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We also need to think about uses of water. Water is used for drinking (~2 liters/day)... Contamination here really matters. Waker is used for cooking (~20

We also need to think about uses of water. Water is used for drinking (~2 liters/day)... Contamination here really matters. Waker is used for cooking (~20 liters per day). Contamination here matters somewhat, since some forms of pollutants will be rendered harmless by cooking. Water is used for washing (~200 liters per day). Contamination here matters a little too, because washing water can touch something which gets eaten etc. Water is used for farming (~2000 liters per day/person fed). Contamination here barely matters - but some things can still make it into foodstuffs. Providing small quantities of clean water is far cheaper than providing large amounts.

kccqzy 1y ago
I noticed that in some countries tap water isn't safe for drinking but good enough for cooking; and everyone buys large plastic 40lb jugs of water for drinking. How much more cost effective would it be to adopt such a system as opposed to safe drinkable tap water?
- londons_explore 1y ago
  Non-drinkable tap water is mostly due to water not being available 24x7x365. If a water system is turned off even momentarily, the pressure drops to zero, and sewage and groundwater seep into the water pipes, making it unsafe to drink. Countries with unreliable power grids usually don't have drinkable tap water for that reason. It can also be because the water isn't treated (ie. it is just rainwater in the pipes). Water treatment actually isn't very expensive though - collecting the water and distributing the water are by far the biggest costs.
  - njarboe 1y ago
    In the west water systems are pressurized using a large reservoir and gravity. I imagine its similar in third world countries? They have unreliable water due to the reasons they have unreliable power: poor ability to plan, not enough supply, undersized systems for current use, deferred maintenance, etc.
    - wingspar 1y ago
      Ad hoc distribution… ‘Unauthorized’ distribution…
  - carlosjobim 1y ago
    Just because you can drink the tap water, doesn't mean you want to drink it. Sure, if you are desperate. But most who have the means will prefer to purchase the better tasting and cleaner water from gallons, rather than drinking the treated water from the tap.
  - Chris2048 1y ago
    > sewage and groundwater seep into the water pipes How does this happen? Are they not sealed?
    - neurostimulant 1y ago
      The pipes network is very long so small leaks will always happen somewhere due to accidents or wear and tear. These small leaks are enough to contaminate the downstream pipes if the water pressure drops and dirty water get in.
    - wingspar 1y ago
      Trees grow, pipes crack. Have irrigation pipe leaks at work. All from trees growing and cracking pipes.
- sandworm101 1y ago
  It isnt thay simple. As i kid we had non-potable water in the pipes. (Middle east) It was recycled water heavy on chlorine, safe for washing but not drinkable. Pressure was never the issue. We drank from a "sweetwater" tap, which also fed the hot water tank and the dishwasher. Using safe potable water to flush toilets is silly. Splitting drinking from other uses is far more efficient.
  - londons_explore 1y ago
    > Splitting drinking from other uses is far more efficient. This isn't universally true. Pipework (laying+maintaining), collection and storage is generally the expensive bit of any water system. The actual purification is fairly cheap. That means having two sets of pipes to every house (one for drinking water, one for mid-grade water) usually costs more than just one set of pipes and having all water drinkable. Thats why it's rarely done. The alternative is you use the pipes for non-potable water, and tell people to buy bottled water for drinking - more than half the world is in this position I believe. It helps that people drink perhaps only 1% of the water they use - so bringing 1% of the water via bottles on the back of a motorbike is viable.
    - sandworm101 1y ago
      That isnt how it is always done. In not-dry countries, the non-potable water is generally collected locally. It is filtered rainwater from cisterns, not piped public water from afar.
    - Chris2048 1y ago
      > two sets of pipes to every house Could you not recycle clean water? e.g. a rough filter & chlorination of shower/dishwasher water to use for other things. Some stages of a dishwasher without harsh chemicals might be used to water a lawn?
- jillesvangurp 1y ago
