NSTM Chapter 533, Potable Water Systems Flashcards
Fresh water is not potable unless it is ___
Safe for human consumption
The only approved method for disinfecting potable water
A halogen, normally bromine or chlorine
Water that is suitable for human consumption
Potable water
Disease carrying microorganisms
Pathogens
The use of a halogen is preferred to other common disinfecting methods because ___
Residual halogen levels can be easily detected and maintained
The ___ is responsible for the delivery of potable water from shore station to ship
Shore station CO
The ship’s ___ are responsible for the receipt, distribution, and quality testing of potable water
Engineer and Medical officers
The ship’s ___ is responsible to the ship’s ___ for the supply and treatment of potable water and for the system components that receive, store, distribute, produce, and treat potable water
EO
CO
The ___ shall ensure that all ship-to-shore connections are made only by trained shore personnel, or in their absence ___
EO
Ship personnel who are properly supervised by authorized shore personnel
___ is responsible for the chloride and hydrogen ion (pH) testing of the ship’s P/W
EO
The ship’s ___ is responsible to the ship’s CO for the quality testing (except ___) and monitoring of P/W handling, treatment, and storage
Medical officer or medical department representative
Chloride and pH testing
The ___ shall evaluate the adequacy of treatment and disinfection of the shore P/W prior to its receipt, and shall ensure that the required halogen residual is present in the P/W and that no potable water hose is used to a nonpotable water system
Medical officer
The hoses and fittings shall be handled so that they will not be immersed in ___ at any time
Nonpotable water
P/W fill connections are __ for large ships and __ for smaller ships
2-1/2 inch
1-1/2 inch
Fill lines for potable water shall not be cross-connected with ___
Any nonpotable waterline or system
If not in use, filling connections shall be ___
Closed with screwcaps attached with keeper chains
Connections shall be at least ___ above the deck with the receiving connection turned ___
18”
Down to protect it from contamination
Filling connections shall be conspicuously designated by a warning plate bearing the inscription ___
POTABLE WATER ONLY in 1” letters
Hoses shall be labeled ___ at ___ intervals
POTABLE WATER ONLY
10”
Hoses shall be stored with the ends ___ in ___
Coupled or closed with screw-type caps
Padlocked, vermin-proof lockers or cabinets
Lockers shall be identified and labeled ___
Potable water hose
Lockers shall be located ___ and ___ off the deck
Out of the weather
18”
Printed instructions outlining step-by-step procedures for ___ shall be posted in a conspicuous location in the hose storage area
Disinfection of P/W hoses
Ships use either ___ or ___ to move P/W from storage tanks to distribution system
Constantly running pumps
Pressure set
If P/W tanks are low in the ship, in relation to pump elevation, the pump is equipped with a ___
Vacuum priming system
Special consideration shall be given to piping installed in the ____, particularly piping on the ___
Bilge area
Suction side of the P/W pumps
Piping in the bilge shall be ___
Hydrostatically tested
___ materials shall not be used for repairs
Lead-containing materials
Sealants and lubricants used for piping repairs shall be done using ____
Silicone compound products complying with SAE-AS8660 and National Sanitation Foundation Standard 61
If operating a pumping system using a constantly pump, make certain that the pump recirculation valve is ___
Open and directed toward the suction side of the pump
The piping, piping components, and plumbing fixtures shall be kept in sound, leakproof condition to ___
Conserve water and prevent contamination
All ship faucets shall be kept leak-free to ___
Conserve water and to maintain pressure
___ are not an acceptable means of separating potable water from the other systems
Valves and blind flanges
Potable water shall not be delivered to other systems, tanks, or facilities that could contain water of an inferior quality, unless an air gap or approved device that will prevent ___ is provided
Backflow and siphonage
Best method of ensuring that the potable water system does not become contaminated
Installation and maintenance of an air gap
An adequate air gap is defined as ___
A distance of two supply pipe diameters between the supply pipe and the maximum overflow in the receiver
All devices that are used in place of an air gap shall be approved by ___
The Foundation for Cross-Connection Control and Hydraulic Research or the American Society of Sanitary Engineers
All P./W hoses are to be disconnected when not in use to prevent ___
Any possible backflow
A warning label plate shall be installed in a conspicuous location at each potable water hose connection inscribed ___ in ___
Disconnect Hose When Not In Use
1” red letters
