The definitions set forth in this section shall apply throughout this chapter unless the context otherwise requires:

(1) "Approved air gap" means a physical separation between the free-flowing end of a water supply pipeline and the overflow rim of an open or nonpressurized receiving vessel. To be an approved air gap, the separation must be at least:

(a) Twice the diameter of the supply piping measured vertically from the overflow rim of the receiving vessel, and in no case be less than one inch, when unaffected by vertical surfaces (sidewalls); or

(b) Threes time the diameter of the supply piping, if the horizontal distance between the supply pipe and a vertical surface (sidewall) is less than or equal to three times the diameter of the supply pipe, or if the horizontal distance between the supply pipe and intersecting vertical surfaces (sidewalls) is less than or equal to four times the diameter of the supply pipe and in no case less than one and one-half inches.

(2) "Approved reduced pressure principle backflow prevention assembly (RPBA)" means an RPBA of a make, model and size that is approved by the Washington state department of health.

(3) "Appurtenances" means all valves, pumps, fittings, pipes, hoses, metering devices, and mechanical devices which are connected to a storage container, or which are used to transfer a material into or out of such container.

(4) "Bulk pesticide" means any registered pesticide which is transported or held in an individual container in undivided quantities of greater than fifty-five U.S. gallons liquid measure or one hundred pounds net dry weight.

(5) "Certified engineer" means a licensed professional engineer, registered in the state of Washington in the discipline in which he/she is practicing.

(6) "Department" means the Washington state department of agriculture.

(7) "Discharge" means a spill, leak, or release, accidental or otherwise, from a storage container, container or appurtenance. It does not include a fully contained transfer of pesticide which is made pursuant to sale, storage, distribution or use.

(8) "Dry pesticide" means pesticide which is in solid form prior to any application or mixing for application, and includes formulations such as dusts, wettable powders, dry flowable powders, granules, and water dispersible granules.

(9) "Liquid pesticide" means pesticide in liquid form, and includes solutions, emulsions, suspensions, slurries, and pesticide rinsates.

(10) "Mini bulk pesticide" means an amount of liquid pesticide greater than fifty-five gallons but not exceeding five hundred gallons which is held in a single container designed for ready handling and transport, which has been filled by the original pesticide manufacturer or repackager, and to which no substance has been added by any person.

(11) "Not technically feasible" means compliance is not physically or technically possible or feasible, and/or compliance cannot be achieved without compromising operational safety, and/or significantly compromising operational access. Monetary cost of compliance alone shall not be sufficient for the department to determine that compliance is not technically feasible.

(12) "Operational area" means an area or areas where pesticides are transferred, loaded, unloaded, mixed, repackaged, refilled or where pesticides are cleaned, or rinsed from containers or application, handling, storage or transportation equipment.

(13) "Operational area containment" means any structure or system designed and constructed to intercept and contain discharges, including storage container or equipment wash water, rinsates, and rainwater from the operational area(s).

(14) "Permanent mixing/loading site" means a site (location) at which more than three hundred gallons of liquid pesticide (formulated product) or three thousand pounds of dry pesticide or at which a total of fifteen hundred pounds of pesticides as active ingredients are being mixed, repackaged or transferred from one container to another within a calendar year: Provided, That wood preservative application systems already regulated by 40 C.F.R., Parts 264.570-575 and Parts 265.440-445 shall be exempt.

(15) "Permanent storage facility" means a location at which liquid bulk pesticide in a single container or aggregate quantities in excess of five hundred U.S. gallons or dry bulk pesticide in undivided quantities in excess of two thousand pounds is held in storage: Provided, That mini-bulk pesticide containers are exempt from this chapter.

(16) "Pesticide" means, but is not limited to:

(a) Any substance or mixture of substances intended to prevent, destroy, control, repel, or mitigate any insect, rodent, snail, slug, fungus, weed, and any other form of plant or animal life or virus, except virus on or in a living person or other animal which is normally considered to be a pest or which the director may declare to be a pest;

(b) Any substance or mixture of substances intended to be used as a plant regulator, defoliant or desiccant; and

(c) Any spray adjuvant.

(d) For the purpose of establishing permanent mixing/loading site threshold values petroleum oils and products containing only Kaolin clay as the active ingredient are exempt from this chapter.

(17) "Primary containment" means the storage of liquid or dry bulk pesticide in storage containers at a permanent storage facility.

(18) "Rinsate" means the liquid generated from the rinsing of any equipment or container that has come in direct contact with any pesticide, including: Recovered sedimentation, washwater, contaminated precipitation, or other contaminated debris.

(19) "Secondary containment" means a device or structure designed, constructed, and maintained to hold or confine a discharge of a liquid pesticide from a permanent storage facility.

(20) "Storage container" means a container, including a rail car, nurse tank or other mobile container, that is used or intended for the storage of bulk liquid or dry pesticide. It does not include a mobile container at a storage facility for less than fifteen days if this storage is incidental to the loading or unloading of a storage container at the bulk pesticide storage facility. Storage container does not include underground storage containers or surface impoundments such as lined ponds or pits.

(21) "Substantially similar protection" means alternative containment and management practices that prevent or control releases to the environment to the same or similar degree as the protections afforded by full compliance with this chapter.

(22) "Temporary field storage" means a storage container with the capacity to store two thousand five hundred gallons or less of bulk liquid pesticide that remains in the same location for no more than fourteen consecutive days in any six-month period. Provided, That temporary field storage containers used to store soil fumigants shall be allowed a maximum capacity of ten thousand gallons or less. Containers must be chemically compatible with the material, which is being stored. Such containers can remain in the same location for no more than fourteen consecutive days in any six-month period. Liquid bulk pesticide application tanks directly attached to an apparatus for the purpose of chemigation are exempt from this chapter.

(23) "Washwater" means the liquid generated from the rinsing of the exterior of any equipment, containers or secondary containment or operational areas which have or may have come in direct contact with any pesticide.