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Oklahoma Administrative Code (Last Updated: March 11, 2021) |
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TITLE 252. Department of Environmental Quality |
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Chapter 626. Public Water Supply Construction Standards |
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Subchapter 11. Chemical Application |
SECTION 252:626-11-4. Additional requirements for specific chemicals
Latest version.
- (1) Housing. Enclose chlorine gas feed and storage and separate them from other operating areas. The chlorine room must:(A) have a shatter resistant, clear glass inspection window installed in an exterior door or interior wall to permit the chlorinator to be viewed without entering the room,(B) be constructed so that all openings between the chlorine room and the remainder of the plant are sealed,(C) be provided with doors equipped with panic hardware and opening only to the building exterior,(D) be on ground floor with easy access for handling cylinders from a ramp or dock at floor level, and(E) provide a gas-tight room to separate gas chlorination equipment, chlorine cylinders and ozone generation equipment from other parts of the building, if the building is used for other purposes. Do not connect floor drains from the chlorine room to floor drains from other rooms. Doors to this room shall only open to the outside of the building, with panic hardware, at ground level and allow easy access to all equipment. One-ton chlorine cylinders shall have separate storage and feed areas. All doors and emergency equipment shall be compatible with chlorine.(2) Ventilation.(A) Provide each room with a ventilating fan with the capacity to provide one complete air change per minute.(B) Locate air inlets near the ceiling and the point of discharge near the floor. Locate the point of discharge to avoid contaminating air inlets to any rooms or structures.(C) Locate switches for fans and lights outside of the room, at the entrance. Provide a labeled signal light indicating fan operation at each entrance where the fan can be controlled from more than one point.(3) Heat. Provide the ability to heat the room to 60EF (15EC) and protect from excessive heat. Keep cylinders at room temperature.(4) Storage of chlorine cylinders. Full and empty cylinders of chlorine gas must be:(A) isolated from operating areas,(B) restrained in position to prevent upset,(C) stored in rooms separate from ammonia storage,(D) stored in areas not in direct sunlight or exposed to excessive heat, and(E) a minimum of a one-ton chlorine container, if more than 150 pounds of chlorine per day is needed.(5) Scales. Provide corrosion-resistant accurate scales for weighing chlorine cylinders. Provide at least a platform scale. Indicating and recording scales are required.(6) Chlorine gas line. Do not allow chlorinator feed lines to carry chlorine gas beyond the chlorinator room, unless gas is fed under vacuum. Lines must be extra heavy weight pipes, resistant to corrosion and slope upward from the cylinder to the chlorinator.(7) Water supply. Provide an ample supply of water to operate the chlorinator. Back-up any booster pumps, according to the back-up power requirements.(8) Handling Equipment. For cylinders up to 150 pounds, provide securing restraints and a hand-truck designed for the cylinders. For one-ton cylinders, provide:(A) a 4,000-pound capacity hoist,(B) a cylinder lifting bar,(C) a monorail or hoist with sufficient lifting height to pass one cylinder over another, and(D) cylinder trunnions to allow exchanging the cylinders for proper connection.(9) Manifolds. Gaseous chlorine cylinders may be connected to a manifold, if all cylinders are maintained at the same temperature or the system is designed for gas transfer from a warm container to a cool container. Do not connect liquid chlorine cylinders to a manifold.(10) Leak detection. Provide an emergency response plan for chlorine leaks. Provide a bottle of 56% ammonium hydroxide solution for detecting chlorine leaks. Where one-ton containers are used, provide a leak repair kit approved by the Chlorine Institute and include caustic soda solution reaction tanks to absorb leaks. At large chlorination installations, provide automatic gas detection and related alarm equipment. Air pollution control regulations may require additional air scrubbing equipment be installed.