Pools Flashcards
what are the 4 leading causes of accidental deaths
- car accident
- falls (number one injury at home)
- fires
- drowning
what is the leading cause of work related accidental death
fires and explosions
what is the ideal human body temperature
98.6 F
about ____ quarts of water can be expelled from the human body a day
6 quarts
how do you convert fahrenheit to celsius
F -32
/9
x 5
convert 95F to celsius
35
how do you convert Celsius to fahrenheit
C x 9
/5
+ 32
kelvin = celsius + _____
273
a 32F day with a 20 mph wind could cause windchill temperatures down to ____
0F
high altitude is any elevation above ____ft (__ miles)
5280 feet or one mile above sea level
at one mile above seal level there is ____ % less oxygen and also less _____
40-45% less oxygen
also less humidity
It takes the average human body ________ days to acclimate to extreme conditions
10-14 days
What are the minimum turnover rates for
pool spa spray ground wading pool medical pool
pool 6 hours spa 30 minutes spray ground 30 minutes wading pool 1 hour medical pool 2 hours
What is the minimum flow (gpm) for a 50,000 gallon pool
139 (50k/360 mins)
DE filters
composition
maximum gpm/ft2
composition - microscopic diatoms (aquatic marine life), calcified, appears like coffee grounds
maximum filtration of 2 gpm/sq foot of filter area
The in and out pressure of a filter should never differ by more than ________ psi
if so the filter needs to be ________
10
backwashed/cleaned/replaced
Cartridge filter max gpm/sq ft
.375 gpm/sq ft
the best type of filter for a pool with more than 30,000 gallons is ____________
sand filter
the most popular type of filter for a spa is __________
cartridge
the best type of filter for a pool with less than 30,000 gallons is _____________
DE filter
sand filters are (more/less) efficient than DE filters
less efficient, but offer faster filtration
Rapid Sand Filter
max filtration rate
minimum depth of media ______
minimum depth of filter gravel___________
effective particle size between ___ and ___ mm
uniformity coefficient not exceeding _____
3 gpm/sq ft
min media depth - 20 inches
min filter gravel depth - 10 inches
particle size - .40 - .55 mm
max coefficient 1.75
High Rate Sand Filters
max filtration rate
effective particle size between ___ and ___ mm
uniformity coefficient not exceeding _____
15 gpm/sq ft
.40 - .55 mm
max coefficient 1.75
Public pool water quality
standard plate count (heterotrophic plate ocunt) shall not exceed _____ CFU per ml
total coliform
membrane filtration method - must be less than ___ CFU per 100 ml
multiple tube fermentation method - must be less than _____ CFU per 100 ml
standard 200 CFU per ml
total coliform
membrane filtration - 1 CFU per 100 ml
fermentation - 2.2 CFU per 100 ml
All pool equipment must be certified by what standard?
NSF/ANSI 50-2012
Chlorine in water breaks into _____ and _____ which together are called _______________
XCl + H20 —> HOCL (Hypochlorous Acid) and OCL- (Hypochlorite ion) + H+ (Hydrogen ion)
together they are Free Chlorine
_____________ is the active killing form of chlorine in water
HOCL, Hypochlorous Acid
Chloramines form when Free chlorine binds with ___________.
Chloramines are not an effective __________
contaminants in the water, usually ammonia compounds.
not an effective disinfectant
unstabilized vs stabilized chlorine disinfectants
unstable - no Carbon atom - sensitive to UV light
stable - contain carbon atom - not sensitive to UV light
Name 6 types of chlorine disinfectants, their physical appearance, stable/unstable, and available chlorine content
unstable
sodium hypochlorite - NaOCl - liquid - 11%
calcium hypochlorite - Ca[OCl]2 - granular, tabs - 70%
lithium hypochlorite - LiOCl - granular - 35% (not used often)
chlorine gas - CL2 - gas - 100%
stable
trichlor - C3N3O3CL3 - tablets mostly, granular - 90%
dichlor - NaCL2C3N3O3 - granular - 60%
the most pH neurtral chlorine type is _____
dichlor
What is cyanuric acid
added to protect unstabilized chlorine form the effects of sunlight.
