The rules and regulations set forth in Part III of the Stockton Municipal Code, Chapter 7, shall be in addition to the Uniform Codes Chapter (Chapter 14) of the Stockton Municipal Code and in no way diminish the authority set forth herein.

No user shall contribute or cause to be contributed directly or indirectly, any pollutant or wastewater which will interfere with the operation or performance of the POTW. These general provisions apply to all users of the POTW whether or not the user is subject to National Categorical Pretreatment Standards or any other national, State or local pretreatment standards or requirements.

For the purpose of verifying compliance with this Section, the Director and/or the Director's designated representative may use a single grab sample collected from any tank, treatment unit, sink, holding tank, trench, sump, process or other device which may discharge waste to the sanitary sewer. The above sample may be collected at the source of discharge prior to the dilution with any other streams.

A user may not contribute the following substances to any POTW:

1. Pollutants introduced into POTW's by a non-domestic source shall not pass through the POTW or interfere with the operation or performance of the POTW. These general prohibitions and the specified prohibitions in Paragraph 2 of this Section apply to all non-domestic sources introducing pollutants into a POTW whether or not the source is subject to other national pretreatment standards or any national, State or local pretreatment requirements.
2. Any liquids, solids or gases which by reason of their nature or quantity within the waste stream are, or may be, sufficient, either alone or by interaction with other substances, to cause fire or explosion, cause the waste stream to have a close cup flashpoint of less than 140 F or 60 C when tested following the procedures and methods specified in 40 CFR 261.21, or may be injurious in any other way to the POTW or the operation of the POTW. At no time shall two (2) 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 (5%) nor any single reading more than ten percent (10%) of the lowest explosive limit (LEL) of the meter. Prohibited materials include, but are not limited to, gasoline, kerosene, naphtha, benzene, toluene, xylene, ethers, alcohols, ketones, aldehydes, peroxides, chlorates, perchlorates, bromates, carbides, hydrides, and sulfides.
3. Solids or viscous substances which may cause obstruction to the flow in a sewer or other interference with the operation of the wastewater treatment facilities.
4. Any wastewater having a pH less than 5.0, more than 10.0, or in excess of the limitations specified in any more stringent permit or regulation or wastewater the user knows or has reason to know has any other corrosive property capable of causing damage or hazard to structures, equipment and/or personnel of the POTW. Excursions in pH greater than 10.0 but less than 12.5 may be allowed providing the duration of these excursions does not exceed: a. A total of sixty (60) minutes continuously for any individual excursion. b. An aggregate of no more than seven (7) hours and twenty-six (26) minutes in any calendar month.
5. Any waste defined as hazardous by any definition set forth in and Federal, State or local regulation, statute, or ordinance, unless such waste has been delisted or decertified by the agency having authority to do so or a variance has been granted by the appropriate Federal, State or local agency, including provisions for discharge to the City sewer, which variance must be approved by the Director.
6. 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 the POTW, 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 the Act.
7. Any noxious or malodorous liquids, gases, or solids which, either singly or by interaction with other wastes, are sufficient to create public nuisance or hazard to life or health, or is sufficient to prevent entry into the sewerage system for maintenance and repair.
8. 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 discharge to the POTW cause the POTW to be in noncompliance with sludge use or disposal criteria, guidelines or regulations developed under the Act; any criteria, guidelines, or regulations affecting sludge use or disposal developed pursuant to the Solid Waste Disposal Act, or State criteria applicable to the sludge management method being used.
9. Any substance which will cause the POTW to violate its NPDES and/or State disposal system permit or the receiving water quality standards.
10. Any wastewater with objectionable color not removed in the treatment process.
11. Any wastewater with heat in amounts which will inhibit biological activity in the POTW resulting in interference, but in no case heat in such quantities that the temperature at the POTW exceeds 40 C (104 F) or exceeds 60 C (140 F) at the point of discharge.
12. Any pollutants, including oxygen-demanding pollutants (BOD, etc.), released at a flow rate and/or pollutant concentration which a user knows or has reason to know will cause interference to the POTW unless the user was in compliance with local limits applicable to its discharge or, if no local limit for parameters discharged exist, can demonstrate that its discharge directly prior to and during the instance of pass through or interference, did not change substantially from its prior discharges when the POTW was in compliance with its NPDES permit. In no case shall a sudden unexpected discharge have a flow rate or contain concentrations or quantities of pollutants that exceed, for any period longer than fifteen (15) minutes, more than five (5) times the average twenty-four (24) hour concentration, quantities, or flow during normal operation.
13. Any wastewater containing radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by applicable State or Federal regulations.
14. Any wastewater which causes a hazard to human life or the environment or creates a public nuisance.
15. Unpolluted water, including, but not limited to, irrigation, condensing cooling water, blow down from cooling towers, or evaporative coolers shall not be discharged through direct or indirect connection to a sanitary sewer unless approved by the City of Stockton.
16. Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin in amounts that will cause interference or pass through.
17. Any trucked or hauled pollutants, except at discharge points designated by the POTW.

Wastes prohibited by this Section shall not be processed or stored in such a manner that they could be discharged to the POTW. All floor drains located in process or materials storage areas must discharge to the industrial user's pretreatment facility before connecting to the POTW.

The City of Stockton may approve the temporary discharge of such water only when no reasonable alternate method of disposal is available.

When the Director determines that a user(s) is contributing to the POTW any of the above enumerated substances in such amounts as to interfere with the operation of the POTW, the Director may take such action as deemed necessary to correct the interference with the POTW.