Wyoming Administrative Code
Agency 020 - Environmental Quality, Dept. of
Sub-Agency 0011 - Water Quality
Chapter 12 - DESIGN AND CONSTRUCTION STANDARDS FOR PUBLIC WATER SUPPLIES
Section 12-5 - Definitions

(a) The following definitions supplement those contained in W.S. § 35-11-103 of the Wyoming Environmental Quality Act.

(b) "Auxiliary source of supply" means any water supply on or available to the water user's system other than an approved public water supply acceptable to the water supplier. These auxiliary waters may include water from another supplier's public potable water supply or any natural source(s), such as a well, spring, river, stream, harbor, and so forth; used waters; or industrial fluids. These waters may be contaminated or polluted, they may be objectionable or they may be from a water source that the water supplier is uncertain of sanitary control.

(c) "Average daily demand" means the total annual water use divided by the number of days the system was in operation.

(d) "Backflow" means the undesirable reversal of flow of water or mixtures of water and other liquids, gases, or other substances into the distribution system of the public water supply from any other source or sources.

(e) "Backflow incident" means any identified backflow to a public water supply distribution system or to the potable water piping within the water user's system benefitting from a water service connection to the public water supply distribution system.

(f) "Back-pressure" means a form of backflow caused when the pressure of the water user's system is greater than that of the water supply system whether caused by a pump, elevated tank, elevated piping, boiler, pressurized process, pressurized irrigation system, or air pressure.

(g) "Back-siphonage" means a form of backflow caused by negative or reduced pressure in the water supply system whether caused by loss of pressure due to high water demands, a line break, or excessive firefighting flows.

(h) "Calculated Dose" means the reduction equivalent dose (RED) calculated using the dose-monitoring equation that was developed through validation testing.

(i) "Contamination" means an impairment of a public water supply by the introduction or admission of any foreign substance that degrades the quality of the potable water or creates a health hazard.

(j) "Cross-connection" means any actual or potential connection between a potable water supply and any other source or system through which it is possible to introduce contamination into the system.

(k) "Degree of hazard" means either a high or low hazard situation where a substance may be introduced into a public water supply through a cross-connection. The degree of hazard or threat to public health is determined by a hazard classification.

(l) "Domestic services" means services using potable water for ordinary living processes.

(m) "Dual check" means a device conforming to American Association of Sanitary Engineers (ASSE) Standard #1024 consisting of two independently acting check valves.

(n) "Groundwater source" includes all water obtained from dug, drilled, bored, jetted, or driven wells; springs that are developed so that the water does not flow on the ground and that are protected to preclude the entrance of surface contamination; and collection wells.

(o) "Hazard classification" means a determination by a Hazard Classification Surveyor as to high hazard or low hazard and the potential cause of backflow as either backpressure or back-siphonage.

(p) "Hazard Classification Survey" means inspection of a premises to identify the potable water systems, the location of any potential cross-connections to the potable water systems, the hazard of the potential backflow, the physical identification of any backflow devices or methods present, and the inspection status of any backflow devices or methods recorded and certified by a qualified Hazard Classification Surveyor.

(q) "Hazard Classification Surveyor" means an individual certified by the USC-Foundation for Cross-Connection Control and Hydraulic Research as Cross Connection Control Specialist (USC-FCCCHR), the ASSE as a Cross-Connection Control Surveyor, or another state certification program submitted with the permit application and approved by the Administrator, or an individual who is a water distribution system operator also certified as a backflow device tester employed by the public water supplier for the service where the survey is being conducted.

(r) "High hazard" means a situation created when any substance that is or may be introduced into a public water supply poses a threat to public health through poisoning, the spread of disease or pathogenic organisms, or any other public health concern.

(s) "Isolated" when referring to cross-connections means the properly approved backflow prevention devices have been installed at each point of cross-connection within the water user's system.

(t) "Low hazard" means a situation created when any substance that is or may be introduced into a public water supply does not pose a threat to public health but that does adversely affect the aesthetic quality of the potable water.

(u) "Maximum daily demand" means the demand for water exerted on the system over a period of 24 consecutive hours, for the period during which such demand is greatest.

(v) "Maximum hourly demand" means the highest single-hour demand exerted on the system. This may or may not occur on the maximum day.

(w) "Mechanical sludge equipment" means the equipment used to physically remove solids from a water treatment process. This may include mechanical drives that use scrapers or differential water levels to collect the sludge.

(x) "Mineralized water" means any water containing more than 500 mg/L total dissolved solids.

(y) "Minor field change" means any in-field adjustment due to previously unknown physical constraints of the project site that do not affect the project's scope. Minor field changes still allow full compliance with the requirements of this Chapter and are shown on the submitted, post-construction as-built plan set for the Division in red.

(z) "Primary disinfection" means disinfection that kills or inactivates bacteria, viruses, and other potentially harmful organisms in drinking water.

(aa) "Reduction Equivalent Dose" means the ultraviolet (UV) dose derived by entering the log inactivation measured during full-scale reactor testing into the UV dose-response curve that was derived through collimated beam testing. RED values are always specific to the challenge microorganism used during experimental testing and the validation test conditions for full-scale reactor testing.

(bb) "Required Dose" means the UV dose in units of mJ/cm2 req needed to achieve the target log inactivation for the target pathogen.

(cc) "Secondary disinfection" means disinfection that provides longer lasting water treatment as the water moves through pipes to consumers.

(dd) "Stabilized drawdown" means a water level that has not fluctuated by more than plus or minus 0.5 foot for each 100 feet of water in the well over at least a six-hour period of constant pumping flow rate. The water column is measured from pre-test static water level to the top of the deepest water bearing fracture that contributes at least 10 percent of total well yield, and plotted measurements that have not shown a trend of decreasing water level.

(ee) "Surface water source" includes all tributary streams and drainage basins, natural lakes, and artificial reservoirs or impoundments upstream from the point of the water supply intake.

(ff) "Validated Dose" means the UV dose in units of mJ/cm2 delivered by the UV reactor as determined through validation testing that is compared to the required dose to determine log inactivation credit.

(gg) "Water service connection" means any water line or pipe connected to a distribution supply main or pipe for the purpose of conveying water to a water user's system.

(hh) "Water supplier" means any entity that owns or operates a public water supply, whether public or private.

(ii) "Water user" means any entity, whether public or private, with a water service connection to a public water supply and includes customers of a public water supplier.

(jj) "Water user's system" means that portion of the user's water system between the water service connection and the point of use. This system includes all pipes, conduits, tanks, fixtures, and appurtenances used to convey, store, or use water provided by the public water supply.