(11) Evaporators. The specifications shall demonstrate that a sufficient volume of chlorine can be supplied.(12) Respiratory protection. Where chlorine gas is handled, provide respiratory air-pac protection equipment that meets the National Occupational Safety and Health (NIOSH) standards. Store the equipment and operating instructions at a convenient location outside the room where chlorine is used or stored. The units must use compressed air, with at least a 30-minute capacity. In the emergency response plan, describe how to maintain the air-pac protection equipment.(b) Acids and caustics.(1) Keep acids and caustics in closed acid-resistant or caustic resistant shipping containers or storage units.(2) Design bulk acid and caustic storage systems with a liquid level indicator, overflow pipe, and receiving basin or drain capable of receiving accidental spills or overflows.(3) Do not handle acids or caustics in open vessels. Pump acid or caustics in undiluted form from original containers through a suitable line to the point of treatment or to a covered day tank.(4) Due to their potential explosive nature, do not store acids and bases together or allow discharge to a common drain.(c) Fluoride. Documentation of approval from the Oklahoma State Department of Health for the use of fluoride for a PWS system shall be submitted to DEQ with the engineering report.(1) Approved fluoride compounds. The following compounds may be used for the fluoridation of PWS systems when approved by NSF:(A) sodium fluoride,(B) sodium silicofluoride, and(C) hydrofluosilicic acid.(2) Storage.(A) Store fluoride chemicals so that substitution for other chemicals used in water treatment can be avoided.(B) Provide storage facilities so fluoride dry chemicals can be stored a minimum of 6 inches from floor surface to prevent moisture build up within chemical (dry chemicals only).(C) Store fluoride compounds in covered or unopened shipping containers inside an enclosure.(D) Do not reuse empty fluoride shipping containers (bags, drums, or barrels).(3) Chemical feed equipment and methods.(A) Scales. Provide accurate scales and loss-of-weight recorders for hydrofluosilicic acid solution feeders.(B) Solution feeders. Provide a positive displacement pump having a stroke rate of not less than 20 strokes per minute for the application of fluoride solution. Do not introduce fluoride solution directly into the suction pipe of a pump or any other pipe or conduit that normally operates under atmospheric or negative pressure.(C) Feed lines. Provide easily accessible feed lines made of corrosion resistant material. Protect feed lines from freezing. If using a horizontal pipe, apply the hydrofluosilicic acid into the lower half of the pipe. Provide anti-siphon devices for all fluoride feed lines. Do not add fluoride compounds before lime-soda softening or ion exchange softening.(D) Dry-chemical feeders. Provide a minimum of 12 gallons of solution water per pound of sodium fluoride or silicofluoride applied. Provide agitation of the chemical and gravity feed from the solution pots. Provide a minimum retention period of 5 minutes for sodium fluoride or 15 minutes for sodium silicofluoride in the solution pot or basin.(4) Protective equipment. Place a sign in fluoride feeding areas, stating that hands and other exposed areas must be washed with liberal quantities of water after handling fluoride materials.(A) Provide the following protective equipment when sodium fluoride and sodium silicofluoride is utilized:(i) gauntlet-type gloves made of neoprene, plasticized polyvinyl chloride, or other equally resistant material,(ii) dust respirator of a type certified by the National Institute of Occupational Safety and Health (NIOSH) for toxic dusts,(iii) an apron or other protective clothing, and(B) Provide the following protective equipment when hydrofluosilicic acid is used:(i) gauntlet-type gloves made of neoprene, plasticized polyvinyl chloride, or other equally resistant material,(ii) chemical safety goggles or shield,(iii) an acid resistant apron made of neoprene or other equally resistant material, and(iv) an operational safety shower and eyewash device in case of emergency.