Legionellosis — also known as Legionnaires’ disease — is a preventable disease as it relates to building water systems. Though it can be considered an inconvenience by some to have to monitor and control the water temperature or water treatment chemical levels, doing so can assure a safe water system free of Legionella bacteria and other micro-organisms.
Legionella bacteria in building water systems has been well-documented and studied. We know how the bacteria grows, how it is transmitted, and how it affects people with suppressed immune systems.
We have at our disposal, information about where and under what conditions it will grow; how it amplifies or grows rapidly under certain temperatures and nutrient conditions; how it is transmitted to humans in aerosolized water droplets containing the bacteria; and how and when the bacteria is inhaled into the lungs, it can grow if the host person has a weakened immune system.
It is also accepted that most of us will all live long enough to reach an age when our immune system will naturally be weakened. So, to say that control measures should only apply to certain types of buildings with people that are at risk is a not addressing the larger picture. The risk is real for anyone with a suppressed immune system in any building where bacteria can grow and multiply in the building water system and be aerosolized.
I have always said that bacteria do not know or care what type of building they are in, or what floor they are on, or if they are in a pipe or a tank. If the conditions for bacteria growth are present, the bacteria will grow. Our goal should be to design a system to minimize conditions that are ideal for growth.
And even with all this knowledge, there is still a need to educate people responsible for the building water systems about the risks associated with Legionella bacteria; teach design professionals how to design systems; and teach building owners/operators and maintenance personnel how to operate and maintain systems to minimize the risk of Legionella bacteria.
We know how to manage building water systems to prevent Legionella bacteria growth, yet we do not mandate education and training or certification for people responsible for design, inspection, operation and maintenance of these systems.
For many years, there have been a variety of resources available on Legionnaires’ disease, including, but not limited to:
These, and many other international documents, have provided guidance on how to control the growth of Legionella bacteria in building water systems. As a member of the ASHRAE 188 and Guideline 12 committees, I have been intimately involved in helping develop the new ASHRAE 188 standard, ASHRAE Standard 188 - Legionellosis: Control of Risk Associated with Building Water Systems, and the soon to be published ASHRAE Guideline 12, which is in the final stages. The 188 standard covers how to manage risks associated with building water systems; how to establish a water management team; and how to establish a water management program for control of various risk factors associated with Legionella bacteria growth.
ASHRAE 188-2015 includes the development of a comprehensive program that involves the following steps:
Code changes needed
Three years ago, I proposed a code change to adopt the ASHRAE 188 standard in the Plumbing Code for the design of building water systems. That code change was met with resistance from a host of lobbyists at the code hearings who stated the standard would cost them money to implement. They felt it would have been too much of an inconvenience with respect to their responsibilities and costs. Building owners historically have opposed additional safety regulations that add costs.
Building owners in the past opposed smoke detectors, fire sprinklers, and carbon monoxide detectors to name a few. I do not expect them to support this new safety standard, but it is just a matter of time before a water management plan will be required for all commercial and public buildings. If they are required to comply and they do not comply, it will also expose them to liability if people get sick or die from legionellosis and it could cost even more money in litigation defense and punitive damage costs.
Legionella training and certification needed
Over a decade ago, I met with another Legionella prevention expert and we discussed the need to develop an education and certification program on Legionnaires’ disease that would cover all of the diverse areas related to knowledge of risks related to Legionella bacteria growth. We discussed the issue at length over many months and we were sure we could produce a training and certification program with a pool of exam questions so that facility owners could have a certification program that demonstrated a minimum level of knowledge in all areas related to Legionnaires’ disease prevention.
The purpose would be to allow building owners/operators to be confident that, the person or persons serving on their building water management team or a consultant providing consulting services for control of Legionella, would have a credential that shows they truly understand the issues. This training was intended to have two levels: A one-day awareness seminar for building water management committee team members, and a three-day technical/operations level certification for any professionals dealing with identification of hazards and application or chemical of physical control limits to control bacteria growth without damaging the piping system or presenting a scalding hazard.
We approached several industry associations and organizations to see if they would sponsor an education and certification program. We saw this as a deadly-serious issue, and many people with limited experience have popped up seemingly overnight selling consulting services as an expert, and it was obvious they could use some training. A few associations we approached turned down the opportunity to develop a training and certification program and expressed concerns over liability if they certified someone and there was an outbreak.
ASSE has already discussed with ANSI about developing a personnel qualification program standard and it has said it'd be willing to work with other organizations to develop a standard that will benefit the entire industry. There is a real need for training and certification so that building owners can be assured that members of their water management and safety teams are properly trained with at least an awareness level certification for water management team members and consultants or water treatment professionals offering services to building owners should have a technician/operations level certification.