  Mostly the water is more or less safe but chlorine is added in many countries. That won't kill you but it's not very nice. And those big containers of water are affordable enough that they are preferable for cooking/drinking. I'm currently staying in Portugal and I'm buying a lot more water than I normally do. Back in Germany, the tap water is fine. But I do buy a lot of sparkling water because I like drinking it. Also, my urologist mentioned that bottled/filtered water is a great way to reduce the chance of kidney stones. The same calcium deposits that eventually destroy your washing machine might cause you some issues with those. So, there's that.
pluto_modadic 1y ago
"far cheaper than providing large amounts" that doesn't factor in the cost of plumbing an entire town with 3 sets. remember photos of the tangle of wires when DC vs AC fought? It's more expensive especially for a suburb of single family homes to plumb in sewers and water mains (long distances for low flows), vs plumbing in duplexes and apartments. having a secondary water system (e.g., purple pipes / grey water), for general lawn/washing and one for drinking/cooking - strikes a good balance. You don't want your potable water system to move too slowly. You also should have water towers at different heights (higher pressure in the potable system). any accidental interconnects (these do happen) will flow /away/ from the potable one. finally, letting people use rainwater, runoff, and letting them recycle lightly used potable water for other uses (like flushing toilets, watering gardens) is good - try to get every liter of water used twice as a goal. bonus: get past the ick factor and allow your sewage to be re-used (purple pipes) as the greywater after treatment at the plant.
- geodel 1y ago
  It is about bottom 2 billion not having safe drinking water. They are surely not having suburban homes with 3 sets of pipes. Its a one water pump + some filtration/cleaning mechanism for few thousand people who come there and collect it type situation.
- carlosjobim 1y ago
  You don't need any plumbing for safe drinking water. It can be delivered to the customer in gallons and bottles. That's how it's done in large parts of the world.
  - CorrectHorseBat 1y ago
    But is that more efficient than having one set of plumbing with safe drinking water? I doubt it. Over here the price difference between drinking water from the tap and the cheapest bottled water is a factor ~200.
    - londons_explore 1y ago
carlosjobim 1y ago
I'm trying to understand your examples. Those are absolutely massive quantities of water you're mentioning for cooking, washing and farming. I assume that you cook and wash yourself like everybody else, and have a basic understanding on how much for example a head of cabbage should be watered each day. So what do you mean with these numbers?
- londons_explore 1y ago
  cooking includes the running tap under which you peel the potatoes, the water you boil the eggs in, etc. washing includes the 150 liters a washing machine uses or the 100 liters in a bath or shower.[3] Spraying things down with a hose really uses a lot too. farming is the one with most variance - but some crops have a super high number of liters of water used per kg of crop harvested. 1kg of rice = 5000 liters of water! [4] For things like beef, you really need to include all the water to grow the grass too... [3]: https://www.ariston.com/en-me/the-comfort-way/news/how-much-water-is-consumed-for-a-shower/ https://www.ariston.com/en-me/the-comfort-way/news/how-much-... [4]: https://www.researchgate.net/figure/Country-average-water-consumption-of-main-crops-in-m-ton-Period-1996-2005-Data_fig7_268518486 https://www.researchgate.net/figure/Country-average-water-co...
  - carlosjobim 1y ago
    I cook everyday and there is absolutely no way that a normal family yet a single person would be using 20l of water per day to cook, unless they were deliberately aiming to use as much water as possible. Including washing dishes etc. The example stated for farming is 2000 liters per person per day for food. I'd like you to pause for a moment and think about that statement. A person can't eat a whole head of cabbage in a day, and you're saying that this head of cabbage would need more than two tons of water per day before it's harvested. Likewise with the washing machine, you're talking about washing a full load per person every day. Who do you know that soils so much his clothes that he needs to wash a full load only for him every day? Water to grow the grass for beef cattle is rain, as I assume at least a small minority of people reading here will know. Your original comment is greatly upvoted and the people here actually believe that two tons of water per day per person is needed to grow their food. Per day. Per Person. I can't fathom what is going on in this forum.
refurb 1y ago
If you have a source of water, providing purified drinking water is stupid cheap. It’s the initial infrastructure that requires investment but after that, purification costs fractions of a penny per liter.

