The following words and terms when used in this chapter shall have the following meanings, unless the context clearly indicates otherwise.

1. (1) Above ground/on ground pool or spa--A removable pool or spa of any shape that is located on the surrounding earth or a pool or spa package located in an excavation below the ground level which may be readily disassembled or stored and reassembled to its original integrity.
2. (2) Actual water level--The specific level of the water observed at any time. This level will vary with specific conditions such as rainfall or number of users (see definition number (43) "Design water level" and number (84) "Operating water level range").
3. (3) Algae--Microscopic plant-like organisms that contain chlorophyll and include green, blue-green or black brown, and yellow-green (mustard) algae.
4. (4) Algaecide--A natural or synthetic substance used for killing, destroying, or controlling algae.
5. (5) Alkalinity--The amount of bicarbonate, carbonate or hydroxide compounds present in water solution (see definition number (132) "Total alkalinity").
6. (6) ACI--American Concrete Institute, P. O. Box 9094, Farmington Hills, MI 48333, telephone (248) 848-3800.
7. (7) ANSI--American National Standards Institute, 11 West 42nd Street, New York, NY 10036, telephone (212) 642-4900.
8. (8) ANSI/NSPI-1, 1991--American National Standards Institute and National Spa and Pool Institute "Standards for Public Swimming Pools" adopted in 1991.
9. (9) ANSI/NSPI-2, 1992--American National Standards Institute and National Spa and Pool Institute "Standards for Public Spas" adopted in 1992.
10. (10) ARC--American Red Cross, 8111 Gatehouse Road, Falls Church, VA 22042, telephone (703) 206-7090.
11. (11) ASHRAE--American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc., 1791 Tullie Circle NE, Atlanta, GA 30329-2305, telephone (800) 527-4723.
12. (12) ASME--American Society of Mechanical Engineers, 346 East 47th Street, New York, NY 10017, telephone (800) 843-2763.
13. (13) ASTM--American Society of Testing Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, telephone (215) 299-5400.
14. (14) Available chlorine--Rating of chlorine containing products for total oxidizing power (see definition number (56) "Free available chlorine").
15. (15) AWWA standards--American Water Works Association, 6666 West Quincy Avenue, Denver, CO 80235, telephone (303) 794-7711.
16. (16) Backwash--The process of cleansing the filter medium and/or elements by the reverse flow of water through the filter.
17. (17) Bacteria--Single-celled microorganisms of various forms, some of which cause infections or disease.
18. (18) Beginner's areas--Water areas in pools which are three feet or less in water depth.
19. (19) Bonded--The permanent joining of metallic parts to form an electrically conductive path that will ensure electrical continuity and the capacity to conduct safely any current likely to be imposed (NEC definition, 1996).
20. (20) Breakpoint--The practice of adding a sufficient amount of chlorinating compound to water to destroy chlorine demand compounds and any combined chlorine which is present. Generally, the level of chlorine added is ten times the level of combined chlorine in the water (see definition number (124) for "Superchlorination").
21. (21) Breakpoint chlorination--The addition of a sufficient amount of chlorine to water to destroy the chlorine demand compounds and any combined chlorine which is present (see definition number (124) "Superchlorination").
22. (22) Bromine--A chemical element (Br₂) that exists as a liquid in its elemental form or as part of a chemical compound which is a biocidal agent used to disinfect pool or spa water.
