LAMPS ASSE QUIZZES
Legionella water management plans should include (2 answers)
- Legionella hazard analysis of the water systems - Legionella control measures
For CT you would record ___, ___, ____, and_____ on a survey
- Location - Number of cells - Number of months/years it typically is operating - Make-up water source
Legionella expertise is not needed to (3)
- Survey a facility's water systems - construct flow diagrams - establish documentation and verification procedures
The scientific community worldwide largely agrees that (select three answers):
- Waterborne legionella bacteria can cause legionnaire's disease - Minimizing legionella in a building water system is the best strategy for minimizing the risk of the disease. - Building water systems should be managed to minimize legionella
The water systems inventory and flow diagrams should include (select two answers):
- points as well as processing steps - names and numbers for each system
legionella expertise is needed to (2)
- specify control measures with monitoring, limits, and corrective actions - establish validation procedures
Per the US EPA National Primary Drinking Water Regulations, the MCL for Total Trihalomethanes (TTHMs) is ______ mg/L and the MCL for Total Haloacetic Acids (HAA5) is _______ ppm:
0.080; 0.060
Per CDC recommendations, a 1 liter sample should be treated with approximately _____ Sodium Thiosulfate (0.1 N solution).
0.5 mL
Per the CDC (US), sample volume collected for Legionella testing should be ________ for outbreak investigations and a minimum of ________ for routine environmental sampling of potable water.
1 liter; 250 mL
According to the [US] Centers for Disease Control and Prevention, approximately what percentage of Legionnaires' disease cases among hospital patients are diagnosed?
10%
If applying the AWWA C651 standard to the hyperchlorination of a new building's domestic water, a chlorine solution must be added to maintain ____ parts per million (ppm) free chlorine throughout the system for a soak time of > or = ___ hours.
100, 3
To validate the effectiveness of piping disinfection, AWWA C651 requires collecting samples for coliform analysis > or = ___ hours after the disinfection procedure, to confirm _____ CFU/mL detected coliform. If required for further validation, samples for heterotrophic plate count (HPC) should be tested to confirm HPC < _____ CFU/mL.
16; zero; 500
. An "outbreak" of Legionnaires' disease means that _____ or more person(s) were exposed to Legionella in the same place and became ill around the same time.
2
According to studies cited by ASSE, adults will incur skin damage (first degree burn) after _______ of contact with water at 60 degrees Celsius (140 degrees Fahrenheit):
2 seconds
For travel, healthcare, and in buildings meeting the ASHRAE 188 criteria requiring a WMP for the potable water system, the CDC (US) defines outbreaks as ________ or more cases associated from the same possible source during a ________ month period.
2, 12
. In the absence of stagnation, biofilm, and other complexities, Legionella pneumophila will multiply within a water temperature range of approximately:
20 degrees C (68 degrees F) to 50 degrees C (122 degrees F)
Per ASHRAE Standard 188, the domestic (potable) water systems in a newly constructed building should be disinfected no more than ____ weeks prior to it being wholly or partially occupied for the purpose for which the building was constructed.
3
After finding Legionella throughout much of a domestic (potable) water system in a U.S. hotel where 3 guests had contracted Legionnaires' disease around the time of their stays, the system is chlorinated at 50 part per million (ppm) for 12 hours. Follow-up testing for Legionella should be performed approximately ___ days after the chlorination procedure to determine whether the chlorination procedure eradicated viable free-floating Legionella, ____ days later to comply with CDC follow-up testing recommendations, and approximately _____ days later to determine whether additional measures are necessary for longer term Legionella control.
3-7, 14, 30-60
In water at 60 degrees C (140 degrees F), Legionella pneumophila die within about:
32 minutes
It may reasonable for a nursing home to perform routine sampling...
4 times a year
Per the US EPA National Primary Drinking Water Regulations, the MCL for Chlorine is _____ ppm. The MCL for Chlorine Dioxide is ______ mg/L.
4.0; 0.8
If a pipe is attached to a hot water tank drain, and the valve on the drain pipe is at the downstream end, then wait about _________ after opening the drain valve before collecting a pre-flush sample to avoid sampling the water in the _________ instead of the water in the tank.
5 seconds; drain pipe
. In disinfecting a new building's domestic water system, the 2021 International Plumbing Code requires either > or = ___ ppm free chlorine for a soak time of 24 hours or > or = _____ ppm free chlorine for a soak time of 3 hours. Your Answer
50, 200
. In a 400-bed, eight-story hospital that routinely tests water systems for Legionella, from how many outlets (e.g., faucets) should hot water samples be collected to get a reasonable representation of the system without overspending?
8 to 12
An example of a bypass in a domestic water system is...
A pipe extending from just before to just after a water meter, pressure reducing valve, or other major valve so the valve can be replaced or repaired without interrupting water service
As it pertains to Legionella water management plans, a control location is:
A point in a water system at which legionella control can and should be applied
A "domestic hot water return pump" typically refers to...
A pump that circulates water from points of use back to a central domestic water heater
Legionnaire's disease is typically treated with
ANTIBIOTICS
In a hospital, if water sampling is carried out properly and a highly-qualified laboratory conducts the culture analysis, Legionella-negative test results indicate:
Acceptable validation of the water management program at the time samples were collected
A large hospital has been tested for Legionella three times within the last six months. After each time, hyperchlorination was performed at 100 parts per million (ppm) free chlorine for 3 hours, but Legionella positivity continues to be greater than 70%. What would be an appropriate plan for this hospital?
After taking immediate, short-term measures to protect patients, install a long-term, continuous supplemental disinfection system that is effective against Legionella and appropriate for this domestic water system.
In surveying domestic water points of building entry (POE), record all but which of the following:
Alkalinity
For a hospital that suspects potential Legionella contamination following an event such as a city water main break, but has reason to believe the contamination has not proliferated through the domestic water system, an objective of any flushing should be to ideally discharge most or all potentially contaminated water:
As far upstream as possible, prior to reaching faucets and other outlets
For most facilities, developing a Legionella water management plan will involve six primary steps including all but which of the following:
Assess the condition and cleanliness of all water related equipment and devices including cooling towers, water heaters, showerheads, and aerators
The water management team at a hospital believes flushing the entire domestic water system is necessary due to potential Legionella risk caused by a specific incident. Flushing of bathroom faucets in occupied patient rooms should be performed:
At low flow (e.g., pencil diameter) to minimize the risk of transmission to patients
Flushing of bathroom faucets in occupied hospital patient rooms should be performed:
At low flow (e.g., pencil diameter) to minimize the risk of water droplets reaching patients
Which of the following is not an essential component of water management plans developed for the purpose of controlling Legionella?
