Administrative Rules of the State of Montana

In addition to the definitions in 50-53-102, MCA, the following definitions apply to these rules.

(1) "Accessible" means readily available for inspection or replacement of parts.

(2) "Activity pool" means any pool designed primarily for play activity that uses constructed features and devices such as, but not limited to, lily pad walks, flotation devices, small slide features, and similar attractions.

(3) "Adult supervision" means a situation whereby a child at rest or play is within the constant sight and hearing of an adult, age 18 or over, who is charged with safeguarding the child. Adult supervision must be of a nature that is uninterrupted, meaning that it is without absences, voids, or distractions that separate adult from child by distance, obstacles, or any hindrance to sight and sound communication.

(4) "Algae" means microscopic plant-like organisms that contain chlorophyll. These organisms include green, blue-green or black, brown, and yellow-green (mustard) algae.

(5) "Air gap" means the unobstructed vertical distance through the free atmosphere between the lowest opening from an inlet pipe and the flood-level rim of a receptacle or floor drain.

(6) "Algaecide" means a natural or synthetic substance used for killing, destroying, or controlling algae growth.

(7) "Alkalinity" means a measure of the amount of bicarbonate, carbonate, or hydroxide compounds present in a water solution. It is the buffering potential for water to change pH.

(8) "ASME" means the American Society of Mechanical Engineers.

(9) "ANSI" means the American National Standards Institute.

(10) "ANSI/NSPI-1 2003" means the American National Standards Institute and National Spa and Pool Institute, Standards for Public Swimming Pools, approved March 10, 2003.

(11) "ANSI/NSPI-2 1999" means the American National Standards Institute and National Spa and Pool Institute, Standards for Public Spas, approved February 4, 1999.

(12) "Antivortex drain cover or plate" means a plate or cover that is affixed to the main outlet of a swimming pool, spa, or other water feature that prevents a vortex from forming as water passes through to the main outlet. Some industry standards may use the term, "Listed Suction Outlet Cover/Grate" to describe this safety feature. See "Listed suction outlet covers".

(13) "Attendant" is a term used with regard to public swimming pools, spas, or other water features that do not require lifeguards. It means a person who oversees the use of a public swimming pool, spa, or other water feature by bathers and provides supervision of the facility and basic assistance to bathers in need. Each attendant must be currently certified by the American Red Cross or American Heart Association in infant, child, and adult cardiopulmonary resuscitation (CPR), and American Red Cross or American Heart Association standard first aid. Attendants must be at least 15 years of age.

(14) "Automated external defibrillator (AED)" means a medical device heart monitor and defibrillator that is approved by the U.S. Food and Drug Administration.

(15) "Backwash" means the process of thoroughly cleansing the filter media and/or elements by reverse water flow.

(16) "Barrier" means a fence, wall, or an enclosed room that is accessible only by a key or electronic card, or other method used to completely surround the public swimming pool, spa, or other water feature and to obstruct or restrict access to it.

(17) "Bather" means any person authorized by the owner, licensee, or certified operator to use a pool, spa, or other water feature or adjoining deck area for the purpose of water sports, therapy, swimming, sunbathing, or related activities.

(18) "Bathhouse" means a structure that contains dressing rooms, showers, and toilet facilities for use at a public bathing place or adjacent to a public swimming pool, spa, or other water feature.

(19) "Bather load" means the maximum number of persons that could be in the pool, spa, or other water feature at any given moment or during any stated period of time. Bather load for a pool, spa, or other water feature are calculated as provided in ARM 37.115.515.

(20) "Breakpoint chlorination" means the addition of a sufficient amount of chlorine to water to destroy the combined inorganic compounds present.

(21) "Bromine" means a chemical element that exists as a liquid in its elemental form or as part of a chemical compound which is a bacteriological agent used to disinfect swimming pool water.

(22) "Brominator" means a device used to apply or deliver a bromine disinfectant to water at a controlled rate. It may also be called a bromine feeder.

(23) "Cardiopulmonary Resuscitation (CPR)" means a lifesaving technique involving chest compressions and/or mouth-to-mouth breathing, to circulate oxygenated blood to vital organs.