(d) Powdered activated carbon. Powdered activated carbon storage and handling must meet the following requirements:(1) store activated carbon in a fireproof compartment or building. Do not store any other material in the same compartment or building with carbon. Provide explosion-proof lights, switches, and motors,(2) install an exhaust fan with a dust collector for each room where carbon is stored or handled,(3) provide wet carbon storage tank dust collectors at the charging point and an agitation device to keep the slurry in suspension,(4) provide pumps for transfer of the slurry to the feeders,(5) construct all tanks, pipes, valves, pumps, agitators, etc., which will come in contact with the carbon slurry, of materials that will withstand the corrosive action of the slurry, and(6) the maximum slurry concentration is 1 pound of activated carbon per gallon of water.(e) Chlorine dioxide.(1) Feed system.(A) Provide fiberglass reinforced vinyl ester plastic (FRP) or high density linear polyethylene (HDLPE) tanks with no internal insulation or heat probes for bulk storage of 25-38% solution sodium chlorite.(B) If centrifugal pumps are used, provide Teflon packing material. Pump motors must be:(i) totally enclosed,(ii) fan-cooled,(iii) equipped with permanently sealed bearings, and(iv) equipped with double mechanical seals or other means to prevent leakage.(C) Provide chlorinated PVC, vinyl ester or Teflon piping material. Do not use carbon steel or stainless steel piping systems.(D) Provide glass view ports for the reactor if it is not made of transparent material.(E) Provide flow monitoring on all chemical feed lines, dilution water lines, and chlorine dioxide solution lines.(F) Do not use excessively hard dilution water in order to avoid calcium deposits. Dilution water must be near neutral pH.(G) Control air contact with chlorine dioxide solution to limit potential for explosive concentrations building up within the generator.(H) The maximum chlorine dioxide concentration in the air is 10% by volume.(2) Storage.(A) Designate space for storage and feeding.(B) Do not store and handle combustible or reactive materials, such as acids or organic materials, in the sodium chlorite area.(C) Provide non-combustible material for construction, such as concrete.(D) Store chemicals in clean, closed, non-translucent containers.(E) Avoid exposure to sunlight, UV light, or excessive heat.(F) Provide a water supply near the storage and handling area for cleanup.(G) Design the parts of the chlorine dioxide system in contact with the strong oxidizing or acid solutions of inert material.(H) Provide adequate ventilation and air monitoring equipment.(I) Provide gas masks and first aid kits outside the chemical areas.(f) Sodium chlorite. The storage and use of sodium chlorite must be approved by the DEQ in the engineering report prior to the preparation of final plans and specifications. Provisions shall be made for proper storage and handling of sodium chlorite to eliminate any danger of fire or explosion associated with its oxidizing nature.(1) Storage. Sodium chlorite shall be stored as follows:(A) Sodium chlorite shall be stored alone in a separate room and in an outside building detached from the water treatment facility. The sodium chlorite shall be stored away from organic materials;(B) Storage structures shall be constructed of noncombustible materials; and(C) The storage structure shall be located in an area where water is provided for fire protection and the structure shall be in an area sufficiently cool to prevent heat induced explosive decomposition of the chlorite.(2) Handling. Sodium chlorite shall be handled as follows:(A) Sodium chlorite shall be handled to prevent spillage;(B) An emergency operation plan shall be developed for the clean up of any spillage; and(C) Storage drums shall be thoroughly flushed prior to recycling and/or disposal.(3) Feeding. Sodium chlorite shall be fed as follows:(A) Positive displacement feeders shall be provided;(B) Tubing for conveying sodium chlorite or chlorine dioxide solutions shall be Type I PVC, polyethylene or materials recommended by the manufacturer;(C) Chemical feeders installed in chlorine rooms shall provide sufficient space or facilities as approved in the specifications;(D) Feed lines shall be installed in a manner to prevent formation of gas pockets and shall terminate at a point of positive pressure; and(E) Check valves shall be provided to prevent backflow of chlorine into the sodium chlorite line.(g) Sodium hypochlorite. Sodium hypochlorite storage and handling procedures shall be arranged to minimize the slow natural decomposition process either by contamination or by exposure. In addition, feed rates shall be regularly adjusted to compensate this progressive loss in chlorine content.