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 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 that may be readily disassembled or stored and reassembled.
2. (2) Actual water level--The water level at any particular point in time, which may vary with specific conditions such as rainfall or number of users. (See definition (47) "Design water level" and (88) "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 (143) "Total alkalinity".)
6. (6) Approved cover or approved drain cover--A suction outlet drain cover that meets the requirements of §265.190(c)(1) of this title (relating to Suction Outlets and Return Inlets at Post-10/01/99 and Pre-10/01/99 Pools and Spas).
7. (7) Approved grate--A suction outlet grate that meets the requirements of §265.190(c)(2) of this title.
8. (8) ACI--American Concrete Institute, P.O. Box 9094, Farmington Hills, Michigan 48333-9094, telephone (248) 848-3800.
9. (9) ANSI--American National Standards Institute, 25 West 43rd Street (4th Floor), New York, New York 10036, telephone (212) 642-4900.
10. (10) ANSI/NSPI-1 1991--American National Standards Institute and National Spa and Pool Institute Standards for Public Swimming Pools adopted in 1991.
11. (11) ANSI/NSPI-2 1992--American National Standards Institute and National Spa and Pool Institute Standards for Public Spas adopted in 1992.
12. (12) ARC--American Red Cross, 8111 Gatehouse Road, Falls Church, Virginia 22042, telephone (703) 206-6000.
13. (13) ASHRAE--American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc., 1791 Tullie Circle NE, Atlanta, Georgia 30329-2305, telephone (800) 527-4723.
14. (14) ASME--American Society of Mechanical Engineers, 22 Law Drive, P.O. Box 2900, Fairfield, New Jersey 07007-2900, telephone (800) 843-2763.
15. (15) ASPSA--American Swimming Pool and Spa Association, 1108 Little River Dr., Elizabeth City, North Carolina 27909, telephone (252) 331-2301.
16. (16) ASTM--American Society of Testing Materials, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428-2959, telephone (610) 832-9500.
17. (17) Available chlorine--Rating of chlorine containing products for total oxidizing power. (See definition (62) "Free available chlorine".)
18. (18) AVS--An atmospheric vent system, as described in §296.190(d)(3)(A) of this title for minimizing risk of entrapment.
19. (19) Backwash--The process of cleansing the filter medium and/or elements by the reverse flow of water through the filter.
20. (20) Backflow prevention device--A device that is designed to prevent a physical connection between a potable water system and a non-potable source such as a pool or spa, or a physical connection between a pool or spa and a sanitary sewer or wastewater disposal system. (See definition (41) "Cross-connection control device".)
21. (21) Bacteria--Single-celled microorganisms of various forms, some of which cause infections or disease.
22. (22) Beginner's areas--Water areas that are 3 feet or less in depth in a pool.
23. (23) Bleeder valve--A device that allows air to be vented from a closed system. (See definition (154) "Valve".)
24. (24) 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 in order to minimize the risk of electrocution. Examples of bonding are the installation of a metal wire from a pool or spa pump to the rebar in the pool or spa wall, or interconnecting all rebar in a pool or spa wall by metal wire prior to pouring concrete in the wall.
25. (25) 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 10 times the level of combined chlorine in the water. (See definition (132) "Super chlorination".)
26. (26) Breakpoint chlorination--The addition of a sufficient amount of chlorine to water to destroy the chlorine demand compounds and any combined chlorine that is present. (See definition (132) "Super chlorination".)
27. (27) Broken stripe--A horizontal stripe that is at least 1 inch wide with uniform breaks in the stripe, with the breaks totaling not more than 75% of the length of the stripe and stripe breaks.
28. (28) Bromine--A chemical element (Br2) that exists as a liquid in its elemental form or as part of a chemical compound that is a biocide agent used to disinfect pool or spa water.
29. (29) Chemical feeder--A mechanical device for applying chemicals to pool or spa water.
30. (30) Chloramine--A compound formed when chlorine combines with nitrogen or ammonia that when found in significant amounts in a pool or spa, may cause eye and skin irritation and may have an objectionable odor.
31. (31) Chlorinator--A device to apply or to deliver a chlorine disinfectant to water at a controlled rate.
32. (32) Chlorine--A chemical element (Cl2) that exists as a gas in its elemental form or as a part of chemical compound that is an oxidant. Chlorine is a biocide agent used to disinfect pool or spa water.
33. (33) Chlorine demand compounds--Organic matter, chloramines, and other such compounds that chlorine reacts with and that depletes chlorine.
34. (34) Chlorine Institute--Chlorine Institute, 2001 L Street North West, Suite 506, Washington, D.C. 20036-4919, telephone (202) 775-2790.
35. (35) Circulation equipment--The mechanical components that 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.
36. (36) 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.
37. (37) Combined chlorine--The portion of the total chlorine pre-10/01/99 in water in chemical combination with ammonia, nitrogen, and/or organic compounds, mostly comprised of chloramines. Combined chlorine plus free chlorine equals total chlorine.
38. (38) Construction date--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.
39. (39) 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.
40. (40) CPSC--United States Consumer Product Safety Commission, Washington, D.C. 20207, telephone (800) 638-2772.
41. (41) Cross-connection control device--A device that is designed to prevent a physical connection between a potable water system and a non-potable source such as a pool or spa, or a physical connection between a pool or spa and a sanitary sewer or wastewater disposal system. (See definition (20) "Backflow prevention device".)
42. (42) Cyanuric acid--A chemical that helps reduce the excess loss of chlorine in water due to the ultraviolet rays of the sun.
43. (43) Decks--Areas immediately adjacent to or attached to a pool or spa that are specifically constructed or installed for sitting, standing, or walking.
44. (44) Deep areas--Water levels in pools that are over 5 feet deep.
45. (45) Department--The Texas Department of Health, General Sanitation Division, 1100 West 49th Street, Austin, Texas 78756, telephone (512) 834-6635.
46. (46) Depth (pool or spa depth)--The vertical distance measured at 3 feet from the pool or spa wall from the bottom of the pool or spa to the design water level.