kccqzy 1y ago

I noticed that in some countries tap water isn't safe for drinking but good enough for cooking; and everyone buys large plastic 40lb jugs of water for drinking. How much more cost effective would it be to adopt such a system as opposed to safe drinkable tap water?

londons_explore 1y ago
Non-drinkable tap water is mostly due to water not being available 24x7x365. If a water system is turned off even momentarily, the pressure drops to zero, and sewage and groundwater seep into the water pipes, making it unsafe to drink. Countries with unreliable power grids usually don't have drinkable tap water for that reason. It can also be because the water isn't treated (ie. it is just rainwater in the pipes). Water treatment actually isn't very expensive though - collecting the water and distributing the water are by far the biggest costs.
- njarboe 1y ago
  In the west water systems are pressurized using a large reservoir and gravity. I imagine its similar in third world countries? They have unreliable water due to the reasons they have unreliable power: poor ability to plan, not enough supply, undersized systems for current use, deferred maintenance, etc.
  - wingspar 1y ago
    Ad hoc distribution… ‘Unauthorized’ distribution…
- carlosjobim 1y ago
  Just because you can drink the tap water, doesn't mean you want to drink it. Sure, if you are desperate. But most who have the means will prefer to purchase the better tasting and cleaner water from gallons, rather than drinking the treated water from the tap.
- Chris2048 1y ago
  > sewage and groundwater seep into the water pipes How does this happen? Are they not sealed?
  - neurostimulant 1y ago
    The pipes network is very long so small leaks will always happen somewhere due to accidents or wear and tear. These small leaks are enough to contaminate the downstream pipes if the water pressure drops and dirty water get in.
  - wingspar 1y ago
    Trees grow, pipes crack. Have irrigation pipe leaks at work. All from trees growing and cracking pipes.
sandworm101 1y ago
It isnt thay simple. As i kid we had non-potable water in the pipes. (Middle east) It was recycled water heavy on chlorine, safe for washing but not drinkable. Pressure was never the issue. We drank from a "sweetwater" tap, which also fed the hot water tank and the dishwasher. Using safe potable water to flush toilets is silly. Splitting drinking from other uses is far more efficient.
- londons_explore 1y ago
  > Splitting drinking from other uses is far more efficient. This isn't universally true. Pipework (laying+maintaining), collection and storage is generally the expensive bit of any water system. The actual purification is fairly cheap. That means having two sets of pipes to every house (one for drinking water, one for mid-grade water) usually costs more than just one set of pipes and having all water drinkable. Thats why it's rarely done. The alternative is you use the pipes for non-potable water, and tell people to buy bottled water for drinking - more than half the world is in this position I believe. It helps that people drink perhaps only 1% of the water they use - so bringing 1% of the water via bottles on the back of a motorbike is viable.
  - sandworm101 1y ago
    That isnt how it is always done. In not-dry countries, the non-potable water is generally collected locally. It is filtered rainwater from cisterns, not piped public water from afar.
  - Chris2048 1y ago
    > two sets of pipes to every house Could you not recycle clean water? e.g. a rough filter & chlorination of shower/dishwasher water to use for other things. Some stages of a dishwasher without harsh chemicals might be used to water a lawn?
jillesvangurp 1y ago
Mostly the water is more or less safe but chlorine is added in many countries. That won't kill you but it's not very nice. And those big containers of water are affordable enough that they are preferable for cooking/drinking. I'm currently staying in Portugal and I'm buying a lot more water than I normally do. Back in Germany, the tap water is fine. But I do buy a lot of sparkling water because I like drinking it. Also, my urologist mentioned that bottled/filtered water is a great way to reduce the chance of kidney stones. The same calcium deposits that eventually destroy your washing machine might cause you some issues with those. So, there's that.