(1) Storage. Sodium hypochlorite shall be stored as follows:(A) In the original shipping containers or in a sodium hypochlorite compatible container; and(B) Storage containers or tanks shall be located in a cool area, away from any sunlight, and vented to the outside of the building.(2) Feeding. Sodium hypochlorite shall be fed as follows:(A) Positive displacement pumps shall be used;(B) To avoid air locking, for or systems using self-priming pumps, the use of a foot valve is required;(C) Where flooded suction is used, arrange pipe work to ease the escape of gas bubbles;(D) Plants utilizing bulk storage of greater than 100 gallons shall be required to use calibration tubes or mass flow monitors which allow for direct physical checking of actual feed rates; and(E) Injectors shall be removable to allow for regular cleaning.(h) Ammonia. Ammonia for chloramine formation shall be added to water either as a water solution of ammonium sulfate, or as aqua ammonia (ammonia gas in water solution), or as anhydrous ammonia (purified 100% ammonia in liquid or gaseous form). Special provisions are required for each form of ammonia as follows:(1) Ammonium sulfate. A water solution is made by addition of ammonium sulfate solid to water with agitation. The tank and dosing equipment contact surfaces shall be made of corrosion resistant non-metallic materials. The point of delivery to the main water stream shall be placed in a region of rapid and turbulent water flow.(2) Aqua ammonia. Aqua ammonia (also known as ammonium hydroxide) feed pumps and storage shall be enclosed and separated from other operating areas. The aqua ammonia room shall be equipped as follows:(A) A corrosion resistant, closed, unpressurized tank shall be used for bulk storage, vented through an inert liquid trap to a high point outside and an incompatible connector or lockout provisions shall be made to prevent the accidental addition of other chemicals to the storage tank.(B) The storage tank shall be fitted with either a cooling/refrigeration and/or with a provision without opening the system to dilute and mix the contents with water to avoid conditions where temperature increases cause the ammonia vapor pressure over the aqua ammonia to exceed atmospheric pressure.(C) An exhaust fan shall be installed to withdraw air from high points in the room and makeup air shall be allowed to enter at a low point.(D) The aqua ammonia feed pump, regulators, and lines shall be fitted with pressure relief vents discharging outside the building away from any air intake and with water purge lines leading back to the headspace of the bulk storage tank.(E) The aqua ammonia shall be conveyed direct from storage to the treated water stream injector without the use of a carrier water stream unless the carrier stream is softened.(F) The point of delivery to the main water stream shall be placed in a region of rapid and turbulent water flow.(G) Provisions shall be made for easy access for removal of calcium scale deposits from the injector.(3) Anhydrous ammonia. Anhydrous ammonia shall be readily available in pure liquefied gas form under moderate pressure in cylinders or as a cryogenic liquid, boiling at -15EC at atmospheric pressure. Anhydrous ammonia shall be handled as follows:(A) Anhydrous ammonia and storage feed systems (including heaters where required) shall be enclosed and separated from work areas and constructed of corrosion resistant materials.(B) Pressured ammonia feed lines shall be restricted to the ammonia room.(C) An emergency air exhaust system, with an elevated intake, shall be provided in the ammonia storage room.(D) Leak detection systems shall be fitted in all areas where the ammonia is piped.(E) Special vacuum breaker/regulator provisions shall be made to avoid potentially violent results of backflow of water into cylinders or storage tanks.(F) The ammonia injector shall either use a vacuum eductor or a perforated tube fitted with a closely fitting flexible rubber tubing seal punctured with a number of small slits to delay the fouling by lime deposits.(G) A provision shall be made for the periodic removal of scale/lime deposits from injectors and carrier piping.(H) Meet OSHA requirements for the installation of an emergency gas scrubber capable of absorbing the entire contents of the largest ammonia storage unit whenever there is a risk to the public as a result of potential ammonia leaks.