Approved hose connections are those equipped with ____
Cutout valve, vacuum-breaker backflow preventer, and a hose connection
All sink and space faucets with hose threads shall be equipped with ___
A hose connection vacuum breaker
Laboratory and ship sink faucets with smaller hose connections shall be equipped with ___ installed at least ___
Approved hose vacuum breakers or a vacuum breaker
6” above the overflow level of the sink
Permanent direct connections to dishwashing machines that are not equipped with an air gap, and to garbage disposal units, urinals, water closets, grease interceptor hoods, or X-ray and photographic equipment shall be made by way of ___ installed at least ___ above the overflow unit services
An approved atmospheric or continuous pressure vacuum breaker, or continuous pressure backflow preventor with internal relief at atmosphere
6”
Permanent direct connections to any nonpotable water tank or piping that can subject the potable water piping to any positive back pressure, no matter how small, can only be made with ___
Approved reduced pressure backflow preventors
All freshwater cooling systems are consideder ___
Contaminated
P/W systems downstream of the reduced pressure backflow preventers are considered ___
Contaminated
All outlets downstream of the reduced pressure backflow preventers must be labeled with a ___
Warning placard indicating that the water is contaminated
All P/W tank sounding tubes shall be provided with ___
Valves or caps and with padlocks
The sounding tube shall have a ___
Label plate
The temperature of hot water supplied for the personal use of the crew shall not exceed ___ to prevent hot water burns
54.4C (130F)
Heaters shall be set to deliver water at no less than ___ to galley grease interceptor hoods and pot sanitizing sinks
71.1C (160F)
Heaters shall be set to deliver water no less than ___ for service to galley dishwashers and laundry machines that are not provided with their own integral booster heaters
82.2C (180F)
If at any point in the system hot water is not delivered at a temperature of at least ___ and the heater is set properly, then a design deficiency may exist
48.9C (120F)
The product water from a distiller
Distillate
RO product water
Permeate
It helps to call the distillate or permeate ___ before it enters the brominator for treatment, and ___ after the brominator
Product water
Potable water
Distillate purity is less than ___
2.3 ppm chloride ions = 4.6 ppm TDS
TDS
Total Dissolved Solids
The upper limit for potable water is ___
500 ppm TDS
Unless determined otherwise, water in harbors, rivers, inlets, bays, landlocked waters, and the open sea within ___ of the entrance to these waterways shall be considered to be polluted
12 miles
The desalting of polluted harbor water or seawater for human consumption shall be avoided except ___
In emergencies
If fresh, brackish, or polluted water is being distilled, the temperature of the first-effect shell shall be maintained at not less than ___
73.9C (165F)
The transfer of evaporator distilled water to the ship;s P/W tank is prohibited if the chloride content exceeds
2.3 ppm
The transfer of product water from an RO unit to the ship’s P/W tanks is prohibited if the conductivity exceeds ___
1000 micromhos/cm (500 ppm TDS)
Regardless of the method of distilling plant operation, the resulting distillate water shall be disinfected by the addition of ___ before it is considered safe for human consumption
A halogen compound
Halogens used for P/W disinfection include ___
Chlorine and Bromine compounds
A measurable trace of ___ or ___ shall be maintained in all parts of the P/W system
FAC
TBR
FAC
Free Available Chlorine
TBR
Total Bromine Residual
Trace readings of FAC or TBR ensure ___
The P/W is free from microbial contamination
That excess of chlorine or bromine remaining in the water after 30 minutes of contact with the water
TBR or FAC
The halogen compound is added to produce an initial concentration of ___
1.0 ppm chlorine or 0.7 ppm bromine
A minimum of ___ FAC or TBR after a 30 minute contact with the water is required
0.2 ppm
Chlorine or bromine depleted in reacting with substances present in the water
Halogen demand
The amount of chlorine or bromine required to produce a 30-minute FAC or TBR residual of 0.2 ppm can very widely because of the ____
Halogen demand
If the residual is ___, and the pH is ___, no additional disinfection may be required
- 2 ppm or more
8. 5 or less
If the amounts of chlorine-demanding substances (such as ammonia) in the water are not known, a dose of no fewer than ___ chlorine or ___ bromine shall be used initially
- 0 ppm
0. 7 ppm
Additional halogen will be required in the pH is in excess of ___ within the ship’s P/W storage or distribution system
8.5
pH
Hydrogen ion concentration
High pH levels will adversely affect the ____ of chlorine and bromine
Disinfectant properties