(24) "Cartridge" means a depth, pleated, or surface type filter component with fixed dimensions designed to remove suspended particles from water flowing through the filter.

(25) "Catch pool" means a body of water located at the terminus of a manufactured water slide attraction that is provided for the purpose of terminating the slide action and providing a route for exit to a deck or walkway area.

(26) "Certified pool operator" means someone who has successfully completed the Certified Pool Operator (CPO) course sanctioned by the National Swimming Pool Foundation, the Aquatic Facility Operator (AFO) course sanctioned by the National Recreation and Park Association, or an equivalent course approved by the department. A certified pool operator must be currently certified, recertified, or must have obtained any Continuing Education Units (CEUs) required by the sanctioning organization.

(27) "Chemical feeder" means a mechanical device used for adding chemicals to the water circulating in a pool, spa, or other water feature.

(28) "Chlorinator" means a device used to apply or to deliver a chlorine sanitizer to water at a controlled rate.

(29) "Chloramines" means compounds that are formed when free chlorine combines with nitrogen-containing compounds such as perspiration or ammonia. They can cause eye and skin irritation, have strong objectionable chlorine-type odors, and low sanitizing capability. Also see "Combined residual chlorine".

(30) "Chlorine" means a chemical agent that exists as a gas in its elemental form or as a part of a chemical compound which is an oxidant. It is a bacteriological agent used to disinfect the water in pools, spas, or other water features.

(31) "Chlorine demand compounds" means organic matter, chloramines, and other compounds that react with chlorine and deplete it.

(32) "Chlorine generator" means equipment that produces chlorine, hypochlorous acid, or hypochlorite on-site for disinfection and oxidation of water contaminants.

(33) "Circulation equipment" means the mechanical components that are a part of a circulation system on a pool, spa, or other water feature. The components have different functions but when connected to each other by piping, perform as a coordinated system for purposes of maintaining water in a clear, sanitary, and desirable condition. The term "recirculation" may be used interchangeable with the term "circulation". Some components of circulation equipment include, but are not limited to:

(a) pumps;

(b) hair and lint strainers;

(d) valves;

(e) gauges;

(f) meters;

(g) heaters;

(h) surface skimmers;

(i) inlet/outlet fittings; and

(j) chemical feeding devices.

(34) "Circulation system" means the arrangement of mechanical equipment components, connected by piping to and from a pool, spa, or other water feature, causing it to flow through the various system components for purposes of:

(a) clarifying;

(b) heating;

(d) returning the water back to the original body of water.

(35) "Clarifier" means a chemical that coagulates and neutralizes suspended particles in water. It can also mean coagulant or flocculent. Examples are inorganic salts of aluminum or iron, and water soluble organic polyelectrolyte polymers.

(36) "Combined residual chlorine" means the portion of the total residual chlorine existing in water in chemical combination with ammonia, nitrogen, and/or organic compounds, mostly comprised of chloramine. The combined chlorine number is the result of subtracting the free residual chlorine levels from the total chlorine levels, as determined by a test kit.

(37) "Contaminant" means any physical, chemical, biological, or radiological substance, or matter in water.

(38) "Critical point inspection" means an inspection performed by the department or its designee that minimally addresses critical health and safety violations outlined in ARM 37.115.301 and 37.115.302, and would include other health and safety violations that may be present, or are pending from prior inspections.

(39) "Critical safety violation" means a health or safety violation that has the potential to imminently cause or result in water contamination illness, serious injury or death, or an environmental or safety hazard. When a critical safety violation occurs, the public swimming pool, spa, or other water feature, or the portion of the facility affected must be closed until the violation has been corrected. Critical safety violations are listed in ARM 37.115.301 and 37.115.302.

(40) "Cross connection" means a physical connection between the potable water system and a nonpotable water source such as a pool, spa, or other water feature. The term also indicates the physical connection between a pool, spa, or other water feature and the sanitary sewer or waste water disposal system.

(41) "Cyanuric Acid (CYA)" is a stabilizer chemical which helps reduce the loss of chlorine in outdoor swimming pools due to the action of ultraviolet rays of the sun. It accumulates on the various surfaces of pools. High levels of CYA require adjustments to pool alkalinity.

