3 ms·
The article doesn't specifically say how much time water spends in pipes, (Minutes? Weeks? Months?) but the linked paper does: >A utility in North Carolina ser
by sbierwagen 7y ago
The article doesn't specifically say how much time water spends in pipes, (Minutes? Weeks? Months?) but the linked paper does:
>A utility in North Carolina serving 300,000 customers with 1,100 miles of main calculated water ages ranging from 2 to 75 hours throughout the distribution system using a fluoride tracer study (DiGiano, Travaglia and Zhang 2000).
> A Midwest utility with a service population of 800,000 and 2,750 miles of main recently found based on a hydraulic model that the water age in the distribution system was typically less than 80 hours while several sites exhibited a water age up to 150 hours (Vandermeyden and Hartman 2001).
> One California utility found water ages exceeding 400 hours in certain areas of the system, particularly dead end areas, under minimum day and average day demand conditions (Acker and Kraska 2001).
> A Canadian utility serving 24,000 people with 86 miles of main estimated water age using a hydraulic model and found that dead-end nodes had a water age ranging from 300 to 600 hours under average day demand conditions (Prentice 2001).
"How long is too long?" It depends, apparently, on what the pipes are made of, how old they are, how corrosive the water is, (Which is what caused the Flint disaster) etc.
- nullwasamistake 7y agoWow. 600 hours is 25 days, that's far too long. The chlorine used to sterilize the supply will be long gone by then.
- zackmorris 7y agoNot necessarily. Many municipal water treatment plants are adding or switching to chloramines, which can be more stable than chlorine gas: https://en.wikipedia.org/wiki/Chloramine https://en.wikipedia.org/wiki/Chloramine The main problem is that they are potentially more carcinogenic. The rarely talked about, but potentially more serious problem, is that chlorine and chloramine are difficult to remove from water by letting it stand or boiling it: https://www.sfwater.org/Modules/ShowDocument.aspx?documentID=6920 https://www.sfwater.org/Modules/ShowDocument.aspx?documentID... https://www.physicsforums.com/threads/does-boiling-water-remove-chloramine.857730/ https://www.physicsforums.com/threads/does-boiling-water-rem... https://www.morebeer.com/articles/removing_chloramines_from_water https://www.morebeer.com/articles/removing_chloramines_from_... It looks like activated charcoal filters are the best way to neutralize it, but I'm having trouble finding numbers for how effective they are at it. https://homebrew.stackexchange.com/questions/3447/what-are-the-various-ways-to-remove-chlorine-chloramine-from-tap-water https://homebrew.stackexchange.com/questions/3447/what-are-t...