Whenever the pH is above 8.5 and chlorine is be be used as the disinfectant, the water shall be treated to provide at least a ___ FAC residual at the end of a 30-minute contact period
0.6 ppm
Whenever the pH is above ___ and bromine is to be used as the disinfectant, the water shall be treated to provide at least a 0.6 ppm TBR residual and the end of a 30-minute contact period
9.5
Minimum residual required for all P/W onboard or taken aboard
Chlorine _____
Bromine _____
- 2 ppm after 30 minutes in tanks
0. 2 ppm after 30 minutes in tanks
Water in P/W distribution system
Chlorine ____
Bromine ____
Trace readings throughout
Trace readings throughout
Water from an area where amebiasis or hepatitis is endemic or unapproved source is used
Chlorine ___
Bromine ___
- 0 ppm after 30 minutes in tanks
2. 0 ppm after 30 minutes in tanks
Disinfecting tanks and systems
Chlorine ___
Bromine ___
100 ppm initially; 50 ppm after 4 hours
N/A
Disinfecting hoses, couplings, and water connections prior to connection to P/W system
Chlorine ___
Bromine ___
100 ppm for 2 minutes
N/A
Scrubbing interior or contaminated tanks when P/W is scarce
Chlorine ___
Bromine ___
100 ppm
N/A
Emergency water supply for drinking and cooking
Chlorine ____
Bromine ____
5.0 ppm after 30 minutes
N/A
All water supplied by public or private systems outside of the US should be considered of ___
Doubtful quality
When shore water quality is in doubt, the Medical Officer, medical department representative, or other responsible officer shall ___
Investigate the water source, make as complete an examination as soon as possible, and advise the CO relative to safeguards
Data on extracontinental sources may be available from
Local US military representatives and from the area Environmental and Preventive Medicine Unit
Approved sources are those approved by ___
US Public Health Service
US Navy Medical Representatives
US Government Representatives
If no P/W is available, nonpotable lake or river water may have to be obtained for drinking and cooking. The water to be treated in such an emergency should be ____
Clear and free of turbidity
Having sediment stirred up
Turbidity
Water not treated with a halogen can be made safe by ___
Bringing it to a rolling boil in a steam kettle, maintaining the rolling boil for 5 minutes, cooling it, and then bring it back to a rolling boil and maintaining the boil for another 5 minutes
In addition to canned drinking water, P/W in ___ and in ___ can be used during an emergency
Battle dressing stations
Water heaters
Calcium hypochlorite is classified as ___
A dangerous material
Contact between calcium hypochlorite and ___ may result in spontaneous combustion
An oxidizable material, such as paint, oil, or cloth
Chlorine is available for disinfecting P/W in the form of ___, a ___
Calcium hypochlorite
Granular solid
Calcium hypochlorite presents a potential hazard because of its ___
Corrosive and chemically active nature
Calcium hypochlorite is a strong oxidizer that can ___ when coming in contact with organic matter
React explosively
Elemental bromine is impregnated on ___
Ion exchange resin beads
Bromine cartridges are less hazardous than calcium hypochlorite since the elemental bromine is ____
Contained in the cartridge assembly and should not come in direct contact with the operator
Storage lockers shall be provided in ___ in sufficient quantities to store a ___ supply of bromine cartridges
Clean, dry storerooms
6-month
Ready service lockers may be installed in the ___ containing bromination equipment
Machinery spaces
A ___ shall be installed on each bromine cartridge stowage locker
Warning plate
A hose with a ___ should be installed in the vicinity of each brominator, supplied with ___
Quick-opening valve
Cold P/W
The hose connection by the brominator shall consist of ___
3/4” IPS piping with a locked open globe valve, a pressure-reducing valve set at 25 psi, a ball valve, a vacuum breaker backflow preventer, a hose coupling, and a 4-foot length of hose
A ___ shall be installed at each brominator
Warning plate
Only approved primary disinfection method
Bromination method
If the bromine method is unavailable, chlorine solutions may be introduced directly into the P/W tanks by the ___ method
Chlorine batch
Bromine treatment of potable water is provided by two types of bromination systems
Proportioning brominator
Recirculating brominator
Installed in the distillate discharge line, provides the initial treatment of distillate before it proceeds to the P/W tanks
Proportioning brominator
Recirculates water to and from a P/W tank, provides supplemental treatment of P/W when the bromine residual degrades below the acceptable level
Recirculating brominator
Brominators installed in the distillate discharge line brominators are called ___
Automatic proportioning brominators
The automatic proportioning brominator comprises three major components
Bypass header assembly
Dual feed valve assembly
Feeder assembly
