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Medicine

Legionnaires' Bacteria Reemerges In Previously Disinfected Cooling Towers 118

schwit1 writes with the New York Times' unsettling report that 15 water-cooling towers in the Bronx that this week tested positive for Legionnaires' disease had been disinfected less than two months ago. From the NYT: After an outbreak of the disease killed 12 people in July and August in the South Bronx, the city required every building with cooling towers, a common source of the Legionella bacteria that cause the disease, to be cleaned within two weeks. ... [The] city found this week that bacteria had regrown in at least 15 towers that had been cleaned recently in the Morris Park section of the Bronx. The testing occurred after a fresh outbreak in that area that has killed one person and sickened at least 12, and spurred an order from health officials for the towers to be disinfected again.
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Legionnaires' Bacteria Reemerges In Previously Disinfected Cooling Towers

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  • So any disinfection must be followed with a permanent antisepsis program, say a little copper in the water?

    • Aren't there numerous strategies for preventing this, including adding more chlorine to cooling water in-house?

      • But, we forgot about lazy, cheap people.
        Yes, chlorine or hydrogen peroxidation would solve this, but require some method to maintain the antiseptic aspect.
        Copper sheeting might shed enough Cu ions for many years, but would ne replacing as it eroded away.

        Newly installed cooling towers deal with this, as this search shows.
        https://www.google.ca/search?q... [google.ca]

        • Newly installed cooling towers deal with this, as this search shows.

          That search clearly isn't showing me what it's showing you, because all I'm getting is a bunch of descriptions of the problem. Pathetically, even the CDC page only describes the problem [cdc.gov], even though the CDC has renamed itself the centers for disease control and prevention. If you actually drill down a couple of links you get to their page on prevention [cdc.gov]... which only covers hot tubs! Your tax dollars at work! No, wait. They're on vacation.

        • by Bengie ( 1121981 )
          I've heard of O3 and UV water treatment. I hear they are very good at killing pretty much living thing.
          • by aurizon ( 122550 )

            yes, ozone and UV = general cellular toxicants.
            Hydrogen peroxide safer but more $$

            • Hmmm, they're all (in high enough concentrations) pretty effective biocides, and given their propensity to oxidise the living daylights out of anything, they'd probably be biocides against silicon-based life forms, if such a thing existed.

              But whether H2O2 is more expensive ... a bit thornier a question. Yes, it's a continuing cost for chemicals. But there is a continuing cost with UV for both the electricity to run the lamps, the plumbing and pumps to force the water past the lamps ; the lamps themselves h

        • that's actually the problem with most technology

          nuclear for example

          i haven't a single doubt that we have the technological means to maintain nuclear plants forever without a single accident

          but what we don't have is the social and political means to do that

          money is always being cut, indefinitely, and the people making that decision are not exactly technically proficient. the incentive to cut costs form the general public and bosses who want to trumpet cost cutting trumps all other concerns, because other concerns, no matter how vital, are simply not understood. combine that with a technical person that responds with anger and arrogance at the idea of vital safety mechanisms being underfunded, the manager will simply disregard him or her as a person with a personality problem, and then disasters happen

          people who champion nuclear, especially on a website like this, understand the technology well, and are correct when they announce we never have to have a nuclear accident ever again due to technological issues

          but they don't consider the political and social aspects of our species that means vital funding of safety mechanisms and maintenance of absolutely crucial technology *will* be broken. it's simply a matter of when, not if

          and then people who champion nuclear get angry at people like me, and accuse us of not understanding the technology. oh we understand the technology is wonderful. but it is you who doesn't understand humanity

          the imperative on cutting costs and doing as little effort as possible is always trumping all other concerns. always. and people like this wind up being the managers, not the underlings. they can't be fired, they do the firing

          incompetence is a force that destroys everything. sober up and accept that

          • by aurizon ( 122550 )

            Well, the greatest power for getting rid of lazy incompetent people is the inability of management to keep its power to manage, = unions.

          • by lgw ( 121541 ) on Sunday October 04, 2015 @03:42PM (#50657459) Journal

            A useful concept here is "Social Tech Level". We have the tech for safe nuclear plants, but we may lack the social tech. Much as, say, Panama had the tech to maintain the canal for many years before it had the social tech. You need both the technical know-how, and enough resources left over after corruption to actually fund it.