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

    1. (A) skimmer system--The design water level shall be at the midpoint of the operating range of the skimmers; or
    2. (B) overflow system--The design waterline shall be at the top of the overflow rim of the gutter system.
48. (48) DPD--A chemical testing reagent (N,N-Diethyl-P-Phenylenediamine) used to measure the levels of free chlorine or bromine in water by yielding a series of colors ranging from light pink to dark red.
49. (49) 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.
50. (50) Disinfectant equipment--Equipment designed to apply or deliver a disinfectant (such as chlorine or bromine) at a controlled rate.
51. (51) Diving board--A recreational mechanism for entering a pool, consisting of semi-rigid board that derives its elasticity through the use of a fulcrum mounted below the board.
52. (52) Diving equipment for competition--Competitive diving boards and fulcrum-setting diving stands intended to provide adjustment for competitive diving.
53. (53) Dwelling or rental dwelling--One or more rooms rented to one or more persons where a Class C pool or spa or a Class D pool is located.
54. (54) Effective filter area--Total surface area through which designed flow rate will be maintained during filtration.
55. (55) Effluent--The water that flows out of a filter, pump, or other device.
56. (56) Facility(ies)--The pool or spa, restrooms, dressing rooms, equipment rooms, deck, enclosure, and other appurtenances directly serving the pool or spa area.
57. (57) 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.
58. (58) Filter--A device that removes undissolved particles from water by recirculating the water through a porous substance (filter media or element).
59. (59) 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.
60. (60) Filter media--A finely graded material (for example, sand, diatomaceous earth, polyester fabric, and anthracite) that removes filterable particles from the water.
61. (61) Floor--The interior bottom surface of a pool or spa.
62. (62) Free available chlorine--That portion of the total chlorine remaining in chlorinated water that is not combined with ammonia or nitrogen compounds and that will react chemically with undesirable or pathogenic organisms. Combined chlorine plus free chlorine equals total chlorine.
63. (63) Handhold--A ledge, coping, rope, railing, deck, or similar construction along the immediate top edge of the pool that provides a slip-resistant surface or grip.
64. (64) Handrail--A railing that is intended to be gripped for resting and/or steadying a person while entering or exiting a pool or spa and that is typically part of a ladder, a set of steps, or deck-installed equipment.
65. (65) Hardness--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.
66. (66) 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.
67. (67) 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.
68. (68) 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.
69. (69) IESNA--Illuminating Engineering Society of North America, 120 Wall Street, Floor 17, New York, New York 10005-4001, telephone (212) 248-5000.
70. (70) Influent--The water entering a filter or other device.
71. (71) 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.
72. (72) 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.