(42) "Deck" means an area immediately adjacent to or attached to a pool, spa, or other water feature that is specifically constructed or installed for sitting, standing, or walking.

(43) "Deep area" means the portion of any pool, spa, or other water feature that has a water depth of five feet or more.

(44) "Department" means the Department of Public Health and Human Services (DPHHS) provided for in 2-15-2201, MCA and its authorized representatives and local boards of health and their authorized representatives who conduct inspections and enforcement actions on behalf of the department.

(45) "Depth" means the vertical distance measured from the bottom of the pool, spa, or other water feature to the designed or actual water level. The measurement must be taken three feet out from the wall of the pool, spa, or other water feature.

(46) "Disinfectant" (sanitizer) means any oxidant, which includes but is not limited to, chlorine, chlorine dioxide, bromine, chloramines, and ozone that is added to water in any part of the treatment or distribution process and that is intended to kill or inactivate pathogenic microorganisms.

(47) "Disinfection" (sanitizing) means the process of destroying organisms that may cause illness.

(48) "Diving board" means a recreational mechanism for entering a pool, consisting of a semi-rigid board which derives its elasticity through the use of a fulcrum mounted below the board.

(49) "Diving envelope" is the area of a pool that is designed for safe diving. Diving area is the same thing.

(50) "Diving platform" is a stationary platform designed for diving.

(51) "DPD" means diethyl-phenylene diamine. It is the only acceptable test method that specifically measures bromine or free available and total residual chlorine levels.

(52) "Effluent" means the outflow water from a filter, pump, pool, spa, or other water feature.

(53) "Employee" means any or all of the following persons who perform any work at a public swimming pool, spa, or other water feature. The term employee includes:

(a) the owner;

(b) a licensee;

(d) a person in charge;

(e) a person having supervisory or management duties;

(f) a person on the payroll;

(g) a family member;

(h) a volunteer;

(i) a person performing work under a contractual agreement; or

(j) any other person performing work.

(54) "Equalizer line" means a pipe located below the water level that draws water into the pump when the water level drops below the skimmer inlet.

(55) "Facility" means a public bathing place and includes any public swimming pools, spas, or other water features, bathhouses, restrooms, dressing rooms, equipment rooms, deck enclosures, and all other appurtenances directly serving the public bathing place.

(56) "Feet of head" means the resistance in a hydraulic system based on the equivalent to the height of a column of water that causes the same resistance (100 feet of head equals 43 pounds per square inch). Also see "Total dynamic head".

(57) "Filter" means a device that separates solid particles from water by recirculation through a porous substance. The term filter includes the following types of filters:

(a) "cartridge filter" means a filter that utilizes a porous element that acts as a filter medium;

(b) "diatomaceous earth filter" means a filter that utilizes a thin coating of diatomaceous earth (DE) or other filter aid over a porous fabric as its filter medium;

(d) "sand filter" means a filter using sand or sand and gravel as a filter medium.

(58) "Filter Medium" means a finely graded material such as sand, diatomaceous earth, polyester fabric or anthracite, that is used to trap solid particles from the influent water and to return clear water to the pool, spa, or other water feature.

(59) "Floor" means those portions of the interior pool surface having a slope of no more than 45 degrees from horizontal.

(60) "Flow-through hot springs pool" means a hot springs pool in which the water is continually flowing and in which the water volume exchange is sufficient to produce a turnover of the entire volume of pool water to waste water discharge every eight hours.

(61) "Flow meter" is a device that measures the rate of flow of water or other liquid through piping.

(62) "Flow rate" means the quantity of water flowing past a designated point within a specified time. It is usually expressed as "gallons per minute".

(63) "Flume" means a trough-like or tubular structure with water that is generally recognized as a water slide that directs the path of travel and the rate of descent by the rider.

(64) "Flume slide" is a slide or slides of various configurations that are characterized by having deep riding channels, vertical and lateral curves, high water flows and which accommodate riders who may or may not use mats, tubes, rafts, and other transport vehicles. The term includes, but is not limited to, family raft rides, inner-tube rides, body slides, and speed slides.

