SECTION 310:315-7-16. Disinfection and pH control

(a)   Chlorinator or other disinfection feeder. The pool shall be equipped with a chlorinator or other residual disinfectant feeder which meets the following requirements: All chemicals and chemical solutions shall be added to the pool water recirculation flow using a feeder that is acceptable to the Department.

(1)   Construction and materials. It shall be of sturdy construction and materials which will withstand wear, corrosion, or attack by disinfectant solutions or vapors and which are not adversely affected by repeated regular adjustments or other conditions anticipated in the use of the device. Feeders requiring field maintenance or cleaning shall be capable of being easily disassembled. The design and construction shall be such as to preclude stoppage from chemicals used or foreign material. The feeder shall incorporate failure-proof features so that the disinfectant cannot feed directly into the pool, the pool piping or pool enclosure following any type of failure of the equipment or its maintenance. Super-chlorination shall be accomplished by the addition of calcium hypochlorite, sodium hypochlorite, or other approved chlorine compounds. Solution chemical feeders and flow through chemical feeders shall be listed as meeting the appropriate National Sanitation Foundation Standard and bear the NSF seal of approval.

(2)   Sizing of disinfection equipment. Solution and gas feeders shall be capable of supplying the equivalent of 1.5 pounds of available chlorine in eight (8) hours, for each ten thousand (10,000) gallons of pool capacity. Feeders used with organic chlorine compounds or other stabilized chlorine shall be capable of supplying the equivalent of 0.5 pounds of available chlorine in eight (8) hours, for each ten thousand (10,000) gallons of pool capacity and the cyanurate concentration in the pool shall be at least thirty (30) mg/1 and shall not exceed one hundred (100) mg/1.

(3)   Erosion type feeders. Erosion type chlorinators using stabilized chlorine compounds shall have a flow meter, calibrated valve, or other device acceptable to the reviewing authority to determine the rate of flow of water through the chlorinator. The device shall be either calibrated in pounds chlorine feed per unit of time or calibrated in gallons of flow per unit of time with an attached chart to convert the water flow rate to pounds of chlorine feed. The feeder shall be capable of continuous delivery within ten (10) percent of the dosage setting.

(4)   Solution type feed pumps. The pump shall have a calibrated rate control and be adjustable from zero (0) to full range. The feeder shall have the capability of feeding the required dosage using a two and one-half (2-1/2) percent solution. (A diagram of a calcium hypochlorite system is shown in Figure III.)

(5)   Existing disinfection equipment. Existing pools with disinfection equipment installed not meeting the requirements of 310:315-7-16 shall be upgraded to this chapter at such time that failure to meet the required water quality can be attributed to inadequate chemical feed equipment.

(6)   Chlorination for normal operation. Chlorination for normal operation is recommended to be introduced before all sand filters. Where super-chlorination is accomplished by chemical feeders, the solution shall be introduced before the sand filter. When the disinfectant is introduced at the suction side of the pump, a device or method shall be provided to prevent air-locking of the pump or recirculation system.

(7)   Chlorination to prevent backflow. The chlorinators shall be designed to prevent the backflow of water into the chlorine container.

(8)   Compressed chlorine gas. When compressed chlorine gas is used, the following additional features shall be provided:

(A)   The chlorine and chlorinating equipment shall be located either out-of-doors or in a separate well-ventilated room. Such rooms should preferably be above ground and shall be provided with vents near the floor which terminate outdoors. The door of the room shall have a viewport and shall not open to the pool enclosure and shall open outward. When located out-of-doors, the cylinders shall be securely anchored to prevent them from falling over and shall be surrounded by a six (6) foot high, woven wire fence, or equivalent, and a locked gate.

