“Act” or “the Act” means the Federal Water Pollution Control Act, also known as the Clean Water Act, as amended, 33 U.S.C. Section 1251 et seq.

“AKART” means all known, available, and reasonable methods of prevention, control, and treatment. AKART shall represent the most current methodology that may reasonably be required for preventing, controlling, or abating the pollutants associated with a discharge. The concept of AKART applies to both point and nonpoint sources of pollution. The term “best management practices” is considered a subset of the AKART requirement.

“Approval authority” means the Washington State Department of Ecology, Water Quality Program Manager.

“Authorized or duly authorized representative of the user” means:

“Best management practices” or “BMPs” means schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to implement the prohibitions listed in VMC 14.10.050(A) and (B) and 40 CFR Part 403.5(a)(1) and (b). BMPs may also include treatment requirements, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw materials storage.

“Biochemical oxygen demand” or “BOD” means the quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedures for five days at 20 degrees centigrade, usually expressed as a concentration (e.g., mg/L).

“Bypass” means the intentional diversion of wastestreams from any portion of an industrial user’s treatment facility.

“Categorical industrial user” or “CIU” means an industrial user subject to a categorical pretreatment standard or categorical standard.

“Categorical pretreatment standard” or “categorical standard” means any regulation containing pollutant discharge limits promulgated by EPA in accordance with Sections 307(b) and (c) of the Act (33 U.S.C. Section 1317) which apply to a specific category of users and which appear in 40 CFR Chapter I, Subchapter N, Parts 405 471.

“City” means the city of Vancouver, the city council of Vancouver, or the director of public works, as appropriate.

“Composite sample” means a representative composite of samples of a waste stream taken throughout the period of a calendar day or equivalent representative 24-hour period when discharges are produced by a regulated activity. Composite samplers must interface with a flow metering device to produce a representative “flow proportionate” composite sample unless the director has determined that flow proportionate samples are not required or the analyte is not amenable to composite sampling (pH, temperature, oil, etc.).

“Control authority” means the city of Vancouver.

“Control document” means a wastewater discharge permit or any other formal written wastewater discharge authorization or prohibition issued by the director.

“Daily limit” or “daily maximum limit” means the maximum allowable discharge of a pollutant over a calendar day or equivalent representative 24-hour period. Where daily limits are expressed in units of mass, the daily discharge is calculated by multiplying the daily average concentration and total flow volumes in the same 24-hour period by a conversion factor to get the desired units. Where daily limits are expressed in terms of a concentration, the daily discharge is the composite sample value, or flow weighted average if more than one discrete sample was collected. Where flow weighting is infeasible, the daily average is the arithmetic average of all samples if analyzed separately, or the sample value if samples are composited prior to analysis.

“Director” means the person designated by the city to supervise the operation of the POTW, and who is charged with certain duties and responsibilities by this chapter. The term also means a duly authorized representative of the director.

“Discharge” is the same as indirect discharge.

“Disruption” means a discharge which causes (either by itself or in combination with other discharges) a deleterious impact on the structure, function, operation, or maintenance of the POTW, including an increase in maintenance or risk of harm to persons.

“Domestic user” or “residential user” means any person who contributes, causes, or allows the contribution of wastewater to the city POTW that the city determines is of similar volume and/or chemical make-up to that of a residential dwelling unit. Discharges from a residential dwelling unit typically include kitchen wastes, human wastes, and housekeeping cleaning materials in volumes and/or concentrations normally discharged from these classes of users and typically include up to 100 gallons per capita per day, 0.2 pounds of BOD per capita per day, and 0.17 pounds of TSS per capita per day.

“Environmental Protection Agency” or “EPA” means the U.S. Environmental Protection Agency or, where appropriate, the Regional Water Management Division Director, the Regional Administrator, or other duly authorized official.

“Existing source” means any source of discharges subject to categorical standards and discharging prior to the promulgation of those standards or otherwise not meeting the definition of a “new source” in this section.

“Grab sample” means a sample which is taken from a wastestream without regard to the flow in the wastestream and over a period of time not to exceed 15 minutes.

“High strength user” means any user who, in any given month, discharges nondomestic wastewater which is found to contain a monthly average of more than 500 pounds per day of BOD or 500 pounds per day of total suspended solids (TSS). Food service establishments that properly implement best management practices (BMPs), and any user classified as an electronics customer in VMC 14.04.230, will not be considered a high strength user.

“Indirect discharge” or “discharge” means the introduction of pollutants into the POTW from any user or nondomestic source subject to this chapter or other state or federal regulations.

“Industrial user” is the same as “user.”

“Industrial waste” means any solid, liquid, or gaseous waste resulting from any industrial, manufacturing, trade, health service, educational institution, business, laboratory, research establishments or facility, or from the development, recovery, or processing of natural resources, excluding domestic waste; any nondomestic waste.

“Industrial wastewater” means wastewater, nondomestic wastewater, process wastewater or any liquid wastestream resulting from any industrial, manufacturing, trade, or business process; or from the development, recovery, or processing of natural resources.

“Instantaneous limit” means the maximum concentration of a pollutant allowed to be discharged at any time, determined from the analysis of a discrete sample. For analytes for which users must take a grab sample for compliance purposes, this standard is the same as the daily maximum limit. For all other pollutants the instantaneous limit shall be twice the daily maximum limit. For analytes for which users must take a composite sample for compliance purposes, this standard is twice the daily maximum limit.

“Interference” means a discharge which causes (either by itself or in combination with other discharges) a violation of the city’s NPDES permit(s) or prevents the intended sewage sludge use or disposal by inhibiting or disrupting the POTW, including its collection systems, pump stations, and wastewater and sludge treatment processes. For example, a discharge from a user which causes a blockage resulting in a discharge at a point not authorized under the city’s NPDES permit(s).

