1. Types of Swimming PoolsEO
Types of Swimming Pools
TP 9

2. Types of Swimming Pools
References:
CFP 213, Health Manual, Chapter 4
CFAO CFAO SANITARY CONTROL OF INDOOR AND OUTDOOR POOLS AND SWIMMING AREAS
General Safety Program – Safety Standards Manual, Chapter 17, Electricity safety
Saskatchewan Health, Water Theme Facility Design/Operational Standards Updated 02/00

3. Types of Swimming Pools
General:
By definition, a swimming pool means “any structure, basin, chamber, or tank containing an artificial body of water for swimming, diving, or recreational bathing and having a water depth of two feet and six inches or more at any point”. A swimming area is any natural body of water which is used in a similar manner to a swimming pool. Swimming pools may be indoor or outdoor and are of three types:

4. Types of Swimming Pools
Fill and Draw Pools:
Pools of this type are static, they are filled with water which is periodically run off to waste and replaced. In general, such pools are no longer approved for communal use, because of the difficulty in keeping the pool water in sanitary, disinfected condition.

5. Fill and Draw Pool

6. Types of Swimming Pools
Flow-through Pools:
In flow through pools there is continuous flow, so that when the pool is in use water is simply flowing in at one end and out to waste at the other, ensuring continuous displacement. Sanitary control of this type of pool is largely dependent upon controlling the quality of the up-stream water. The out-flowing water may become a source of pollution downstream.

7. Flow-through Pool

8. Flow-through Pool

9. Types of Swimming Pools
Recirculating Pools:
Design
Basically, a recirculation system continuously
pumps the same water through
filtration/disinfection apparatus and equipment
and returns it to the pool, Make up water being
added when necessary.
Design
Basically, a recirculation system continuously pumps the same water through filtration/disinfection apparatus and equipment and returns it to the pool, make-up water being added when necessary. Pools, having a rectangular shape sloping floors which permit gradation from shallow to deep ends, and vertical walls are the patterns in common use. The pool must be so sited, built, equipped, and finished that cleanliness and safety are facilitated. Pool walls and floor surfaces require a smooth, impervious, and easily cleanable finish.

11. Types of Swimming Pools
Recirculating Pools:
The recirculation system provides:
circulation of the water through the pool by pumps;
withdrawal of the water from the pool for treatment and return to the pool as clean water; and
treatment of the water by filtration and disinfection to approved standards, and by the application of any other treatment processes which may be found necessary.
the Recirculating pool is regarded as the most desirable, from the health standpoint, of the three types of swimming pools discussed.

12. Types of Swimming Pools
Pool Operation:
A typical swimming pool piping system is illustrated in
Fig Various modifications exist but all conform to
the same principles:
the pool is filled with water from a potable source;
the water is continuously circulated by pumping through the filters after having hair and lint removed by a straining device; and
the filtered water is disinfected and returned to the pool.

13. Types of Swimming Pools
Pool Water Supply:
The water supply must satisfy the normal bacteriological and chemical requirements for drinking water. Of special importance to recirculation pool operation is a supply which has low turbidity and a neutral pH. The water supply to the pool must be protected against contamination from back siphonage or cross connection.

14. Types of Swimming Pools
Filters:
Swimming pool filters are commonly of two types:
Rapid Sand; and
Diatomaceous earth.

15. Types of Swimming Pools
Filters:
Filters must be of such capacity that the entire pool volume can be recirculated through them not less than three time in 24 hours of operation.
CFHS personnel should note that efficient swimming pool filtration requires a flow rate of two to three gallons per square foot of filter surface per minute while operating, and 10 to 15 gallons per square foot per minute when the filter is being backwashed. The flow rate will be reduced as the filter becomes clogged with matter removed from the water. A flow meter is therefore required so that the filter may be backwashed as soon as the rate drops.

16. Types of Swimming Pools
pH of Pool Water: It has been shown that a high pH in water retards disinfection by chlorine and may favour algal growths. However, a drop in pH (below 7.2) may cause conjunctivitis or dermatitis and will certainly give rise to a strong chlorine odour. Accurate control of the pH of pool water is essential, especially so where hypochlorite solutions are used for pool water disinfection as these have a tendency to drop the pH. It must also be remembered that to ensure proper alum flocculation a pH range of 7.2 – 7.6 is desirable.