23. (23) Catch pools--Bodies of water located at the termination of a manufactured water slide attraction provided for the specific purpose of terminating the slide action and providing a means for exit to a deck or walkway area.
24. (24) Chemical feeder--A mechanical device for applying chemicals to pool or spa water.
25. (25) Chloramine--A compound formed when chlorine combines with nitrogen or ammonia which when found in significant amounts in a pool or spa, may cause eye and skin irritation and may have an objectionable odor.
26. (26) Chlorinator--A device to apply or to deliver a chlorine disinfectant to water at a controlled rate.
27. (27) Chlorine--A chemical element (Cl₂) that exists as a gas in its elemental form or as a part of chemical compound which is an oxidant. Chlorine is a biocidal agent used to disinfect pool or spa water.
28. (28) Chlorine demand compounds--Organic matter, chloramines and other such compounds that chlorine reacts with and which depletes chlorine.
29. (29) Chlorine Institute--Chlorine Institute, 2001 L Street North West, Suite 506, Washington, DC 20036-4919, telephone (202)775-2790.
30. (30) Circulation equipment--The mechanical components which are a part of a circulation system on a pool or spa. Circulation equipment may include but is not limited to, categories of pumps; hair and lint strainers; filters; valves; gauges; meters; heaters; surface skimmers; inlet/outlet fittings; and chemical feeding devices. The components have separate functions, but when connected to each other by piping, perform as a coordinated system for purposes of maintaining pool or spa water in a clear, sanitary, and desirable condition for use.
31. (31) Circulation system--An arrangement of mechanical equipment or components, connected by piping to a pool or spa in a closed circuit. The function of a circulation system is to direct water from the pool or spa, causing it to flow through the various system components for purposes of clarifying, heating, purifying, and returning the water back to the original body of water.
32. (32) Clarifier (also called Coagulant or Flocculent)--A chemical that coagulates and neutralizes suspended particles in water. There are two types of clarifiers: inorganic salts of aluminum or iron, and water-soluble organic polyelectrolyte polymers.
33. (33) Combined chlorine--The portion of the total chlorine existing in water in chemical combination with ammonia, nitrogen, and/or organic compounds, mostly comprised of chloramines. Combined chlorine plus free chlorine equals total chlorine. Combined chlorine is calculated from the results of measuring the free and total chlorine with a test kit.
34. (34) Construction date/date of construction--the date that a building permit for construction of the pool or spa is issued by a municipality or, if no building permit is required, written documentation of the date that excavation or electrical service to the pool or spa begins, whichever is first.
35. (35) Coping--The cap on the pool or spa wall that provides a finishing edge around the pool or spa. The coping can be formed, cast in place or pre-cast, or pre-fabricated from metal or plastic materials.
36. (36) CPSC--United States Consumer Product Safety Commission, Washington, D.C. 20207, telephone (301) 504-0400.
37. (37) Cross-connection--A physical connection between the potable water system and a non-potable source such as a pool or spa, or a physical connection between a pool or spa and the sanitary sewer or wastewater disposal system.

