Unless the context clearly requires otherwise, the definitions in this section apply throughout this chapter.

"Agricultural water use" means the use of water for irrigation and other uses related to the production of agricultural products. These uses include, but are not limited to, construction, operation, and maintenance of agricultural facilities and livestock operations at farms, ranches, dairies, and nurseries. Examples of these uses include, but are not limited to, dust control, temperature control, and fire control.

"Alarm" means an integrated system of sensor instruments or devices that continuously monitor a specific function or process and automatically alert operators to abnormal conditions by means of visual or audible signals, or both.

"Approved air gap" means the physical separation between the free-flowing end of a water supply pipeline and the overflow rim of an open or nonpressurized receiving vessel that has the following minimum separations:

• 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 (vertical sidewalls); and

• Three times the diameter of the supply piping, if the horizontal distance between the supply pipe and the 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 the 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.

"Approved backflow prevention assembly" means an RPBA, RPDA, DCVA, DCDA, PVBA, or SVBA used for protecting a potable or reclaimed water supply.

"Aquifer" means a geologic formation, group of formations, or part of a formation capable of yielding a significant amount of groundwater to wells or springs.

"Augmentation" means the intentional addition of water to rivers and streams of the state or other surface water bodies through the zone of saturation or to the surface water.

"Backflow assembly tester" or "BAT" means a person meeting the requirements of chapter 246-292 WAC and certified under chapter 70.119 RCW to inspect, field test, maintain, and repair backflow prevention assemblies, devices, and air gaps that protect public water systems.

"Beneficial purpose" or "beneficial use" means the uses of reclaimed water for domestic, stock watering, industrial, commercial, agricultural, irrigation, hydroelectric power production, mining, fish and wildlife maintenance and enhancement, recreational, and thermal power production purposes, and for preservation of environmental and aesthetic values, and for all other uses compatible with the enjoyment of the waters of the state. Beneficial purpose or beneficial use of reclaimed water includes all uses authorized under chapter 90.46 RCW, and contained within WAC 173-219-390.

"BOD5" means five-day biochemical oxygen demand.

"CBOD5" means five-day carbonaceous biochemical oxygen demand.

"Certified operator" means a person who meets the requirements of WAC 173-219-250.

"Class A reclaimed water" means a water resource that meets the treatment requirements of this chapter, including, at a minimum, oxidation, coagulation, filtration, and disinfection.

"Class A+ reclaimed water" means a water resource that meets the treatment requirements of this chapter for Class A reclaimed water and any additional criteria determined necessary on a case-by-case basis by health for direct potable reuse.

"Class B reclaimed water" means a water resource that meets the treatment requirements of this chapter, including, at a minimum, oxidation, and disinfection.

"Commercial, industrial, and institutional use" means nonpotable uses of water to produce products, provide goods and services, or for associated sanitary uses such as toilet flushing. The term does not include land application or irrigation uses.

"Constructed beneficial wetlands" means those wetlands intentionally constructed on nonwetland sites to produce or create natural wetland functions and values.

"Constructed treatment wetlands" means wetland-like impoundments intentionally constructed on nonwetland sites and managed for the primary purpose of further treatment or retention of reclaimed water as distinct from creating natural wetland functions and values.

"Cross-connection control specialist" or "CCS" means an individual meeting the requirements of chapter 246-292 WAC and certified under chapter 70.119 RCW to develop and implement a cross-connection control program.

"DCDA" means double check detector assembly.

"DCVA" means double check valve assembly.

"Depressional wetland" means a wetland that occurs in topographic depressions where the elevation of the surface within the wetland is lower than in the surrounding landscape, and the lowest point of elevation is within the boundary of the wetland.

"Direct potable reuse" means the process in which Class A+ reclaimed water is introduced into an existing water distribution, storage, or treatment system without an environmental buffer.

"Distributor" means the person authorized through a use agreement with a reclaimed water generator to distribute or supply reclaimed water to users. A distributor may also be a generator or a user. Users that distribute reclaimed water to use areas through a gravity conveyance system for agricultural water uses are not distributors.

"DO" means dissolved oxygen.

"Domestic wastewater" means wastewater from greywater, toilet, or urinal sources.

"Ecology" means the Washington state department of ecology.

"Engineering report" means a document that examines the engineering and administrative aspects of a reclaimed water facility, as required under this chapter.

"Food crops" means any crops intended for human consumption.

"Generator" means any person that generates any type of reclaimed water for a use regulated under this chapter. A generator may also be a distributor or a user.

"Groundwater" means water in a saturated zone or stratum beneath the surface of land or below a surface water body.

"Groundwater recharge" means introduction of reclaimed water to groundwater aquifers and includes the following:

• Indirect recharge: Where reclaimed water is introduced to groundwater through surface or subsurface infiltration or percolation, where the introduced water travels through an unsaturated vadose zone and the commingling with groundwater of the state is not immediate.

• Direct recharge: Where reclaimed water is released directly and immediately into groundwater of the state through direct injection or other means.

"Health" means the Washington state department of health.

"Inadequately treated water" means water treated by a reclaimed water treatment process that does not meet reclaimed water permit limits and standards.

"Land application" means use of reclaimed water as permitted under this chapter for the purpose of irrigation or watering of landscape vegetation. Land application in this chapter is not synonymous with land treatment or reference to a biosolids land application.

"Lead agency" means either the department of health or the department of ecology that has been designated by this chapter as the agency that will coordinate, review, issue, and enforce a reclaimed water permit issued under this chapter.

"Most recent edition" means that version of a specific guidance or reference document in effect at the time lead agency begins the feasibility and design review process.

"Net environmental benefit" means that the environmental benefits of the reclaimed water generation project are greater than the environmental impacts associated with the project.