73. (73) 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.
74. (74) 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.
75. (75) Local regulatory authority--The local enforcement body or authorized representative having jurisdiction over pools, spas, and associated facilities.
76. (76) May--An advisory statement or a good practice and is not legally required.
77. (77) MSHA--Mine Safety and Health Administration, 2002 Thayer Center, Oakland, Maryland 21550, telephone (301) 334-3831.
78. (78) Multi-port valve--A device that allows the multi-directional control of the passage or flow of water through a system. (See definition (154) "Valve".)
79. (79) NEC--National Electric Code, published by NFPA. (See definition (81) "NFPA".)
80. (80) NEMA--National Electric Manufacturers Association, 1300 N. 17th Street, Suite 1847, Rosslyn, Virginia 22209, telephone (703) 841-3200.
81. (81) NFPA--National Fire Protection Association, 11 Tracy Drive, Avon, Massachusetts 02322, telephone (800) 344-3555.
82. (82) NOx--(also written nox) Nitrogen oxides or the sum of the nitric oxide and nitrogen dioxide found in the flue gas or emission point of a source.
83. (83) NRPA--National Recreation and Park Association, 650 West Higgins Road, Hoffman Estates, Illinois 60195-3402, telephone (847) 843-7529.
84. (84) NSFI--NSF International, (National Sanitation Foundation International), 789 N. Dixboro Drive, Ann Arbor, Michigan 48115, telephone (800) 673-6275.
85. (85) NSPF--National Swimming Pool Foundation, 224 East Cheyenne Mountain Blvd., Colorado Springs, CO 80906, telephone (719) 540-9119.
86. (86) NSPI--National Swimming Pool Institute, 2111 Eisenhower Avenue, Alexandria, Virginia 22314, telephone (703) 838-0083.
87. (87) 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.

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

    1. (A) skimmer system--Two inches above to 2 inches below the midpoint of the operating range of the device, or manufacturer's maximum stated operating range; or
    2. (B) overflow (gutter) system--The manufacturer's maximum stated operating range above the design water level.
89. (89) Organic matter--Perspiration, urine, fecal matter, saliva, suntan oil, cosmetics, lotions, dead skin, and similar debris introduced to water by users and the environment.
90. (90) ORP--The potential level of oxidation-reduction produced by strong oxidizing (sanitizing) agents in a water solution. Oxidation level is measured in millivolts by an ORP meter.
91. (91) OSHA--United States Department of Labor, Occupational Safety and Health Administration, 200 Constitution Avenue N.W., Washington, D.C. 20210, telephone (800) 321-6742.
92. (92) Outlet--(See definition (131) "Suction outlet".)
93. (93) Overflow system--Overflows, surface skimmers, and surface water collection systems of various design and manufacture for removal of pool or spa surface water.
94. (94) 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.
95. (95) Parts per million (PPM)--A unit of measurement in chemical testing that 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).
96. (96) 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, 1 to 7 being acidic, 7 being neutral, 7 to 14 being basic and, 14 being most basic.
97. (97) Plaster--A type of interior finish (a mixture of cement and aggregate) that is applied to a concrete pool or spa and that is either white or meets the observable "black disk" requirement in §265.184(f) of this title (relating to General Construction and Design for Post-10/01/99 Pools and Spas) and §265.185(c) of this title (relating to General Construction and Design for Pre-10/01/99 Pools and Spas).
98. (98) 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.

