XI. Swimming Pools & Bathing XI. Swimming Pools & Bathing BeachesBeaches

A. Regulations &A. Regulations &

B. Design and safetyB. Design and safety

Objectives:Objectives:

List and describe regulations List and describe regulations affecting water quality in pools and affecting water quality in pools and bathing beaches.bathing beaches.

Discuss design and safety consider-Discuss design and safety consider-ations for pools and bathing beachesations for pools and bathing beaches

Regulation of water quality in Regulation of water quality in pools, beaches:pools, beaches:

Sanitary quality of swimming Sanitary quality of swimming water is determined by microbial, water is determined by microbial, chemical, and physical tests described chemical, and physical tests described in in Standard Methods for the Examination Standard Methods for the Examination of Water and Wastewaterof Water and Wastewater, performed by , performed by competent laboratory personnel.competent laboratory personnel.

APHA Joint Committee on APHA Joint Committee on Swimming Pools and Bathing Swimming Pools and Bathing

Places Recommendations:Places Recommendations:

Microbial parameters Microbial parameters (pools):(pools):– Plate count - < 200 CFU/ml.Plate count - < 200 CFU/ml.– Coliforms - < 1.0/50 ml.Coliforms - < 1.0/50 ml.– Staphylococci - < 50/100 ml.Staphylococci - < 50/100 ml.

Joint Committee Joint Committee recommendations (continued):recommendations (continued):

Physicochemical parameters (pools) -Physicochemical parameters (pools) -– pH - 7.2 to 8.0.pH - 7.2 to 8.0.– Alkalinity - 50 - 150 mg/L.Alkalinity - 50 - 150 mg/L.– Clarity - 6 inch disc readily visible.Clarity - 6 inch disc readily visible.

8” Secchi disc used for natural waters.8” Secchi disc used for natural waters.

Standards for bathing beaches:Standards for bathing beaches:

Microbiological standards -Microbiological standards -– Total coliforms - < 500/100 ml.Total coliforms - < 500/100 ml.– Fecal coliforms - < 100/100 ml.Fecal coliforms - < 100/100 ml.– Fecal Fecal StreptococciStreptococci - < 100/100 ml. - < 100/100 ml.– SalmonellaSalmonella, enteroviruses - 0/100 ml., enteroviruses - 0/100 ml.

Standards for bathing beaches Standards for bathing beaches (continued):(continued):

Physicochemical parameters:Physicochemical parameters:– pH - 6 to 9.pH - 6 to 9.– Color - no abnormal changes.Color - no abnormal changes.– Mineral oils - < 0.4 mg/L.Mineral oils - < 0.4 mg/L.– Surfactants - < 0.4 mg/L.Surfactants - < 0.4 mg/L.– Phenols - < 0.005 mg/L.Phenols - < 0.005 mg/L.– Dissolved oxygen - 8.0 to 12.0 mg/L.Dissolved oxygen - 8.0 to 12.0 mg/L.– Tarry residue, floating debris - absent.Tarry residue, floating debris - absent.

Swimming pool design:Swimming pool design:

Types of pools -Types of pools -– RecirculatingRecirculating

water is circulated, filtered, and water is circulated, filtered, and chlorinated.chlorinated.

– Fill-and-draw - (no circulation).Fill-and-draw - (no circulation).– Flow-through (500 gal/bather/day).Flow-through (500 gal/bather/day).– Partly artificial.Partly artificial.

Design considerations, bathing Design considerations, bathing load limits for pools:load limits for pools:

Provide for diving, swimming, non-Provide for diving, swimming, non-swimming areas in poolswimming areas in pool

Depth - varies with diving boardDepth - varies with diving board– 8’6” deep for 2 ft diving board up to8’6” deep for 2 ft diving board up to– 12’ deep for a 10 ft diving board.12’ deep for a 10 ft diving board.

300 ft300 ft22 pool area per diving board. pool area per diving board. 15-30 ft15-30 ft22 pool area per bather. pool area per bather.

Safety considerations for pools:Safety considerations for pools:

Diving injuries (head strikes) is the Diving injuries (head strikes) is the primary injury in pools.primary injury in pools.– Diving boards should be eliminated in Diving boards should be eliminated in

unsupervised areas.unsupervised areas. Nonslip pool bottoms & run out areas Nonslip pool bottoms & run out areas

help prevent slips due to wet surfaces.help prevent slips due to wet surfaces. Water slides should terminate in at Water slides should terminate in at

least 3 feet of waterleast 3 feet of water

Safety considerations for Safety considerations for bathing beaches:bathing beaches:

Standards for evaluation must be Standards for evaluation must be interpreted based on several factors:interpreted based on several factors:– Sanitary survey of the area (pollution).Sanitary survey of the area (pollution).– Microbiological, chemical, physical Microbiological, chemical, physical

water quality.water quality.– Epidemiological data indicating related Epidemiological data indicating related

illness.illness.– Economic, social, psychological impact.Economic, social, psychological impact.