Ron George - Proposed training outline
The Legionella bacteria awareness and Technician/Operations certification training program was to cover:
1. The history of Legionnaires’ disease,
2. Biology – Legionella the bacteria,
3. Chemistry –
a. A discussion of different chemicals used to control Legionella bacteria growth
b. Dissipation rates for each chemical
c. Effective levels for continuous water treatment
d. Effective levels for emergency disinfection of the piping system
e. Levels at which the chemicals can be corrosive to the piping system
4. Environment conditions conducive to legionella bacteria growth
5. Plumbing engineering and maintenance
6. HVAC engineering and maintenance
7. Fluid dynamics
8. Heat transfer,
9. Plumbing/piping specialties (Temperature/pressure gauges, control valves, etc.)
10. The Legionella bacteria gestation period from exposure to symptoms
11. pH discussion and water hardness vs neutral vs acidic discussion
12. Biofilm discussion
13. Water temperatures conducive to Legionella bacteria growth
14. Water temperatures that will cause scald injuries. (Moritz & Henriques) Time vs Temperature charts.
15. Pipe materials that can contribute to biofilm formation
16. How aging/stagnant water contributes to growth (dissipation of water treatment chemicals)
17. The velocity conditions that can lead to release of large amounts of bacteria into the piping system (surges in flow, fire flows, water hammer, construction activity, etc.)
18. Piping configurations that promote growth (dead legs, seldom used fixtures, etc.)
19. Valves, accessories and where temperature gauges and water sampling ports should be located to allow proper monitoring of the building water systems in order to verify or validate system compliance with the water safety or water management programs control limits
20. How to conduct a hazard assessment of the potential risks associated with a building water system
21. How to draw building water system flow diagrams
22. How each piece of equipment or component works and a basic understanding of how systems could be designed and maintained to control or minimize bacteria growth and aerosolization
It will take collaboration of several experts to come up with a comprehensive training and certification program.
Legionella deaths in the U.S.
In the U.S., Legionnaires’ disease is relatively common. It is estimated that more than 25,000 cases of Legionnaires’ disease are diagnosed each year. Many other cases are misdiagnosed as simply pneumonia, so the actual number of cases is likely much higher. Out of the confirmed cases, Legionnaires’ disease causes more than 4,000 deaths each year. Most of these deaths occur in the summer or fall when the municipal water temperatures are warmer and can support Legionella bacteria growth and amplification in both the municipal system and the building water distribution piping.
Four thousand people die every year from Legionnaires’ disease. To put this into perspective, it is equivalent to about 29 average sized commercial airplanes crashing every year or a commercial airplane crashing every two weeks with no survivors. (The average commercial airliner has about 137 seats) If the airline industry had the same death rate as the Legionnaires’ disease death rate, there is a pretty good chance the Federal Aviation Industry would ground all commercial airplanes immediately and launch an investigation into the cause of the crashes along with congressional hearings and massive media attention. The result would likely be new safety rules put into place to prevent the planes from crashing in the future.
I am sure if you bought a ticket for a trip somewhere on a commercial airliner you would want the pilot to be properly trained and certified to fly the plane you were on. Yet, with Legionella bacteria, we do not require any special training or certification to design, inspect, install, operate or maintain a building water system. We know about the disease and the control measures that should be applied in design and installation, and now we need to mandate these control measures in building water systems.
Healthcare facilities and Legionnaires’ disease
The significant amount of Legionnaires’ disease cases occurs in the healthcare setting, because hospitals and nursing homes are full of people with suppressed or weakened immune systems and hospitals are often large complex buildings with lots of fixtures that don’t get used as much as they should. So, why are we not taking the Legionella bacteria issue and the thousands of deaths associated with Legionnaires’ disease seriously? It has been easy for a hospital that does not look for Legionella bacteria to not find it. They can explain Legionnaires’ disease related deaths as a simple case of pneumonia on medical reports and ignore the real issue. With more awareness there are more cases being reported that were previously written off as pneumonia related deaths. There are many interest groups that are involved in this issue and some of them want to correct it while some want to downplay it because it is an inconvenient disease that leads to expensive remediation efforts and sometimes expensive litigation costs. Legionnaires’ disease is very preventable if we commit to prevention.
ASSE motto: “Prevention Rather Than Cure”
The American Society of Sanitary Engineering (ASSE) has a motto: “Prevention Rather Than Cure.” The motto was developed many years ago as ASSE members, which included inspectors, engineers, contractors and others in the plumbing industry, who were striving to provide safe plumbing for buildings rather than deal with the diseases and illnesses caused by poor, or lack of, plumbing and sanitary facilities. Providing safe plumbing systems is still important for disease prevention. New challenges to providing safe plumbing systems are presenting themselves each day.
Water conservation efforts increase bacteria levels
Recently, we have had to deal with challenges related to reduced water flows in the form of water conservation, which contributes to aging water and bacteria growth. One of the unintended consequences of the efforts to save water is chlorine or water treatment chemical dissipation in water that now takes five to six times longer to get from the water treatment plant to the end user. As strange as it may sound, saving water is making our plumbing systems unsafe. Since the 1992 Energy Policy Act, water flow rates overall are about 20 percent or less than the pre-1992 flow rates. As water flows are continually reduced, in a sort of water conservation limbo, the flow velocities in water mains, which are sized for fire flows, are so low it is allowing the water to age in the piping systems.