38. (38) Cyanuric acid--

    1. (A) Any one of a number of chemical compounds also called stabilizers.
    2. (B) A chemical that helps reduce the excess loss of chlorine in water due to the ultraviolet rays of the sun.
39. (39) Decks--Those areas immediately adjacent to or attached to a pool or spa that are specifically constructed or installed for sitting, standing, or walking.
40. (40) Deep areas--Water levels in pools which are five feet or deeper.
41. (41) Department--The Texas Department of Health, 1100 West 49th Street, Austin, TX 78756, telephone (512) 834-6635.
42. (42) Depth (pool or spa depth)--The vertical distance measured at three feet from the pool or spa wall from the bottom of the pool or spa to the design water level.

43. (43) Design water level--The design water level defined in one of the following ways:

    1. (A) Skimmer system--The design water level shall be at the midpoint of the operating range of the skimmers.
    2. (B) Overflow system--The design waterline shall be at the top of the overflow rim of the gutter system.
44. (44) Disinfectant--Energy or chemicals used to kill undesirable or pathogenic (disease-causing) organisms, and having a measurable residual at a level adequate to make the desired kill.
45. (45) Diving board--A recreational mechanism for entering a pool, consisting of semirigid board that derives its elasticity through the use of a fulcrum mounted below the board.
46. (46) Diving equipment, competition--Competitive diving boards and fulcrum-setting diving stands intended to provide adjustment for competitive diving.
47. (47) Dwelling or rental dwelling--One or more rooms rented to one or more persons where a Class C or Class D pool or spa is located.
48. (48) Effective filter area--Total surface area through which designed flow rate will be maintained during filtration.
49. (49) Effluent--The water that flows out of a filter, pump, or other device.
50. (50) Facility(ies)--The pool or spa, restrooms, dressing rooms, equipment rooms, deck, enclosure, and other appurtenances directly serving the pool or spa area.
51. (51) Feet of head--A basis for indicating the resistance in a hydraulic system, equivalent to the height of a column of water that would cause the same resistance (100 feet of head equals 43 pounds per square inch). The dynamic head is the sum of all resistances in a complete operating system.