99. (99) Pool--Any man-made permanently installed or non-portable structure, basin, chamber, or tank containing an artificial body of water that is used for swimming, diving, aquatic sports, or other aquatic activity other than a residential pool and that 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. The term does not include a spa or a decorative fountain that is not used as a 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:

       1. (i) lodging such as hotels, motels, apartments, condominiums, or mobile home parks;
       2. (ii) property owner associations, private organizations, or clubs; or
       3. (iii) a school, college or university while being operated for academic or continuing education classes. 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 wading pool with a maximum water depth of 24 inches at any point.
100. (100) Pool yard or spa yard--An area that has a pool yard or spa yard enclosure and that contains a pool or spa.
101. (101) Pool yard or spa yard enclosure--A fence, wall, or combination of fences, walls, gates, windows, or doors that completely surround a pool or spa.
102. (102) Post-10/01/99 pool or spa--A pool or spa built on or after October 1, 1999, unless otherwise indicated. See §265.181(b) of this title.
103. (103) Post-10/01/99 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 pre-10/01/99 pool or spa structures have been removed.
104. (104) Potable water--Water that is bacteriologically safe and otherwise suitable for drinking and is regulated by the Texas Commission on Environmental Quality or local regulatory authority as a drinking water system.
105. (105) Pre-10/01/99 pool or spa--A pool or spa built before October 1, 1999, unless otherwise indicated. See §265.181(b) of this title (relating to General Provisions).
106. (106) Precipitate--A solid material that is forced out of a solution by some chemical reaction and that settles out or remains as a haze in suspension (turbidity).
107. (107) Pressure differential--The difference in pressure between two parts of a hydraulic system, such as the influent and effluent of a filter.
108. (108) PSI--Pounds per square inch.
109. (109) Pump--A mechanical device, usually powered by an electric motor that causes hydraulic flow and pressure for the purpose of filtration, heating, and circulation of pool and spa water.
110. (110) Push-pull valve--A device that allows the dual direction control or flow of water through a system. (See definition (154) "Valve.")
111. (111) Rate of flow--The quantity of water flowing past a designated point within a specified time, such as the number of gallons flowing in 1 minute (gallons per minute).
112. (112) Regulatory authority--Any federal, state, or local enforcement body or authorized representative having jurisdiction over pools, spas, and associated facilities.
113. (113) Residential pool or spa--A pool or spa that is located on private property under the control of the property owner or the owner's tenant and that is intended for use by not more than two resident families and their guests. It includes a pool or spa serving only a single-family home or a duplex.
114. (114) Return inlet or inlet--The aperture or fitting through which the water under positive pressure returns into a pool or spa.
115. (115) Ring buoy--A ring-shaped floating buoy capable of supporting a user.
116. (116) Rope and float line--A continuous line that is not less than 1/4 inch in diameter and that 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.
117. (117) Scale--The precipitate that forms on surfaces in contact with water when the hardness, pH, or total alkalinity levels are too high.
118. (118) Self-closing and self-latching device--A device that causes a gate to automatically fully close and latch without human or electrical power.
119. (119) Separation tank--A tank used in conjunction with a filter to facilitate the separation of filtrate material for disposal.
120. (120) 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.
121. (121) Shall--Mandatory provisions of these regulations.
122. (122) Shallow areas--Pool water areas that are 5 feet deep or less.
123. (123) Shock treatment--The practice of adding significant amounts of an oxidizing chemical to water to destroy ammonia and nitrogenous and organic contaminants in water.
124. (124) Skimmer weir--Part of a skimmer that adjusts automatically to small changes in water level to assure a continuous flow of water to the skimmer.
125. (125) Slide--A recreational feature with a flow of water and an inclined flume or channel by which a rider is conveyed downward into a pool.
126. (126) Slip-resistant--A surface that has been treated or constructed to significantly reduce the chance of slipping.
127. (127) Spa--A constructed permanent or portable structure that is 2 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 and that 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. A spa, as is defined in these rules, does not refer to a business establishment such as a day spa or a health spa. Industry terminology for a spa includes, but is not limited to, "hydrotherapy pool," "whirlpool," "hot spa," "hot tub," etc. A spa does not include a residential spa. (See definition (113) "Residential pool or spa".)
128. (128) Special aquatic activity device--An interactive play device, such as a slide, spray stream, or similar item, utilizing water that is recirculated.
129. (129) Stabilizer--A chemical that helps reduce the excess loss of chlorine in water due to the ultraviolet rays of the sun. (See definition (42) "Cyanuric acid".)