Automatic proportioning brominators are capable of feeding bromine at ___
Two feed rates
Dual feed rate automatic proportioning brominators are set to provide a fixed rate of either ___ at the low feed rate or ____ at the high feed rate
- 7 ppm TBR
2. 7 ppm TBR
The ___ rate of feed is to be used if the ship is distilling water when operating in contaminated waters
High
The bypass header assembly contains a ___
Flow switch, time totalizing meter, cartridge change indicator light, system operating indicating light, fixed orifice, test tap, and inlet and outlet flanges
Provides a visual indication of the time remaining before the next scheduled cartridge change
Time totalizer
Caused a pressure differential which causes a percentage of the water to be diverted through the dual feed valve assembly and the feeder assembly
Fixed orifice
The dual feed have assembly is a ____
Two-position ball-type valve with a reduced size, cross drilled hole in the ball
Basically a pressure vessel which houses the bromine cartridge
Feeder assembly
___ are provided at the base of the feeder assembly, the top incorporates an ___
Inlet and outlet tubing connections
Air-bleeder valve
The top of the feeder assembly is secured in place by ___
A V-band clamp
Elemental bromine introduced into the ___
Bypass water stream
The bromine release rate is proportional to ___
Water flow rate, temperature, and water quality
The bromine cartridge is fabricated of ___
Non-brittle plastic
Bromine cartridges have a full service capability of ___
24 months from the date the cartridge was filled
When using older bromine cartridges, the ___ must be used to increase the halogen residual in the P/W tanks
Recirculating brominator
MACHALT
Machinery Alteration
Capable of feeding bromine at two feed rates
Automatic proportioning brominators
The RO brominator is designed to provide the required levels of halogen residuals for inlet water connections that are ___
Unique to the product of the RO plant
Water produced by RO plants is typically ___ in temperature and ___ in TDS connection that water produced by conventional evaporators
Lower
Higher
___ reduced the rate at which bromine is fed from the bromine cartridge. ___ increases this rate of bromine feed
Low temperature
High TDS concentration
Difference between the RO brominator and conventional distilling plant brominator
RO brominator has two canister assemblies installed for parallel flow, and a bypass flow valve to allow continuous adjustment
Designed to treat water in P/W storage tanks
Recirculating brominator
Flow through the cartridge in a recirculating brominator is limited by ___ to achieve the required bromine feed into the selected tank
The timing device
After the timing device terminates the bromine feed, water recirculation continues for an additional calculated time period to ___
Disperse the bromine throughout the tank
Set when manufactured to feed a specific quantity of bromine to the water
Recirculation brominators
In a recirculating brominator, the initial 0.7 ppm bromine feed is obtained by ___
Setting the bromine timer to the feed time indicated on the instruction plate mounted on the brominator
Feed time is based on ___
Water quality and temperature
To increase the initial residual the ___ must be increased
Feed time
Secure power to the time totalizers before performing maintenance on the brominators. The ___ will be shorted out if the time totalizer cover is removed while the totalizer is energized
Solid state relay
Bromine cartridges should be removed from the canisters whenever the brominator is not to be used for ____
14 or more days
Stainless steel canisters are manufactured with an inner coating to protect the canister from ___
The corrosive bromine environment
The cartridge may be retained for future use as long as there is ____
A red color in the bromine resin
The partially spent cartridge may be temporarily stored in ___
Its original shipping container
The tubing connected to the brominator is ___
Nylon-reinforced Polyvinyl Chloride (PVC)
The tubing will discolor from ___ to ___ for the hose upstream of the canister and ___ for the hose downstream of the canister
Transparent
Amber
Dark brown
The PVC hose on the brominator should be replaced after ___ or when ____
5 years of service
The brominator is overhauled
Each bromine cartridge should be ___ before insertion into the canister assembly
Visually inspected
Bromine cartridges should not be used if beaded resin is ___
Visible in, or spills out of, the nipple when pointed downward
Bromine impregnated resin will release ___
Hazardous vapors
If the cartridge is found to be defective ___
Place the cartridge in its original container, dispose of the repackaged cartridge IAW procedures for hazardous waste disposal
Bromine resin could cause injury if it comes in contact with ___
Skin
Using alternate disinfectants in the place of the bromine cartridge will result in ___
Incorrect calculations
