REHS/RS Recreational Water Questions and Answers 100% Pass

REHS/RS Recreational Water Questions and Answers 100% Pass What would you expect from a swimming pool with a high pH reading? Cloudiness and irritation to the eyes What chemical raised pH in a pool? Sodium Carbonate (soda ash/caustic soda) What chemical oxygenates swimming pools? Sodium Carbonate How would a swimmer most likely contract Legionella pneumophila from a pool? inhalation of pool water vapor What bacteria is contracted through inhalation of pool water vapor? Legionella pneumophila What is swimming pool clarity measured in? nephelometric turbidity units (NTU's) What is the highest recommended level of NTU in a swimming pool? .5 NTU (it shall not be exceeded) What microbe is responsible for skin infections in a whirlpool? Pseudomonas aeruginosa What is the turnover rate formula? volume of pool(gallons)/pump flow rate(gallons per minute)x60(minutes per hour) What is turnover rate measured in? hours What is turnover rate? The amount of time it takes for the entire contents of a pool to pass through the filter What should the turnover rate of a pool be? 6-8 hours Water depth should be marked for every how many feet of pool depth change? two feet What types of cleaning systems are there for pools? Gutter (overflow) and skimmer If pools are less than 30 feet wide with a surface area less than 1600 feet, what can be used instead of a gutter system? skimmer system How must pool size be designed? to fit the expected number of swimmers How must the fresh water supply line enter the pool? It has to drain to pool through an approved air gap Where should pool inlets be located in large pools with outlets more than 5 feet from end wall? every 20 feet Why should pool inlets be located a minimum of 10-15 inches below the water line? to prevent loss of disinfectant How large should the main drain grate be to prevent dangerous suction effects? 4 times the area of the discharge pipe What happens when chlorine is added to water? an acid is formed What must the connection between the pool drain and the sanitary sewer be provided with? an air gap no less than 2 pipe diameters of discharge pipe. What is required in pools to help prevent electrocution? lighting, circuits, and nearby receptacles should be protected with Ground Fault Circuit Interrupters. The current of electricity can be interrupted with a...? GFCI (Ground-Fault-Circuit-Interrupter What is cyanuric acid used for? Used to reduce chlorine loss by protecting free cholorine in pool from sun's UV rays What should cyanuric acid concentrations be? 10-100 mg/L, 30-50 ppm in normal conditions and 60-80 ppm in high sun exposure If there is diarrhea in a pool, what is the chlorine level raised to and for how long? 20 ppm for 12 hours 45 mins What are ideal chlorine levels in a pool? 1-3 ppm chlorine works best at what temperature? 68 degrees F Pool testing equipment should be at what temperature? 36-85 degrees F What is the ideal pH range in a pool? 7.2-7.8 What chemical will lower pH in a pool? trichlor What is the slowest pool filter cartridge What does sodium thiosulfate do to chlorine? neutralizes/removes How long should public swimming pools run their recirculation and disinfection equipment constantly...24/7 What is the max temp for a hot tub? 102-104 degrees F What chemical neutralizes chlorine (found in water sample bottles)? sodium thiosulfate Cyanuric acid should be maintained at what ppm? 30-50 What is the leading cause of pool-associated outbreaks in the US? Cryptosporidium What is breakpoint chlorination? point where the disinfectant demand has been met and all undesirable contaminants in the pool are oxidized. What are the four things that pool design should allow? 1)safety of swimmers 2)complete circulation of water 3)ability to clean venue 4)supervision of bathers Does the bottom of the pool have to be visible? Yes, duh. What should the floor slope of pools be? Water under 5 ft - less than 1 ft drop for every 12 ft Water over 5 ft - less than 1 ft for every 3 ft how many means of access do pools need? At least 2 what colors should be used below water line? Light colors only What must be utilized in pools where the water table exerts pressure on an empty pool? Hydrostatic relief valve or underground drain system What water depths need to be marked? the minimum depth. the maximum depth. each end of the pool. breaks in floor slopes btwn deep and shallow ends. What is the max allowed distance between depth markers? 25 feet For water less than five feet, at what intervals shall depth be marked? 1 foot Why do aquatic venues with multiple pools on the same system need to be able to be separated? For separated water treatment How should floor inlets be distributed? evenly throughout pool and no greater than 20 feet apart Where should wall inlets be placed? five feet from skimmer. isolated. in corners. At what rate should the gutter system remove pool's upper surface? At least 125% of total recirculation flow Surge tanks are a requirement for what? gutter pools How much area does one skimmer cover? 500 square feet What's the max size of a skimmer pool? 30 ft across. discharge and suction flow rates? discharge 8ft/s. suction 6ft/s What should happen after a vomit situation? Free chlorine residual raised to 2 mg/L and maintained for 25 minutes. Tell me about staffing? they have to be there and trained How far away from a pool do unprotected overhead electrical wires have to be? 20 horizontal feet Is an emergency lighting source important? A fence? The lack of glass on deck? They're musts. Some studies indicate that swimmers have a higher over-all ilness rate than do non-swimmers, regardless of what? bathing water quality What is the flow arrangement a treatment system of a pool should be? skimmer/gutter line, main drain line, adjustment valves, hair strainer, disinfectant feeder, filter aid and pH feeder, pump, filters, adjustable inlets What chemicals have been used for pool disinfection? chlorine, chloro-iso-cyanurates, bromine, and iodine What is the most effective method of maintaining pool water quality? continuous recirculation, chlorination, and filtration What pH is optimal for eye irriation, but not for chlorine effectiveness? 7.5-7.6 What doesthe acidity-alkalanity balance affect? Eye irritaion, water coagulation, and the effectiveness of chlorine What does one do to raise the pH of a pool? add soda ash/sodium carbonate To mix acid and water, always: add acid to water What is a chemical commonly used to improve water clarity? alum At what temperature should pool chemistry test kits be stored? 36-85 degrees