17. Types of Swimming Pools
pH of Pool Water:
To adjust pH upwards soda ash is added by means of
A chemical feeder. To lower the pH, sodium
bisulphate, hydrochloric, or phosphoric acid may be
used. Tests for pH are usually made colorimetrically,
although electronic devices exist for this purpose. In
Canadian Forces pools it is required that pH must be
Maintained between 7.2 and 7.6 when there is a free
available chlorine residual between 0.4 and 1 mg/l.
High pH readings (8.0 to 8.9) are permitted where a
high free chlorine residual (over 1mg/l) is required.

18. Types of Swimming Pools
Coagulants – Alum:
Where alum is used in a rapid sand filter it is usually
applied ahead of the filters. The amount required is
generally two ounces per square foot of filter surface.
Alum solution should be applied rather slowly, six to
Eight hours to feed the amount needed. It is highly
important that the alum should be thoroughly mixed
with the influent, otherwise, being acid, the alum will
floc in the pool instead of on the filters.

19. Types of Swimming Pools
Chlorination:
Swimming pool water should, when disinfected
by chlorination, show a free available chlorine
residual of not less than 0.5 mg/l or higher in
all parts of the pool.

20. Types of Swimming Pools
Temperature:
Where a pool is artificially heated the water
temperature is maintained at 23°C to 26°C.
Ambient air temperature in an indoor pool where the
water is heated is required to be not more than 4°C
warmer or more than 1°C cooler than the pool water at
any time when in use. Ventilation must be so adjusted
that draughts are prevented. CFHS personnel must be
In possession of suitably calibrated thermometers
when making this part of an inspection.

21. Types of Swimming Pools
Bather Load:
The number of bathers in the pool at any time
must not exceed one person per 25 square
feet of water surface area.

22. Types of Swimming Pools
Pool Cleaning:
The frequency of pool cleaning depends upon
such factors as the type of pool, bather load,
efficiency of filter operation, chemical
treatment and disinfection, and the results of
laboratory tests. Visible dirt in small quantities
may be removed by vacuuming.

23. Types of Swimming Pools
Pool Cleaning:
The presence of scum or floating debris calls for
immediate removal. Generally, the pool should be
emptied and thoroughly cleaned with sufficient
frequency to, at all times, maintain a high standard of
sanitation and attractive appearance. The adherence
to strict rules of personal hygiene, coupled with the
provision of adequate bathing and toilet facilities, have
a distinct bearing upon the pool’s water quality and
appearance.

24. Types of Swimming Pools
Sanitary facilities:
Sanitary facilities shall be provided as follows:
Bath-houses:
Separate sections must be provided for men and women. The construction must be such as to facilitate thorough daily cleaning.

25. Types of Swimming Pools
Sanitary facilities:
Barriers shall be placed at the entrances and exits of dressing rooms to break the line of sight. Floors shall be of impervious material, have a pitch of 1/4 inch per foot, slope to a proper drain. Walls and partitions shall be of smooth material without open cracks or joints.

26. Types of Swimming Pools
Sanitary facilities:
Showers - Separate shower facilities shall be provided for each sex. A minimum of one shower per 40 bathers shall be provided. The use of shower boards is not recommended; instead, shower floors should be thoroughly cleaned and disinfected daily.

27. Types of Swimming Pools
Sanitary facilities:
Toilets - The men’s bath-house shall have a minimum of one toilet and one urinal per 60 males. The women’s bath-house shall have a minimum of one toilet per 40 females.

28. Types of Swimming Pools
Personal Hygiene:
The Canadian Forces require a high standard
of personal hygiene from users of swimming
pools, and the following precautions are to be
taken:

29. Types of Swimming Pools
Personal Hygiene:
Suitable instructions, covering personal
hygiene shall be displayed prominently in the
locker rooms: i.e..
all persons using the swimming pool must take a cleansing shower, using warm water and soap, before entering the pool;
all bathers who have used the toilet must shower before entering the pool;

30. Types of Swimming Pools
Personal Hygiene:
persons having skin disease, sore or inflamed eyes, cold, nasal or ear discharges, or any communicable diseases will not be allowed in the pool;
spitting, spouting of water, blowing the nose, etc, in the pool is prohibited. If spitting is necessary, scum gutters must be used;

31. Types of Swimming Pools
Personal Hygiene:
blowing the nose to remove water may force infectious matter into the sinuses and inner ear and cause serious consequences;
no articles of food are permitted in the bath-house or pool enclosure;
no smoking is permitted in the pool area; and

32. Types of Swimming Pools
Personal Hygiene:
no boisterous or rough play, except supervised water sports, is permitted in the pool, on runways, on diving boards, floats, platforms, or in dressing rooms and shower rooms.