(65) "Free available chlorine" means the portion of the total chlorine remaining in chlorinated water that is not combined with ammonia, nitrogen, or other organic compounds and that will react chemically with undesirable or pathogenic organisms.

(66) "Full facility inspection" means an inspection performed by the department that addresses compliance with all applicable rules, including review of records.

(67) "Gutter" means an overflow trough in the perimeter wall of a pool or spa that is a component of the circulation system or where excess water can flow to a waste water discharge outlet.

(68) "Handrail" is a support device that is intended to be gripped by a user for the purpose of resting or steadying. It is typically located within or at exits to the pool, or spa, or a part of a set of steps.

(69) "Hardness" means the amount of calcium and magnesium salts dissolved in water. It is measured by a test kit and expressed as parts per million (ppm) of equivalent calcium carbonate.

(70) "Hot springs pool" means an indoor or outdoor structure or basin containing an artificial body of naturally hot water that is intended for swimming, soaking, or recreational bathing. The term includes but is not limited to hot springs spas, hot springs swimming pools, and hot springs wading pools.

(71) "Hot tub" means a spa.

(72) "Hydrotherapy pool" or "therapeutic pool" or "therapy pool" means a unit that may have a therapeutic use. Its features may include, but are not limited to:

(a) hydrotherapy jet circulation;

(b) hot water;

(d) mineral baths;

(e) air induction bubbles; or

(f) any combination thereof.

(73) "Influent" means water entering a filter, pool, or other device.

(74) "Interactive play attraction" means a manufactured water play device or a combination of water-based play devices in which water flow volumes, pressures, or patterns are intended to be varied by the bather without negatively influencing the hydraulic conditions of other devices. These address only the water treatment and filtration requirement for such attractions.

(75) "Invited guest" means an individual who is visiting a family member or friend and uses the privately owned pool, spa, or other water feature upon invitation.

(76) "Ladder" is a structure for ingress/egress that usually consists of two long parallel side pieces joined at intervals by crosspieces or "treads".

(77) "Langelier index" means a numerical calculation, based on the Langelier water balance equation that indicates whether the water may be corrosive or scale forming. Also known as "Saturation Index".

(78) "Lazy river" means a constructed water course through which people travel by use of flotation devices. They are manufactured streams of near-constant depth in which the water is moved by pumps or other means of propulsion to provide a river like flow that transports bathers over a defined path.

(79) "Lap pool" means any indoor or outdoor swimming pool with a minimum depth exceeding three feet six inches and a maximum depth not exceeding seven feet with a minimum length of 40 feet.

(80) "License" means the document issued by the department that authorizes a person to operate a public swimming pool, spa, or other water feature.

(81) "Licensee" means the person or other entity that is legally responsible for the operation of a public swimming pool, spa, or other water feature and any adjacent facility, and who possesses a valid license to operate the public swimming pool, spa, or other water feature.

(82) "Lifeguard" means a qualified person who is responsible for supervision and lifesaving at a licensed public bathing place or public swimming pool. Under this chapter, "lifeguard" means either a certified lifeguard or a licensed lifeguard with the certification or training as set forth in ARM 37.115.1603.

(83) "Listed suction outlet cover/grate" means a suction outlet cover/grate which has been tested, certified, and listed by a nationally recognized testing laboratory in accordance with ASME A112.19.8-2007.

(84) "Listed safety vacuum release system" means a safety vacuum release device tested and certified by a nationally recognized testing laboratory in accordance with ASME A112.19.8-2007 or ASTM F2387-04.

(85) "Local board of health" or "board" means a local board as defined in 50-1-101, MCA.

(86) "Local health officer" or "officer" means a local health officer as defined in 50-1-101, MCA.

(87) "Multisectional pool" is a pool that has a number of different uses such as zero entry pool, lazy river, and slide pool, but which may have interconnecting areas.

(88) "National Sanitation Foundation International" (NSFI or NSF), means an independent, nonprofit organization of scientists, engineers, educators, and others engaged in research and testing and in the development of standards in selected public health and environmental areas.