Average annual temperature of the water in the fire protection system
Legionella is
Bacteria that typically live inside biofilm or amoebae
Before sampling, a building operator should...
Be prepared to respond properly to the test results
An office building has two types of drinking fountains. Five that were installed new within the last 2 years have a bottle filler and carbon filter. The other five, installed when the building was constructed 15 years ago, are traditional bubbler fountains with no carbon filtration. Which statement is most reliable?
Because the bottle fillers have carbon filters and probably more parts and thus surface area than the bubblers, they are likely to be more prone to Legionella growth than are the bubblers, but neither fountain type can be assumed to have or not have Legionella.
A control measure for a cooling tower is to keep basins free of build-up. Which of the following would be an example of limits for this control measure?
Buildup in the basin must not exceed 1/2 inch (1 cm) in depth.
Which of the following is important in selecting a laboratory for Legionella culture of water and swab samples in the United States?
CDC ELITE certification
Which of the following would likely be most helpful in determining the degree of organic load in a building's domestic water system following a water main break?
Chlorine levels in the cold water at the building entry and from faucets, compared with recent readings for the building
An ice machine on a patient floor in a hospital has tested Legionella-positive each month for the past 6 months even though it has been cleaned and disinfected after each Legionella finding. The best next step could include all but which of the following?
Clean and disinfect the machine weekly.
A control measure for a cooling tower is to keep basins free of build-up. Which of the following would be an example of corrective action for this control measure?
Clean the basin if the depth of the buildup is greater than 2 cm or if deposits are green.
According to the table on control measures in ASSE 12000 WICRA Forms, water temperatures should be monitored to ensure:
Cold water is < = 65 F and hot water > = 110 F
To collect duplicate samples for the purpose of validating the proficiency and quality assurance of your primary laboratory...
Collect at least twice the normal volume of water into one bottle and pour the water from there into two smaller sample bottles
Legionella control measures should be ____ and ____
Comprehensive and effective in controlling legionella
Information from outbreak investigations indicates that the following events need to be well managed to minimize the risk of Legionnaires' disease associated with a building's domestic water system (select 2 answers):
Construction project involving a shutdown of a significant part of the building's domestic water system A major break, by the property next door, in the city water main serving the building
Many outbreaks of Legionnaires' disease that have been reported in scientific literature were shown to be associated with which of the following?
Construction projects or water main work
In most cases, all but which of the following will be appropriate if Legionella is found in a sample collected from a Whirlpool spa:
Continue the current operation and maintenance program but with increased water temperature
Comparing the temperatures of the domestic hot water supply and return can help to:
Detect excessive heat loss in the system
Major building construction could present a higher than normal Legionella risk associated with a building's...
Domestic hot and cold water
In a hotel that had never been tested for Legionella, 20 samples of hot water were collected from the domestic (potable) water system, a pre-flush and post-flush sample from each of its two 1000-gallon (3,785-liter) water heaters and 16 samples from guest room faucets. Legionella was found only in the pre-flush samples from the water heaters, at 220 colony forming units per milliliter (CFU/mL) and 140 CFU/mL. What would be a reasonable response to these test results?
Drain and clean the water heaters and ensure they are on a regular purge and clean schedule
An example of a typical point-of-use domestic water heater is which of the following?
Electric tank-less or small tank-type water heater located in and for a restroom sink
If you take pictures of a decorative (ornamental) fountains for a Legionella water management plan, include shots of all but the following:
Equalizing Line
A "hospital-acquired" case of Legionnaires' disease means
Evidence indicates the patient's case was caused by exposure to Legionella while in the hospital.
As the owner of an office building, you maintain the central water systems but tenants maintain small systems in kitchenettes within their leased spaces. What might be reasonable steps to control Legionella throughout the building's potable plumbing systems (select 4 answers):
Explain to tenant that maintaining its kitchenette water devices for Legionella control is important for protecting people who occupy its space as well as people occupying other parts of the building Provide the tenant with a list of Legionella control measures for its equipment and request the measures be recorded in a log Seek advice from a competent attorney about requiring Legionella-preventive maintenance in the tenant's lease Request access to inspect and test the tenant's water devices
If a building's domestic water system is temporarily shut down due to a construction project, or potentially affected by an incident such as a city water main break, which of the following would most likely affect the severity of Legionella risk associated with the event?
Extent of the domestic water system affected, in terms of both percentage and water volume
T or F: Testing cooling tower water for bacteria weekly using dip slides would be a reliable method of validating a Legionella water management plan.
F
t or f: Studies have shown that installing large carbon filters on the water supply to a building is an excellent method of Legionella control.
FALSE
t or f: Swab samples rather than water samples should always be collected from showers because swab test results provide the better indication of Legionella risk at the time of sample collection.
FALSE
T or F: If Legionella is found in a sample collected from a bottled water dispenser, the problem can usually be solved by getting bottles of water from a different vendor.
False
T or F: In the United States, if Legionella found is found in the public water supply to your building, you should not bother notifying the public water supplier because the US EPA does not require water utilities to test for Legionella.
False
True or False: . Flow diagrams for a Legionella water management plan must show the routing of piping between buildings and be drawn at 1/4-inch scale.
False
True or False: A Legionella water management plan must have pictures.
False
True or False: Bottled water dispensers (BWDs) do not need to be included in surveys for Legionella water management plans because Legionella has not been found in water dispensers that are filled with mountain water, spring water, and water that has been treated with reverse osmosis.
False
True or False: Evidence examined by the CDC after discovering Legionella indicates the bacteria had not caused illness prior to the outbreak in 1976.
False
True or False: Heating hot water systems (HHW) refer to systems with water heaters supplying domestic (potable) hot water to faucets and showers.
False
True or False: Only smokers or persons who are immunocompromised or elderly are at risk of contracting Legionnaires' disease and of dying from it.
False
True or False: Pontiac fever is a highly contagious illness with a death rate of nearly 50%
False
True or False: The US Centers for Medicare and Medicaid Services (CMS) memorandum QSO-17-30-Hospitals/CAHs/NHs requires that hospitals test their water systems for Legionella?
False
True or false: During a large hospital's normal to high periods of hot water demand, Legionella bacteria in water entering a primary 12-gallon semi-instantaneous water heater set at 60 degrees Celsius (140 degrees Fahrenheit) will likely die before exiting the water heater.