52. (52) Filter--A device that removes undissolved particles from water by recirculating the water through a porous substance (a filter medium or element) such as the following.

    1. (A) Medium filter--A filter that utilizes a medium, for example, sand, gravel or other medium that under normal use will not have to be replaced frequently.
    2. (B) Diatomaceous earth filter--A filter that utilizes a thin coating of diatomaceous earth over a porous fabric as its filter medium.
    3. (C) Cartridge filter--A filter that utilizes a porous element that acts as a filter medium in cartridge.
    4. (D) Vacuum filter--A filter that operates under a vacuum from the suction of a pump.
53. (53) Filter element--A device within a filter tank designed to entrap solids and conduct water to a manifold, collection header, pipe, or similar conduit and return it to the pool or spa. A filter element usually consists of a septum and septum support, or a cartridge.
54. (54) Filter medium--A finely graded material (for example, sand, diatomaceous earth, polyester fabric, anthracite) that removes filterable particles from the water.
55. (55) Floor--The interior bottom surface of a pool or spa.
56. (56) Free available chlorine--That portion of the total chlorine remaining in chlorinated water that is not combined with ammonia or nitrogen compounds and which will react chemically with undesirable or pathogenic organisms. Combined chlorine plus free chlorine equals total chlorine.
57. (57) Grab rail--Tubular rails used to enter or leave a pool or spa, usually made of stainless steel or chrome-plated brass (see definition number (58) "Handhold/handrail").
58. (58) Handhold/handrail--A device that is intended to be gripped by a user for the purpose of resting and/or steadying a person and that is typically located within or without the pool or spa or as part of a set of steps or deck-installed equipment.
59. (59) Hardness of water--The amount of calcium and magnesium dissolved in water measured by a chemical test kit and expressed as parts per million (ppm) of equivalent calcium carbonate.
60. (60) Heat exchanger--A device with coils, tubes or plates that absorbs heat from any fluid, liquid or air, and transfers that heat to another fluid without intermixing the fluids.
61. (61) Heat pump--A refrigeration compressor, usually electrically driven, that is operated in reverse. To obtain heat, the evaporator side (cooling coil) is exposed to warm water, air or ground. The evaporator coil absorbs the heat from this source and transfers it to the condenser coil where it discharges the heat to the pool or spa to be heated.
62. (62) Hot tub--A spa constructed of wood with sides and bottoms formed separately and joined together by pressure from surrounding hoops, bands, or rods; distinct from spa units formed of plastic, concrete, metal, or other materials.
63. (63) IESNA--Illuminating Engineering Society of North America, 140 Wall Street, Floor 17, New York, NY 10005-4001, telephone (212) 248-5000.
64. (64) Influent--The water entering a filter or other device.
65. (65) Interactive play attractions--Manufactured devices using sprayed, jetted, or other water sources contacting the users that do not incorporate standing or captured water as part of the user activity area.
66. (66) Jump board--A recreational mechanism for entering a pool that has a coil spring or comparable device located beneath the board which is activated by the force exerted in jumping on the board.
67. (67) Labeled--Equipment or material to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation that maintains periodic inspection of production of labeled equipment or materials and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.

