§ 165.23 Water Chemistry and Testing Requirements.
RCNY § 165.23
The chemical quality of water in the pool and/or spray ground shall not cause irritation to the eyes or skin of the bathers or have other objectionable physiological effects on patrons. The water shall be chemically balanced to maintain clarity, proper disinfection, total alkalinity, and pH levels as specified below: (a) Disinfectant residual. All pools and/or spray grounds in use shall be automatically and continuously disinfected by means of equipment that is in compliance with the provisions of this Article and that uses a disinfectant which is approved by the department. Silver/copper ion generators, ozone and other disinfectants may be used only as a supplement to chlorine or bromine.
(1)Chlorine residual. (A) Pools. Where chlorine is used as a disinfectant, and the pool water pH is less than or equal to 7.8, the dosage of chlorine or chlorine compound shall be sufficient to maintain a concentration of at least 0.6 mg/l free chlorine throughout the pool. When pH is between 7.8 and 8.2, a concentration of at least 1.5 mg/l free chlorine residual shall be maintained. During use, pool water shall not exceed a free chlorine residual of 5.0 mg/l or a pH of 8.2. The pH of water in the spa pool shall be maintained between 7.2 and 7.8, and a minimum free residual chlorine of 1.5 mg/l shall be provided. Spa pools shall be chlorinated to 10 mg/l (shock treatment) at least once a week at end of daily usage period. (B) Spray Grounds. When calcium hypochlorite or sodium hypochlorite are used to disinfect a spray pad and the spray pad treatment tank, the dose of chlorine or chlorine compound shall be sufficient to maintain a concentration of at least 2.0 mg/l free chlorine throughout the system including the treatment tank and water emanating from the spray features. A free chlorine residual of 10.0 mg/l shall not be exceeded in any spray pad treatment tank during use. Spray pad treatment tank water pH shall be maintained between 7.2 and 7.8.
(2)Superchlorination and superoxidation. When combined chlorine (chloramines) in excess of 0.5 mg/l is detected in pool and/or spray ground treatment tank water, the water shall be superchlorinated to attain a free chlorine concentration of at least 10 times the combined chlorine concentration, or oxidized by other means to eliminate the combined chlorine. Hand feeding of chemicals directly into the pool and/or spray ground treatment tank is permitted for purposes of superchlorination or superoxidation when the pool and/or spray ground is closed to the public.
(3)Bromine. (A) When bromine is used as a disinfectant, the pH of water shall be maintained between 7.2 and 7.8, and a minimum bromine residual of 1.5 mg/l shall be provided. Spa pools shall be maintained at a bromine residual between 3 mg/l and 6 mg/l. A maximum of 6 mg/l bromine residual shall be permitted in any pool during use. (B) The pH of the spray pad treatment tank water and water emanating from the spray features shall be maintained throughout the system between 7.2 and 7.8 and a minimum bromine residual of 4.4 mg/l shall be provided.
(4)Silver/copper. When silver/copper or copper ion generators are authorized, the concentration of copper shall not exceed 1.3 mg/l and the concentration of silver shall not exceed 0.05 mg/l.
(5)Ozone. When ozone is authorized, ozone concentration in pool water shall not exceed 0.1 mg/l and the ambient air zone concentration shall be less than 0.1 mg/l at all times either in the vicinity of the ozonator or at the pool water surface.
(6)Ultraviolet Light. The light intensity meter reading of the ultraviolet unit shall be monitored and recorded at least two times daily. The light intensity shall be maintained at the manufacturer's specified level for the flow rate. When the output intensity falls below the setpoint intensity, conditions causing decreased ultraviolet light intensity at the sensor shall be evaluated and corrected. The ultraviolet lamp(s) shall be replaced when the decreased ultraviolet light intensity is due to lamp failure.
(7)Other disinfectants. Use of cyanuric acid-based chlorine (or any other chlorine stabilizer) is prohibited. Pools found using or containing any cyanuric compound shall be closed, drained and refilled prior to continued use. Disinfectants other than those listed in 24 RCNY Health Code § 165.45(l) may be used only if approved by the department and the New York State Department of Health.
(b)Total alkalinity. The total alkalinity of the pool water shall be maintained within the range of 80 to 120 mg/l.