Bromine disinfectant
tablets usually, 27% available bromine content
used more in spas because it naturally lowers the pH
can be destroyed by sunlight but cyanuric acid does not work for bromine
Name some other methods that can be used to disinfect public pools
ozone (gas)
chlorine generation (salt)
UV light
free chlorine requirements for pools and spa/wading/sprayground
with and without CYA
w/o cya
pools min 1, max 10
spas min 3 max 10
w/ cya
pools min 2 max 10
spas min 3 max 10
bromine residual minimum in pools vs spas
pools min 2ppm, spas/wading/spray min 4ppm
minimum and maximum pH
maximum CYA concentration
max combined chlorine concentration
max spa temp
7.2-7.8
100 ppm CYA max
max .4 ppm combined chlorine
max spa temp 104F
a wading pool has a max depth of ___
18 ‘’ at the deepest point
What are the two types of tests for pool/spa water
Orthotoludene (ortho test) - measure total chlorine, heat sensitive
DPD - Diethyl-Phenylene-Diamine - measures free chlorine, combined chlorine, not heat sensitive
sample water should be taken at a depth of ______
12-18 inches
What are two common chemicals used to raise the pH and one common chemical to lower the pH
raise pH
Sodium carbonate “soda ash” NaCO3
Sodium hydroxide “caustic soda” NaOH
lower pH
Hydrochloric acid “muriatic acid” HCL
copper in pool water can not be above _____ ppm
.2 ppm
TDS (water hardness) should be between ___ and ___ ppm
175-300 ppm
TDS = total dissolved solids
Which chemical is commonly used to neutralize chlorine
Sodium thiosulfate
algae growth can be controlled by used what chemical
Copper sulfate (CuSO4)
in swimming pools ___% of water going through the skimmer and ___% goes through the main drain
75% skimmer
25% main drain
What does “feet of head/head pressure” mean in regards to the pump
the flow pressure of resistance caused by the pipes and equipment
an increase in the head pressure results in ______
a reduction of flow
What is cavitation
bubbling in the circulation system which can damage the pump
What is the required dynamic head capacity for a pump paired with the follow type of filters
pressure DE vacuum DE rapid sand high rate sand cartridge
pressure DE 60ft vacuum DE 20'' vacuum, 40 ft head rapid sand 45 ft high rate sand 60 ft cartridge 60 ft
a lifeguard must have what type of training?
American Red Cross or YMCA
CPR certification
pool records must be kept for ___ years
2 years
which safety devices must be at a public pool
17 ‘’ maximum life ring
12 foot minimum body hook
what to do for pool fecal/vomit/blood contamination events
formed fecal/vomit:
diarrhea:
blood:
close the pool, ensure pH is 7.5 or lower and water temperature is 77F or higher
formed fecal/vomit - maintain FC 2ppm for at least 25 minutes
diarrheal stool 20 ppm chlorine for at least 12.75 hours
if CYA present: lower pH to 6.5 40 ppm FC for at least 30 hours
blood - check if FC is within range, if in range pool stays open
backwash filters, replace cartridge filters
document incident
what is an ancillary facility
areas used in conjunction with pool - locker rooms, pool deck, showers etc.
a depth line is required at ____ feet for pools that are deeper than ___ ft
4.5 feet if deeper than 5 feet
pools deeper than ___ feet require a no diving marker
6 feet
pool/spa decks must be a minimum of ___ feet
4 feet
pool enclosure must be ___ feet high with gaps not to exceed ____ inches
horizontal bars must be a minimum of ___ feet apart
5 feet high
no more than 4’’ spacing
horizontal bars 4 feet apart
chain link fencing can be used if not greater than ___ inches horizontally
1.75 ‘’
what are the pool and spa capacity
spa 1 user per 10 sq ft (surface area/10)
pools 1 user per 20 sq ft (surface area /20)
studies indicate that swimmers have a higher overall illness rate of non swimmers:
regardless of bathing water quality
due to poor regulatory practice3
if they are over 50 years old
if they swim in pools
regardless of bathing water quality
the treatment system of a pool is typically recommended to be installed in which of the following flow arrangements?
skimmer/gutter line adjustment valves main drain line hair strainer pump pH feeder filter filter aid pumps adjustable inlets disinfectant feeder
skimmer/gutter line main drain line adjustment valves hair strainer filter aid pump filters disinfectant feeder pH feeder adjustable inlets
swimming pool water clarity is measured in NTU or nephelometer turbidity units. It is recommended that a level of 0.5 NTU
shall be maintained
shall no be exceeded
is the minimum
is the maximum
shall not be exceeded
when mixing acid and water always…
add water to acid
add acid to water
add soda ash to acid
stir while pouring water into the acid
add acid to water
when chlorine is added to water…
one acid is formed
two primary acids are formed
HCl is considered the primary product
ozone is produced in large quantities
two primary acids are formed
the best control of swimmers itch at a bathing beach is to
add copper sulfate
increase the chlorine residual
lower the chlorine residual
lower the water level and allow plants to dry out
add copper sulfate
swimmers itch is caused by
algae growth
the preferred method for controlling sewage from watercraft is the use of…
onboard holding tanks
shipboard discharge
incinerator toilet
compost toilet
onboard holding tanks
the microbe primarily responsible for skin infecitons in whirlpools is
e coli
pseudomonas aeruginosa
shigella sonnet
salmonella typhi
pseudomonas aeruginosa
water in wading pools should be recirculated every
60 mins
90 mins
120 mins
180 mins
60 mins
the following type of swimming facility is generally prohibited
home outdoor pool
fill and draw pool
natural flow through pool
recirculating pool
fill and draw pool
the main drain should have a grate that is how much larger than the area of the discharge pipe to prevent dangerous suction effets
four times
five times
six times
seven times
four times larger