False
t or f: Only large cooling towers present a Legionella risk. Small ones do not hold enough water to harbor and emit Legionella.
False
Total coliform tests can indicate the possibility of _______________.
Fecal contamination
A key difference between a cold water sample from a hotel bathroom faucet and a cold water sample from a drinking fountain in a hotel lobby is:
For the faucet but not the drinking fountain, the sample could contain Legionella released from biofilm that had been contaminated by hot water
XYZ Corporation owns four office buildings. Two of the buildings are located in the same city, about three miles apart, are both 12 stories high, and have nearly identical water systems. The other two buildings are located in different cities, one of which has 15 stories and the other 22 stories. The corporate director of engineering, who oversees the maintenance of all four buildings, wants a Legionella water management plan for all four buildings. How many plans will be required?
Four, one for each building
For a successful Legionella testing program, building operators must do all but which of the following:
Get benchmark total bacteria counts prior to collecting samples for Legionella testing
Sodium Thiosulfate should be used in water samples to neutralize __________ between sample collection and analysis.
Halogen biocides such as chlorine
Which of the following is not likely to be a control location?
Heating hot water system
a central domestic hot water system typically
Heats water in an equipment room or other central location and distributes the hot water to faucets throughout much of the building
In preparing to reopen a 35-story office building that has been shut down and occupied only by one or two maintenance personnel for four months, the facility management company has the domestic (potable) water system and cooling towers tested for Legionella. At the time samples were collected, no disinfectant residual was found in water running from a spigot near the upstream side of the backflow preventer located on the incoming water line at the point of building entry (POE) in the mechanical room, nor was a disinfectant residual detected in hot or cold water at the 13 restroom faucets tested. The cooling tower samples tested Legionella-negative, but Legionella pneumophila serogroup 6 was found in 3 of 5 cold-water and 7 of 8 hot-water samples from the domestic water system at average concentrations of 9 colony forming units per milliliter (CFU/mL) in the cold water and 16 CFU/mL in the hot water. The building has no supplemental disinfection system. What would be a reasonable first step to take in response to these test results?
Hire a water treatment company with expertise in domestic water remediation to hyperchlorinate and flush the hot and cold domestic water system, and retest for Legionella 3 to 7 days and again 30 to 60 days after the procedure.
The domestic (potable) water system in a college dormitory is tested for Legionella prior to reopening for the fall semester after having been closed and unoccupied for 11 weeks. Legionella was found in 8 of 12 samples collected, at concentrations ranging from 1 to 70 colony forming units per milliliter. Student move-in day is 10 days away. The public water supply is treated with chlorine. At the point of entry (POE) to the building, a free chlorine residual was not detected until running water for more than 10 minutes but eventually reached 0.7 parts per million free chlorine. What is likely the best option among these four?
Hire a water treatment company with expertise in domestic water remediation to hyperchlorinate and flush the hot and cold domestic water system, and retest for Legionella 3 to 7 days and again 30 to 60 days after the procedure.
. Ice machines have been linked to Legionnaires' disease in...
Hospital Patients
Heating hot water systems are closed-loop systems that typically supply which of the following?
Hot water coils in air handling units
The WMP team decides to perform a full shut down and offline disinfection of a cooling tower after Legionella pneumophila is detected at 1,400 colony forming units per milliliter (CFU/mL) in a sample from the tower basin. Which is the best order for the following procedures?
Hyperchlorinate, drain and shut down, power wash and brush all surfaces and components, hyperchlorinate
If plans include shutting down three floors of a hotel for six months during which those three floors will be unoccupied, which of the following measures would likely be the most effective and practical for Legionella control?
If the plumbing is configured so that the three floors can be isolated and drained by shutting off valves, then drain the piping serving those floors provided it does not cause corrosion
Which of the following could be a likely cause of inconsistent or inadequate hot water temperatures at faucets or shower in a building? (select 2 answers):
Inadequate balancing of the hot water recirculation system Stagnation because of low use or system design
A control measure for a cooling tower is to keep basins free of build-up. Which of the following would be an example of monitoring for this control measure?
Inspect the basin weekly for dirt or sediment buildup. Measure the depth of buildup and note its color.
Legionella pneumophila serogroup 1 was found in a cold-water sample from a domestic (potable) water faucet in a hospital intensive care unit patient room. After running cold water at the faucet for two minutes, no disinfectant residual was found. Which remediation method would be an appropriate consideration for this faucet?
Install a sub-micron (< 0.2 micron) filter on the faucet while investigating other solutions
Master thermostatic mixing valves are typically...
Installed just downstream of central water heaters to reduce the temperature of water supplied to most or all points of use in the building
Pipes that connect one domestic water system with another, typically so that either system can supply the other, are referred to as crossover lines. The Legionella risk associated with stagnation in crossover lines can be minimized most effectively by (select two):
Installing a valve and drain at both ends so the line can be flushed to waste instead of to the building outlet Avoiding the crossover lines altogether
Legionella risk associated with crossover lines can be minimized most effectively by (select 2 answers):
Installing a valve and drain at both ends so the line can be flushed to waste instead of to the building outlets Avoiding the crossover lines altogether
If measuring water temperature at a faucet from which a water sample is collected, measure the temperature by placing the thermometer probe...
Into the stream of water flowing from the faucet after a pre-flush sample is collected or before a post-flush sample is collected
In a hospital, water samples were collected from 15 domestic (potable) water outlets, three of which were Legionella-positive. The three positive samples were from ice machines that tested Legionella-positive on the last three sampling dates. The Legionella concentrations found in the ice machine samples were 8, 15, and 9 colony forming units per milliliter (CFU/mL). The WMP team should:
Investigate the three Legionella-positive ice machines, take appropriate remedial measures in those three ice machines, and consider the same or similar remedial measures (e.g., removing filters) in the facility's other ice machines.
A central domestic water point-of-entry filter typically...
Is installed in an equipment room, perhaps on the domestic water supply to the building
All but which of the following are true about the polymerase chain reaction (PCR) method of Legionella testing:
It involves growing Legionella on special media
Why would a heating hot water system supplying water to air handling units not likely be a control location?
It presents little potential for exposure to Legionella.
Testing for Legionella by the culture method, the potential for a false positive is very low because...
Legionella are grown on special media
Pipes extending past the point of flow are sometimes referred to as dead-legs. Which of the following are two key factors in determining the potential effect a dead-leg has on the rest of the domestic water system (select two)?