The bromine feed rate of either 0.7 ppm or 2.7 ppm is a ___
Nominal rate
The best place to test for residuals is the ___
P/W tanks by way of the recirculating brominator
A lower water temperature will result in __ bromine released
Less
The rate of bromine feed will ___ with an increase in flow rate
Increase
A ___ in bromine feed rates occurs with a reduction in TDS
Decrease
___ bromine cartridges are required in a continental USA port receiving shore water or in a foreign port receiving approved ready-for-use P/W
0
The number of bromine cartridges required daily while at sea or operating in uncontaminated waters equals the complement times ___
0.0005
While at sea or in port, operating distilling plants in contaminated waters or in any port receiving water from shore that is contaminated or of doubtful quality, the number of bromine cartridges required daily equals complement times ___
0.002
The chlorination disinfection method is considered the least desirable because ___
It usually results in overchlorination and it exposes the P/W to potential contamination
After pouring chlorine solution into the P/W tank, at least ___ of P/W must be poured into the tank to flush the concentrated chlorinated water into the tank
1 gallon
If the tank is full before adding chlorine, the water should be mixed using the ___
P/W pumps and recirculating piping
A chlorinator may be installed in either the ___ or in the ___
Distilling plant distillate line
Shore fill line
The distillate line is generally provided with a chlorinator driven by an ___
Electric motor
The shore fill line is generally provided with a chlorinator that is ___
Hydraulically actuated or driven by an electric motor
The chlorinator injects hypochlorite solution into the water system in proportion to ___
The volume of water flowing through a meter
The distillate line and fill line may both be served by a fill line chlorinator unit if the distilling plant is ___
Large enough to permit sufficient flow through the unit
The amount of chlorine required to be absorbed by these materials is called the ___
Chlorine demand
A dosage rate of 1 oz of granular calcium hypochlorite (70%) per 5000 gallons of water yields ___ ppm chlorine. Because of chlorine demand, this dosage rate will probably produce an FAC residual of about ___ ppm after a 30-minute contact period
- 0
0. 2
The biological safety of water is dependent upon the ___
Residual concentrations of FAC or TBR
____ is to be maintained regardless of water source
FAC or TBR
It is normal for halogen residuals to ___ after the initial treatment
Decline
The halogen residual decline is ____
50% per 24 hour period
Testing for FAC or TBR residuals shall be performed by the ship’s ___
Engineering and medical departments
The medical department shall test for FAC or TBR residual as follows ___
Prior to receipt
Once daily
From points varied throughout the ship
The engineering department shall test for FAC or TBR residual as follows ___
Whenever cartridges are changes
After a 30-minute contact period
Prior to putting P/W tank into service
The occasional absence of trace readings in remote parts of the ship does not, in the absence of ___, indicate the need to increase the halogen dosage
Positive bacteriological findings
Water samples shall be taken from a P/W tank with care to ensure that ____
A representative sample of water is taken
Water sample is not contaminated by personnel taking the sample
The contents of the tank are not contaminated
It is preferred to sample from ____ rather than ___
Petcocks on the tank or P/W pump or the bromine recirculation system
Sounding tubes
When the P/W pump or the bromine recirculation system test connection is used, ___
The pump should be run for several minutes to clear the piping of nonrepresentative water
Chlorine or bromine residuals are determined by using either the _____ or ___ test methods. The ___ is preferred
Diethyl p-phenylenediamine (DPD)
Orthotolidine
DPD test method
Use of chlorine standards for bromine residual determination will produce ___
Erroneous readings
If the chlorine test kit is used to determine the bromine residual, the reading shall be multiplied by ____ to obtain the actual TBR in ppm
2.25
Ships equipped with bromine systems will receive ___ shore water
Chlorinated
If the water is tested for chlorine residuals using a bromine test kit, thee ___ shall be used to determine the chlorine residual
Chlorine comparator scale
Two types of residual chlorine are measured by testing water ____
Free available
Combined
The bactericidal action rate of chlorine is modified by ___
The combination of chlorine with other compounds
The bactericidal action of FAC is approximately ___ more effective than that of combined chlorine
30 times
I the test for chlorine, combined chlorine is distinguished from free chlorine by ___
The time at which the color develops after the addition of DPD to the water sample
FAC reacts ___
Rapidly
