1. Pollutants which either alone or by interaction may create a fire or explosive hazard in the POTW, a public nuisance or hazard to life, or prevent entry into the sewers for their maintenance and repair or are in any way injurious to the operation of the system or operating personnel. This includes waste streams with a closed cup flashpoint of less than 140 degrees Fahrenheit (60 degrees Celsius) using the test methods specified in 40 CFR Part 261.21.

2. Wastewater having a pH less than 5.5 or more than 10.0, or otherwise having any other corrosive property capable of causing damage or hazard to structures, equipment, or personnel. Discharges outside this pH range may be authorized by a permit issued by the city pursuant to a finding that the system is specifically designed to accommodate a discharge of that pH.

3. Solid or viscous substances in amounts which may cause obstruction to the flow in the sanitary sewer or other interference with the operation of the sanitary sewer system or POTW. In no case shall solids greater than one-quarter inch (0.64 centimeter) in any dimension be discharged. Specifically prohibited substances in amounts that produce interference include, but are not limited to: grease, animal guts or tissues, paunch manure, bones, hair, hides or fleshings, entrails, whole blood, feathers, ashes, cinders, sand, spent lime, stone or marble dusts, metal, glass, straw, shavings, grass clippings, rags, spent grains, spent hops, waste paper, wood, plastics, gas, tar asphalt residues, residues from refining or processing of fuel or lubricating oil, mud, or glass grinding or polishing wastes.

4. Pollutants, including oxygen demanding pollutants (BOD, etc.), released in a discharge at a flow rate and/or pollutant concentration which, either singly or by interaction with other pollutants, will cause interference with the POTW.

5. Wastewater having a temperature which will interfere with the biological activity in the POTW, has detrimental effects on the collection system, or prevents entry into the sanitary sewer. In no case shall wastewater be discharged which causes the wastewater temperature at the treatment plant to exceed 104 degrees Fahrenheit (40 degrees Celsius).

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

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 VMC 14.10.140.

9. The following are prohibited unless approved by the director under extraordinary circumstances, such as lack of direct discharge alternatives due to combined sewer service or need to augment sewage flows due to septic conditions (as required under WAC 173-216-050):

10. 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 a hazard to life, or to prevent entry into the sanitary sewers for maintenance or repair.

11. Wastewater which imparts color which cannot be removed by the treatment process, such as, but not limited to, dye wastes and vegetable tanning solutions, which consequently imparts color to the treatment plant’s effluent, thereby violating the city’s NPDES permit(s).

12. Wastewater containing any radioactive wastes or isotopes except in compliance with applicable state or federal regulations.

13. Stormwater, surface water, ground water, artesian well water, roof runoff, subsurface drainage, swimming pool drainage, condensate, deionized water, noncontact cooling water, and unpolluted water, unless specifically authorized by the director.

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

15. Medical wastes, except as specifically authorized by the director.

16. Wastewater causing, alone or in conjunction with other sources, the treatment plant’s effluent to fail a toxicity test.

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

18. Fats, oils, or greases of animal or vegetable origin in amounts that may cause obstructions or maintenance problems in the sanitary sewer system or in the POTW, or total petroleum hydrocarbon (nonpolar oil and grease) concentrations that exceed 50 milligrams per liter.

19. Wastewater causing any single reading over 10 percent of the lower explosive limit based on an explosivity meter reading at the point of discharge into the POTW or at any point in the POTW.

20. Any substance which will cause the POTW to violate its NPDES and/or other disposal system permit(s).

21. Any dangerous, extremely hazardous, or hazardous wastes as defined in rules or regulations published by the Washington State Department of Ecology or by EPA, except as specifically approved by the director.

22. Any persistent pesticide and/or pesticides regulated by the Federal Insecticide Fungicide Rodenticide Act (FIFRA) as amended.

23. Any wastewater containing toxic pollutants in sufficient quantity, either singly or by interaction, to injure or create interference with any wastewater treatment process, constitute a hazard to humans or animals, or to exceed the limitation set forth in categorical pretreatment standards, or state or local standards.

24. Any substance which may cause the POTW’s effluent or treatment residues, sludges, or scums, to be unsuitable for reclamation and reuse or which causes interference with the reclamation process. In no case shall a substance be discharged to the POTW that will cause the POTW to be in noncompliance with sludge use or disposal criteria, guidelines or regulations developed under Section 405 of the Act; or with any criteria, guidelines, or regulations affecting sludge use or disposal developed pursuant to the Solid Waste Disposal Act; or with the Clean Air Act, the Toxic Substances Control Act, or state standards applicable to the sludge management method being used.

25. Any slug load as defined in this chapter, or any pollutant, including oxygen demanding pollutants, released in a single extraordinary discharge episode or such volume or strength as to cause interference to the POTW; or released with a flow rate exceeding the permitted peak flow, or 10 percent of the capacity of the available trunk sewer, whichever is greater.