12.06.020 General sewer use requirements.
A. Prohibited Discharge Standards.
1. General Prohibitions. No user shall introduce or cause to be introduced into the POTW any pollutant or wastewater which causes pass through or interference. These general prohibitions apply to all users of the POTW whether or not they are subject to categorical pretreatment standards or any other national, state, or local pretreatment standards or requirements.
2. Specific Prohibitions. No user shall introduce or cause to be introduced into the POTW the following pollutants, substances, or wastewater:
a. 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;
b. Wastewater having a pH less than 6.5 or more than 10.5, or otherwise causing corrosive structural damage to the POTW or equipment;
c. 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 one-half inch.
d. 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;
e. 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);
f. Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin, in amounts that will cause interference or pass through;
g. 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;
h. Trucked or hauled pollutants, except at discharge points designated by the City Engineer in accordance with HRMC 12.06.030(D);
i. 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 sewers for maintenance or repair;
j. 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;
k. Wastewater containing any radioactive wastes or isotopes except in compliance with applicable state or federal regulations;
l. Storm water, surface water, ground water, artesian well water, roof runoff, subsurface drainage, swimming pool drainage, condensate, deionized water, noncontact cooling water, and unpolluted wastewater, unless specifically authorized by the City Engineer;
m. Sludges, screenings, or other residues from the pretreatment of industrial wastes;
n. Medical wastes, except as specifically authorized by the City Engineer in an individual wastewater discharge permit;
o. Wastewater causing, alone or in conjunction with other sources, the treatment plant’s effluent to fail a toxicity test;
p. Detergents, surface-active agents, or other substances which may cause excessive foaming in the POTW;
q. Fats, oils, or greases of animal or vegetable origin in concentrations greater than 100 mg/l; or
r. 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 or any single reading over 10 percent of the lower explosive limit of the meter.
Pollutants, substances, or wastewater prohibited by this section shall not be processed or stored in such a manner that they could be discharged to the POTW.
B. National Categorical Pretreatment Standards. Users must comply with the categorical pretreatment standards found at 40 CFR Chapter I, Subchapter N, Parts 405 through 471.
1. Where a categorical pretreatment standard is expressed only in terms of either the mass or the concentration of a pollutant in wastewater, the City Engineer may impose equivalent concentration or mass limits in accordance with 40 CFR 403.6(c).
2. When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the City Engineer may convert the limits to equivalent limitations expressed either as a mass of pollutant discharged per day or effluent concentration for purposes of calculating effluent limitations applicable to individual industrial users.
3. When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the City Engineer shall impose an alternate limit using the combined wastestream formula in 40 CFR 403.6(e).
4. A CIU may obtain a net gross adjustment to a categorical pretreatment standard in accordance with 40 CFR 403.15.
C. Oregon State Pretreatment Standards. Users must comply the Oregon State Pretreatment Standards codified at OAR 340-045-0063.
D. Local Limits.
1. The City Engineer is authorized to establish local limits pursuant to 40 CFR 403.5(c). The following table includes the established local limits:
Pollutant | Local Limit |
|---|---|
Arsenic | 0.24 mg/La |
Cadmium | 0.12 mg/La |
Chromium (Total) | 5.0 mg/Lb |
Copper | 3.97 mg/La |
Cyanide | 1.25 mg/La |
Lead | 1.17 mg/La |
Mercury | 0.042 mg/La |
Molybdenum | 0.37 mg/La |
Nickel | 2.57 mg/La |
Selenium | 0.50 mg/La |
Silver | 0.72 mg/La |
Zinc | 7.92 mg/La |
Flow | No Limit Adopted |
BOD5 | 250 mg/L Surcharge Limitc |
TSS | 250 mg/L Surcharge Limitc |
pH | 6.5 – 10.5 S.U. |
Ammonia | No Limit Adopted |
Oils and Grease |
100 mg/L Total |
Temperature | 40°C (104°F) at POTW; 60°C (140°F) from SIU |
Flammability | Specified as no material with a closed-cup flashpoint less than 140°F |
aRefer to Appendix C, Oregon Department of Environmental Quality Local Limit Workbook Page 5.
bThe calculated limit is 36.5 mg/L. The Resource Conservation and Recovery Act (RCRA) sets a statutory limit of 5.0 mg/L for total chromium. Under RCRA, chromium concentrations above 5.0 mg/L are classified as hazardous. While chromium in wastewater is not covered by RCRA because of the Domestic Sewer Exclusion, the City of Hood River elects to not allow the discharge of waste at concentrations that would otherwise be classified as “hazardous,” and therefore, a limit of 5.0 mg/L is adopted.
cThese are set as standards for surcharges and not local limits. Hood River bases surcharge on concentrations above normal domestic waste strength, which are set at 250 mg/L for BOD5 and 250 mg/L for TSS.
Note: All metals are expressed as total recoverable.
°C = Degrees Celsius
°F = Degrees Fahrenheit
BOD5 = Five-day biochemical oxygen demand
LEL = Lower explosive limit
mg/L – Milligrams per liter
SIU = Significant industrial user
SU = Standard units
TSS = Total suspended solids
2. No person shall discharge wastewater containing restricted substances into the municipal wastewater system in excess of limitations specified in its wastewater discharge permit, or adopted by resolution by the City. The City Engineer shall publish and revise standards (local limits) for specific restricted substances. These standards shall be developed in accordance with 40 CFR Part 403.5 and shall implement the objectives of this chapter. Standards published in accordance with this section will be deemed pretreatment standards for the purposes of Section 307(d) of the Act.
At his/her discretion, the City Engineer may impose mass limitations in addition to or in place of concentration-based limitations. The City Engineer may also revise or modify the standards (local limits) as required, or if deemed necessary to comply with the objectives presented in HRMC 12.06.010(A), or the general and specific prohibitions in subsection (A) of this section, or to ensure compliance with state, federal and local law.
3. The City Engineer may develop best management practices (BMPs), by ordinance or individual wastewater discharge permits, to implement local limits and the requirements of subsection (A) of this section.
E. City’s Right of Revision. The City reserves the right to establish, by ordinance or in individual wastewater discharge permits, more stringent standards or requirements on discharges to the POTW consistent with this chapter.
F. Dilution. No user shall ever increase the use of process water, or in any way attempt to dilute a discharge, as a partial or complete substitute for adequate treatment to achieve compliance with a discharge limitation unless expressly authorized by an applicable pretreatment standard or requirement. The City Engineer may impose mass limitations on users who are using dilution to meet applicable pretreatment standards or requirements, or in other cases when the imposition of mass limitations is appropriate.
G. Application of Most Stringent Limitations. For a discharge regulated by categorical pretreatment standards or other federal, state or local discharge limitations or requirements, the most stringent limitations and requirements will apply.
H. Deadline for Compliance With Categorical Standards. Compliance by existing sources with categorical pretreatment standards shall be within three years of the date the standard is effective unless a shorter compliance time is specified in the appropriate subpart of 40 CFR Chapter I, Subchapter N.
New sources shall install and have in operating condition, and shall start up all pollution control equipment required to meet applicable pretreatment standards before beginning to discharge. Within the shortest feasible time (not to exceed 90 days), new sources must meet all applicable pretreatment standards. (Ord. 2075 §2 (Exh. A), 2023)