Length versus diameter of dead-leg Water volume in dead-leg versus volume in system
Legionella risk associated with cold water storage tanks can be minimized by:
Locating the tank away from sunlight and other heat sources
The scientific community worldwide largely agrees that the best strategy for preventing Legionnaires' disease, with current technology, is to
Manage building water systems to minimize Legionella bacteria
The scientific community worldwide largely agrees that the best strategy for preventing Legionnaires' disease, with current technology, is to:
Manage building water systems to minimize Legionella bacteria
Guidelines, standards, and regulations designed to prevent Legionnaires' disease are based primarily on which of the following strategies:
Minimizing Legionella bacteria in building water systems
A cooling tower drift eliminator helps to minimize Legionella risk by...
Minimizing the volume of water droplets discharged from the cooling into the air by the cooling tower fans
For each control measure, the Legionella water management plan should include (select 3 answers):
Monitoring to determine whether it is performed properly Control limits Corrective action to implement if the control limit is not met
Are most cases of legionnaires disease diagnosed? What type of cases are diagnoses?
Most cases of Legionnaires' disease are not diagnosed and many cases that are diagnosed result in death or long term disabilities.
Water returned to a cooling tower to be cooled by the tower would most likely enter...
Near the top, at the "hot deck"
A 7-story office building has been shut down for nine months during which the domestic water system has remained filled with water and the building unoccupied. A company plans to move into 6 of the 7 floors. Which of the following would likely be the most effective and practical Legionella preventive measure?
No more than one week prior to occupancy, disinfect the entire domestic water system - hot and cold - by maintaining free chlorine at 100 parts per million for 3 hours
With respect to domestic water systems in building, "stagnant" describes water that is...
Not flowing
The domestic (potable) water system in a hospital has had Legionella positivity averaging 45% over six sampling dates in the past 12 months. The hospital does not have a supplemental disinfection system but has hyperchlorinated the domestic water at 20 parts per million free chlorine for a 2-hour period three times in the past 9 months. The public water supply at the point of building entry (POE) has had a disinfectant residual ranging from 0 to 0.2 parts per million over the last four months, has tested Legionella-positive (Legionella pneumophila serogroup 1) in 2 of the last 3 sampling rounds, and has a temperature range of 68 to 78 degrees F (20 to 26 degrees C) for six months of the year. What steps should the hospital's WMP team consider?
Notify the water provider of the POE Legionella and disinfectant test results. Install a continuous supplemental disinfection system that is effective against Legionella and appropriate for this domestic water system.
Which four of the following are the most import factors to consider in responding to incidents or planning for shutdowns or other projects that could increase the risk of Legionnaires' disease associated with a building's domestic water system (select four)?
Occupant susceptibility to infections Regulations for secondary (i.e., supplemental) disinfection Duration of the incident or shutdown Whether the affected portion of the system can be valved off (isolated) and drained
Over the last 12 months, a total of 100 samples have been collected from a domestic (potable) water system in a hospital, 30 cold-water and 70 hot-water samples. 14 of the cold-water samples were collected from 6 patient-floor piped-in water dispensers that are treated by reverse osmosis (RO) with pre- and post-RO carbon filters. The other 16 cold-water samples were from different drinking fountains and cold-water faucets. Legionella was found in 19 of the 100 samples, 3 of which were hot-water samples from the same ICU patient room faucet, at an average of 45 colony forming units per milliliter (CFU/mL), all Legionella pneumophila serogroup 6. The other 16 positives were cold water samples from the 6 piped-in water dispensers, at an average of 64 CFU/mL, Legionella pneumophila serogroup 1. What would be reasonable steps in response to these results?
On the ICU patient room faucet, install and maintain a sub-micron filter validated to block Legionella unless and until post-corrective retests are Legionella-negative, and either replace or remediate the 6 piped-in water dispensers as well as any other dispensers of the same type.
In interpreting Legionella culture results, a colony-forming unit (CFU) can be considered as:
One living Legionella organism
Positivity should be calculated based on test results for:
Only samples collected from the domestic water (plumbing) system
The Legionella risk associated with stagnation in a bypass around a major valve on the water supply line entering a building can be minimized most effectively and practically by (select the two best options):
Opening the bypass regularly If the bypass has a valve at both ends and a drain between, flush water from the bypass to a drain before allowing water to pass through it to the building
For a given building, where is the public water main tap usually located?
Outside the building, in a pit near the street
Which acronym in this course referred to a building that has instantaneous or small tank-type water heaters for individual restrooms, apartment units, or sinks but no central domestic hot water system?
POUDHW
Domestic water crossover lines are:
Pipes that connect one system with another, typically so that either system can supply the other
To get the truest picture of the Legionella level in the water supply to the facility, collect a _________ sample of the incoming water supply from a relatively clean valve located as far _________ in the system as possible.
Post-flush; upstream
Although there are exceptions, a ________ hot water sample from a faucet is generally more likely than a ________ hot water sample from the same faucet to have Legionella, and at higher concentrations; therefore, ________ samples are generally a better indicator of potential risk.
Pre-flush; post-flush; pre-flush
A hotel has 16 decorative fountains. Of these three, what would be the best way to interpret Legionella test results for samples collected from the decorative fountains?
Presence of Legionella or Legionella concentrations per sample in a given fountain
Which type of shower valve is designed to control the volume of hot and cold water coming through it based on assumed temperatures, in part to protect the bather against sudden bursts of either hot or cold water?
Pressure balance valves
A facility tests each of its 5 cooling towers monthly during the operating season. Each cooling tower has its own basin rather than sharing a common basin with any other tower. All cooling tower samples (one per cooling tower basin per month) have tested Legionella-negative for the last 6 months but in the most recent sampling round, one cooling tower sample had 1200 colony forming units per milliliter (CFU/mL) of Legionella pneumophila serogroup 1. What would be an appropriate response to these test results?
Promptly disinfect and retest the cooling tower that tested 1200 CFU/mL.
For a water management plan aimed specifically at controlling Legionella, the objective of the water systems hazard analysis is to (select 2 answers):
Provide reasoning for whether or not the building water systems identified in the facility survey present a significant potential for Legionella growth and transmission Provide reasoning for determining locations at which Legionella control measures can and should be applied
If done properly, testing water systems for Legionella can...
Provide the most direct feedback on the effectiveness of the Legionella control program
Which is NOT an example of a point of water use (POU)?