68. (68) Ladders--

    1. (A) Deck ladder--A ladder ascending from ground level outside the pool or spa to the level of a deck.
    2. (B) In-pool or in-spa ladder--A ladder located in a pool or spa to provide ingress and egress from the deck.
69. (69) Leisure rivers--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 which transports users over a defined path which may include water features and play devices.
70. (70) Listed--Equipment or materials included in a list published by an organization acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of listed equipment or materials, and whose listing states either that the equipment or material meets appropriate designated standards or has been tested and found suitable for use in a specified manner.
71. (71) Local regulatory authority--The local enforcement body or authorized representative having jurisdiction over pools, spas, and associated facilities.
72. (72) May--An advisory statement or a good practice which exceeds ordinary care and is not legally required (see definition number (103) "Recommended").
73. (73) MSHA--Mine Safety Health Administration, 4015 Wilson Boulevard, Arlington, Va. 22203, telephone (703) 235-1452.
74. (74) National Swimming Pool Foundation--National Swimming Pool Foundation, 10803 Gulfdale, Suite 300, San Antonio, Texas, 78216, telephone (512) 525-1227.
75. (75) New pool and/or spa construction--The activity of building or installing a pool and/or spa structure, and its component parts, where no such structure has previously existed or where previously existing pool or spa structures have been removed.
76. (76) NEC--National Electric Code, distributed by NFPA (see definition number (78) "NFPA").
77. (77) NEMA--National Electric Manufacturers Association, 2101 L Street, NW, Washington, D.C. 20037, telephone (202) 457-8400.
78. (78) NFPA--National Fire Protection Association, Batterymarch Park, Quincy, MA 02269, telephone (617) 770-0700 or (800) 344-3555.
79. (79) NRPA--National Recreation and Park Association--National Recreation and Park Association, 650 West Higgins Road, Hoffman Estates, IL 60195-3402, telephone (708) 843-7529.
80. (80) NSFI--NSF International, (National Sanitation Foundation International), 3475 Plymouth Road, P.O. Box 130140, Ann Arbor, MI 48113-0140, telephone (313) 769-8010.
81. (81) NSPF--National Swimming Pool Foundation, 10803 Gulfdale, Suite 300, San Antonio, TX 78216, telephone (210) 525-1227.
82. (82) NSPI--National Swimming Pool Institute, 2111 Eisenhower Avenue, Alexandria, VA 22314, telephone (703) 838-0083.
83. (83) Offset ledge--a horizontal shelf or ledge projecting toward the interior of a pool from the vertical wall that provides a safe footing for a pool user to stand on in deep areas of the pool.

84. (84) Operating water level range--The operating water level defined in one of the following ways:

    1. (A) Skimmer system--Two inches above to two inches below the midpoint of the operating range of the device, or manufacturer's maximum stated operating range.
    2. (B) Overflow (gutter) system--The manufacturer's maximum stated operating range above the design water level.
85. (85) Organic matter--Perspiration, urine, fecal matter, saliva, suntan oil, cosmetics, lotions, dead skin, and similar debris introduced to water by users and the environment.
86. (86) ORP--The oxidation reduction potential level produced by strong oxidizing (sanitizing) agents in a water solution. Oxidation level is measured in millivolts by an ORP meter.
87. (87) OSHA--United States Department of Labor, Occupational Safety and Health Administration, 200 Constitution Avenue, Washington, D.C. 20210, telephone (800)321-6742.
88. (88) Overflow system--Overflows, surface skimmers, and surface water collection systems of various design and manufacture for removal of pool or spa surface water.
89. (89) Owner/operator--Fee title holder of the property upon which the pool or spa is located, and/or business manager, complex manager, property owners, association manager, rental agent or other individual who is in charge of the day to day operation or maintenance of the property. The owner/operator is responsible to ensure that the pool or spa and associated facilities comply with state and local pool or spa design, construction, operation, and maintenance standards.
90. (90) Parts per million (PPM)--A unit of measurement in chemical testing which indicates the parts by weight in relation to one million parts by weight of water. For the purposes of pool or spa water chemistry, ppm is considered to be essentially identical to the term milligrams per liter (mg/L).
91. (91) pH--A value expressing the relative acidic or basic tendencies of a substance, such as water, as indicated by the hydrogen ion concentration. The pH is expressed as a number on the scale of zero to 14, zero being most acidic, one to seven being acidic, seven being neutral, seven to 14 being basic and 14 being most basic.
92. (92) Plaster--A type of interior finish (a mixture of white cement and aggregate), which is white or lightly tinted which is applied to a concrete pool or spa.
93. (93) Plummet--A line perpendicular to the water surface and extending vertically to a point located at the front end of the diving board and at the center line directly in front of the diving board.