33. Types of Swimming Pools
Chemistry:
Hydrogen Ion Concentration (pH) - it may be noted that pH levels above
8.1 can favour the growth of algae, particularly where the water may
contain free carbon dioxide. Of the various chemicals recommended for
pH adjustment, the following appraisal should be made before using any
one of them:
Soda ash (Sodium carbonate). Use to raise pH. Generally safe. Less effective than caustic soda.
Caustic soda. Hazardous to handle or use without protective clothing, especially goggles. Not considered to be a safe chemical.
Sodium bisulphate. Used to lower pH. Generally safe.
Hydrochloric & Sulphuric acids. Can be used to lower pH but is highly unsafe.

34. Types of Swimming Pools
Alum (Aluminum Sulphate):
A pressure sand filter can not be operated
without using a coagulant; the coagulant of
choice being alum. Other alum compounds
such as ammonium aluminum sulphate may
be used provided that there is chemical
supervision, because these compounds are
complex in themselves and may add to the
Water treatment problem.

35. Types of Swimming Pools
Alum (Aluminum Sulphate):
Alum, in an aqueous solution, has an acid
reaction. On mixing alum with water in the correct
proportions, aluminum hydroxide is formed, as a white
gelatinous precipitate which adheres to the sand
grains in the filter forming a mat having similar
properties to biological film formed in a slow sand filter.
This mat enables the filter to remove and retain
suspended matter present in the water.

36. Types of Swimming Pools
Alkalinity:
Alkalinity and pH. The pH is not a complete measurement of water alkalinity because carbonate and bi-carbonate alkalinity does not react to a pH test. This is specially important when complaints of eye and skin irritation are received in those cases where the pool pH is over 8.3

37. Types of Swimming Pools
Tests for alkalinity. Carbonate - bicarbonate alkalinity can be determined by the reaction of the water with phenolphthalein solution. A pinkish colour reaction to three to four drops of phenolphthalein solution in 50 mg/l of the water indicated carbonate. Reducing the pH to 8.3 or below removes carbonate alkalinity. The total alkalinity is best determined by titration in a laboratory. In swimming pool waters a total alkalinity of mg/l is desirable.

38. Types of Swimming Pools
Chemical Disinfection:
Three elements of the halogen group or their
compounds have been used in the disinfection
of swimming pool water:
chlorine
bromine
iodine
General. Three elements of the halogen group or their compounds have been used in disinfection of swimming pool water - chlorine, bromine, and iodine. Of these, chlorine is the disinfectant most commonly used in swimming pool water treatment. The method of application of chlorine in a recirculation system may utilize liquified chlorine gas in cylinders or prepared solutions of sodium or calcium hypochlorite.

39. Types of Swimming Pools
Effects on pH:
The application of chlorine to water as a gas results in
the formation of acids which lower the pH. It is for this
reason that treatment with soda ash is necessary.
Calcium hypochlorite only slightly affects pH, but this
depends on the chemistry of the water at source.
Sodium hypochlorite is prepared by bubbling chlorine
gas through a caustic alkali in the solution which will
cause the pool water pH to rise, rendering the use of
sodium bisulphate necessary.

40. Types of Swimming Pools
Chloramines:
These compounds are formed from chlorine
and ammonia. they have been used for
disinfection of pool water but their bactericidal
effect is slower than chlorine or iodine.

41. Types of Swimming Pools
MAINTENANCE - Control of Algal Growths:
Algal growths are favoured by a pH below 8.1.
An incipient algal growth may be detected by a
Sudden rise in pH, caused by algae removing
carbon dioxide. Algae will also deviate chlorine,
increasing chlorine demand. The free residual
chlorine treatment, properly applied, prevents
growth of algae

42. Types of Swimming Pools
MAINTENANCE - Control of Algal Growths:
Shaded pools are less susceptible to algal
problems because of reduction in direct
sunlight. Routine superchlorination is an
excellent preventive. Where a massive algal
growth has developed the pool must be
drained, scrubbed with strong (5 %)
hypochlorite or copper sulphate solution, and
thoroughly flushed.

