# Tap water: what would be the correct percentages? **URL:** \ **Category:** Factual Questions\ **Created:** [November 9, 2009, 10:53pm UTC](https://boards.straightdope.com/t/tap-water-what-would-be-the-correct-percentages/516957 "2009-11-09T22:53:23Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [November 9, 2009, 10:53pm UTC](https://boards.straightdope.com/t/tap-water-what-would-be-the-correct-percentages/516957/1 "2009-11-09T22:53:23Z")
Consider this statement: “X percent of the world’s population still don’t have access to clean, drinkable water on tap. Y percent of all the people who ever lived in the 20th century didn’t have this.” I’m trying to establish the right percentages to slot in for ‘X’ and ‘Y’. Or, if exact figures are never going to be possible, I’d like to at least establish credible, plausible numbers backed up by some citable source(s). When I refer to potable water ‘on tap’, I mean either in your home or very nearby, so that (as in the UK or all of the USA I know of) it is so easy and convenient to access drinking water at any time that it’s easy to take it for granted. Bottled supplies don’t count. My point is to underline that something so important, that it’s so easy to take for granted, is actually something of a miracle of technology, engineering and infrastructure; one that many, many people in the world and in history either do not have or did not have. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 9, 2009, 11:34pm UTC](https://boards.straightdope.com/t/tap-water-what-would-be-the-correct-percentages/516957/2 "2009-11-09T23:34:47Z")
You also want to define “drinkable”. Many places have running water systems with pathogens that the locals have all gotten used to, but which will wreak havoc with tourists. ---
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [November 10, 2009, 1:50am UTC](https://boards.straightdope.com/t/tap-water-what-would-be-the-correct-percentages/516957/3 "2009-11-10T01:50:46Z")
> [@Chronos](#): > > You also want to define “drinkable”. Many places have running water systems with pathogens that the locals have all gotten used to, but which will wreak havoc with tourists. Satisfactory and sufficiently clean for locals, forget about tourists. ---
**Author:** ![NinetyWt](https://avatars.discourse-cdn.com/v4/letter/n/cc9497/32.png) [@NinetyWt](https://boards.straightdope.com/u/NinetyWt)\ **Post date:** [November 10, 2009, 2:32am UTC](https://boards.straightdope.com/t/tap-water-what-would-be-the-correct-percentages/516957/4 "2009-11-10T02:32:54Z")
Page 6 of [this website (pdf)](http://www.unicef.org/specialsession/about/sgreport-pdf/sgreport_adapted_stats_eng.pdf) has some statistics, and also says: > [@](#): > > During the decade, global coverage rose from 77 per cent to 82 per cent. This means that nearly 1 billion more people gained access to improved drinking water sources\* during the 1990s. … but > > Some 1.1 billion people still lack access. Coverage remains low, especially in poor rural areas of Africa and in informal peri-urban settlements. Water quality problems have grown more severe, as dangerous levels of arsenic in groundwater have emerged in several Asian countries during the decade. > > Issue > In 1990, the challenge of ensuring universal access to safe drinking water by 2000 meant reaching 1.2 billion people, or 23 per cent of the world’s population, with clean, sustainable water supplies. This challenge remained despite the gains made during the International Drinking Water Supply and Sanitation Decade > (1981-1990). The data is from WHO/UNICEF. I’m not sure how to get at your second statistic. ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [November 10, 2009, 6:18am UTC](https://boards.straightdope.com/t/tap-water-what-would-be-the-correct-percentages/516957/5 "2009-11-10T06:18:39Z")
Obvious problem with your second statement: does it count if a person lived their whole life without running water but then got it in the last few years of 20th century? What if they lived mostly in the 19th century and never had it in the 20th either?