94. (94) Pool--Any man-made permanently installed or non-portable structure, basin, chamber, or tank containing an artificial body of water for swimming, diving, or recreational bathing and having a depth of at least 18 inches at any point, other than a single or double family (duplex) residential pool, which is operated by an owner, lessee, operator, licensee or concessionaire, regardless of whether a fee is charged for use. The pool may be either publicly or privately owned. Pools may be diving or nondiving. If diving, they shall be further classified into types indicating the suitability for use with diving equipment. The term does not include a decorative fountain which is not used as a wading or swimming pool. References within the standard to various types of pools are defined by the following categories:

    1. (A) Class A pool--Any pool used, with or without a fee, for accredited competitive aquatic events such as Federation Internationale de Natation Amateur (FINA), United States Swimming, United States Diving, National Collegiate Athletic Association (NCAA), National Federation of State High School Associations (NFSHSA), events. A "Class A" pool may also be used for recreation.
    2. (B) Class B pool--Any pool used for public recreation and open to the general public with or without a fee.
    3. (C) Class C pool--Any pool operated for and in conjunction with lodgings such as hotels, motels, apartments, condominiums, mobile homes parks, property owners associations, clubs, etc. or a school, college or university while being operated for academic or continuing education classes or clubs or practice events (excluding competition events as per subparagraph (A) of this paragraph). The use of such a pool would be open to occupants, members or students, etc. and their guests but not open to the general public.
    4. (D) Class D pool--A splasher pool with a maximum water depth of 36 inches at any point or wading pool with a maximum depth of two feet at any point.
    5. (E) Class E pool--A special purpose pool such as wave or surface action pools, catch pools, leisure rivers, interactive play attractions, vortex pools, and other such pools used primarily for aquatic attractions. Also see §265.181(b)(2)(C) of this title (relating to General Provisions) and §265.204(a) of this title (relating to Water Quality) which applies to Class E pools.
    6. (F) Type VI pool--A pool suitable for the installation of diving equipment up to 2/3 meter above the water (see ANSI/NSPI-1, 1991).
    7. (G) Type VII pool--A pool suitable for the installation of diving equipment up to 3/4 of a meter above the water (see ANSI/NSPI-1, 1991).
    8. (H) Type VIII pool--A pool suitable for the installation of diving equipment up to one meter above the water (see ANSI/NSPI-1, 1991).
    9. (I) Type IX pool--A pool suitable for the installation of diving equipment up to three meters over the water (see ANSI/NSPI-1, 1991).
95. (95) Pool or spa yard--An area that contains a pool or spa.
96. (96) Pool or spa yard enclosure--A fence, wall, or combination of fences, walls, gates, windows, or doors that completely surround a pool or spa.
97. (97) Potable water--Water which is bacteriologically safe and otherwise suitable for drinking and is regulated by the Texas Natural Resource Conservation Commission or another regulatory authority as a drinking water system.
98. (98) Precipitate--A solid material which is forced out of a solution by some chemical reaction and which settles out or remains as a haze in suspension (turbidity).
99. (99) Pressure differential--The difference in pressure between two parts of a hydraulic system, such as the influent and effluent of a filter.
100. (100) PSI--Pounds per square inch.
101. (101) Pump--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 and spa water.
102. (102) Rate of flow--The quantity of water flowing past a designated point within a specified time, such as the number of gallons flowing in one minute (gpm).
103. (103) Recommended--An advisory statement or a good practice which exceeds ordinary care and is not legally required (see definition number (72) "may").
104. (104) Regulatory authority--The federal, state, or local enforcement body or authorized representative having jurisdiction over pools, spas, and associated facilities.
105. (105) Removable--Capable of being disassembled with the use of only simple tools such as a screwdriver, pliers, or wrench.
106. (106) Residential pool or spa--A pool or spa that is located on private property under the control of the property owner and intended for use by not more than two resident families and their guests.
107. (107) Return inlet or inlet--The aperture or fitting through which the water under positive pressure returns into a pool or spa.
108. (108) Ring buoy--A ring-shaped floating buoy capable of supporting a user.
109. (109) Rope and float line--A continuous line not less than 1/4 inch in diameter, which is supported by buoys and attached to opposite sides or ends of a pool to separate the deep and shallow ends or mark exercise or racing lanes.
110. (110) Scale--The precipitate that forms on surfaces in contact with water when the calcium hardness, pH, or total alkalinity levels are too high.
111. (111) Self-closing and self-latching device--A device that causes a gate to automatically fully close and latch without human or electrical power.
112. (112) Separation tank--A tank used in conjunction with a filter to facilitate the separation of filtrate material for disposal.
113. (113) Service animal--A guide dog, signal dog, or other animal trained to do work or perform tasks for the benefit of an individual with a disability, including but not limited to, guiding individuals with impaired vision, alerting individuals with impaired hearing to intruders or sounds, or providing minimal protection or rescue work, such as pulling a wheelchair, or fetching dropped items.
114. (114) Shall--Mandatory provisions of these regulations.
115. (115) Shallow areas--Pool water areas which are less than five feet deep.
116. (116) Shock treatment--The practice of adding significant amounts of an oxidizing chemical to water to destroy ammonia and nitrogenous and organic contaminants in water.
117. (117) Skimmer weir--Part of a skimmer which adjusts automatically to small changes in water level to assure a continuous flow of water to the skimmer.
118. (118) Slip-resistant--A surface that has been treated or constructed to significantly reduce the chance of a user slipping.
119. (119) Spa--A constructed permanent or portable structure that is two feet or more in depth and that has a surface area of 250 square feet or less or a volume of 3250 gallons or less which is intended to be used for bathing or other recreational uses and is not drained and refilled after each use. It may include, but is not limited to, hydrojet circulation, hot water, cold water, mineral baths, air induction bubbles, or any combination thereof. Industry terminology for a spa includes, but is not limited to, "hydrotherapy pool," "whirlpool," "hot spa," "hot tub," etc.
120. (120) Splasher pool--A Class D pool with a maximum water depth of 36 inches at any point.
121. (121) Stabilizer--A chemical that helps reduce the excess loss of chlorine in water due to the ultraviolet rays of the sun (see definition number (38) "Cyanuric acid").