"Nonlead agency" means health or ecology when they are not the lead agency as defined in this chapter.

"Nonpotable" means water that is not approved by health or a local health jurisdiction as being safe for human consumption.

"Nonpotable reuse systems" means systems that collect and treat nonpotable water, including greywater, from a single building or property for nonpotable reuse at the single building or property, with no discharge to waters of the state, as regulated under WAC 51-56-1500 and by the appropriate authority having jurisdiction, or a rule adopted by health. When reuse occurs on nearby properties, these may be called on-site nonpotable water systems or decentralized nonpotable water systems.

"NPDES" means the National Pollutant Discharge Elimination System.

"Operator" means a person who operates a reclaimed water facility and/or distribution system, and if applicable, who meets the operator certification requirements in the permit.

"Owner" means a person with a security interest in a reclaimed water facility regulated under this chapter.

"Permittee" means any entity issued a reclaimed water permit under this chapter.

"Person" means any state, individual, public or private corporation, political subdivision, governmental subdivision, governmental agency, municipality, copartnership, association, firm, trust estate, or any other legal entity whatever.

"pH" means the negative logarithm of the hydrogen ion concentration, measured in standard units or s.u.

"Plans and specifications" means the detailed engineering drawings and specifications prepared by a licensed professional engineer, used in the construction or modification of reclaimed water facilities, and other related facilities.

"Potable water" or "drinking water" means water safe for human consumption and approved under chapter 246-290 or 246-291 WAC.

"Potable water supply intake" means the works or structures at the head of a conduit through which water is diverted from a source (e.g., river or lake) into a treatment plant producing potable water. With or without treatment, it may also include a groundwater well and appurtenances, and any physical structures used for collecting spring and groundwater that is under the influence of surface water sources for potable supply.

"Private utility" means all utilities, both public and private, which provide sewerage and/or water service and that are not municipal corporations as defined by RCW 36.94.010. The ownership of a private utility may be in a corporation, nonprofit or for profit, in a cooperative association, in a mutual organization, or in individuals.

"PVBA" means pressure vacuum breaker assembly.

"Reclaimed water" means water derived in any part from a wastewater with a domestic wastewater component that has been adequately and reliably treated to meet the requirements of this chapter, so that it can be used for beneficial purposes. Reclaimed water is not considered a wastewater.

"Reclaimed water facility" or "facility" means the treatment plant, equipment, storage, conveyance devices, and dedicated sites for reclaimed water generation.

"Reclaimed water permit" or "permit" means an operating permit identifying the terms and conditions, the required level of treatment, operating conditions, and use-based standards, issued to a generator of reclaimed water by the lead agency.

"Recovery of reclaimed water stored in an aquifer" means the recovery of reclaimed water artificially stored in an underground geological formation for beneficial use.

"Recovery period" means a period of time defined by the duration, rate, and schedule of withdrawal of reclaimed water for a beneficial use from an underground geological formation.

"Reliability" means the ability of a system or component(s) thereof to perform a required function under permit stated conditions for a permit stated period.

"Reliability assessment" means both an evaluation performed and a report by a professional engineer on the reliability of facility components, equipment, and certified operators that are used or proposed to be used to generate and manage reclaimed water.

"RPBA" means reduced pressure backflow assembly.

"RPDA" means reduced pressure detector assembly.

"Source water" means raw or treated wastewater with a domestic component that supplies a reclaimed water facility.

"Streamflow" or "surface water augmentation" means the intentional use of reclaimed water for rivers and streams of the state or other surface water bodies, for the purpose of increasing volumes.

"Surface percolation" means the controlled application of water to the ground surface or to unsaturated soil for replenishing groundwater.

"SVBA" means spill resistant vacuum breaker assembly.

"T10" means the effective contact time, the time it takes ten percent of a slug tracer volume to pass through the reactor, or the time where ninety percent of reclaimed water is kept in contact with a disinfection residual within the contact reactor.

"Third-party guarantor" means an entity approved by the lead agency to provide standby management services if a generator fails to operate a reclaimed water facility in compliance with this chapter.

"TSS" means total suspended solids.

"Unit process" means one or more defined grouped processes that perform an identified step in a process.

"Use" means an application of reclaimed water in a manner and for a purpose, as designated in a permit or use agreement, and in compliance with all applicable lead agency and permit requirements.

"Use agreement" means an agreement or contract between the generator and the distributor or user, or between the distributor and user, that identifies terms and conditions for reclaimed water distribution and use to ensure compliance with the reclaimed water permit conditions.

"Use area" means any facility, building, or land area, surface water, or groundwater identified in the use agreement.  

"USEPA" means the United States Environmental Protection Agency.

"User" means any person who uses reclaimed water.

"Waters of the state" means lakes, rivers, ponds, streams, inland waters, underground waters, salt waters and all other surface waters and watercourses within the jurisdiction of the state of Washington, as defined in RCW 90.48.020.

"Water table" means the upper surface of groundwater saturation.

"Wetland" or "wetlands" means areas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted to life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands regulated under chapter 90.46 RCW shall be delineated in accordance with the manual adopted by the department of ecology pursuant to RCW 90.58.380.

"Wetland enhancement" means intentional actions taken to improve the functions, processes, and values of existing wetlands.

"Wetland mitigation" means a sequence of intentional steps or actions taken to reduce impacts to wetlands. Unless the context refers to the entire mitigation sequence, or clearly indicates other steps, the term "wetland mitigation" means compensatory mitigation or the compensation stage of the wetland mitigation sequence, where impacts to wetland functions are offset through the creation, restoration, enhancement, or preservation of other wetlands.

"Wetland restoration" means intentional actions taken to return historic functions and processes to a former or degraded wetland site.