(89) "Nonself-contained hot tub" means a hot tub that is made of an acrylic or thermoplastic shell molded at the factory to comfortably fit the body's contours. It does not have water heating and circulating equipment as an integral part of the product, and may employ separate components such as an individual filter, pump, heater, and controls or assembled combinations of various components.

(90) "NTU" means Nephelometric Turbidity Unit (NTU). NTU is a means of measuring turbidity in a sample by using an instrument called a nephelometer. The normal measuring range is 0 to 100 NTUs. Also see "Turbidity".

(91) "Other regulatory authority" means another agency that may have jurisdiction over some aspect of the construction or operation of public swimming pools, spas, or other water features or related facilities. The term includes, but is not limited to, the Montana Department of Environmental Quality (DEQ), the Environmental Protection Agency (EPA), the Occupational Safety and Health Administration (OSHA), the Montana Department of Labor and Industry (DOLI), the United States Department of Justice (DOJ) and those agencies enforcing state and local building codes.

(92) "Oxidation reduction potential (ORP)" means the measurement of the oxidizing properties of any sanitizer being used in a pool, spa, or other water feature, and is measured in millivolts (mV) by an ORP meter. Also known as "high resolution reduction" or "HRR".

(93) "Oxidizers" means products used to destroy organic and inorganic contaminants in water.

(94) "Overflow gutter system" means overflows, gutters, surface skimmers, and surface collection systems of various design and manufacture used for removal of water from a pool, spa, or other water feature.

(95) "Ozone (O³)" means a gaseous molecule composed of three atoms of oxygen that is generated on-site and used for oxidation of water contaminants. Ozone can also be used to regenerate bromine from bromide ions and as a supplemental contact sanitizer in conjunction with an EPA-registered sanitizer that provides a constant residual.

(96) "Ozone contact concentration" means the amount of ozone that is dissolved in pool, spa, or other water feature.

(97) "Ozone generator" means a device that produces ozone, generally exposing oxygen or air to corona discharge or ultraviolet light.

(98) "Pathogens" means disease-causing microorganisms.

(99) "Parts per million (ppm)" means a unit of measurement of a chemical concentration which indicates the parts by weight in relation to one million parts by weight of water. It is equivalent to the term milligrams per liter (mg/l).

(100) "Person" means a person, firm, partnership, corporation, organization, or the state or any political subdivision of the state.

(101) "Person in charge" means the individual present at a public swimming pool, spa, or other water feature and the related facilities who is responsible for the operation at the time of inspection.

(102) "pH" means the symbol for the negative logarithm of the hydrogen ion concentration, which is a measure of the degree of acidity or alkalinity of a solution. Values between zero and seven indicate acidity. Values between seven and 14 indicate alkalinity. The value for pure distilled water is seven, which is considered neutral.

(103) "Plaster" means a mixture of white cement and aggregate used as a type of interior finish, which is white or lightly tinted, and is applied to a concrete pool, spa, or other water feature.

(104) "Plumbing system" means:

(a) the water supply and distribution pipes;

(b) plumbing fixtures and traps;

(d) sanitary and storm sewers and building drains, including their respective connections, devices, and appurtenances within the premises; and

(e) water-treating equipment.

(105) "Plummet line" means a vertical line extending from the center point of the front edge of the diving platform or springboard to the water's surface.

(106) "Plunge pool" means the pool located at the end of a flume. It is also known as a "catch pool".

(107) "Point A" means the point on the surface of the pool directly below the end of the diving board through which the plummet line passes. All references in the diving envelope calculations are in reference to "Point A".

(108) "Public bathing place" means a facility with one or more artificial bodies of water with a restroom or other bathhouse facilities operated for persons other than only the owner's family or invited guests. Synonymous with "swimming area".