“Local limits” means effluent limitations developed for users by the director to specifically protect the POTW from the potential of pass through, interference, and intended biosolids uses. Such limits shall be based on the POTW’s site-specific flow and loading capacities, receiving water considerations, and reasonable treatment expectations for nondomestic wastewater.

“Medical waste” means isolation wastes, infectious agents, human blood and blood products, pathological wastes, sharps, body parts, contaminated bedding, surgical wastes, potentially contaminated laboratory wastes, and dialysis wastes.

“Minor industrial user” or “MIU” means any industrial user that does not otherwise qualify as a significant industrial user of the POTW and is identified by the director as having the potential to discharge wastewater that, when taken into account with the wastewaters of other industrial users, may have a significant impact on the POTW; or is classified as such by the director.

“Monthly average” means the arithmetic mean of the effluent sample results collected during a calendar month or specified 30-day period. Where composite samples are required, grab samples taken for process control or by the control authority are not to be included in a monthly average.

“Monthly average limit” means the limit to be applied to the monthly average to determine compliance with the requirements of this chapter.

“New source” means:

“Noncontact cooling water” means water used for cooling which does not come into direct contact with any raw material, intermediate product, waste product, or finished product. Noncontact cooling water may contain protective additives.

“Nondischarging categorical industrial users” or “NDCIUs” means any person that generates wastewater subject to a categorical standard that does not discharge those wastewaters subject to the categorical standard to the POTW. NDCIUs are considered a potential source of indirect discharge.

“Pass through” means a discharge which exits the POTW into waters of the United States in quantities or concentrations which, alone or in conjunction with a discharge or discharges from other sources, is a cause of a violation of any requirement of the city’s NPDES permit(s), including an increase in the magnitude or duration of a violation.

“Person” means any individual, partnership, copartnership, firm, company, corporation, association, joint stock company, trust, estate, governmental entity, or any other legal entity; or their legal representatives, agents, or assigns. This definition includes all federal, state, and local governmental entities.

“pH” means the logarithm (base 10) of the reciprocal of the concentration of hydrogen ions expressed in standard units. pH is an expression of the intensity of the alkaline or acid condition of a liquid. The pH may range from zero to 14, where zero is most acid and 14 most alkaline.

“Pollutant” means dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, sewage sludge, munitions, medical wastes, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, municipal, agricultural and industrial wastes, and certain characteristics of wastewater (e.g., pH, temperature, TSS, turbidity, color, BOD, carbonaceous oxygen demand, toxicity, or odor).

“Pretreatment” means the reduction of the amount of pollutants, the elimination of pollutants, or the alteration of the nature of pollutant properties in wastewater prior to, or in lieu of, introducing such pollutants into the POTW. This reduction or alteration can be obtained by physical, chemical, or biological processes; by process changes; or by other means, except by diluting the concentration of the pollutants unless allowed by an applicable pretreatment standard.

“Pretreatment facilities” means wastewater treatment equipment, unit, device, facility or portions thereof designed for providing pretreatment of wastewater.

“Pretreatment requirements” means any substantive or procedural requirement related to pretreatment imposed on a user, other than a pretreatment standard.

“Pretreatment standards” or “standards” means pretreatment standards shall mean discharge prohibitions (VMC 14.10.050), categorical pretreatment standards (VMC 14.10.060), state pretreatment standards (VMC 14.10.070), local limits (VMC 14.10.080), and site specific limits based on potential for vapor toxicity, explosion, sewer corrosion, or other detrimental effects to the POTW.

“Publicly owned treatment works” or “POTW” means a treatment works, as defined by Section 212 of the Act (33 U.S.C. Section 1292), which is owned by the city. This definition includes any devices or systems used in the collection, storage, treatment, recycling, and reclamation of sewage or industrial wastes of a liquid nature and any conveyances which convey wastewater to a treatment plant.

“Residential user” is the same as a domestic user.

“Septage” is the same as septic tank waste.

“Septic tank waste” or “septage” means sewage and typically associated solids from domestic activities pumped from a septic tank serving one or more private residences. The director may also consider wastes from chemical toilets, campers, trailers, or cesspools to be septic tank waste so long as they are absent chemicals at concentrations which might inhibit biological activity at the POTW.

“Sewage” means human excrement and gray water (from household showers, toilets, kitchens, clothes and dish washing, and related domestic activities).

Significant Industrial User or SIU. Except as provided in subsection (3) of this definition, a “significant industrial user” is:

“Slug load” or “slug discharge” means any discharge of a nonroutine, episodic nature, including but not limited to an accidental spill or a noncustomary batch discharge, which has a reasonable potential to cause interference or pass through, or in any other way violate the POTW’s regulations, local limits or permit conditions. This includes discharges at a flow rate or concentration which could cause a violation of the prohibited discharge standards of VMC 14.10.050.

“Standards” is the same as pretreatment standards.

“Stormwater” means any flow occurring during or following any form of natural precipitation, and resulting from such precipitation, including snowmelt.

“Total suspended solids” or “TSS” means the total suspended matter that floats on the surface of, or is suspended in, water, wastewater, or other liquid, and which is removable by laboratory filtering.

“User” or “industrial user” means any person that does not qualify as a domestic user and is a source, or potential source, of indirect discharge.

“Wastewater” means any combination of liquid and water carried industrial wastes and sewage from residential dwellings, commercial buildings, industrial and manufacturing facilities, and institutions, whether treated or untreated, which are contributed to the POTW.

“Wastewater treatment plant” or “treatment plant” means that portion of the POTW which is designed to provide treatment of municipal sewage and industrial waste. (Ord. M-4431 § 3, 2023; Ord. M-3970 § 2, 2010)