43. Types of Swimming Pools
MAINTENANCE - Filter Sand Purging:
Failure to properly backwash filters will give rise to:
Calcification caused by calcium compounds
adhering to grains of sand, resulting in the formation of impermeable masses or (cakes); and
Mud balls which are of biological origin, caused by the multiplication of bacteria. This causes solid aggregation of sand, dirt, and hair into “mud balls”. These mud balls disrupt the filter bed, so that uniform filtration is impossible.

44. Types of Swimming Pools
MAINTENANCE - Filter Sand Purging:
Corrective Measures (Purging). When either of the two conditions
previously described arises, the filter, or filters, must be purged.
The methods commonly used are:
replacement of the entire sand bed if the condition is of long standing in either case.
calcification, if not too far advanced, may be corrected by purging with an acid wash. The filter is opened and drained and the chemical spread over the surface. The filter is then closed and sufficient water admitted to just cover the surface. After six hours, the filter is thoroughly backwashed.
for mud balls, the same procedure as under 2b above is used. Lye or calcium hypochlorite may be substituted for sodium biusulphate, but involve special hazards and are better avoided.

45. Types of Swimming Pools
BATHING PLACES - Wading Pools:
This type of pool is designed for outdoor used by small
children. A continuous flow, shallow, spray type pool
is the design most favoured by sanitarians. The water
supply may be fresh, potable water which is rapidly run
to waste, or recirculated, in which case treatment is the
same as for recirculation swimming pools. Wading
pools require the same precautions with regard to
construction, operation, and safety as swimming pools.

46. Types of Swimming Pools
BATHING PLACES - Wading Pools: Such pools can, unless carefully supervised, become foci of infection, especially for those communicable diseases peculiar to children. Contact with a wading pool should be ascertained when investigating any case caused by droplet infection, or direct contact, and involving small children, during the summer months. Notwithstanding these drawbacks, a wading pool in which the water is adequately treated, and where those wading are supervised, is infinitely safer than a beach wading area.

47. Types of Swimming Pools
Inspection:
Records:
Daily pool records are maintained by the BCEO. Copies of these records should be available either at the pool, or through the BCEO, or the PERI staff. Of special importance to CFMS preventive medicine personnel are those records pertaining to:
chemical tests for chlorine residual, pH, and alkalinity;

48. Types of Swimming Pools
Inspection:
Records:
bacteriological water samples;
number of bather per day - if bathing is on a unit basis the unit designation should be recorded; and
dates and time of tests of emergency telephone, or for electrical ground fault.

49. Types of Swimming Pools
Inspection:
Inspection Procedure:
So many enter-related factors, which bear upon health, exist at a swimming pool that a check-list type of inspection form should be utilized. A suggested form for this purpose is appended as Annex A to this chapter. When making a routine inspection, CFHS personnel should conduct tests for chlorine residual and pH, also alkalinity if required. Samples for bacteriological examination should also be secured, first aid kits inspected, and emergency communication system tested. Any existing adjacent facilities for refreshment service must also be include in this inspection.

50. Types of Swimming Pools
Annex A – Swimming Pool Report
CFP 213, Chapter 4 – Section 416
INSPECTION, Records & Inspection
Procedure
Annex A – Swimming Pool Inspection Report

51. Types of Swimming Pools
Water Theme Facility Design/Operational Standards
Safety
Electrical
Disinfection (play equipment in pods)
Operational of wave pools and water slides
Problem solving (wave pools and water slides)
TP #9 (j) (3)-(7)
Instructor: Discuss in general terms

52. Types of Swimming Pools
Salt Water Pools & Spas:
Saltwater swimming pools and spas rely on chlorine- or bromine-generating devices to sanitize the water. They require the same basic care as traditional pools and spas to control disease-causing microorganisms, algae and organic matter.
The main difference is that saltwater pools and spas rely on chlorine- or bromine-generating devices to sanitize the water whereas traditional pools and spas can use chlorine or bromine chemical products. As with traditional pools and spas, the minimum free available chlorine or equivalent bromine levels must be maintained at 1-3 ppm for swimming pool water and at 3-5 ppm for spa water.
(misc)
Health Canada – Residential Swimming Pool and Spa Sanitation

53. QUESTIONS