            For all our competing systems of government, we don't seem to have made much progress in "social tech level" in the past 100 years. If anything, the basic systems of administration haven't improved in this regard, but the skill in corrupting them has gone way up (whether corporate corruption or good old fashioned Old Boys Network corruption).

            Whether Socialist, Communist, or Capitalist, each in it's own way we can't seem to get the job done, so I think it's something quite distinct from economic system. I think there's just a problem of administration, transparency, and reporting results to solve. E.g., I don't care if the road gets built by the mayor's nephew, I care whether it's build on-time and to-spec, and how much it cost - if it merely cost more than it should, that's the least-bad problem. Cost-cutting is a good thing, but it takes a back seat to getting the actual job done.

            • Chernobyl was unsafe. Aside from that, I don't know of unsafe reactors. Fukushima made some nice drama, but it was never particularly dangerous. Nuclear power appears to be the safest around.

          • that's actually the problem with most technology

            nuclear for example

            i haven't a single doubt that we have the technological means to maintain nuclear plants forever without a single accident

            but what we don't have is the social and political means to do that

            Actually, a lot of us are simply numerically literate and realize that *every* a) energy source suffers from the issues that you whine about and b) nuclear has a great history despite having accidents sometimes.

          • by CrimsonAvenger ( 580665 ) on Sunday October 04, 2015 @05:23PM (#50657957)

            but they don't consider the political and social aspects of our species that means vital funding of safety mechanisms and maintenance of absolutely crucial technology *will* be broken. it's simply a matter of when, not if

            Or perhaps we understand that quite well. And decide that it's not that big a problem.

            Civilian nuclear power deaths in the USA, to date: zero.

            Military nuclear power deaths in the USA, to date: four? Basically the people in the room with the test reactor (that fit in a bathtub) when someone pulled the control rod (yes, there was only one) out by hand.

            Hmm, 70 years of nuclear power in the USA, with so few casualties. I could wish the highways were that safe. Or Airline travel. Or trains. Or COAL MINING. Or Oil drilling. Or even hydropower dams.

            Hell, more people have died just this year installing solar cells than have died in nuclear power accidents in the USA in all of history.....

            • Minor nitpick: There were only 3 people in the room when they pulled the control rod out, and it wasn't the only control rod. Unfortunately, it was the center rod, and in the reduced power state they had the reactor running in, it was by far the most important control rod. It also didn't help that the rod was removed quickly, probably because it had become stuck and they had to yank on it to free it (though there was no way to confirm that).

              https://en.wikipedia.org/wiki/... [wikipedia.org]

          • Re: (Score:3, Insightful)

            by Solandri ( 704621 )

            and then people who champion nuclear get angry at people like me, and accuse us of not understanding the technology. oh we understand the technology is wonderful. but it is you who doesn't understand humanity

            We understand humanity. You don't understand statistics. When there's a nuclear accident, it's big and scary and gets reported by all the press. When there's a coal, wind, or solar accident, it's small and doesn't get reported by the press. If you base your statistics on what's reported on the news

          • by rtb61 ( 674572 )

            More simply, the lowest tender rarely produces good results. Just because they contracted the lowest tender to clean the towers does not mean it was actually done. So they tendered for a piece of paper saying it had been done and someone went up there and drained the system and immediately refilled it. Incompetence is not as destructive as corruption and corruption is what always gets incompetence in the door, greed driven stupidity.

          • by dbIII ( 701233 )
            The problem with civilian nuclear is that community outrage about safety resulted in the cheap option of hiding safety issues instead of dealing with them.
        • Just having copper in the system won't kill legionella; it can live in copper-piped water systems just fine. Active copper-silver ionization will, but that requires active maintenance, as does every other effective method for treating legionella (UV, ozone, Cu-Ag ionization, chlorine).

          • by aurizon ( 122550 )

            yes, once a film forms, copper is not effective. new copper or silver ions must enter the water at a steady rate.

      • by Anonymous Coward

        This particular bacterium can hitch a ride inside amoebas so it can become a little more resistant to chlorine because of that.