Public water main tap
Workers at a nursing home notice that water at several faucets is discolored. After inquiring, the facility director at the nursing home finds out the city just finished repairing a water main break nearby. Which response is best if taken in the order listed?
Restrict water use in the building, flush water at the building point of entry (POE) until it is clear and a chlorine residual is detected, flush outlets in utility areas (non-resident) areas until the water is clear and a chlorine residual is detected, flush all other outlets beginning with those nearest to the POE, release water restrictions.
. Before or during an event that could promote Legionella contamination in the domestic water system of a hospital, which of the following measures would be reasonable considerations for effectively reducing Legionella risk for patients at especially high risk of contracting Legionnaires' disease (select 2 answers)?
Restricting water use for those patients On faucets and showers used by those patients, installing submicron (< 0.2 micron) filters validated for blocking Legionella bacteria
With respect to Legionella risk, which is true about decorative fountains?
Risk can be minimized by diligently treating and maintaining the fountain for Legionella, maximizing the distance between the fountain and people, and minimizing water spray
For a water sample, the sample number and sample description should be written on the...
Sample bottle and sample log (chain of custody)
The American Society of _________ Engineers has issued several standards for various types of valves that automatically compensate for temperature or pressure.
Sanitary
A decorative (ornamental) fountain in a hotel lobby includes a waterfall cascading down to a trough that has underwater lights of various colors and a sponge-like material onto which rocks are situated. Liquid chlorine is manually added to the fountain once weekly. One sample is collected from the fountain quarterly and tested for Legionella. In six of the last six quarterly samplings, Legionella pneumophila has been found in the fountain samples at concentration averaging 9 colony forming units per milliliter (CFU/mL). Of these four, which would be the best course of action?
Shut down and drain the fountain, remove the lights or replace them with a lower-heat model, remove the sponge material, thoroughly clean the fountain, incorporate a safe method of continuous disinfection, put the fountain back into service, and retest for Legionella.
The following will likely be needed for each routine sampling round
Sodium Thiosulfate
Legionella control measures should be (select 2 answers):
Specific Clearly written and formatted
All but which of the following should be recorded for a central domestic hot water system?
Sulfur reducing bacteria test results for the system
Which of the following is typically NOT a source of supply for lawn irrigation systems?
Tee off the domestic hot water return
Water restrictions" implemented at a nursing home after Legionnaires' disease was diagnosed in two residents might include which of the following?
Temporarily prohibiting the use of faucets and showers
For most facilities, developing a Legionella water management plan will involve six primary steps including all but which of the following:
Test the water systems for Legionella to determine whether or not Legionella control measures are necessary
A 25-story office building that has been fully occupied for many months is tested for Legionella for the first time. 24 samples are collected, one hot and one cold pre-flush water sample from a restroom on the even numbered floors. Each restroom has a 15-gallon water heater supplying its faucets. On the day samples were collected for Legionella testing, the free chlorine residual was 0.9 parts per million (ppm) at the point of entry (POE) to the building, 0.5 to 0.8 ppm in the cold water at the outlets sampled, and 0.2 to 0.4 ppm in the hot water at the outlets sampled. Legionella was found in one sample, a hot water sample from a restroom on the 14th floor, at 8 colony forming units per milliliter (CFU/mL). What would be the most reasonable response to these test results?
Test to confirm a free chlorine residual in the hot and cold water at the Legionella-positive outlet and then run the hot and cold water at that outlet for 5 minutes, wearing appropriate PPE. Collect a pre-flush and post-flush sample from the water heater, send it to the lab for Legionella testing, and then drain and flush the heater before returning it to service. Also confirm that the hot water temperature is within the target range.
Which of the following would provide the most direct and reliable validation of a Legionella management plan for the plumbing system in a hotel or office building:
Test water samples for legionella with proper sample methodolgy and interpretation of results
For Legionella control, what is important to consider for domestic hot water system design and equipment (select 3 answers):
The amount of surface area in piping, valves, and other components Water storage or holding time Hot water temperatures in various parts of the system
Which of the following performance measurements is likely to be least beneficial for managing Legionella risk in the domestic water system of a large building?
The difference between the average cold water outlet temperature for your building versus the national average for buildings of similar size and type
If Legionella is found in a sample collected from a decorative fountain, the appropriate action to take will depend on several factors including all but the following:
The difference in the Legionella concentrations found in pre-flush and post-flush sample
In hyperchlorinating a domestic water system of a new building, the success of the disinfection procedure will depend in large part on two factors:
The disinfectant concentration and the amount of time the disinfectant is in the system
As defined in this course, positivity is:
The percentage of samples in which Legionella is found
A limitation in responding to Legionella test results based solely on concentrations (e.g., CFU/mL) per sample is:
The quantitation (CFU/mL) reported by labs for a sample can vary significantly, even several fold.
In deciding whether to sample the same faucets and showers each round, or different ones, the following was suggested in this course: Sample __________ outlets as the previous round if the primary objective is to evaluate the effectiveness of a recent remediation procedure or a new continuous disinfection system. For normal, routine sampling done to validate a Legionella prevention program, do not re-sample outlets that tested ______________ until other outlets have been sampled.
The same; Legionella-negative
In the United States, Legionella test results for routine samples collected in the absence of Legionnaires' disease should be reported to:
The water management team and certain other employees that should know the test results for the performance of their jobs
In responding to Legionella test results for samples collected from cooling towers, primary considerations would include all but which of the following
The weather forecast, especially regarding wind direction and speed
How many legionella species are there?
There are more than 50 legionella species, less than half of which have been linked to legionnaires' disease.
For Legionella control, it's best to operate redundant water heaters and pumps so that:
They are alternated frequently (e.g., daily or weekly), to minimize stagnation
which is NOT true about swamp coolers?
They are used to chill cooling tower water
What is an appropriate purpose for sampling?
To validate the effectiveness of a Legionella control program
For Legionella culture procedures at a laboratory, water sample bottles should be filled.
To within about 2 centimeters (3/4 inch) of the top
T or F: If Legionella is found in a sample from an outlet in a room occupied by a high-risk person, appropriate protective measures should be taken even if the potable (domestic) water positivity is below your threshold.
True
T or F: If action is taken only when certain Legionella strains are detected, opportunities to prevent Legionnaires' disease could be missed in part because finding any Legionella strain indicates the water system - as presently designed, operated, and maintained - is conducive to Legionella growth.
True
T or F: Validation does not pertain to particular steps or control measures but to the overall effectiveness of the plan in accomplishing its purpose: to prevent legionellosis by reducing the hazard (Legionella bacteria).
