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Comment by londons_explore | Hacker News Reader

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.

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"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.

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.

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.

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.

refillable water bottles are how it's done in most of the world.

You go to a water shop, hand over a bottle, and they give you a one filled with a 15 liters of water, and you'll probably pay around 5 USD cents for that. The water will be filtered (but probably not with reverse osmosis, so there might still be a few viruses and a little lead contamination in it).

The bottles will be filled thousands of times in their lifespan. The cost is higher per liter than piped water, but per person per year it's lower, due to the fact these people perhaps use only 5 liters per day of bottled water, and do clothes washing in non-potable rainwater off their roof.

Hell, I do this for my drinking water in the United States. My tap water is perfectly safe to drink, but even after running through a brita filter it tastes aweful, so it's worth the 30 minutes a month it takes to got get RO filtered water from the water store.

What's actually cheaper is not bottled water, it's a village well.

And what water do you think a poor person will prefer to drink:

a) Some of the highest quality drinking water in the world, taken from a regional or national spring and delivered to their home for a very accessible price?

b) Slightly muddy well water that they have to go and fetch in a village well? Assuming they live in a village and assuming that there's ground water available.

Which water would you prefer to drink?

The comment I was replying to was talking about plumbing, so my response regarded settlements larger than villages. Any village where the ground water is good to drink have already dug a well, so no use in telling them to dig a well.

I'd prefer to drink Dom Pérignon and eat off golden plates, but I don't always get what I want.

There are vast degrees of poverty of availability or unavailability of infrastructure, across both the developed and developing world.

Shipping in bottled water, for instance, isn't a solution when the cost of shipping into the area (due to poor road infrastructure, or poor weather, or conflict zones) has prohibitive - or even intermittent - problems.

People already live around sources of water. At the scale of a township, it's generally long-term cheaper to figure out how to make your sources of water potable than to introduce a permanent dependency on a distant third party supplier, and a complex logistic network for something as fundamental as drinking water.

> ...delivered to their home for a very accessible price?

> ...have to go and fetch from a village well.

If someone can figure out to 'very accessibly' deliver bottled water from hundreds of miles away to your home, why wouldn't they be able to 'very accessibly' deliver locally sourced water to your home?

And if you have to go from your home to a distribution center for those bottles, how is that better than the proverbial village well?

Here is the reality: In large parts of the world, very high quality drinking water is available in large, reusable jars and bottles, for a cheap price which poor people can afford. While the tap water ranges from undrinkable to bad tasting.

Now you might think that it is outrageous that they buy and drink this water, that they don't deserve it and should wait for plumbing or better government water treatment. That they should be denied one of the basics of life in the holy name of hacker efficiency. Do you think they give a fuck about what you think? You are literally arguing to take away people's good drinking water because they live somewhere with lacking infrastructure.

> If someone can figure out to 'very accessibly' deliver bottled water from hundreds of miles away to your home, why wouldn't they be able to 'very accessibly' deliver locally sourced water to your home?

Because locally sourced water is not of the same quality or even drinkable many times. A river or a spring is in a fixed place geographically and not everybody can live on top of it. If you lived an hour or two from a large spring with high quality water, you wouldn't want to drink foul-tasting water from the tap or try to dig a well for some brackish water.

> And if you have to go from your home to a distribution center for those bottles, how is that better than the proverbial village well?

They deliver it to your door and with your permission they will cary the jars into your home and put them wherever you tell them to.

> Over here the price difference between drinking water from the tap and the cheapest bottled water is a factor ~200.

Does it take the cost of building city-wide plumbing installation and the water treatment facility into account? Someone (probably the government) have to pay for it and many 3rd world nations can't afford to pay for them except for a handful of cities (usually the capital city).

I remember reading that in some Western countries up to half of the ultra clean drinking water disappears because of leaking pipes...

What does it matter if it's more efficient or not? I want to drink clean water today, I get a gallon delivered to my home.

Also, when comparing prices for necessities, the only thing that matters to an individual is the actual amount, not any percentage comparison. You've fallen into a mental trap that I've seen a lot of people fall into, by comparing prices by percentages. If most people in a developing country can easily afford clean water delivered to their homes, then it doesn't matter if it's percentage wise more expensive. Same thing if you buy some ramen noodles. It doesn't matter in the slightest if they cost 50c or $1.

Because we're not talking about what it costs for an individual, we're talking about how to get clean water to everyone in the world.

You’re right it would be crazy to pipe clean water to our homes for drinking and deliver less clean water via ditch for irrigation. No wait, that’s perfectly sane, normal and common.

> remember photos of the tangle of wires when DC vs AC fought?

This sounds like someone confused a picture of early telegraph poles with multiple circuits, before high density cables were developed.

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?

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.

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.

Ad hoc distribution… ‘Unauthorized’ distribution…

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.

> sewage and groundwater seep into the water pipes

How does this happen? Are they not sealed?

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.

Trees grow, pipes crack. Have irrigation pipe leaks at work. All from trees growing and cracking pipes.

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.

> 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.

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.

> 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?

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.

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?

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-...

[4]: https://www.researchgate.net/figure/Country-average-water-co...

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.

I just looked at my water bill, I am at about 150L/person/day, which is about average for my country. It includes drinking, cooking and washing. So less than then the 200+20+2 estimate but not by that much, if you enjoy baths and lengthy showers, 222L is possible.

And from what I've seen 2000L/person/day for agriculture is not too outlandish. The production of your garden is likely to be tiny compared to what you eat. A head of cabbage is maybe 1/10th of you daily calorie needs, and compared to animal products, vegetables have low water requirements.

So maybe it is not exactly right, but the orders of magnitude look correct. At least for the first world.

In the Netherlands farmers and industry pay a lower rate than households.

It is only recently with climate change that an ATTEMPT is made to get water use down. For millennia the country drowned in water and the issue was pumping it to the sea not preserving it.

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.

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