    • by dwywit ( 1109409 )

      Perhaps coat the vulnerable surfaces with copper? If it's too expensive to provide electro-plated ducting, then spray some copper-rich paint onto the relevant parts.

      It works for sailing ships. Don't know if it'll work for this particular beastie.

    • In other words don't overlook the human element in any plan that requires 100% efficacy.

    • by fuzzyfuzzyfungus ( 1223518 ) on Sunday October 04, 2015 @11:54AM (#50656377) Journal
      I'd be curious to know if the design of these cooling towers(unfortunately, results for 'cooling towers' tend to be heavy on the really big ones used by power plants, which aren't terribly relevant except sharing certain basic principles of operation) would allow for UV sterilization.

      The idea that you can actually 'disinfect' something in the real world, outside of a cleanroom or high end operating room, for more than a few minutes to hours is mostly a polite fiction. Any sort of real world plumbing arrangment is going to be hosting assorted biofilms and other incredibly durable bacterial reservoirs more or less inevitably. As the massive success of modern sanitation systems has proven, you can get water 'clean enough' for the more-or-less-healthy to stay that way; but if you actually need to exterminate almost all the bacteria, you are picking a whole different fight.

      If, though, you only need to ensure that the contents of the droplets emitted by the cooling system in operation are reasonably disinfected, intense UV in the outflow ducts might be able to do that, and UV isn't high energy enough to do too much violence to metal parts(plastics/rubber/etc. can be trouble; but you won't be commiserating with nuclear reactor operators over radiation embrittlement issues.)
      • by Hall ( 962 ) on Sunday October 04, 2015 @01:03PM (#50656715)

        You said the key word there: Biofilms

        Odds are that they never actually (or fully) disinfected the system. A lot of bacteria remained, sheltered by biofilm, and disinfectants are proven to be ineffective against biofilm. After they "cleaned" it and checked the bacteria levels, it was just a matter of time before the biofilm naturally continued releasing the bacteria...

      • by aurizon ( 122550 )

        Proper antibacterial design, with maintenance, never provides a growth medium for whatever bacteria the winds bring in = no films in the first place. Sadly, human nature and bad maintenance = eventual fail mode = biofilms and mats can form that constantly shed bacteria into the air flow.

        • Proper antibacterial design, with maintenance, never provides a growth medium for whatever bacteria the winds bring in = no films in the first place.

          Potable water systems, made of copper, which have never had anything but potable water go through them STILL get biofilms on them.

          • by aurizon ( 122550 )

            Yes, it depends on the anti-corrosion additives that are in the water. The proper ones block copper oxidation. Back when I was a young engineer, we had a boiler system that was protected this way, and we took samples evry month and sent them off to the boiler chemical company, who then sent us a list of actions to rebuild the additive prifile.

            I expect external cooling towers are much the same, as this search reveals.
            Just text to schedule, add the chemicals and all is well.

            https://www.google.ca/search?q... [google.ca]

      • "intense UV in the outflow ducts might be able to do that"

        And the easiest way to prevent UV embrittlement of plastics is to use stainless steel where the lights are. That's a solved problem.

        The issue is that a lot of these installations predate disinfection requirements and/or management cheap out by not replacing sterilising lamps or skimping on the sodium hydrochlorite purchases.

        There need to be criminal penalties and personal liability for lax processes when it comes ot public health issues. These have a

    • by CharlieG ( 34950 )

      I spent a summer working for a place that had oh, 15-20 towers. TWICE a week we dosed the tower with biocides and rust preventatives, and once every 2 weeks samples from each of the towers went out for analysis. Then again, I know from my father, who worked in the field, the place I was at was 'odd' in that we did way more PM than any other place he knew of (he was in the repair end, I was doing operating). Sounds like the places with the problem aren't putting in the money. The problem with tower water

      • by aurizon ( 122550 )

        Yes, maintenance, bactericide, algaecide have to be a well oiled routine, especially in the summer time

        • by CharlieG ( 34950 )

          We were insane. Every machine room was swept daily, floors stripped and waxed 1x/week (in the machine room!!), readings and wipe down of the machines was done 4x/day, so you could see if there were any leaks etc. Spares were labels and neatly hung. Each machine room had a spare TOWER and spare compressor in line - just open valves, and turn on. Building also ran at 100% fresh air, all electrostatically precipitated. Yes, the building was a virtual clean room. Did I say we were a BIT crazy?

