discharge or cause to be discharged any stormwater, surface water, groundwater, roof runoff or subsurface drainage into the wastewater treatment system.

(b)

Storm sewers. The discharge of sanitary wastewater into storm sewer systems is prohibited without exception. Uncontaminated cooling water may be discharged into the storm sewer system, provided that a National Pollutant Discharge Elimination System (NPDES) permit is obtained from the Environmental Protection Division (EPD) of the state department of natural resources.

(c)

Garbage. No person shall discharge or cause to be discharged any garbage that has not been properly shredded. The installation and operation of any garbage grinder equipped with a motor of three-fourths horsepower or greater shall be subject to the review and approval of the director.

(d)

Prohibited substances national requirements. No user shall contribute or cause to be contributed, directly or indirectly, any pollutant or wastewater which will pass through or interfere with the operation or performance of the POTW. These general prohibitions apply to all such users of a wastewater treatment system whether or not the user is subject to national categorical pretreatment standards or any other national, state or local pretreatment standards or requirements. A user shall not contribute the following substances to the wastewater treatment system (40 CFR 403.5):

(1)

Pollutants which create a fire or explosive hazard in the POTW, including, but not limited to, waste streams with a closed-cup flash point of less than 140 degrees Fahrenheit (60 degrees Celsius) using the test methods specified in 40 CFR 261.21;

(2)

Any wastewater having a pH less than five or more than 11, unless approved by the director, or any wastewater that has any other corrosive property capable of causing damage or hazard to structures, equipment and/or personnel of the POTW;

(3)

Solid or viscous substances which can cause obstruction to the flow in a sewer or other interference with the operation of the wastewater treatment system, such as, but not limited to: grease, garbage with particles greater than one-half inch in any dimension, animal guts or tissues, paunch manure, bones, hair, hides or fleshings, entrails, whole blood, feathers, ashes, cinders, sand, spent lime, stones, marble dust, metal, glass, straw, shavings, grass clippings, rags, spent grains, spent hops, waste paper, ground paper products, wood, plastics, gas, tar, asphalt residues, residues from refining, or processing of fuel or lubricating oil, mud or glass grinding or polishing wastes;

(4)

Any pollutants, including oxygen demanding pollutants (BOD, etc.) released at a flow rate and/or pollutant concentration which will cause interference to the POTW. In no case shall a slug load have a flow rate or contain concentration or qualities of pollutants that exceed for any time period longer than 15 minutes more than five times the average 24-hour concentration, quantities, or flow during normal operation;

(5)

Any wastewater having a temperature which will inhibit biological activity in the POTW resulting in interference, but in no case wastewater which causes a temperature at the introduction into the POTW in excess of 40 degrees Celsius (104 degrees Fahrenheit); unless the approval authority, upon request of the POTW, approves alternate temperature limits. Any discharge with temperature in excess of 40 degrees Celsius (104 degrees Fahrenheit) shall require the written approval of the director;

(6)

Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin, in amounts that will cause interference or pass through;

(7)

Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity that may cause acute worker health and safety problems;

(8)

Trucked or hauled pollutants, except at discharge points designated by the director in accordance with section 90-86.

(e)

Prohibited substances; discretionary. No person shall discharge or cause to be discharged the following substances, materials, waters or wastes if it appears likely, in the opinion of the director that such wastes can harm either the sewers, sewage treatment process, or equipment; have an adverse effect on the receiving stream or can otherwise endanger life, limb, public property, or constitute a nuisance. In forming his opinion as the acceptability of these wastes, the director will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment plant process, capacity of the sewage treatment plant, degree of treatability of wastes in the sewage treatment plans and other pertinent factors, these prohibited substances are the following:

(1)

Any noxious or malodorous liquids, gases, solids or other wastewater which either singly or by interaction with other wastes are sufficient to create a public nuisance or hazard to life or are sufficient to prevent entry into the sewers for maintenance and repair;

(2)

Any wastewater, which imparts color that can not be removed in the treatment process, such as, but not limited to, dye wastes and vegetable tanning solutions;

(3)

Any wastewater containing any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the director in compliance with applicable state or federal regulations;

(4)

Any liquids, solids or gases which by reason of their nature of quantity are or may be sufficient either alone or by interaction with other substances to cause a fire or explosion or be injurious in any other way to the wastewater system or the operation of the POTW. At no time shall two successive readings on an explosion hazard meter, at the point of discharge into the system (or at any point in the system) be more than five percent nor any single reading over ten percent of the lower explosive limit (LEL) of the meter. Prohibited materials include, but are not limited to, gasoline, kerosene, naphtha, benzene, and any other substances which the city, the state or the EPA has notified the user is a fire hazard to the system;

(5)

Any wastewater containing toxic pollutants in sufficient quantity, either singly or by interaction with other pollutants, to injure or interfere with any wastewater treatment process, constitute a hazard to humans or animals, create a toxic effect in the receiving waters of POTW, cause the POTW to fail a toxicity test or to exceed the limitation set forth in a categorical pretreatment standard. A toxic pollutant shall include, but not be limited to, any pollutant identified pursuant to Section 307(A) of the Act; and 40 CFR 129.