130. (130) Steps, recessed steps, ladders, and recessed treads--A 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 (73) "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 step holes.
131. (131) Suction outlet--The aperture or fitting through which the water is drawn from the pool or spa. A skimmer is not considered a suction outlet for purposes of these rules.
132. (132) Super chlorination--The practice of adding a sufficient amount of chlorinating compound to water to destroy chlorine demand compounds and any combined chlorine that is present. Generally, the level of chlorine added is 10 times the level of combined chlorine in the water. (See also definition (26) "Breakpoint chlorination".)
133. (133) Surface skimmer system/Through wall skimmer--A device installed in the wall of an in-ground pool or spa, or above-ground pool or spa that permits the continuous removal of floating debris and surface water to the filters.
134. (134) Surge pit--A collecting tank or sump that allows the pool drain(s) and surface collection system to flow into it by gravity.
135. (135) SVRD--A safety vacuum release device, as described in §296.190(d)(3)(B) of this title for minimizing risk of entrapment.
136. (136) SVRS--A safety vacuum release system that consists of either an SVRD or an AVS, as described in §296.190(d)(3) of this title for minimizing risk of entrapment.
137. (137) Swimout--A recessed area outside of the general perimeter of the pool designed to facilitate the entry and exit of swimmers from a pool.
138. (138) TCEQ--Texas Commission on Environmental Quality, P.O. Box 13087, Austin, Texas 78711-3087, telephone (512) 239-1000.
139. (139) TDLR--Texas Department of Licensing and Regulation, Boiler Division, P.O. Box 12157, Austin, Texas 78711, telephone (800) 803-9202.
140. (140) TDS--Total dissolved solids, i.e., a measure of the total amount of dissolved matter in water (for example, calcium, magnesium, carbonates, bicarbonates, metallic compounds).
141. (141) Test kit--A device for monitoring a specific chemical level in pool or spa water.
142. (142) Therapeutic pool or spa--A pool or spa that is operated exclusively for therapeutic purposes, such as physical therapy, and is under the direct supervision and control of licensed medical personnel.
143. (143) 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.
144. (144) Total chlorine--The sum of both the free available and combined chlorine.
145. (145) Toxic--A substance that has an adverse physiological effect on human beings or other living organisms.
146. (146) Turbidity--Cloudy condition of water due to the presence of fine particulate materials in suspension that interferes with the passage of light.
147. (147) Turnover rate--The period of time (usually in hours) required to circulate a volume of water equal to the total pool or spa capacity.
148. (148) UFC--Uniform Fire Code, published by the International Fire Code Institute, 5360 Workman Mill Road, Whittier, California 90601-2298, telephone (800) 423-6587.

149. (149) 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.
150. (150) UL--Underwriters Laboratory, 333 Pfingsten Road, Northbrook, Illinois 60062-2096, telephone (847) 272-8800.
151. (151) User--A person using a pool or spa and adjoining deck area for the purpose of water sports, recreation therapy or related activities.
152. (152) User load--The number of persons in the pool or spa area at any given moment, or during any stated period of time.
153. (153) 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.
154. (154) 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). See definitions (23) "Bleeder valve", (78) "Multi-port valve", and (110) "Push-pull valve".
155. (155) Velocity--The speed at which a liquid flows between two specified points, expressed in feet per second.
156. (156) 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.
157. (157) Wading pool--A Class D pool that has a maximum depth of 2 feet at any point.
158. (158) Walls--The interior pool or spa wall surfaces consisting of surfaces from plumb to a slope of 11 degrees from plumb.
159. (159) 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.
160. (160) Water action pools--A pool designed to simulate breaking or cyclic waves for the purpose of general play or surfing.
161. (161) Water lounge--A horizontal area of a pool that adjoins the pool wall at a depth of from 2 inches to 10 inches, is used for seating and play.
162. (162) Weir--Part of a skimmer that adjusts automatically to small changes in water level to assure a continuous flow of water to the skimmer.
163. (163) YMCA--Y.M.C.A. of U.S.A. (Y.M.C.A.), 101 North Wacker, Chicago, Illinois 60606, telephone (800) 872-9622.
164. (164) Zero depth entry 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 September 1, 2004, 29 TexReg 7704.