City of Oregon Sanitary Sewer Discharge Limitations and Prohibitions
(Oregon Municipal Code Chapters 925 & 927)
925.30 Substances Limited
The following described substances, materials, waters or waste shall be limited in discharges to municipal systems to concentrations or quantities which will not harm either the sewers, wastewater treatment process or equipment, will not have an adverse effect on the receiving stream, or will not otherwise endanger lives, limb, public property, or constitute a nuisance. The Director may set limitations lower than the limitations established in the regulations below if in his opinion such more severe limitations are necessary to meet the above objectives. Deliberate dilution with unpolluted water to meet the concentrations established in the regulations below shall not be acceptable. In forming his opinion as to the acceptability, the Director will give consideration to such facts as the quantity of subject waste in relation to flows and velocities in the sewers, materials of construction of the sewers, the wastewater treatment process employed, capacity of the wastewater treatment plant, degree of treatability of the waste in the wastewater treatment plant and other pertinent factors. The limitations or restrictions on materials or characteristics of waste or wastewater discharged to the sanitary sewer, which shall not be violated without approval of the Director, are as follows:
(a) Wastewater having a temperature higher than 150o F
(b) Wastewater containing more than 100 milligrams per liter of petroleum oil, nonbiodegradable cutting oils, product of mineral oil origin, or floatable oils, fat, wax or grease.
(c) Any garbage that has not been properly shredded.Garbage grinders may be connected to sanitary sewers from homes, hotels, institutions, restaurants, hospitals, catering establishments or similar places where garbage originates from the preparation of food in kitchens for the purpose of consumption on the premises or when served by caterers.
927.04 General Discharge Prohibitions
No discharger shall contribute or cause to be discharged, directly or indirectly, any of the following described substances into the POTW or otherwise to the facilities of the City:
(a) Pollutants which create a fire or explosion hazard in the POTW, including, but not limited to, waste streams with a closed cup flashpoint of less than 140 degrees Fahrenheit or 60 degrees Centigrade using the test method described in 40 CFR 261.21.
(b) Solid or viscous substances which will or may cause obstruction to the flow in a sewer or other interference with the operation of the POTW.
(c) Any wastewater having a pH less than 6.0 or higher than 11.0 or having any other corrosive property capable of causing damage or hazard to structures, equipment or personnel of the system.
(d) Any wastewater containing toxic pollutants in sufficient quantity, either singly or by interaction, to injure or interfere with any wastewater treatment process, which constitute a hazard to humans or animals, or to exceed the limitation set forth in this chapter. A toxic pollutant shall include but not be limited to any pollutant identified in the USEPA Priority Pollutant List.
(e) 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.
(f) Any substance, which may cause the POTW's effluent or treatment 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 Section 405 of the Act; any 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, Resource Conservation and Recovery Act or State standards applicable to the sludge management method being used.
(g) Any substances, which will cause the POTW to violate its NPDES and/or other disposal system, permits.
(h) Any substance with objectionable color not removed in the treatment process, such as, but not limited to, dye wastes and vegetable tanning solutions.
(i) Any wastewater having a temperature which will inhibit biological activity in the POTW resulting in interference; but in no case, wastewater with a temperature at the introduction into the POTW wastewater treatment plant which exceeds 40o C (104o F).
(j) Any slugload, which means any pollutant, including oxygen demanding pollutants (BOD, etc.), released in a single extraordinary discharge episode of such volume or strength as to cause interference or pass through at the POTW.
(k) Any unpolluted water including, but not limited to, non-contact cooling water, except such water as may be discharged to a sewer which is designated to carry storm water.
(l) Any wastewater containing any radioactive wastes or isotopes of such half-life or concentrations as exceed limits in compliance with applicable State or Federal regulations.
(m) Any wastewater, which causes a hazard to human life or creates a public nuisance.
(n)Discharges of petroleum oil, nonbiodegradable cutting oil or products of mineral oil origin in amounts that will cause interference or pass through.
(o) Any trucked or hauled pollutants except at discharge points designated by the Director.
(p) The discharge of hazardous wastes (as defined in Section 1004 of the Resource Conservation and Recovery Act) into a pipeline connected to the public sewer, which is dedicated to only the discharge of hazardous wastes is prohibited. The discharge of hazardous wastes to the headworks of the wastewater treatment plant by truck and rail is also prohibited.
(Ord. 117-1993. Passed 6-14-93.)
When the Director determines that a discharger is contributing any of the above enumerated substances in such amounts as to interfere with the operation of the POTW, the Director shall: advise the discharger of the impact of the contribution on the POTW; and develop effluent limits for such discharger to correct the interference with the POTW.
(Ord. 107-1991. Passed 6-24-91.)
927.05 Limitations on Wastewater Strength
(a) National Categorical Pretreatment Standards.
(1)National categorical pretreatment standards as promulgated by the US Environmental Protection Agency (U.S. EPA) pursuant to the Act shall be met by all dischargers of the national industrial categories. An application for modification of the regulated categorical pretreatment standards may be considered for submittal to the Approval Authority by the Director when the City's wastewater treatment system achieves consistent removal of the pollutants as defined by 40 CFR 403.7.
(2) The City reserves the right to derive equivalent mass and concentration limits in lieu of categorical standards, in accordance with 40 CFR 403.6(c).
(b) Right of Revision. The City reserves the right to amend this chapter to provide for more stringent limitations or requirements on discharges to the POTW where deemed necessary to comply with the objectives set forth in Section 927.01.
(c) Dilution. No discharger shall increase the use of potable or process water in any way, nor mix separate waste streams for the purpose of diluting a discharge as a partial or complete substitute for adequate treatment to achieve compliance with the standards set forth in this chapter.
(Ord. 107-1991. Passed 6-24-91.)
(d) Local Discharge Limitations. No discharger shall discharge wastewater containing concentrations of the enumerated materials, which exceed the following values. The City reserves the right to revise local discharge limitations to reflect new or modified NPDES permit limits for effluent and/or sludge.
Maximum Daily Concentration (mg/l)
30-Day Average Concentration (mg/l)
Arsenic - total (As)
|Cadmium - total (Cd)||1.24||1.24|
|Chromium - hexavalent (Cr6+)||5.21||3.32|
|Copper - total (Cu)||25.4||-|
|Cyanide - total (CN)||-||13.1|
|Lead - total (Pb)||13.9||10.2|
|Mercury - total (Hg)||0.0050||0.0007|
|Nickel - total (Ni)||11.8||6.08|
|Silver - total (Ag)||-||2.76|
|Zinc - total (Zn)||32.0||18.8|
(Ord. 117-1993. Passed 6-14-93.)