(B)   Where gaseous chlorine equipment is provided below grade in a filter room, or in any part of a building which provides housing, the mechanical proportioning device and cylinders of chlorine shall be housed in a reasonably gas-tight, corrosion-resistant, and mechanically vented enclosure. Air-tight duct work from the bottom of the enclosure to atmosphere in an unrestricted area and a motor-driven exhaust fan capable of producing at least one (1) air change per minute shall be provided. Automatic louvers of good design near the top of the enclosure for admitting fresh air are required. An opening at least eighteen (18) inches square, glazed with clear glass, and artificial illumination shall be provided in an amount such that the essential performance of the equipment may be observed at all times without opening the enclosure. The floor area of the enclosure shall be of adequate size to house the chlorinator, fan, scales, and one (1) extra chlorine cylinder.

(C)   Electrical switches for the control of artificial lighting and ventilation shall be on the outside of the enclosure adjacent to the door.

(D)   The chlorine equipment shall be of rugged design capable of withstanding wear without developing leaks.

(E)   Chlorine cylinders shall be anchored to prevent their falling over and shall be provided with platform scales having a capacity of at least one (1) cylinder of chlorine. An approved chlorine cylinder valve stem wrench shall be provided.

(F)   The chlorine feeding device shall be designed so that during accidents or interruptions of the water or electric power supply, the chlorine feed will shut off automatically and leaking chlorine gas will be vented outdoors. The device shall be capable of delivering chlorine at its maximum rate without releasing chlorine gas to the atmosphere.

(G)   A gas mask designed for use in a chlorine atmosphere and of a type approved by the U.S. Bureau of Mines shall be provided. A fresh replacement canister shall also be furnished.

(H)   The gas mask shall be kept in a closed cabinet accessible without a key and located well away from the gas chlorinator or the room where the gas chlorinator is installed, such that it may easily and safely be reached and be put on out of range of possible gas fumes.

(I)   Canister-type gas masks are suitable only with low concentrations of chlorine gas. In the event of a serious leak, the fire department shall be called.

(b)   Brominators or other disinfectant devices. Where brominators or other disinfectant devices are proposed, the design with respect to equipment, maintenance, and safety shall be in accordance with the applicable provisions of 310:315-7-16.

(c)   Prohibitions and exceptions

(1)   Hand feeding. Hand feeding of disinfectants to maintain normal disinfectant residuals is not acceptable; however, the addition of chlorine solution by hand may be used periodically to super-chlorinate for algal control. Super-chlorination shall be accomplished at times when the pool is closed and a safe range of chlorine disinfection shall be attained before patrons are permitted to return to the pool.

(2)   Local ordinances. Where local ordinances exceed the requirements of this chapter, the local ordinances shall prevail.

(d)   Electrolytic chlorine generators. The electrolytic chlorine generator shall be of sturdy construction and of materials which will withstand continual usage typical of public pools and the feed rate shall be adjustable from zero (0) to full range. The generator shall be capable of feeding a chlorine dosage of one and one-half (1-1/2) pounds of available chlorine in eight (8) hours for each ten thousand (10,000) gallons of pool capacity. The generator unit shall be UL approved and a failure-proof electrical interlock with the recirculation pump shall be incorporated into the system such that the generator operates only during recirculation pump operation. The generator units shall be installed according to the manufacturer's instructions and the saline content of the pool water shall be maintained in the required range specified by the manufacturer. Ventilation and housing shall meet the requirements of 310:315-7-16 for compressed chlorine gas.

(e)   Feeders for pH adjustment. Feeders for pH adjustment shall be provided on all pools using gaseous chlorine for disinfection. They shall be adjustable from zero (0) to full range, and shall meet the requirements of 310:315-7-16. When soda ash is used for pH adjustment, the maximum concentration of soda ash solution to be fed shall not exceed one-half (1/2) pound soda ash per gallon of water. Feeders for soda ash shall be capable of feeding a minimum of three (3) gallons of the above soda ash solution per pound of gas chlorination capacity. The minimum size of the solution reservoir(s) shall not be less than fifty (50) percent of the maximum daily capacity of the feeder. The solution reservoir(s) shall be marked to indicate contents.