True
True or False: As biofilm grows, fragments of it break off and flow into the water, delivering potentially high levels of Legionella to faucets, showers, and drinking fountains
True
True or False: Biofilms that form on valves and fittings and pipe walls can not only feed Legionella bacteria but also protect them from disinfectants.
True
True or False: Central domestic hot water systems refer to domestic (potable) water heaters, typically located on the lowest or highest floor of a building, that supply hot water throughout the building, usually (but not always) with recirculation.
True
True or False: Legionellosis is any illness caused by Legionella bacteria. The two most common types are Pontiac fever and Legionnaire's disease.
True
True or False: The purpose of flow diagrams is to simply show each step where water is received, processed, or used — where it comes from and where it flows to. Flow diagrams are not plumbing drawings. They do not need to be to scale or show the piping layout. Unnecessary details should be omitted.
True
True or False: The water systems inventory and flow diagrams should include points and processing steps for all water systems, not just the ones deemed to present a Legionella risk.
True
True or false: Legionella expertise is not needed to survey a facility's water systems and construct flow diagrams for a Legionella water management plan.
True
When applying supplemental disinfection in a domestic (potable) water system, disinfection byproducts are a concern with all but which of the following:
Ultraviolet light
Which of the following, if applied in a domestic (potable) water system near the point of building entry (POE), is least likely to provide a disinfectant residual throughout the system?
Ultraviolet light
For cooling towers serving new buildings, a water treatment program effective for Legionella control should be implemented:
Upon startup of the cooling tower, even if the building is not yet occupied
When opening a major domestic water system valve (e.g., a valve on the incoming water supply to a building), open it...
Very slowly, in small increments, in part to minimize jolt to the system
Which of the following is the only document that can be viewed while taking the ASSE 12080 exam
WICRA
Record information for a kitchen or laundry central hot water system if:
Water heaters located in a basement equipment room supply hot water for a kitchen or laundry but not to faucets in other parts of the building
Record information for a central domestic hot water system (DHW) if:
Water heaters located in a basement equipment room supply hot water to faucets and showers throughout the building, with recirculation back to the heaters.
If you take pictures of a central domestic hot water systems for a Legionella water management plan, include shots of the following (select 3 answers):
Water heaters, mixing valve, hot water return pumps
For cooling tower basin samples, adding Sodium Thiosulfate with a dropper bottle instead of using bottles pre-treated with Sodium Thiosulfate tablets...
Will help to avoid dumping the Sodium Thiosulfate
To get the clearest picture of what a user will be exposed to, collect a water sample from a faucet...
Without removing the aerator or even touching the tip of the faucet beforehand
If equipment is installed to inject a chemical disinfectant into the domestic hot and cold water in a building for Legionella control, water first drawn from faucets used weekly is more likely than not to have ______ level of that disinfectant than water first drawn from faucets used daily.
a lower
A hotel resort has 3 buildings on the same property. The 3 buildings are supplied from the same city water main at the street. Over the last 12 months, the domestic (potable) water systems in the 3 buildings, along with the cooling towers, have been tested for Legionella 3 times. All the cooling tower samples have been Legionella-negative. A total of 90 samples from the domestic water systems have been tested for Legionella: 10 samples (3 cold-water and 7 hot-water) per building per sampling round. One incoming water supply sample was also tested each sampling round, from a different building each time, so each of the building feeds has been tested once; Legionella was found in none of the incoming water supply samples. For all the samples over the last 12 months, Legionella positivity and average concentrations for the three domestic water systems were as follows: Tower A: 3% (1/30), 5 colony forming units per milliliter (CFU/mL). Tower B: 7% (2/30), 4 CFU/mL. Tower C: 53% (16/30), 27 CFU/mL. 11 of the Legionella-positives in Tower C were in the hot water and 5 in the cold water. All Legionella-positive samples had Legionella pneumophila serogroup 6. To investigate Tower C's higher Legionella positivity and average concentrations, which of the following should the WMP team review?
all of the above
A plan for flushing the domestic (potable) water system in a building after an extended shutdown will depend in part on which of the following?
all of the above
What should be considered in deciding on a domestic (potable) water supplemental disinfection technology aimed to control Legionella and intended for continuous, long-term use?
all of the above
Which of the following should be considered when determining Legionella control measures to include in a water management plan?
all of the above
In this course, collecting both pre-flush and post-flush samples from drinking fountains sampled was recommended since many drinking fountains ________.
are rarely used
When checking water temperatures in an intensive care room occupied by a hospital patient, run the water at...
at low flow to minimize risk of transmission
Legionnaires' disease is caused by Legionella...
bacteria
Sample descriptions should include all but which of the following:
calcium hardness level
Chlorite is a disinfection byproduct of ______________.
chlorite
If a hot water tank's drain line tees off the cold water inlet, be sure to ________ the valve on the cold water supply to the tank before collecting the sample to ensure the sample is collected from the tank and not from the cold water supply.
close
Turbidity is a measure of water ___________________.
cloudiness
Compared to portions of a domestic hot water system (DHWS) that are used several times a day, segments of the DHWS that are stagnant for a day or longer will likely be...
cooler
In the United States, the CDC recommends which of the following as the primary method for Legionella testing?
culture
The National Primary Drinking Water Regulations state that long term exposure to lead in drinking water at levels above the MCL could cause __________________________ in children.
delays in physical or mental development; learning deficits
The minimum number of Legionella organisms a laboratory can detect using its technology and methods is referred to as:
detection limits
Checking the city water ___________ level at the same tap from which the incoming water supply sample is collected can provide good information for the Legionella prevention program.
disinfectant
The water systems survey for a Legionella water management plan should include which of the following?
domestic (potable) hot water systems
. To sample water near the bottom of a cooling tower basin, dip the bottle into the water top _______ and then rotate it _______, avoiding excessive sediment.
down, upward
A master thermostatic mixing valve is typically installed just ______________ of a water heater to ____________the temperature of water sent to outlets.
downstream, reduce
The quality and proficiency of your laboratory can be validated by having a second laboratory - one known for quality and proficiency in Legionella testing - test _________ water samples.
duplicate
Legionella control measures should be (select 3 answers):
evidence based, current, doable
According to the CDC Toolkit titled "Developing a Water Management Program to Reduce Legionella Growth & Spread in Buildings," the purpose of the toolkit is to help:
facility personnel develop and implement a water management program to reduce their building's risk for growing and spreading Legionella
T or F: . In a hospital with patients at high risk of contracting Legionnaires disease and little to no disinfectant residual in the water supply to the facility, it is especially important to implement a thorough and vigorous flushing program, ensuring that every outlet is flushed at the highest flow for at least 5 minutes daily.