Other associated bathing areas:Other associated bathing areas:

Whirlpools, spas, and hot tubs may Whirlpools, spas, and hot tubs may be associated with pools.be associated with pools.– Infections with Infections with P. aeruginosa P. aeruginosa have been have been

associated with several hot tubs.associated with several hot tubs.– L. pneumophila L. pneumophila has also been isolated has also been isolated

from hot tubs.from hot tubs.– 3.0 mg/L free chlorine recommended to 3.0 mg/L free chlorine recommended to

prevent infections.prevent infections.– Temp. of 100-102Temp. of 100-10200 F recommended. F recommended.

SummarySummary:

Standards and recommendations for Standards and recommendations for pool quality include potential pool quality include potential

microbial, chemical, and physical microbial, chemical, and physical contaminants affecting aesthetic and contaminants affecting aesthetic and

health concerns.health concerns. Pool design and maintenance can Pool design and maintenance can

contribute to both safety and contribute to both safety and environmental health concerns.environmental health concerns.

Swimming Pools, Swimming Pools, Bathing BeachesBathing Beaches

Treatment, sampling, testing of Treatment, sampling, testing of water qualitywater quality

Objectives - students should:Objectives - students should:

Distinguish among different methods Distinguish among different methods used to treat water for pools and used to treat water for pools and bathing beaches.bathing beaches.

List, describe, and discuss sampling List, describe, and discuss sampling and testing techniques for pool and and testing techniques for pool and bathing beach water.bathing beach water.

Pool water treatment:Pool water treatment:

Disinfection - Chlorine, bromine, Disinfection - Chlorine, bromine, iodine, and UV radiation.iodine, and UV radiation.– Chlorine and bromine are the chemical Chlorine and bromine are the chemical

treatments of choice.treatments of choice.– UV radiation plus hydrogen peroxide is UV radiation plus hydrogen peroxide is

also effective for swimming pools.also effective for swimming pools.– 0.6 mg/L free available residual chlorine 0.6 mg/L free available residual chlorine

recommended.recommended.

Pool water treatment Pool water treatment (continued):(continued):

Control of pH, corrosion, scale.Control of pH, corrosion, scale.– pH should be adjusted to above 7.4. pH should be adjusted to above 7.4.

(Eye irritation occurs below pH 7.4).(Eye irritation occurs below pH 7.4).

– Addition of soda ash (sodium carbonate) Addition of soda ash (sodium carbonate) raises pH (lowered by chlorine).raises pH (lowered by chlorine).

– High pH promotes scale formation and High pH promotes scale formation and can be lowered by addition of fresh water can be lowered by addition of fresh water or acids (HCl, Hor acids (HCl, H22SOSO44, sodium bisulfiate). , sodium bisulfiate).

Treatment of bathing beaches:Treatment of bathing beaches:

If turnover rates are unsatisfactory If turnover rates are unsatisfactory for natural waters, disinfection may for natural waters, disinfection may be necessary.be necessary.– Chlorine or other disinfectant can be Chlorine or other disinfectant can be

added in dry or liquid form.added in dry or liquid form.– Natural waters can also be recirculated, Natural waters can also be recirculated,

filtered and chlorinated similarly to filtered and chlorinated similarly to human-made pools.human-made pools.

Control of bathing beaches:Control of bathing beaches:

Control of algaeControl of algae– Copper sulfate doses of 5 lb/mg every 2-4 Copper sulfate doses of 5 lb/mg every 2-4

weeks usually controls algal growth.weeks usually controls algal growth. Control of aquatic weeds.Control of aquatic weeds.– Lowering of water levels during winter Lowering of water levels during winter

will kill plants.will kill plants. Elimination of pathogenic protozoa.Elimination of pathogenic protozoa.– CuSOCuSO44 and elimination of plants will help. and elimination of plants will help.

Sampling of pool, Sampling of pool, bathing beach waterbathing beach water

Water samples should be collected by Water samples should be collected by plunging collection bottle downward and plunging collection bottle downward and forward till filled.forward till filled.

Sampling points should be near bathing Sampling points should be near bathing beach area or pool outlet(s).beach area or pool outlet(s).

One sample per 300 ft of beach in about 2 One sample per 300 ft of beach in about 2 ft depth of water recommended.ft depth of water recommended.

Sodium thiosulfate is used to eliminate Sodium thiosulfate is used to eliminate free chlorine in chlorinated pool samples.free chlorine in chlorinated pool samples.

Summary:Summary:

Treatments for disinfection of pools Treatments for disinfection of pools (and other bathing areas) include (and other bathing areas) include

chlorinaton, bromination, iodination, chlorinaton, bromination, iodination, and UV radiation.and UV radiation.

Control of pH as well as algae and Control of pH as well as algae and weeds may be necessary in some weeds may be necessary in some

circumstances.circumstances. Periodic sampling ensures safe levels.Periodic sampling ensures safe levels.