(c)Testing kits. Each pool or spray ground facility shall have functional colorimetric water testing equipment for free chlorine and combined chlorine, or total bromine; pH; total alkalinity; calcium hardness; copper concentration when silver/copper or copper ion generator is used; and ozone concentration when ozone generating equipment is used. FAS-DPD test kits are acceptable. A supply of appropriate reagents for making each type of test shall be maintained on site, shall be stored in their original labeled containers and shall be replaced every six months or as recommended by the manufacturer. When colorimetric tests are used, color standards shall be furnished for each of the tests, that allow an accurate comparison of the sample to be tested from standpoint of color and density, and shall be reasonably permanent and no fading. Electronic residual and pH monitoring devices may be used in addition to the test kit.
(d)Records and testing. A bathing establishment operation record including all test results shall be maintained on a daily basis by the establishment. Whenever tests indicate that an inadequate disinfectant level, inadequate ultraviolet light intensity or inappropriate pH value are present, immediate action shall be taken to reestablish an appropriate disinfectant level and pH value. Pool water shall be manually tested and results recorded as indicated below, including pool water systems equipped with an automatic monitoring device to control pH and disinfectant residual in water: (1) For pH, free chlorine or bromine residual the water shall be tested at least three times. Tests shall be at the beginning of the day, during the day's peak bather load, and at the end of the day; or more frequently, as needed, throughout each day to maintain the standards required by this Article.
(e)Saturation index. For the purposes of this Article the saturation index shall be used to determine chemical balance of the water, and whether the water is corrosive (undersaturated) or scale forming (oversaturated). The Department may require that the bathing establishment determine the saturation index monthly or at any other frequency required to maintain water clarity, proper disinfection, alkalinity and pH levels. S.I. = pH + TF + CF + AF - 12.1 Where: pH = actual reading 12.1 = constant TF = Temperature Factor (Table 1) CF = Calcium Hardness Factor (Table 1) AF = Total Alkalinity Factor (Table 1) When saturation index is between -0.5 and +0.5, the water is balanced and within tolerance limits. The optimum saturation index is zero. When saturation index is above +0.5, the water is super-saturated with CaCO3 which may deposit a coating or scale in the pipeline, particularly metal filters, valves and pumps. When saturation index is below -0.5, water will dissolve CaCO3 and may be corrosive. Table 1: Numerical Values for Saturation Index Formula TemperatureF° (C°)TFCalciumHardnessCFTotalAlkalinityAF32 (0)0.050.350.737 (3)0.1251.0251.446 (8)0.2501.3501.753 (12)0.3751.5751.960 (16)0.41001.61002.066 (19)0.51501.81502.276 (24)0.62001.92002.384 (29)0.73002.13002.594 (34)0.84002.24002.6105 (40)0.98002.58002.9128 (53)1.01,0002.61,0003.0 Example: Given temperature 68 degrees, total hardness 200 mg/l, total alkalinity 20 mg/l, CaCO3 and pH = 7.8 S.I. = pH + TF + CF + AF - 12.1 *(Calcium hardness = 0.70 × 200 = 140 mg/l) S.I. = 7.8 + 0.52 + 1.76 + 1.22 - 12.1 = (-) 0.8 Therefore, the water is corrosive. Note: Saturation index is best maintained slightly on the positive side within the tolerance limits. Normal Control Levels:pH = 7.4 - 7.8Temperature:78 - 80 degrees (indoors)Total alkalinity:80 - 120/mg/lFree chlorine:0.6 (minimum) saturation index (-) 0.5 - (+) 0.5 calcium hardness: 180 - 250 mg/lAlkalinity Control:To increase – 1 1/2 lb of sodium bicarbonate NaHCO3 baking soda will raise the alkalinity of 10,000 gallons of water by 10 mg/l. To lower – add no more than one pint (1/8 gallon) of muriatic acid per 5,000 gallons of pool water (or 1.25 lb of sodium bisulfate). Addition of such compounds may be added by hand into the water while the pool is closed. This will lower alkalinity by 12 mg/l.pH:To increase – use soda ash. To decrease – muriatic acid or sodium bisulfate.Hardness Control:Calcium hardness is assumed to be 70% of total hardness. To increase – 1 lb of calcium chloride will raise the calcium hardness of 10,000 gallons of water by 11 mg/l. It should be added in small amounts by hand into the water while the pool is closed. To lower, dilute with soft water.
