1. Pollutants which create a fire or explosive hazard in the POTW, including, but not limited to, wastestreams with a closed-cup flashpoint of less than 140 degrees F (60 degrees C) using the test methods specified in 40 CFR 261.21;

2. Wastewater having a pH less than 6.0 or more than 11.0 SU, or otherwise causing corrosive structural damage to the POTW or equipment;

3. Solid or viscous substances in amounts which will cause obstruction of the flow in the POTW resulting in interference but in no case solids greater than 1/2 inch in any dimension;

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 greater than 140 degrees F (60 degrees C), or which will inhibit biological activity in the treatment plant resulting in interference, but in no case wastewater which causes the temperature at the introduction into the treatment plant to exceed 104 degrees F (40 degrees C);

6. Petroleum oil, non-biodegradable 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 MMC 13.05.130;

9. Noxious or malodorous liquids, aldehydes, 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 sewers for maintenance or repair;

10. 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;

11. Wastewater containing any radioactive wastes or isotopes except in compliance with the current “Oregon Regulations for the Control of Radiation” (OAR 333-120-0520);

12. Stormwater, surface water, ground water, artesian well water, roof runoff, subsurface drainage, condensate, deionized water, noncontact cooling water, and unpolluted wastewater, unless specifically authorized by the Director;

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

14. Medical wastes, except as specifically authorized by the Director in a city control mechanism;

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

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

17. Fats, oils, or greases of animal or vegetable origin in amounts that will cause interference or pass through;

18. Wastewater causing two readings on an explosion hazard meter at the point of discharge into the POTW, or at any point in the POTW, of more than 10 percent of the Lower Explosive Limit or any single reading over 20 percent of the Lower Explosive Limit of the meter.