122. (122) Steps, recessed steps, ladders, and recessed treads--Means of pool and spa ingress and egress that may be used separately or in conjunction with one another.

     1. (A) Steps--A riser/tread or series of risers/treads extending down from the deck and terminating at the pool or spa floor. Included are recessed steps that have the risers located outside of user areas.
     2. (B) Ladders--A series of vertically separated treads or rungs connected by vertical rail members or independently fastened to an adjacent vertical pool or spa wall (see definition number (68) "Ladders" for particular ladder types).
     3. (C) Recessed Treads--A series of vertically spaced cavities in the pool or spa wall creating tread areas for stepholes.
123. (123) Suction outlet or outlet--The aperture or fitting through which the water under negative pressure is drawn from the pool or spa.
124. (124) Superchlorination--The practice of adding a sufficient amount of chlorinating compound to water to destroy chlorine demand compounds and any combined chlorine which is present. Generally, the level of chlorine added is ten times the level of combined chlorine in the water (see also definition number (21) "Breakpoint chlorination").
125. (125) Surface skimmer system/Through wall skimmer--A device installed in the wall of an inground pool or spa, or above ground/on ground pool or spa that permits the continuous removal of floating debris and surface water to the filters.
126. (126) Swimouts--A recessed area outside of the general perimeter of the pool designed to facilitate the entry and exit of swimmers from a pool.
127. (127) TDLR--Texas Department of Licensing and Regulation, Boiler Division, P. O. Box 12157, Austin, TX 78711, telephone (512) 463-2904.
128. (128) TDS--Total dissolved solids. A measure of the total amount of dissolved matter in water (for example, calcium, magnesium, carbonates, bicarbonates, metallic compounds).
129. (129) Ten/twenty rule--The ability of a lifeguard to identify a trauma or distress situation within ten seconds of its initiation and be physically at the victim's side and performing a rescue or other care as appropriate within 20 seconds after the initial identification of the victim.
130. (130) Test kit--A device for monitoring a specific chemical level in pool or spa water.
131. (131) TNRCC--Texas Natural Resources Conservation Commission, P. O. Box 13087, Austin, TX 78711-3087, telephone (512) 239-1000.
132. (132) Total alkalinity--A measure of the ability or capacity of water to resist change in pH; also known as the buffering capacity of water. Measured with a test kit and expressed as ppm; consists mainly of carbonates, bicarbonates and hydroxides.
133. (133) Total chlorine--The sum of both the free available and combined chlorine.
134. (134) Toxic--A substance that has an adverse physiological effect on human beings or other living organisms.
135. (135) Turbidity--Cloudy condition of water due to the presence of fine particulate materials in suspension that interferes with the passage of light.
136. (136) Turnover rate--The period of time (usually in hours) required to circulate a volume of water equal to the total pool or spa capacity.
137. (137) UFC--Uniform Fire Code, published by the International Fire Code Institute, 5360 Workman Mill Road, Whittier, CA 90601-2298, telephone (562) 699-0124.

138. (138) Underwater light--A fixture designed to illuminate a pool or spa from beneath the water surface. An underwater light includes either of the following:

     1. (A) wet niche light--a watertight and water-cooled light unit placed in a submerged, wet niche in the pool or spa wall and accessible only from the pool or spa; or
     2. (B) dry niche light--a light unit placed behind a watertight window in the pool or spa wall.
139. (139) UL--Underwriters Laboratory, 333 Pfingsten Road, Northbrook, IL 60062-2096, telephone (708) 272-8800.
140. (140) User--Any person using a pool or spa and adjoining deck area for the purpose of water sports, recreation therapy or related activities.
141. (141) User load--The number of persons in the pool or spa area at any given moment, or during any stated period of time.
142. (142) Vacuum--The reduction of atmospheric pressure within a pipe, tank, pump, or other vessel. Vacuum is measured in inches of mercury. Each inch of mercury is equivalent to 1.13 feet of head. The typical maximum vacuum is 30 inches of mercury, or 33.9 feet of head.

143. (143) Valve--Any device in a pipe that will partially or totally obstruct the flow of water (as in a ball, gate or globe valve) or permit flow in one direction only (as in a check or foot valve).

     1. (A) Bleeder valve--A device that allows air to be vented from a closed system.
     2. (B) Multi-port valve--A device that allows the multi-directional control of the passage or flow of water through a system.
     3. (C) Push-pull valve--A device that allows the dual directional control or flow of water through a system.
144. (144) Velocity--The speed at which a liquid flows between two specified points, expressed in feet per second.
145. (145) Vortex pool--Circular pools equipped with a method of transporting water in the pool for the purpose of propelling riders at speed dictated by velocity of the moving stream.
146. (146) Wading pool--A Class D pool that has a maximum depth of two feet at any point.
147. (147) Walls--The interior pool or spa wall surfaces consisting of surfaces from plumb to a slope of 11 degrees from plumb.
148. (148) Waste water disposal system--A plumbing system used to dispose of backwash or other water from a pool or spa or from dressing rooms and other facilities associated with a pool or spa.
149. (149) Water action pools--A pool designed to simulate breaking or cyclic waves for the purpose of general play or surfing.
150. (150) Y.M.C.A. of U.S.A.--Y.M.C.A. of U.S.A. (Y.M.C.A.), 101 North Wacker, Chicago, IL 60606, telephone (800) 872-9622.
151. (151) Zero depth pool--A pool in which the pool floor intersects the water surface along at least one side of the pool.

Source Note:The provisions of this §265.182 adopted to be effective June 17, 1999, 24 TexReg 4365.