3 ms·

But if it just went through some heat exchangers, it's not like if it was dirty? As far as I know, nuclear power plants return the water they consume to the riv

by cm2187 9mo ago

But if it just went through some heat exchangers, it's not like if it was dirty? As far as I know, nuclear power plants return the water they consume to the rivers they extracted it from.

jacquesm 9mo ago
Heat exchangers could easily contaminate the water. If they're not kept hot enough they could be breeding ground for Legionella and a whole raft of other bacteria. Clean water is science, not just a matter of bulk pumping stuff from one place to another (though that's definitely a part of it). Water treatment plants are complex and have a ton of QA on their product. You can't just run it into a factory and pretend it is the same stuff going in modulo some increase in temperature.
- cm2187 9mo ago
  But you are talking about drinking water. I would be surprised if they even use that for cooling. But any non human consumption use of water (like agriculture) should happily use that water, shouldn't it?
  - jacquesm 9mo ago
    No, agriculture has fairly strict standards about the quality of the water, they can't use gray water to irrigate. Of course it will still work but depending on where you live the produce may then no longer be fit for human consumption. You can use it for irrigating your lawn but not for vegetables, especially not if you plan on selling them. But 'light' gray water requires relatively little treatment before you can use it again, however this could still be quite expensive compared to just letting it go. I wonder if they've done any quantitative research on this that's public.
    - pera 9mo ago
      That's very interesting, thanks! I had no idea that legionella risk was a thing for data centers. This article mentions that to avoid the risk most data centers treat the water with disinfectants which are sometimes toxic: https://www.scaleway.com/en/blog/making-the-energy-efficiency-regulations-water-smart-the-next-step-for-eu-lawmakers/ https://www.scaleway.com/en/blog/making-the-energy-efficienc...
      - jacquesm 9mo ago
        They're really nasty bacteria and once in a system they are hard to get rid of because then you have to heat everything to temperatures that the system normally might never reach. That's why central heating systems that run 'low' every now and then stoke up to 60 degrees or more on the secondary circuit for tap water. And data centers are the perfect location, endless 35 to 45 degree water. Cooling towers are the main problem for this, another is aerosols of water that has been sitting in the sun for a while, for instance in a garden hose exposed to the sun.
  - schainks 9mo ago
    This is America. Our toilets use _clean potable water_ to flush our shit. Drinking water from the mains is metered, so it is observable from the business perspective. Life finds a way. Heat exchangers and datacenter plumbing absolutely breed life and put things into the water that were not there when it was pumped in. Imagine if a datacenter used a shady supplier of pipe that used, say, lead in their alloy. Do you want that datacenter grey water going into crops?
    - cm2187 9mo ago
      The water from the lake isn't drinking water either, it is contaminated with all sort of stuff including dead animals and animals excrements. But it doesn't mean it is not suitable for agriculture.
    - galkk 9mo ago
      Do you think that water that the water that flows from kitchen sink and water that flushes in the toilet in normal house/apartment come from different pipes in any other place of the world?
      - JasonADrury 9mo ago
        Many homes around the world do in fact have separate drinking water taps in the kitchen. But yes, it rarely enters the building via different pipes. I'm sure that's a thing somewhere too.
- direwolf20 9mo ago
  Do legionella multiply faster in a heat exchanger than a river?
  - BigTTYGothGF 9mo ago
    Yes, that's how you get outbreaks (https://www.cdc.gov/control-legionella/php/toolkit/cooling-towers-module.html https://www.cdc.gov/control-legionella/php/toolkit/cooling-t...)

by cm2187 9mo ago

But if it just went through some heat exchangers, it's not like if it was dirty? As far as I know, nuclear power plants return the water they consume to the rivers they extracted it from.

jacquesm 9mo ago

Heat exchangers could easily contaminate the water. If they're not kept hot enough they could be breeding ground for Legionella and a whole raft of other bacteria. Clean water is science, not just a matter of bulk pumping stuff from one place to another (though that's definitely a part of it). Water treatment plants are complex and have a ton of QA on their product. You can't just run it into a factory and pretend it is the same stuff going in modulo some increase in temperature.

cm2187 9mo ago
But you are talking about drinking water. I would be surprised if they even use that for cooling. But any non human consumption use of water (like agriculture) should happily use that water, shouldn't it?
- jacquesm 9mo ago
  No, agriculture has fairly strict standards about the quality of the water, they can't use gray water to irrigate. Of course it will still work but depending on where you live the produce may then no longer be fit for human consumption. You can use it for irrigating your lawn but not for vegetables, especially not if you plan on selling them. But 'light' gray water requires relatively little treatment before you can use it again, however this could still be quite expensive compared to just letting it go. I wonder if they've done any quantitative research on this that's public.
  - pera 9mo ago
    That's very interesting, thanks! I had no idea that legionella risk was a thing for data centers. This article mentions that to avoid the risk most data centers treat the water with disinfectants which are sometimes toxic: https://www.scaleway.com/en/blog/making-the-energy-efficiency-regulations-water-smart-the-next-step-for-eu-lawmakers/ https://www.scaleway.com/en/blog/making-the-energy-efficienc...
    - jacquesm 9mo ago
      They're really nasty bacteria and once in a system they are hard to get rid of because then you have to heat everything to temperatures that the system normally might never reach. That's why central heating systems that run 'low' every now and then stoke up to 60 degrees or more on the secondary circuit for tap water. And data centers are the perfect location, endless 35 to 45 degree water. Cooling towers are the main problem for this, another is aerosols of water that has been sitting in the sun for a while, for instance in a garden hose exposed to the sun.
- schainks 9mo ago
  This is America. Our toilets use _clean potable water_ to flush our shit. Drinking water from the mains is metered, so it is observable from the business perspective. Life finds a way. Heat exchangers and datacenter plumbing absolutely breed life and put things into the water that were not there when it was pumped in. Imagine if a datacenter used a shady supplier of pipe that used, say, lead in their alloy. Do you want that datacenter grey water going into crops?
  - cm2187 9mo ago
    The water from the lake isn't drinking water either, it is contaminated with all sort of stuff including dead animals and animals excrements. But it doesn't mean it is not suitable for agriculture.
  - galkk 9mo ago
    Do you think that water that the water that flows from kitchen sink and water that flushes in the toilet in normal house/apartment come from different pipes in any other place of the world?
    - JasonADrury 9mo ago
      Many homes around the world do in fact have separate drinking water taps in the kitchen. But yes, it rarely enters the building via different pipes. I'm sure that's a thing somewhere too.
direwolf20 9mo ago
Do legionella multiply faster in a heat exchanger than a river?
- BigTTYGothGF 9mo ago
  Yes, that's how you get outbreaks (https://www.cdc.gov/control-legionella/php/toolkit/cooling-towers-module.html https://www.cdc.gov/control-legionella/php/toolkit/cooling-t...)