(109) "Public swimming pool" means an artificial pool and related facilities for swimming, bathing, wading, or other aquatic therapy or recreation. The term includes, but is not limited to, natural hot water pools, spas, splash decks, water slides, lazy rivers, and wave pools. The term does not include swimming pools located on private property, including the private common area property of owner-occupied condominium developments that is used for swimming or bathing only by the owner, members of the owner's family, or their invited guests. The term also does not include medicinal hot water baths for individual use. For purposes of these rules, a "swimming pool" or "pool" is either a privately owned public swimming pool or spa, or a public swimming pool as defined here:

(a) "Privately owned public swimming pool or spa" means any swimming pool, spa, or other water feature operated in conjunction with lodging facilities such as motels, hotels, campgrounds, apartments, and condominiums that are rented or leased; in conjunction with a health club or athletic club, or any other nongovernmentally owned or operated swimming pool, spa, or other water feature; or

(b) "Public swimming pool or spa" means any swimming pool, spa, or other water feature operated by a person as owner, licensee, lessee, or concessionaire, whether or not a fee is charged. Any person who is charged money or any other consideration to use the pool is not an invited guest for the purposes of this definition.

(110) "PSI" means pounds per square inch.

(111) "Pump" means a mechanical device, usually powered by an electric motor, which causes hydraulic flow and pressure for the purpose of filtration, heating, and circulation of pool, spa, or other water feature.

(112) "Pump capacity" means the volume of liquid a pump is capable of moving during a specified period of time against a given total head.

(113) "Pump curve" means a graph of performance characteristics of a given pump under varying horsepower, flow, and resistance factors. It is used in checking and sizing a pump.

(114) "Rate of flow" means the quantity of water flowing past a designated point within a specified time, such as the number of gallons flowing past during one minute.

(115) "Remodel" or "renovate" mean a substantial or material alteration. In the context of these rules, the terms mean the activity of restoring or upgrading all or part of a public bathing place or public swimming pool structure and its component parts. Remodeling or renovation may include rebuilding or replacing system components that are not identical or substantially similar to existing components such as pipes, drains, filtration systems, disinfectant systems, circulation systems, and/or pool decks that use different materials or different from the existing component or design. The terms do not include painting, replacing tile or caulk, other such cosmetic changes, or replacing a worn or broken component for the same component, such as replacing a pump with a pump that is identical or substantially similar.

(116) "Responsible adult" means an adult, age 18 or over, who is charged with safeguarding the child.

(117) "Return inlet" means the aperture or fitting through which water under pressure returns into the pool, spa, or other water feature.

(118) "Return piping" is the piping that is referred to as effluent, returning water to the pool or spa.

(119) "Ring buoy" means a ring-shaped floating buoy capable of supporting a bather, and which has an attached rope.

(120) "Risk" means the likelihood that an adverse health effect will occur within a population as a result of a hazard in the water of a public swimming pool, spa, or other water feature.

(121) "Rope and float line" or "float line" means a continuous line not less than one-half inch in diameter, which is supported by buoys and attaches to opposite sides or ends of a pool to separate the deep and shallow ends in a pool that is greater than five feet in depth. A rope and float line may also be used to separate pools of different uses or types.

(122) "Safety Vacuum Release System (SVRS)" is a system or device capable of providing vacuum release at a suction outlet in case of a high vacuum occurrence due to a suction outlet flow blockage.

(123) "Sanitizer". See "Disinfectant".

(124) "Saturation index" means a mathematical calculation, based on the interrelation of temperature, calcium hardness, total alkalinity and pH, that predicts if pool water is corrosive, scale-forming, or neutral. It can also mean a number that indicates whether water will have a tendency to deposit calcium carbonate scale from a solution, or whether it will be potentially corrosive. When correctly balanced, the water will be neither scale-forming nor corrosive. Also see "Langelier Index".

Five factors are used in the computation:

(a) pH;

(b) total alkalinity;

(d) temperature; and

(e) total dissolved solids (TDS).

(125) "Scale" means the precipitate that forms on surfaces in contact with water when the calcium hardness, pH, or total alkalinity levels are too high.

(126) "Self-contained hot tub" means a hot tub that has a cabinet that houses the controls, the pump, heater, and filter. Most portable hot tubs are made of an acrylic thermoplastic shell and are surrounded by a cabinet made of wood, alternative wood, or thermoplastic. It can be moved to another location and reinstalled, and all control, water heating, and water circulating equipment are an integral part of the product. It may be permanently wired or cord connected. It is also known as a "portable hot tub".

(127) "Self-closing or self-latching" means a device which causes a gate to automatically fully close and latch without human or electrical power.