false
T or F: A hotel with high domestic water Legionella positivity and concentrations installs a supplemental disinfection system. Assuming the supplemental disinfection system was properly selected, designed, and installed, it should be able to control Legionella with little or no maintenance or inspection. Moreover, it should allow the facility to eliminate many of the domestic water control measures in its WMP.
false
T or F: The water management team must include all employees and vendors who will have any part of implementing the plan, which for large facilities may require more than 30 team members.
false
The water management team must include all employees and vendors who will have any part of implementing the plan, which for large facilities may require more than 30 team members.
false
t of f: Pneumophila is the only Legionella species that has been linked to Legionnaires' disease in the United States.
false
t or f: . Cooling towers present little or no Legionella risk if they are located 8 meters (25 feet) from windows, outdoor air intakes, and sidewalks
false
t or f: A negative test for coliform or heterotrophic bacteria (HPC) confirms the absence of Legionella and other pathogens.
false
t or f: An 8-story apartment building has a small water heater in each apartment, rather than a central domestic hot water system. If about half of the residents complain about discolored hot and cold water coming out of faucets and showers following a city water main break, flushing procedures would not need to be considered since the building is served by "point-of-use" rather than central water heaters.
false
t or f: If Legionella sampling and testing is performed properly, the test results can provide sufficient justification for eliminating a Legionella control program entirely.
false
t or f: If a domestic water system is disinfected upon filling the system by maintaining chlorine at 50 parts per million (ppm) for 24 hours, the owner can be confident that the domestic water is Legionella-safe for the building occupants, even if the building is not occupied until 18 months after the disinfection procedure was performed.
false
t or f: It is very uncommon to find Legionella in samples from bottled water dispensers since they are supplied with purified water.
false
t or f: The Legionella positivity for all the samples collected from the hot and cold potable water system should be the primary consideration in determining whether to disinfect an ice machine that tested positive for Legionella.
false
t or f: Which of the following should be considered when determining Legionella control measures to include in a water management plan?
false
true or false: Automated booster pumps are typically used to pump water to lower floors when city water pressure is too high.
false
true or false: Because Legionella culture is a very simple process and the proficiency is pretty much the same among laboratories, it makes sense to shop for Legionella analysis services based on price.
false
true or false: Because domestic water heaters used for large building centralized systems have such sophisticated technology, facility personnel can be confident that the peak hot water temperature at all faucets throughout the building will be within 1 degree C (2 degrees F) of the water heater temperature setting.
false
true or false: If a building has two domestic water heaters that normally operate 24/7 to supply hot water to all faucets in the building, and one of the water heaters will be taken out of service for two weeks for repairs, Legionella could be released from biofilms into the hot water system if the project is not managed properly, but only if the building has 10 or more stories. The situation would not present a significant risk for buildings with fewer than 10 stories.
false
Collect cooling tower samples from a part of the basin that is _________ the fresh water make-up discharge into the basin.
far from
Domestic hot water systems commonly supply which of the following?
faucets
. Assuming a property had all of the following types of water systems or devices, for which one would routine sampling likely provide the least benefit for the purpose of water management decisions?
fire protection system
Legionella control measures should be implemented in building water systems and devices that can harbor and transmit Legionella including all but which of the following:
fire protection systems
Many cases of Legionnaires' disease have been associated with Legionella bacteria transmitted from all but which of the following types of water systems or devices:
fire protection systems
According to the "Infection Control Risk Groups" outlined in the ASSE 12000 WICRA Forms document, Neuro Intensive Care Units are classified as:
high risk
Chlorine's disinfection effectiveness will be _________ in water at pH 7.4 than in water at pH 8.2?
higher
For the purpose of developing a water management plan, the objectives of a facility survey are to __________ the water systems and key components of the water systems.
identify
To collect a hot water pre-flush sample from a faucet, fill the sample bottle __________ after opening the hot valve.
immediately
The verification person must review documentation to verify
implementation of the plan
. According to the CDC Toolkit titled "Developing a Water Management Program to Reduce Legionella Growth & Spread in Buildings," reported cases of Legionnaires' disease in the United States ________________________________ from 2000 to 2015:
increase by nearly 4.5 times
What effect does stagnation likely have on the amount of time water remains in building piping?
increases the time
Studies have shown that a legionella infection can be contracted by
inhaling or aspirating into the lungs legionella bacteria transmitted from water
Assuming a property had all of the following types of water systems or devices, for which one would routine sampling likely provide the least benefit for the purpose of water management decisions?
irrigation system
Water softening equipment is typically NOT installed on lines supplying which of the following:
lawn irrigation systems
States that regulate supplemental disinfection of domestic (potable) water systems typically require reporting of test results for all but which of the following per the Safe Drinking Water Act?
legionella
If the city water supply to a building is treated with chlorine, segments of the domestic cold water system (DCWS) that are stagnant for two days are more likely than not to have _______ free chlorine levels than segments of DCWS used several times a day.
lower
Compared to Legionella, the optimum temperature range for multiplication is ____________ for Pseudomonas aeruginosa and slightly ____________ for Mycobacteria avium (4.009).
lower, higher
Water lost from a cooling tower by evaporation is replenished by...
makeup water
Per the US EPA Safe Drinking Water Act (SDWA), National Primary Drinking Water Regulations, "MCL" stands for:
maximum contaminant level
Which of the following systems does not need to be surveyed for a Legionella water management plan?
medical gas systems
With respect to Legionella control, avoiding unnecessary piping, valves, fittings, and fixtures in domestic water systems is beneficial because it:
minimizes surface area
In simple terms, the detection limit is the _________ number of Legionella organisms the lab can detect by its methods.
minimum
Each legionella control measure must be
monitored to determine whether it is performed to a designated standard (control limit)
All other factors the same, Legionella bacteria embedded in biofilm are ______ resistant than free-floating Legionella bacteria to chemical disinfectants and high temperatures.
more
Systems or devices that can harbor and transmit Legionella and have been implicated in cases of Legionnaires' disease include all but which of the following:
natural gas piping
. Samples should reach the laboratory no later than ______ after collection.
one day
Sampling should be scheduled on a day that allows the samples to arrive at the laboratory no more than ______ after collection.