(6)

Any substance which may cause the POTW's effluent or any other product of the POTW such as residues, sludges, or scums, to be unsuitable for reclamation and reuse or to interfere with the reclamation process. In no case, shall a substance discharged to the POTW cause the POTW to be in noncompliance with sludge use or disposal criteria, guidelines or regulations developed under Sections 257, 405, and 503 of the Act, and criteria, guidelines or regulations affecting sludge use or disposal developed pursuant to the solid waste disposal act, the clean air act, the toxic substances control act, the resource conservation and recovery act, or state criteria applicable to the sludge management method being used;

(7)

Any substances which will cause the POTW to violate its NPDES permit or the receiving water quality standards;

(8)

Any wastewater which causes a hazard to human life or creates a public nuisance;

(9)

Any waters or wastes containing concentrated acid iron pickling wastes or concentrated plating solutions whether neutralized or not;

(10)

Materials which exert or cause unusual concentrations of inert suspended solids, such as, but not limited to fuller's earth, lime slurries, and lime residues; or of dissolved solids, such as, but not limited to, sodium chloride and sodium sulfate;

(11)

Sludges, screenings, or other residues from the pretreatment of industrial wastes;

(12)

Detergents, surface-active agents, or other substances which may cause excessive foaming in the POTW.

(f)

Correcting interference. When the director determines in accordance with sound engineering standards that a user is contributing to the POTW any of the substances that are listed in section 90-84(e) in such amount as to interfere with the operation of the POTW, the director shall enforce specific limits to implement the prohibitions listed in section 90-83(d) and (e).

(g)

Conditional discharges. No user shall discharge wastewater which exceeds the following concentration limits unless he has received the written permission of the director, or has contracted with the city in writing to discharge specific contaminants in excess of these limits:

TABLE 1

Parameter	Monthly Average	Concentration (mg/l) Daily Average	Daily Maximum
BOD 5	300	400	—
COD	750	1,000	—
Suspended Solids	300	400	—
Oil and grease	60	100	—
Ammonia (NH3)	—	—	24.6
Antimony	4	8	—
Arsenic	—	—	0.009
Barium	—	—	2,611
Cyanide	—	—	1.4
Manganese	4	8	—
Pentachlorophenol	—	—	0.253
Phenolic compounds	—	—	226
Phosphorous	20	40	—
Selenium	—	—	0.025
Cadmium	—	—	0.022
Chromium (hexavalent)	1	2	—
Chromium (total)	—	—	1.4
Cobalt	2	5	—
Copper	—	—	1.13
Lead	—	—	0.268
Magnesium	4.0	8.0	—
Mercury	—	—	0.0019
Molybdenum	—	—	0.037
Nickel	—	—	0.295
Silver	—	—	0.027
Tin	2	4	—
Zinc	—	—	3.2

 

For pollutants with a daily maximum concentration limit, the daily and monthly average limits shall equal the daily maximum limit.

The concentration limits in subsection (g) of this section are set by the city as maximal. These limits apply to the discharges from all industrial users and other users (as appropriate) before they enter and are mixed with the public sewerage system. The actual sampling location for each industrial user will be stipulated in the permit. The limits may be reduced by order of the director at any time when it is found that the wastewater treatment plant does not meet its proper limits of treatment, and the director may establish concentration limits for other substances as may be appropriate. All users on the system must comply with all such standard limits within a reasonable time period established by the director, or as required by other regulatory agencies.

The pollutants listed in subsection (g) of this section shall be analyzed to the appropriate detection limits as specified by the state environmental protection division. If the results for a given sample are such that a parameter is not detected at or above the specified detection limit, a value of "not detected" shall be reported for that sample and the detection limits will also be reported. A value of "not detected" shall be considered as within the allowable concentration limits listed in this section.

All pollutant analyses, including sampling techniques, to be submitted as part of a wastewater discharge permit application or report shall be performed in accordance with the techniques prescribed in 40 CFR 136, unless otherwise specified in an applicable categorical pretreatment standard. If 40 CFR 136 does not contain sampling or analytical techniques for the pollutant in question, sampling and analyses must be performed in accordance with procedures approved by EPA.

Except for oil and grease, temperature, pH, cyanide, phenols, sulfides, and volatile organic compounds, the user must collect wastewater samples using flow proportional composite collection techniques. If flow proportional sampling is infeasible, the director may authorize the use of time proportional sampling or a minimum of four grab samples where the user demonstrates that this will provide a representative sample of the effluent being discharged. In addition, grab samples may be required to show compliance with instantaneous discharge limits. Samples for oil and grease, temperature, pH, cyanide, phenols, sulfides, and volatile organic compounds must be obtained using grab collection techniques.

(Ord. of 9-14-1999, § 18-53)