(128) "Serious accident or injury" means any accident or injury:

(a) requiring emergency services response where a person requires medical treatment as determined by the emergency medical response personnel, including a drowning that does not result in death;

(b) resulting in a person seeking medical attention at a medical facility, hospital emergency room, or admittance to a hospital;

(d) resulting in a death.

(129) "Sewage" means liquid waste containing animal or vegetable matter in suspension or solution and may include liquids containing chemicals in solution.

(130) "Shallow area" means any portion of a pool where the water depth ranges from zero feet to five feet.

(131) "Shock treatment" means the practice of adding significant amounts of an oxidizing chemical to water to destroy organic and inorganic contaminants in the water.

(132) "Sight barrier" means a fence system that prevents entry but allows visual observation. Also see "Barrier".

(133) "Signal word" means a visual alerting device in the form of a decal or label placard or other marking such as an embossing, stamping, etching, or other process that advises the observer of the nature and degree of the potential hazard(s) that can cause property damage, injury, or death. It can also provide safety precautions, describe evasive actions to take, or provide other directions to eliminate or reduce a potential hazard. Aquatic safety signage shall conform to specifications as described in the ANSI Z-535 series of standards on product safety signs and labels. The following signal words mean:

(a) "CAUTION" indicates a potentially hazardous situation that, if not avoided, could result in minor or moderate injury. It may also be used to alert against unsafe practices;

(b) "WARNING" indicates a potentially hazardous situation that, if not avoided, could result in death or serious injury; and

(c) "DANGER" indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury. This signal word is to be limited to the most extreme situations.

(134) "Skimmer" means a device installed in the pool, spa, or other water features that permits the removal of floating debris and surface water to the filter.

(135) "Skimmer cover" means a removable lid to close the deck opening to the skimmer housing.

(136) "Skimmer equalizer pipe" means a connection from the skimmer housing to the pool or spa below the weir that is sized to satisfy pump demand and prevent air lock or pump loss of prime.

(137) "Skimmer weir" means the part of a skimmer which adjusts automatically to small changes in water level to assure a continuous flow of water to the skimmer.

(138) "Slip-resistant" means a surface which has been treated or textured to significantly reduce the chance of a bather slipping in wet conditions.

(139) "Sodium hypochlorite" or "NaOCL" means a clear liquid form of an inorganic chlorine compound obtainable in concentrations of five to sixteen percent available chlorine, also known as liquid bleach or bleach.

(140) "Spa" means an artificial pool that is designed for recreational bathing or therapeutic use and is not drained, cleaned, or refilled for individual use. A spa includes, but is not limited to, a therapeutic pool, hydrotherapy pool, whirlpool, hot tub, or Jacuzzi-type whirlpool bath. A spa consists of a warm water reservoir with hydromassage jets.

(141) "Splash deck" means a constructed area over which water is sprayed or jetted to contact bathers, but is not allowed to gather and stand. A splash deck may also be known as an "Interactive Play Attraction", a "spray pool", or a "zero depth spray pool". Flow-through splash decks do not recirculate water through a filtration system; whereas recirculation splash decks reuse treated water.

(142) "Springline" means a line from which the pool wall breaks from vertical and begins its radius arc of the curvature (for cove construction) to the bottom of the pool.

(143) "Stabilizer" means a chemical which helps reduce the excess loss of residual chlorine in water due to ultraviolet rays of the sun. Also see "Cyanuric Acid".

(144) "Steps" means a riser and a tread or a series of risers and treads extending down from the deck and terminating at the pool floor. The term also includes recessed steps that are set into the pool wall.

(145) "Suction piping or influent piping" means piping that is connected to the suction side of the pump.

(146) "Suction outlet" means the aperture or fitting through which water under negative pressure is drawn from the pool, spa, or other water feature.

(147) "Superchlorination" means the rapid addition of a high dose of chlorine to water for the purpose of eliminating combined chlorine levels; reducing cloudy water, slime formation, musty odors, algae and bacteria counts; and/or improving the water's ability to maintain effective sanitizer residual. Also see "shock treatment" or "breakpoint chlorination".