one day
Sample descriptions should ideally include all but which of the following:
outdoor wind speed
Per the memorandum referencing "QSO-17-30-Hospitals/CAHs/NHs," the US Department of Health & Human Services, Centers for Medicare and Medicaid Services (CMS), requires that all but which of the following facility types implement a water management program to reduce the risk of Legionella and other opportunistic pathogens:
outpatient clinics
A ___________ cold water sample is more likely than a ________ cold water sample from a faucet to minimize the effect of hot water on the test results.
post flush, pre flush
For the purpose of a water management program for building water systems, "domestic water" has basically the same meaning as...
potable water
OSHA recommends wearing a ____________ while collected samples from cooling towers.
respirator
Which is typically NOT a water processing step?
showering
Per the CDC (US), a sample collected for Legionella testing from a cooling tower that is a possible source in a Legionnaires' disease outbreak investigation should be collected after the cooling tower has been _______________ and before it has been ________________.
shut down; hyperchlorinated or drained
Comparing pre-flush and post-flush results can be useful for indicating the extent to which _________ is affecting detectable Legionella at an outlet.
stagnation
For fire protection systems (FIRE), irrigation systems (IRR), and heating hot water systems (HHW), note the type of backflow prevention, if any, on the line:
the line from the domestic (potable) water system supplying the FIRE, IRR, or HHW, if applicable
A backflow preventer (BFP) upstream or just downstream of the point where a city water supply enters a building typically protects what?
the public water supply
. One water management plan can cover several buildings if all are located ________________, served by the same water supply, and _________________.
the same campus, managed by the same personnel
. Which type of shower valve limits the maximum water delivery temperature based on temperature sensors, providing more reliable temperature control?
thermostatic valves
Cooling towers are commonly used for which of the following?
to cool water in chillers
Checking domestic cold water temperatures can be beneficial for a Legionella prevention program... (select 2 answers):
to know the temperature of the water supply at various times of the year to detect heat gain by comparing the water temperature at the point of building entry with temperatures at faucets
Heterotrophic Plate Count (HPC) and total cell count (TCC) are tests for _________ bacteria counts rather than tests for a particular _____________.
total, pathogen
T OR F: Even though Legionella bacteria typically grows better in hot than cold plumbing systems, in most cases cold water as well as hot water should be collected when sampling plumbing systems.
true
T or F: A Legionella hazard analysis notes which water systems identified in the facility survey present a significant potential for Legionella growth and transmission, and locations at which Legionella control measures can and should be applied. The hazard analysis does not typically vary from one system to another of the same type.
true
True or False: Control measures are the most important part of a Legionella water management plan because they are what minimize the risk of Legionnaires' disease.
true
t or f: A backflow preventer (BFP) is designed to ensure that, at the point where it is installed, water flows through it in only one direction, preventing water downstream of the BFP from flowing "backwards" past the BFP.
true
t or f: At faucets known to get very little use, it may be worth the extra cost to collect both a pre- and post-flush hot water sample instead of just one or the other since the effect of prolonged stagnation is difficult to predict.
true
t or f: Drift eliminators are important for minimizing Legionella risk associated with cooling towers because they reduce the emitting of water droplets into the air.
true
t or f: For potable (domestic) water systems, opportunities to prevent Legionnaires' disease could be missed if Legionella test results are interpreted based only on the concentration per sample, positivity, or strains found, rather than all three along with other applicable factors.
true
t or f: Legionnaires' disease is almost entirely environmental. It is not transmitted from person to person.
true
t or f: On back-up (secondary) water supply feeds to a building, a valve should be installed near the building entry - and a drain line just upstream of that valve - to allow the line to be thoroughly flushed to a drain prior to opening a valve that releases water to points of use within the building.
true
t or f: Per the CDC (US), a full investigation should be conducted if only 1 or more cases of Legionnaires' Disease have been identified at a correctional facility or other facility where people cannot leave the premises
true
t or f: Proper balancing of a domestic hot water recirculation system can be important for proper water temperature and flow.
true
t or f: Properly managing temporary domestic water system or building area shutdowns is crucial for minimizing the risk of Legionnaires' disease.
true
t or f: Stagnation in redundant water heaters, pumps, and piping can be minimized by leaving both open and operating if doing so is feasible for the system design and operation.
true
t or f: The criteria that must be considered for requiring sampling in a law are not exactly the same as the criteria for justifying sampling for a particular building.
true
t or f: The primary function of an expansion tank is to absorb air or pressure from the plumbing system on which it is installed.
true
t or f: To avoid inadvertently dumping Sodium Thiosulfate when collecting samples from cooling tower basins, it may work better to collect the sample into an untreated bottle and then add Sodium Thiosulfate with a dropper bottle.
true
t or f: Using standardized sample description abbreviations on the sample log allows for maximum information for each sample on the laboratory's report of the Legionella test results.
true
true or false: . Temperature variation within a water heater or hot water storage tank can be minimized by insulating the outside of the tank or installing a pump to circulate the water within the vessel.
true
true or false: A Legionella water management plan should be regularly updated based on the latest scientific findings, new technologies, and Legionella test results.
true
true or false: Cold water storage tanks should ideally be located away from sources of heat.
true
true or false: Some shower valves have a combination of thermostatic and pressure balance features.
true
true or false: Temperature problems can be caused by infiltration of hot water into the cold system, or cold into the hot, at cross connections such as shower mixing valves, bedpan washers, or kitchen sink sprayers.
true
true or false: With respect to Legionella control, three factors to consider in the design and selection of water heaters and mixing valves are stagnation, temperature, and surface area.
true
According to ASHRAE Standard 188, water management programs (WMPs) must have __________ to show "initial and ongoing confirmation that the program, when implemented as designed, controls hazardous conditions throughout the building water systems."
validation
If you must install an expansion tank, how should it be mounted?
vertically
A Z-plate strainer is typically used to remove large particles from water flowing into a...
water meter
Which of these types of samples are appropriate for validating the effectiveness of a Legionella water management plan?
water samples
. Testing water samples total bacteria (heterotrophic plate count) is an acceptable Legionella validation method for:
whirlpool spas
Which type of strainer typically has a drain valve located on a stem extending at an angle below the strainer?
y-type strainer
Per the US EPA Safe Drinking Water Act (SDWA), National Primary Drinking Water Regulations, the MCLG for Legionella is _____ . The MCL for Legionella is a _________________ based on the EPA's belief that if Giardia and viruses are removed or inactivated, Legionella will be, too.
zero; treatment technique