  • by Anonymous Coward on Sunday October 04, 2015 @08:37AM (#50655633)

    I work in legionella management in the UK, cooling towers must be disinfected every 6 months, no shit the legionella came back, it's present everywhere in the environment. The US has very lax laws for public water safety, see also New York's hideous water towers/roof tanks

    • by Anonymous Coward

      Does UV work against legionella? Installing UV-leds citywide should be easier than the lost cause of trying to get irresponsible building owners to do their part for the society.

      • by Anonymous Coward

        I've not seen uv used on cooling towers, usually high powered uv lamps are used on boreholes and surgical/pharma systems, closed stuff, but not something as crude as a cooling tower sump. Normally sumps are just chlorinated, but the sump water has to be changed every now and then as evaporation concentrates the chemicals which corrode the tower

    • by Anonymous Coward

      I'm a student at one of the schools in the current outbreak. After the previous one in the South Bronx a month or two ago, the city required all cooling towers to be disinfected within two weeks. So these towers were disinfected, but Legionella came back nonetheless. Is that common?

      • Yes. Legionella is everywhere. It's a common soil bacteria.

        Disinfection only lasts a short time and the bacteria is commonly brought in on the soles of shoes.

        Many of the rooftop sites I worked on (radio masts) had strict procedures about working near cooling towers, including a requirement to wear clean-room overshoe booties whilst outside and in plantrooms to try and avoid contamination from this vector and _no_ sites allowed public roof access - the roof doors were usually pretty solid assemblies.

  • by hyades1 ( 1149581 ) <hyades1@hotmail.com> on Sunday October 04, 2015 @09:28AM (#50655851)

    Speaking at a hastily-called press conference only a few hundred miles from the buildings in question, Tower-cleaning specialist and former Volkswagen Vice President Gesundheit Krappstadtz stated unequivocally that all cleaning and disinfection operations had been performed with full attention to the requirements of New Jersey's famously strict environmental regulations.

  • ... do they use, if any ? Nalco, Betz, Evoqua are big national brands. What changed? cost cutting, the organics into the water, management/technical experience
  • by mark_reh ( 2015546 ) on Sunday October 04, 2015 @10:29AM (#50656067) Journal

    because it provides a good environment for them. It is not at all surprising that the bacteria would be found in a recently disinfected cooling tower. The only way to stop that from happening is to somehow make the cooling tower environment a less friendly one for the bugs.

    • because it provides a good environment for them. It is not at all surprising that the bacteria would be found in a recently disinfected cooling tower. The only way to stop that from happening is to somehow make the cooling tower environment a less friendly one for the bugs.

      I know! I know! Put a politician, preferably fairly high level (they get more dangerous as they age) in the tower. That's a pretty unfriendly environment. If it's a bad infestation, you can temporarily install a committee. Monitor everything on C-Span.

    • "The only way to stop that from happening is to somehow make the cooling tower environment a less friendly one for the bugs."

      Like disinfecting them, as was recently done?

      • by Anonymous Coward

        Disinfecting them makes them more attractive because there is now less competition!

      • Disinfection, alone, is a bit like kicking some hobos out from under a bridge. Without further action, they'll just be replaced by more hobos.

      • I was thinking more along the lines of chemical additives to alter the pH or shifting the temperature range at which the things work, etc. Bacteria need a source of food of some sort. It might be possible to identify it and eliminate it from the towers. Maybe they consume fungus. If you can stop the fungus you stop the things that feed on it.

  • by Anonymous Coward

    The only effective sterilisation regimes include mechanical abrasion. Good old fashioned scrub brush and soap, plain and simple. I have personally observed bacterial colonies survive under a 95% ethanol solution for over a week under their own biofilm protection. It takes elbow grease, you have to scrub all surfaces to be sterilised with mechanical abrasion and soap, only then can sterilisation chemicals or antibiotic agents have any useful effect.

    • by Anonymous Coward

      What about pressure cleaning?

      • Doesn't seem like a great idea given that legionella is mostly hazardous when it is carried by airborne water droplets that can be breathed in.

  • Maybe they should try disinfectant this time

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