(148) "Surge chamber" means a storage vessel within the recirculating system used to absorb the water displaced by bathers. Also known as "surge pit" or "surge tank".

(149) "Swimming area" means a facility with one or more artificial bodies of water and a restroom or other bathhouse facility that is operated for persons other than only the owner's family or invited guests. The term is synonymous with "public bathing place".

(150) "Tamperproof or vandal-proof" means requiring special tools to alter or remove portions of the equipment.

(151) "Temperature measuring device" means a thermometer, thermocouple, thermistor, or other device that indicates the temperature of food, air, or water.

(152) "Test kit" means a device for monitoring or measuring a specific chemical residual or other parameter in the water of a pool, spa, or other water feature.

(153) "Total alkalinity" means the ability of water to resist change in pH. It is also known as the buffering capacity of water, and consists mainly of carbonates, bicarbonates and hydroxides. Total alkalinity is measured with a DPD test kit and measured in parts per million (ppm).

(154) "Total available chlorine" or "total chlorine" means the sum of both free available and combined chlorine.

(155) "Total dissolved solids" or "TDS" means a measure of the total amount of dissolved matter in water including, but not limited to, calcium, magnesium, carbonates, bicarbonates, or metallic compounds.

(156) "Total Dynamic Head" or "TDH" is the sum of all resistances in a complete operating system. One pound per square inch is equivalent to 6.89 KiloPascal (kPa). One pound per square inch is also equivalent to 70.3 grams per square centimeter. One hundred feet of head is equivalent to 296.47 KiloPascal (kPa). One hundred feet of head is equivalent to 3.02 kilograms per square centimeter. Also see "Feet of head".

(157) "Tourist home" means a privately owned house or condominium that is not occupied by an owner or manager and that is rented, leased, or furnished in its entirety to transient guests on a daily or weekly basis.

(158) "Turbidity" means a cloudy condition of the water due to the presence of extremely fine particulate materials in suspension which interfere with the passage of light. "Turbidity" also means the cloudy appearance of water caused by the presence of suspended and colloidal matter. A turbidity measurement is used to indicate the clarity of the water. Turbidity is measured in NTUs.

(159) "Turnover" or "turnover rate" means the period of time, usually expressed in hours, required to circulate a volume of water equal to the capacity of the pool, spa, or other water feature.

(160) "Vanishing edge or negative edge" means a water-feature detail in which water flows over the edge of at least one of the pool walls and is collected in a catch basin.

(161) "Velocity" means the speed at which a liquid flows between two specified points. Velocity is expressed in feet per second (FPS).

(162) "Virginia Graeme Baker Pool and Spa Safety Act" (VGBPSSA) means the Virginia Graeme Baker Pool and Spa Safety Act, 15 USC 8001-8005 (2007).

(163) "Vortex pool" means a circular pool equipped with a method of transporting water in the pool for the purpose of propelling riders at speeds dictated by the velocity of the moving stream.

(164) "Wading pool" means a pool in which the water depth does not exceed two feet.

(165) "Wall" means any interior pool wall surface with a slope of no more than 11° from vertical.

(166) "Waste water" is water that is backwashed from the filter and sent to the sanitary sewer or other approved disposal method.

(167) "Waste water disposal system" means a plumbing system used to dispose of backwash or other water from a pool, spa, or other water feature or from dressing rooms and other facilities associated with a public bathing place.

(168) "Water feature" means an artificially created recreational structure or area using moving water. These features may include but are not limited to splash decks, water slides, lazy rivers, and wave pools.

(169) "Water line" means the middle point of the operating range of the skimmer system if the pool is so equipped; or where an overflow system is in use, the height of the overflow rim.

(170) "Water slide" means a slide adjacent to or in a pool with a water flow in it that originates above the surface of the pool water and ends with a drop into the pool. It consists of a trough-like slide or tubular structure that directs the path of travel and the rate of descent by the rider. Also see "Flume".

(171) "Wave pool" means a pool designed for the purpose of producing breaking wave action in the water that does not use sheet flow technology.

(172) "Zero depth pool" means a pool with a sloping entry starting above the water line at deck level and ending below the water line. There is no depth to the pool at the point a swimmer enters the water. It is also known as a "beach entry".