Here's what I'm curious about: how much water is used for every liter of drinking water? It seems clear that a "liter of water", which could be all kinds of polluted, is NOT the same as a liter of bottled or tap water. A liter of drinkable water has to undergo some filtration process, etc. and I'd be extremely interested in seeing how much water is used in that process. That would help put the headline's figure in context.
Very little water is lost in municipal water filtration. The largest loss is generally evaporation from dam reservoir which is on the order of 10%. Depening on location temperature, humidity, ect.
Don't forget you drink the same water you bathe with. At scale it's producing a lot of water.
PS: Now a lot of water is lost after filtration by leaks/breaks in water pipes. But, that's mostly an economic choice as water is really cheap replacing pipes is expensive.
The point he is making is not reduced to that, it is that you should judge things with the same metrics. I.e. how much water is used for bottled water? For running water? How much harmful chemicals can you find in soft drink, bottled water, tap water? (because running water may be very cost-efficient, but it comes with a price, the dizzying quantity of chlorine you can find inside being one).
Just giving one number out of your hat is a dishonest persuasive move (unless everybody already knows the numbers for all the previous questions), precisely because the author knows very well that most people cannot put that number into perspective. This is not a very scientific attitude for something published in a 'scientific' journal.
Despite what you might think water is not a particularly limited resource.
At the municipal level 1 cent ~= 1,000+ gallons of water but this can vary greatly by location. As a customer in many ways you are paying for pipes not water.
PS: California farmers often pay ~70$ on average per acre foot or 325,851 gallons. But, they also get a lot of water for far less than that it's the rare edge cases that are really expensive. http://westernfarmpress.com/water-70-24-million-acre-foot
I agree with you.
But what if you want to drink pure/purified water? You can do for little to no cost in certain conditions, but for city people there are either bottled water or some purifying systems that can be costly and of various levels of efficiency. Then, how much water does one liter of water costs?
But then you could argue that people don't need to drink purified water, tap water is good enough, lead levels, chlorine levels (etc) are low enough. But this is another question from the previous one, that should also be discussed taking the whole picture into account.
> But then you could argue that people don't need to drink purified water, tap water is good enough, lead levels, chlorine levels (etc) are low enough.
Distilled water will also osmotically drain you, although not at any level you should be worried about. But it's not at all clear that it's "better for you" than water with stuff in it.
To compare to this article you'd also have to calculate the amount of water used to make the pipes, dig the ditches, create the machinery to dig the ditches (and pro-rate the machinery's life time against the amount of time it's used to dig water pipe trenches), fuel used, etc, etc.
Your scale is off. The city of Philadelphia for example loses 60 million gallons per year to leaks out of 250 million gallons pumped from the river. (excluding leaks at the home and business level estimated at 1trillion gallons per year in the US.)
To get anywhere close to similar levels from the article you replacing there entire system every 20 years would need to take 20 * 60m * 340 = 408 Trillion gallons of water.
You'd have to distinguish between potable water and just any water too.
https://en.wikipedia.org/wiki/Drinking_water mentions that Christchurch, NZ has a sufficient supply of pure enough water that no treatment is required. So you could probably build a passive filtration system for a one time cost. It just may not be fast enough to treat enough water if your population is too big.
My guess is it varies greatly to due the source of the water. At the extreme, I would guess that desalination of saltwater to make it usable for drinking water would likely consume huge amount of water per drink unit of water.
Given that it's a pretty obvious question, find it interesting that it is not addressed; reason likely is most reporters do not do investigative journalism, but many will publish as is a story forwarded to them.
Lastly, it's very likely some water used was not drinkable to start, reused, etc. - which is to say, it's a complex topic and without a clear question and an understanding of why it is being ask, you'll always get an answer that appears to answer something.
How would desalination cost water? You vaporize water, catch and cool it back to water, and there you go. The cost here is energy, which varies greatly depending on the sun.
Unclear how much you know about the topic, but there are a number of ways to desalinate salt water, including just mixing non-toxic saltwater with drinkable freshwater; that said, it requires 31 liters of freshwater to make one liter of saltwater drinkable.
Normal saltwater has a salt concentration of 3.5% and to be drinkable that must be reduced to 1000 ppm (parts per million); which is to say, say for 100 liters of saltwater, you'll lose at least 3.5 liters just to reclaim the freshwater itself.
Beyond that it'll depend on the system how much additional volume is lost in the desalination process; quick Google finds some systems that lose 20% of the volume per unit processed.
Lastly, your reference to energy consumption brings up an example of additional sources of water lose. Water used to cool systems, water used to clean systems, leaks/waste, etc.
When you need 31 galles of freshwater to make 1 gallon salt water drinkable, you have 32 gallons of drinkable water. Those 32 gallons are not wasted. When you make one jeans or a t-shirt, you may need many more gallons. You cannot drink that water afterwards, so that totally different.
Reference to using freshwater for desalination has nothing to due with waste, but to make the point that boiling saltwater is only one of many ways to desalinate saltwater.
Not that I post for rep, or for that matter care about downvotes, but if you're expressing that the above comment was not of use, on-topic, opinionated, bad tone, etc. - it's not clear why. Please comment so that I might be able to address your concerns. Cheers!
There are a few more parts you can buy for the home install to make it more efficient. I can see the manufacturers leaving it out due to install space and cost.
My system is relatively new, but this thread has my thinking of ways I can better use that 4 gallons of waste.
That's handy to know. I was investigating whether I could make my hydroponics system recycle the water but the waste ratio made it unattractive - it was only for science.
Not just drinking water, but what of any liquid sold at the store? How much water does that milk take to produce by the gallon, orange juice, and such. I do know that in many plants most of the water is recycled as its cheaper than sending it out of plant. Even car washes recycle water for reuse.
At home I have a 1:1 ratio. I've got my own well and my own pump, so every liter of water I get out of the well flows out through my tap. I guess you could argue that the electricity needed to work the pump may be produced by means that waste water.
The mine that dug the iron that made your pipes contaminated a lot of water.
In the vegan world its standard to count every drop of rain that hit the livestock pasture as being used, therefore its fair to count the rain that ran off the factory roof where the pump was manufactured as used.
Wells don't dig themselves and although that doesn't happen often, it does take a lot of water to do it, and make the gear to do it, and get the diesel fuel out of the ground and onsite to run the drilling rig.
I drink every drop from a can/bottle, usually, but I am a bit wasteful in the kitchen sink and probably only half the tap water is swallowed. Not to mention my dishwasher uses 5 gallons or 10 gallons or whatever small number every time it cycles and washes my drinking cup (so my drinking cup's share is only maybe 1/2 cup of dishwasher cycle water, but, maybe I was only thirsty for 1/2 cup of water leading to 50% efficiency right there). And of course the dishwasher uses electricity (water) and detergent (water) and natgas to heat the water (contaminated fracking water).
I bet using the usual journalist sophistry techniques I could get your home sink up to 10:1 ratio pretty easy. Maybe not the hundreds to one ratio in the article, but close.
I get your bitter cynicism, but as someone who has worked with industrial processes, this is exactly how we quantify things.
The world is insanely inefficient, and those inefficiencies are REAL even if we have been that inefficient since prehistoric time. All of the points you mention are actual opportunities for improvement, and a 1% reduction in any of them would amount to an enormous savings in water use, fuel use, increase in long term profit, etc.
Modern dishwashers are in fact very frugal with water. The ones sold here typically take about 10 litres (2.5 gal) for a main program.
For some of us, it's irritating of course: the program takes a long time due to the attempts to save water, and we have no shortage of clean water here whatsoever, so time is wasted to save water which could be wasted.
The dishwasher etc is not part of producing the drinking water. It's just a way of consuming it.
But I get your point about the entire construction of the well. And the drilling rig, say it drills 500 wells in its life span. Then you have to consider the water that went in to building the rig, divided by 500. And the water that goes in to disassembly and recycling. And the water that went in to building the drill rig factory. And that went into building the tools that were used to build the factory. Etc.
