(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° F (60° C) using the test methods specified in 40 CFR 261.21;
(b) Wastewater having a pH less than 6.0 or more than 9.0, 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;
(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 150° F, 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°° F (40° C);
(f) Petroleum oil, non-biodegradable 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 Wastewater Superintendent in accordance with § 52A.10(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 Washington’s NPDES permit;
(k) Wastewater containing any radioactive wastes or isotopes except in compliance with applicable state or federal regulations;
(l) Stormwater, surface water, ground water, artesian well water, roof runoff, subsurface drainage, swimming pool drainage, condensate, deionized water, non-contact cooling water, and unpolluted wastewater, unless specifically authorized by the Superintendent;
(m) Sludges, screenings, or other residues from the pretreatment of industrial wastes;
(n) Medical wastes, except as specifically authorized by the Wastewater Superintendent in a 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.
(r) Wastewater causing 2 readings on an explosion hazard meter at the point of discharge into the POTW, or at any point in the POTW, of more than 4% or any single reading over 8% of the lower explosive limit of the meter.
(s) 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.
(t) No person shall discharge any wastewater which will cause the city to violate any conditions of its NPDES permit.
(B) National Categorical Pretreatment Standards. The categorical pretreatment standards found at 40 CFR Chapter I, Sub-chapter N, Parts 405-471 are hereby incorporated.
(1) Where a categorical pretreatment standard is expressed only in terms of either the mass or the concentration of a pollutant in wastewater, the Superintendent may impose equivalent concentration or mass limits in accordance with 40 CFR 403.6(c).
(2) When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the Superintendent shall impose an alternate limit using the combined wastestream formula in 40 CFR 403.6(e).
(3) A user may obtain a variance from a categorical pretreatment standard if the user can prove, pursuant to the procedural and substantive provisions in 40 CFR 403.13, that factors relating to its discharge are fundamentally different from the factors considered by EPA when developing the categorical pretreatment standard.
(4) A user may obtain a net gross adjustment to a categorical standard in accordance with 40 CFR 403.15.
(C) Local limits (daily maximum limits).
(1) The following pollutant limits are established to protect against pass through and interference. No person shall discharge wastewater containing in excess of the following daily maximum limit:
Pollutants (Total Metals) | Maximum Concentration (mg/L) | |
Pollutants (Total Metals) | Maximum Concentration (mg/L) | |
Arsenic | As | 1.0 |
Cadmium | Cd | 0.5 |
Chromium | Cr | 1.0 |
Copper | Cu | 0.5 |
Cyanide | CN | 0.23 |
Lead | Pb | 0.5 |
Mercury | Hg | 0.01 |
Nickel | Ni | 0.5 |
Selenium | Se | 0.07 |
Silver | Ag | 0.43 |
Zinc | Zn | 0.5 |
Pollutants (Other) | Maximum Concentration (mg/L) | |
Pollutants (Other) | Maximum Concentration (mg/L) | |
PH | 6.0 to 9.0 | |
Phosphorus | 25 | |
Oil and grease | 100 | |
Fluoranthene | 0.076 | |
Phenanthrene | 0.34 | |
Total Phenols | 25.0 | |
Total Petroleum Hydrocarbons | ||
Pollutants (Surcharges) | Maximum Concentration (mg/L) | |
BOD* | 300 | |
TSS* | 300 | |
TKN* | 35.0 | |
* Additional charges for treating stronger than normal waste shall be made. Normal domestic sewage waste strength should not exceed a biochemical oxygen demand (BOD) of 300 milligrams per liter of fluid, suspended solids in excess of 300 milligrams per liter of fluid, or Total Kjeldahl Nitrogen (TKN) in excess of 35 milligrams per liter of fluid. Surcharges for stronger than normal waste will be set in § 52A.34(B).
(2) The above limits apply at the point where the wastewater is discharged to the POTW. All concentrations for metallic substances are for “total” metal unless indicated otherwise. The Superintendent may impose mass limitations in addition to the daily maximum limits above.
(D) City’s right of revision. The City of Washington reserves the right to establish, by ordinance
or in wastewater discharge permits, more stringent standards or requirements on discharges to the POTW.
(E) 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 Superintendent 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.
(Ord. 5-2007, passed 6-25-2007; Am. Ord. 15-2007, passed 12-10-2007; Am. Ord. 3-2015, passed 2-9-2015)