pluto_modadic 1y ago

"far cheaper than providing large amounts" that doesn't factor in the cost of plumbing an entire town with 3 sets. remember photos of the tangle of wires when DC vs AC fought? It's more expensive especially for a suburb of single family homes to plumb in sewers and water mains (long distances for low flows), vs plumbing in duplexes and apartments. having a secondary water system (e.g., purple pipes / grey water), for general lawn/washing and one for drinking/cooking - strikes a good balance. You don't want your potable water system to move too slowly. You also should have water towers at different heights (higher pressure in the potable system). any accidental interconnects (these do happen) will flow /away/ from the potable one. finally, letting people use rainwater, runoff, and letting them recycle lightly used potable water for other uses (like flushing toilets, watering gardens) is good - try to get every liter of water used twice as a goal. bonus: get past the ick factor and allow your sewage to be re-used (purple pipes) as the greywater after treatment at the plant.

geodel 1y ago
It is about bottom 2 billion not having safe drinking water. They are surely not having suburban homes with 3 sets of pipes. Its a one water pump + some filtration/cleaning mechanism for few thousand people who come there and collect it type situation.
carlosjobim 1y ago
You don't need any plumbing for safe drinking water. It can be delivered to the customer in gallons and bottles. That's how it's done in large parts of the world.
- CorrectHorseBat 1y ago
  But is that more efficient than having one set of plumbing with safe drinking water? I doubt it. Over here the price difference between drinking water from the tap and the cheapest bottled water is a factor ~200.
  - londons_explore 1y ago

carlosjobim 1y ago

I'm trying to understand your examples. Those are absolutely massive quantities of water you're mentioning for cooking, washing and farming. I assume that you cook and wash yourself like everybody else, and have a basic understanding on how much for example a head of cabbage should be watered each day. So what do you mean with these numbers?

londons_explore 1y ago
cooking includes the running tap under which you peel the potatoes, the water you boil the eggs in, etc. washing includes the 150 liters a washing machine uses or the 100 liters in a bath or shower.[3] Spraying things down with a hose really uses a lot too. farming is the one with most variance - but some crops have a super high number of liters of water used per kg of crop harvested. 1kg of rice = 5000 liters of water! [4] For things like beef, you really need to include all the water to grow the grass too... [3]: https://www.ariston.com/en-me/the-comfort-way/news/how-much-water-is-consumed-for-a-shower/ https://www.ariston.com/en-me/the-comfort-way/news/how-much-... [4]: https://www.researchgate.net/figure/Country-average-water-consumption-of-main-crops-in-m-ton-Period-1996-2005-Data_fig7_268518486 https://www.researchgate.net/figure/Country-average-water-co...
- carlosjobim 1y ago
  I cook everyday and there is absolutely no way that a normal family yet a single person would be using 20l of water per day to cook, unless they were deliberately aiming to use as much water as possible. Including washing dishes etc. The example stated for farming is 2000 liters per person per day for food. I'd like you to pause for a moment and think about that statement. A person can't eat a whole head of cabbage in a day, and you're saying that this head of cabbage would need more than two tons of water per day before it's harvested. Likewise with the washing machine, you're talking about washing a full load per person every day. Who do you know that soils so much his clothes that he needs to wash a full load only for him every day? Water to grow the grass for beef cattle is rain, as I assume at least a small minority of people reading here will know. Your original comment is greatly upvoted and the people here actually believe that two tons of water per day per person is needed to grow their food. Per day. Per Person. I can't fathom what is going on in this forum.

refurb 1y ago

If you have a source of water, providing purified drinking water is stupid cheap. It’s the initial infrastructure that requires investment but after that, purification costs fractions of a penny per liter.