Flushing water mains to maintain chlorine levels
Aging water is a term used by many water utilities to address water that has been held in the piping system so long that the water treatment chemicals have dissipated down to levels that are no longer effective at killing bacteria and other micro-organisms in the water main. As a former member of a water and sewer board, we would have water quality issues at the ends of our distribution system. We would have water department employees go to hydrants at the ends of the system and open fire hydrants and flush water from them at a flow rate in excess of 2,000 gallons per minute for 15 to 30 minutes until the chlorine test strips showed adequate chlorine levels. That is 30,000 to 60,000 gallons of water dumped at each hydrant. This flushing operation performed twice monthly at dozens of hydrants is more than a 1,000,000-gallons per month flushed away during the summer months in our small community, which just about negated the water savings mandated in the plumbing codes for low-flow fixtures. Many other water utility officials I have talked to said they are doing similar flushing operations. I thought if the fixtures all flowed a slightly higher flow rate, we would not need to dump water from fire hydrants at the end of every water main in the system in order to bring the chlorine levels up. The lack of adequate water treatment chemicals will allow a biofilm to develop on the walls of a water main when bacteria is present in the source water. The bacteria will grow and thrive in the biofilm until there is a high-velocity flow event that dislodges or sloughs-off a large amount of this biofilm. Events that can dislodge biofilm are include, surge flows, fire flows, water hammer, construction activities, and water main breaks to name a few.
If a building owner is not monitoring the incoming water supply quality, bacteria can be introduced into a building water distribution system in doses so high the normal water treatment levels cannot control bacteria growth. If there is no secondary water treatment, or if the temperatures are kept in the ideal bacteria growth temperature range, it could lead to a bloom of bacteria to very high levels and it will significantly increase the chances of transmitting bacteria to susceptible persons. If building service filters are used, they should be duplexed to allow water to flow into the building while cleaning, backwashing or replacing the media in the other filter. Point-of-use filters with multiple cartridges down to a 0.01-micron filter is recommended to filter out any Legionella bacteria when there have been emergency issues requiring water filters.
Emergency disinfection procedures
Each year, there are many Legionnaires’ disease cases and the normal response to an outbreak is to provide emergency disinfection of the plumbing system. In some of the investigations I have performed, I have discovered the building maintenance personnel are not always properly trained for conducting proper thermal or chemical disinfection techniques. In some cases, the water heater is not capable of heating the water up to a thermal disinfecting temperature and in other cases water was not flowed from every fixture or long enough from every fixture to properly disinfect the piping system. In other cases where chemical disinfection is performed, I have found the chemical disinfection levels were so high, it was destroying the piping system. Chlorine, chlorine dioxide, sodium Hypochlorite and other water treatment chemicals can be very corrosive to the plumbing system when used for hyperchlorination when used for continuous disinfection at elevated levels.
Recent Legionnaires’ disease outbreaks
Quincy, Illinois, — Veterans Administration facility in 2015, 2016, 2017
A Veterans Administration facility in Quincy, Illinois has had three consecutive years of problems in their facility. Thirteen people have died and many more have become ill over a three-year time period. Politicians and government officials have struggled with explanations for what is causing the problem. It is an easy fix if you know what you are doing. Albert Einstein once said, “The definition of insanity is doing the same thing over and over again but expecting different results.” The Veterans Administration needs to reevaluate its VA directive 1061 that covers how it controls Legionella bacteria hazards in VA facilities. The 1061 directive was quickly put together following a Legionnaires’ disease outbreak that killed five people and sickened many more at the Pittsburgh, Pennsylvania Veterans Hospital and it was developed at a time when the spotlight was shining on many other problems with the VA medical facilities that required a quick response. The repeated outbreaks at the Illinois facility indicates to me, that if the VA folks are following the VA 1061 directive, it is not working. The VA 1061 directive allows long dead legs up to 25 feet and it allows hot water storage temperatures very close to the bacteria growth temperatures, which will more likely than not allow the system to have Legionella growth temperatures in the circulated distribution system. My review of the facility shows it is at the edge of town. Yes, that means at the end of the water main and likely there is minimal water treatment chemical residuals that were coming into the facility from the Quincy, Illinois water supply, which gets its water from a river, which will be a high bacteria source. Legionnaires’ disease is preventable! So, there is obviously room for improvement in the VA 1061 directive or they should consider adopting the ASHRAE 188 standard.
Many of the veterans who died were in the nursing facility for the entire exposure time it takes to come down with Legionnaires’ disease. In the summer of 2015 many residents were sickened, and 12 residents died. Many of the residents had not left the facility, which indicates they got the disease from a water source at the facility and not out in the community. Improvements came after a 2015 CDC report said the outbreak “occurred in a setting with no formal water management plan, no Legionella specific prevention plan, limited Legionella testing, and limited monitoring of water treatment parameters.” The facility spent millions of dollars on water treatment systems and in subsequent years, there have been more outbreaks, but they were less widespread. People getting sick without dying is like crash landing a plane and everyone survives. Some people will be happy there are survivors, but others would ask, “why are the planes still crashing?”
The continual outbreaks over three years indicates the preventative measures were not adequate and were not being properly implemented when the disease came back in 2016 where it sickened five more people and then it came back again in 2017, sickening three and contributing to the death of another veteran.
Other recent Legionnaires’ disease outbreaks include: