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Show HN: An interactive map of countries by tap water quality (iswatersafetodrink.in)
124 points by smayr 68 days ago | hide | past | web | favorite | 93 comments

The primary/top database (Numbeo) you source is of dubious quality - i.e. Opinion based. Other sources vary wildly in reputation and don't offer information down to the city level you offer in search. The link to the CDC is to the homepage and offers no further depth on the subject you are reporting on.

Don't understand why you have a marketing type message that offers a calculation cost of savings from not drinking bottled water. It is not based on if the place searched has drinkable tap water or not. Also where do you get these prices?

As a tech demo it is fine - as a reputable source of information its on par with John Daly recommending Grey Goose to prevent Coronavirus.

This site is contributing to confusing or mis-information about tap water quality. For those who don't take the time to consider your sources, it is doing them a dis-service. You should label this at the top as a non-scientific tool of evaluating of tap water. It almost seems like you are working for a bottled water company.

I'm confused your takeaway here. It definitely does have very "pop-science" data, throwing together whatever data is available in order to create an appealing product that seems to tell you something. The agenda is definitely more pro-environmental and anti-water bottle though. If they were trying to show a more neutral comparison of bottled cost to tap for a region, it wouldn't be phrased in terms of a savings.

For the map itself, Numbeo is not the primary source, that would be the WHO data, which is weighted 3 times more than the data coming from Numbeo to put an emphasis on a more reliable data source.

The cost-saving from not drinking bottled water is not necessarily dependent if the water is drinkable or not, as water filters are widely available and can offer substantial savings -> https://home.howstuffworks.com/save-money-with-water-filter1... The prices are taken from Numbeo and are the average prices for 1.5L bottles. I am aware this is not a perfect calculation method, I am planning to add a cost-saving calculator soon which will offer more flexibility.

Regarding the reputable source of information, you are right. Country-level data can never be a good decision-tool to chose if you can drink tapwater somewhere or not. It has to happen on an area-basis and include scientific reports, which are hard to get as of 2020 as there is no single source/database/API for that, except for very few countries (including the US and Austria), I'm working on that and I'll try to improve the UI so it reflects that one should check the water quality in the area of interest rather than the country itself.

IDK, for me it looks more like a taste map than a quality map. In Spain northern regions have almost perfect water where mediterranean regions do have taste and more problems due the nature of their sources of water. I mean, it's not very useful. You'd drink tap water in my city or Madrid, you wouldn't like it in Barcelona, although you can.

> Don't understand why you have a marketing type message that offers a calculation cost of savings from not drinking bottled water.

I thought that might also be prone to inaccuracies. For example, I live in North York (a burb of Toronto) in an area where our water is paid for in the taxes. So we'd probably save a whole lot more than the estimate by not drinking bottled water. Since it is part of our taxes, we would still be paying for the taps even if we opted for bottled water.

Not to disrespect any country, but the fact that Tunisia ranks higher than Italy it's a bit ridiculous...

Which country exactly would be disrespected in this case? :D

On a serious note, Italy indeed has some tap water problems https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in... , although common sense and the internet telling me that I'd rather drink tap water in Italy than in Tunisia...

You clearly have never been to Belgium (and I’m sure other EU countries) where, who ever can afford it, only drinks filtered water, and typically water fountains in offices have cucumber or mint etc to give it a more palatable flavour. To say it’s the same water as in, ie Sweden is ludicrous.

Hi HN! I made this while I was lockdown-bored.

The data sources are linked on the website. I plan to add scientific reports on water-levels soon on a city-level.

I want to raise awareness on how saving money and the environment often comes hand in hand when it comes to drinking water. For most people around the globe drinking straight tap water or using a water filter is a better solution than giving money to bottling companies like Nestlé!

I'd like to monetize this by either adding affiliate links to water filtration systems. Hope this helps! I think plastic pollution is one of our greatest challenges right now and I’d like to contribute to fixing that.

I've checked my city here is the link, https://www.iswatersafetodrink.in/Russia/Nizhny-Novgorod I don't know where 350$ is coming from. Most of the people here order drinking water in 20L bottles. Bottles are not thrown away, but collected and reused by water company. We spend about 150$/year*person on this, including delivery costs.

You are right, that's one thing I missed. Water bottle prices are determined on a country-level (I assume average bottle prices are higher in Moscow, I should show them ideally on a city-level) and I'm assuming people are buying 1.5L bottles for simplicity's sake. I am planning to provide a calculator soon to add more flexibility to the savings calculations.

I've lived in many places where the tap water is not safe to drink, and in all those places, nobody except tourists was buying 1.5L bottles of water.

In Germany, tap water has super high quality but people still buy 1 liter bottles, because fancy name or sparkling. I appreciate the pro-nature advertisement!

I think a city level would be great, and interesting. Looking at national numbers misses a lot. For example, Canada and the USA are very similar.

However, I live in Vancouver, and when I went to Chicago last year, the tap water was unbelievably bad (tasting). Even the complimentary bottled water in my hotel was bad.

Indeed, just looking at the data on a country-level misses a lot! I am working on providing city-level data, which by the way is substantially harder as the data for most places is hidden deep on some government websites as a PDF, sometimes outdated, sometimes not available at all!

I think it would better to provide "No data" for French Guiana?

Do you mean because of the contradictory data sources? (WHO saying mostly safe, CDC no, Numbeo 50%)?

I saw it now, it's an issue with the GeoJSON, I'll fix that soon!

Looks fantastic! What mapping tool did you use?

It says "Leaflet" in the corner: https://leafletjs.com/

Yes Leaflet in combination with a CartoCDN basemap

This is nice! However I don’t think it’s very accurate to put a number to a whole country, when even the health of the pipes in your own house or even in your neighborhood can affect the quality a lot.

I agree. Our tap water in Portland, Oregon is superb. But when I travel to other states, like California, I'm not sure how they can drink their tap water. At least in Southern California it tastes bad and has the distinct smell of chlorine. Though I suppose if you live with it 24/7 you might get used to it and not notice the taste.

Funny you'd say, I live in Portland, Oregon, and we do not drink the water, except after filtering or heating. We think we've seen enough negative reporting on the water quality, even if it's just touchy-feel reporting about the dead birds in the uncovered water treatment basins. To us, the water doesn't even taste as good as maybe in, say, the Netherlands. Yes, chlorine taste at times.

Even California tap water varies immensely depending on where you are. SoCal is generally bad, which is probably related to most of their water being imported. My hometown, on the other hand, is in the Sierra's and fed by spring water that's pretty identical to the Crystal Geyser water they bottle a few mountains down. San Francisco has pretty great water too, though they did flood what was reportedly the most beautiful place in California to secure it.

Indeed. My mom lives on the other side of town, and has her water delivered by a different water source/plant than my home is. Her water is noticeably worse than mine, a lot more chlorine taste.

Water at my place is very good though, almost as good as some of the best bottled water, and way better than mediocre bottled water.

> By continuing you agree to our use of cookies

In what pertains to the EU, that might not be legal and may lend you in trouble. If you haven’t yet, you should make sure you’re allowed to do that (or even better, don’t do it).

Good point, thanks, I missed that! TBH I need to brush up on GDPR law. FYI The website itself is not using any cookies, but GA and the Crisp chat are using them.

It would be interesting to add statistics for consumption of bottled water for individual countries where this data is available. Bottled water is consumed in many countries even when the quality of tap water is perfectly safe.

For example, here is per capita consumption of bottled water in Europe in 2017, by country:


Note that this includes sparkling water. At least in Germany, I would estimate >80% of bottled water being sold to be sparkling.

That's interesting, I'll look into that! Sparkling water might be indeed a reason why people buy bottled water, although there are household solutions for that as well.

Well, above 'sparking water' was written, but 'mineral water' was meant. Sold in bottles and in restaurants and commonly purchased is indeed mineral water. What you can easily do at home is carbonize the water and make it sparkling, without, of course, the (real or imagined) health benefits and different taste of mineral water.

Nice. One thought... the greatest "oh that's neat" payoff for me was seeing a note that in some county, bottled water was widely available. And in another, not. Which prompted me to wonder which countries that was/wasn't true for, and how it relates to tap quality. But the UI didn't seem to make that easy to explore.

So perhaps pull more information up to the top level? At least on desktop?

One pattern of use is "exploring the world". On desktop, this might involve clicking once to get the little popup, with a side-effect of unpredictably zooming and panning the map; then clicking again to get an info page; and then back page to return to the map. For every country of interest.

I wonder if this could be made lighter weight? The country outline is nicely highlighted upon mouseover. One might imagine adding much of the info page core content, somewhat abbreviated, to a slightly larger popup. And even showing that popup upon mouseover (with perhaps a delay, or mouse velocity tracking for intent). So then one might simply mouse move around the world, seeing water quality, bottle availability, etc, and able to more easily spot "oh that's neat".

Thanks for your thoughts! I'll try and make it easier to "explore the world" as you said, definitely going to remove the "zoom in". I initially tried to keep the data shown on the map compact to keep the page load time reasonable, I'll see what I can do!

Hey man, really like it. Found out that the water where I am might be a bit sketchy - didn't know.

What are you using for the city/country autocomplete?

Hey, glad you like it!

Yes I am using Awesomplete with some custom CSS and loading the autocomplete results on page load (I figured that's more performant in my case than loading it on each keystroke).

Looks like it's Awesomplete: https://leaverou.github.io/awesomplete/

Something like this is interesting, but I find it's missing a lot of the info that I care about. For example, here in Denmark, because our underground is chalk instead of rock, our water has high amounts of calcium - this makes the water 'hard', which means we can rinse off soap very easily in the shower, but most of our water-appliances and coffee machines struggle with limescale, and towels need to be washed with a lot of fabric softener or they will come out kinda stiff and scratchy. I'm sure there are other local concerns such as this (e.g. chlorine levels) that would be nice to look up.

Taking 'hard' water for granted since I was born, it's quite surprising and interesting that water cannot rinse off the soap.

This year I went abroad for a business trip. In the hotel, after washing my hands or taking showers, I found I couldn't rinse off the soap. I was so confused because it was so hard to do it, plus I brought my own soap. I inspected, smelled, and tasted the water carefully and didn't find any difference. In the end, I learned there is such a thing called 'hard' water.

I live in an area of "soft" water. I knew of the concept but I had no idea it affected the rinsing off of soap. I had also never noticed that soap might have rinsed off easier when traveling. (And even if I had, I'd probably just have assumed the soap to be different.)

Conversely, I suppose the buildup of limescale might surprise me if I were to spend time in an area where water is significantly "harder".

I'm dubious about the Numbeo value for the UK - 75.36 / 100 seems pretty low. UK tap water is of an extremely high standard.

It's of a high standard, but I wouldn't say extremely high. Many places with lower population and large amounts of deep aquifer water have much better quality water than the UK.

It'd be interesting to know how much chlorine, if any, is added to make the tap water potable. There are many places in the world where it's perfectly safe to drink the tap water, but not pleasant.

When I was travelling in Canada I was checking if the water was safe to drink. And the government website argued it was safe to drink tapwater precisely because it was purified with the help of chlorine. In Netherlands many of us have the opposite view that it's not safe to drink tapwater if there is chlorine in it (let alone the taste). Interesting contrasts in cultures :)

I think you may have misunderstood. It is pretty standard to use chlorine in the purification process, but that chlorine is not left in the water. There should be negligible chlorine in any water coming out of the tap. I've certainly never been able to smell it let alone taste it anywhere in Canada.

There is residual chlorine or today more likely chloroamine in tap water. Part of the reason for that is to keep pathogens from growing in the pipes. Though depending on season and basic water quality there may be none.

If you care, ascorbic acid or one of it's salts line sodium ascorbate reduces[1] chlorine and chloroamine. Takes just a tiny amount, works instantly.

[1] Chlorine -> chloride. chloroamine-> chloride + NH3.

I could have misunderstood! But when you can smell it when you shower and taste it when you drink it, there is a considerable amount of residue of chemicals in the water. Maybe I smell it because I'm used to water without it. I don't know if it's actually harmful, but when there are alternatives widely deployed, for instance in the Netherlands I don't see the reason for taking the risk.

Canada is a very large country with a wide variety of water. I'm quite surprised that you were somewhere where you were able to smell/taste chlorine in the water as that has not been my experience, but at least one other commenter seems to agree with you. That said, small amounts of chlorine are perfectly safe.

I grew up in a city where chlorine is not used. In Canada, and almost every other country I've lived in, I can clearly taste the chlorine in the water, while locals always insisted it was tasteless.

Lake Ontario (Canada) water definitely has some chlorine taste/smell, but you get used to it and it is perfectly safe.

Maybe Canada is an exception, but in most places the chlorine is left in the water because the distribution network isn't entirely sterile.

Missed the Canada part. Canada likely has very pure water from snow melt.

So half a year they have to get it from north or preserve in sterile tanks? :) I live near Urals above 99% of Canadians and there is no snow for 6 months.

An example, San Francisco historically got it's water from the Hetch Hetchy Reservoir. It's all from alpine snow melt and springs. Used to not be chlorinated because it's organic content is very low. I assume a lot of Canada is the same.


There is more precipitation during a warmer half of the year on their territory outside of ocean shores where it's in reverse, also the gap between those grows further to north.

Most Ontario Canada's water is from the great lakes

This is a rather common effect. Does a lot of police on the streets make you feel safe or unsafe? There are obvious and opposite arguments for both possible answers.

In general, the taste of tap water in The Netherlands is better than in for example Belgium. Both have the same rating (and both are safe, not just as tasteful). Mind there are be locational differences in taste, water in Gent (BE) tastes better than in Kortrijk (BE) and water in Arnhem (NL) better than in Amsterdam (NL).

That's indeed interesting! Chlorine in the tap water seems to be one of the major factors why people buy bottled water, even though otherwise it might be perfectly healthy.

It seems to be by city and not by country. For example, Toronto and Mississauga Ontario, Canada, have different ratings. The initial map is by country, but that's a given.

I was initially surprised by the Toronto/Mississauga results, but then I remembered Mississauga had one of the best mayors they could have possibly asked for, until she retired after serving her office for 36 years. She must have been doing something right.

One thing i found interesting while living in Dubai was that (from what I heard) the water authorities provided potable water to buildings, but most buildings had dubious storage/distribution.

I always bought bottled water there, that decision felt justified when my water came out sandy one day. (Though I suspect the building). I had friends who drank tap water for years and were okay, so mileage varies.

That's a very interesting fact, thanks for that!

In many parts of New York City, the water contains tiny bugs called copepods[1] (actually a rather interesting bug).

For some, that is an issue. For some that is an advantage (protein!!). For most, it makes no difference.

But I wonder how common such a thing is outside NY, and what other surprises our water contains.

[1] https://www.foxnews.com/science/whats-in-your-water-probably...


LOL GTFO. This is nonsense.

Hey, can you tell me why? Don't know specifics about Fiji.

> The municipal water supply in Suva, Nadi and other large towns is chlorinated and can usually be trusted, but elsewhere avoid untreated tap water.

This is true everywhere in the world, is it not? What are you judging if not the municipal water supply?

This is sourced from Lonelyplanet and to my judgment this means tap water is drinkable in larger towns, while it's not in smaller towns in general.

This is not the same across the world, in countries like Switzerland, for example, you can drink the tap water virtually anywhere, while in some African countries this is not even true for the capital cities.

It's interesting how many places have contradictory advice depending on who you're listening to.

Eg. Hong Kong: WHO says it's safe. CDC says it isn't.

One suggestion: If the top-level advice is that water from a country (eg. Japan) is that it's safe, it would be useful to call out particular places in that country where it isn't. (eg. Fukushima in the case of Japan)

WHO's index of 96/100 for Russia (contradicting all other sources) makes me question WHO methodology or sources. I get that my personal experience cannot be authoritative source (except for myself) and is purely a single data point at best, but still...

Russia is a vast country, but as a former local (north-west region) I'd say that it's generally not a good idea to drink tap water there. I haven't talked much about water quality intentionally, but I believe everyone I know holds a similar opinion, and doesn't drink unboiled tap water.

It could be "safe" in a sense that one probably won't get sick from occasionally drinking it, but anecdotally - in comparison to bottled water, tap water is of questionable quality just about everywhere in Russia.

Unless we talk about separate kitchen taps with reverse osmosis systems. Even then, most people I know, don't drink that water directly but only use that to fill the kettle for boiling.

A lot of Russians also believe things like drinking water with ice cubes will give you a sore throat. I wouldn't put too much stock in something just because the locals believe it.

Personally, I think the water boiling thing is one of the dumber things they do because, at least in most of the big cities, the thing that is most likely to be wrong with the water is not bacteria and other things that would be killed by boiling your water but rather heavy metals (and, last I checked, boiling my water does not remove lead!).

Also, anecdotally, I've yet to die from drinking from drinking unfiltered Tomsk tap water & never noticed abnormal levels of anything nasty during blood work. I think there is a lot of paranoia about the water system here that has generally been undeserved over the past decade or so.

I call bullshit omn that map. The water in the us tastes like cholrine and is better rated than the one in germany and bosnia, which both don't have that. Also the water is not adviced to be drank from tap in portugal where i was recently, and it is rated with 80?!?!?

Tap water quality differs from one municipality to another, so I wonder about the value of a map by county. E.g., in Germany the quality is generally good, almost universally safe to drink, but in some rural areas with intense agriculture, the water might be so rich in nitrates, that occasionally (seasonally?) it is recommended that pregnant women and small children drink bottled water.

The taste and suitability to make tea differs wildly w/o impacting health (matter of carbon content). And it's not quite clear to me, whether the amount of chlorine should affect the listed water quality. Some people are sensitive to it, I'm not. And you can always let it sit for a while and the chlorine will evaporate.

Thank you for not calling it a heat map.

I was so close to doing that before finding the correct term :D

As others have noted, it would be cool to see this broken down into more meaningful units.

You won't be able to map out every individual house with it's copper/plastic/lead piping, but watershed maps might be nice for this. Also would look way cooler. :)

Try https://MyTapWater.org or https://www.ewg.org/tapwater/ for better info in the US

Thanks for those links! It seems https://www.data.gov/ is a great source for US tap water data used by both websites!

Looks good, but probably not very usable. I know some areas in germany, where you cannot drink the water because of too much chalk. But in general it is very good in germany.

But in spain for example I could never find a tab, I could drink of - way too much chlorine.

That's a good point, I think it very much depends on the area you are in, that's why I added sub-pages for each country, e.g. https://www.iswatersafetodrink.in/germany/Munich. Although to be fair they are still lacking serious data, I'm working on that!

Someone in the chat was kind enough to provide me a good water quality source for Hamburg, if anyone is interested here is the link: https://www.hamburg.com/residents/housing/12792124/water-qua...

>where you cannot drink the water because of too much chalk

Is this a taste issue or a health issue?

Well, for me, that would be allmost the same, as I believe taste has a biological reason, as a strong indicator whether something is good or bad for my health. (no, pure sugar does not taste good for me)

But officially science says currently no, chalk in water is not a health issue and maybe even good.

(but I would not be surprised, if that changes in the future, like with many other things)

This is ridiculous man, the size of Australia, how can you sum it up to one number and compare it to the rest of the world. Just ends up saying a binary system of drinkable <> gives you the run.

Belgium having the same quality on the map as the Netherlands shows me that the source of then information is wrong or the scale isn’t nuanced enough to be of any use to me. Belgian tap water should, on any scale, be at least a category lower than Dutch tap water.

Belgian tap water is horrible compared to Dutch water. Source: I lived in Brussels for 5 years. Could be just the brusselonian water, but there is a reason that bottles water is a thing that everyone buys in Belgium and practically nobody buys in the Netherlands.

You are right, I should have specified that tap water quality doesn't include the taste of it.

Apart from that Belgium tap water is perfectly safe to drink! I don't know specifics about the tap water in Belgium but something as simple as a carbon filter removes Chlorine and a lot of the bad taste!

I have been to Belgium before, to Brussels and Leuven, as far as I remember I liked the tap water better in Leuven, but that's just anecdotal. What I want to say with that is that tap water usually varies from area to area.

Taste/appearance and safety are not really the same thing. Many places have water that people find unpleasant due to mineral content or other factors, but which is safe to drink.

Huh, the water in Saint Pierre and Miquelon is only 91/100, worse than the US and Canada.

This is awesome. It would be nice to be able to see the quality by state/city too.

Click on the country and then "find out more"


“Explore other Countries in Australia”.


Yes. Funny how North America shows the opposite correlation.

It's a worldwide correlation. But of course communism is not the only factor at play here. Population density, total population, size of country, and so on. They all play a part. In North America the correlation is skipped because these other factors are so vastly different between the countries. In South America not so much. Except for Brazil.

There's exactly one "communist" country on earth, which is North Korea. And that happens to be quite good on this metric.

Whatever correlation you are imagining in South America is completely spurious, even with your litany of reasons to exclude anything that doesn't fit your worldview. Most every government on the continent has switched between left- or right-leaning governments at least once in the last decade, and I assure you tap water quality changes much slower.

Brasil, for example, switched from Da Silva (left) to Bolsonaro (right) just a little more than a year ago. And, oh, look: the map's CDC data is from 2018: https://www.cdc.gov/healthywater/drinking/data/index.html

The Scandinavian countries that are frequently cited as examples any advanced nations' left strives to imitate are obviously killing it on drinking water quality, as well.

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