You are wrong about several things:

Firstly the water chemistry point. Good drinking water and ultrapure water is not the same and the carbonate hardness and pH can vary a good deal in good drinking water and within this variation there is a huge difference in the solubility of lead. Therefor is is plausible that changing the water source can result in lead dissolving.

Secondly, the water in Flint has been tested before and the lead has increased together with other water quality problems after the change.

To answer to your question ("Why do people think that the water they drink, the food they eat, etc, is contaminate free?"). Because we regulate pollution much more than is done in your country. Also, we test food and drinking water with many chemical analysis much more frequently than you do.

Obviously it has also been illegal to use lead in drinking water installations here for several generations.

You are wrong about several things:

Firstly the water chemistry point. Good drinking water and ultrapure water is not the same and the carbonate hardness and pH can vary a good deal in good drinking water and within this variation there is a huge difference in the solubility of lead. Therefor is is plausible that changing the water source can result in lead dissolving.

Secondly, the water in Flint has been tested before and the lead has increased together with other water quality problems after the change.

To answer to your question ("Why do people think that the water they drink, the food they eat, etc, is contaminate free?"). Because we regulate pollution much more than is done in your country. Also, we test food and drinking water with many chemical analysis much more frequently than you do.

Obviously it has also been illegal to use lead in drinking water installations here for several generations.

Dear Luisiana:

I study social values change and what I can say from this point of view --environmental problems are not my field- is that society has started to become aware of environmental issues only in recent decades. Culture change is slow. Not only common people, but also journalists, politicians and others are becoming gradually conscious on the many facets of the problem. So I think it is not rare that this kind of news often "explode" in the media and that people usually don't realize how widespread the problem is. 

@Henrik,

To your point, which happens to be classic. You say, "We regulate better than others..." Well, do you think that your food is free of slave-labor? Do you really think that low price was just for you? Do you really think pesticides, herbicides and GMOs are not soaked into your food? 

It is important to reconcile the fact that everything is polluted, in other words, there is no such thing as pristine, not any more there is...

Here's a little diddly for ya: every human has plutonium in their system and it is from all the nuclear tests that have occurred decades ago. It is so common for people to think: if I throw this into the sea, it will no longer be a problem. It's a problem, all right, and not just for you, but for everybody else on the planet.

Firstly, my main point was that the the chemistry and environmental engineering behind your Flint water comment is dead wrong. This likely makes me classic as these disciplines by long experience are useful. The lack of this insight by public employees in Flint is the reason for the polluted water.

My point to your statement question is more exactly that here we regulate more, stronger, with many and verified data, and in a highly transparent system. So we can minimize fraud with results (Flint) and pick up new contaminants as early as possible. Therefore we know that food, water and the environment is polluted and to which extend so we can ensure that our exposure is low while yours is likely higher but certainly much less recognised. 

Regarding the plutonium pollution it is likely that there are extremely low concentrations of this in my food (but not the water) which we also quantify concentrations to the extent it is relevant. We can even add to the information that it comes mostly from irresponsible experiments performed by your country.

Switching water sources in Flint, Michigan, has resulted in “toxic waste” levels of lead contamination, putting an entire county in a health state of emergency.

http://www.healthline.com/health-news/how-toxic-is-water-in-flint-012516#1

This essentially tells us how the government is unconcerned about the well-being of its ordinary citizens, even in a self-claimed democratic country such as the U.S., but things in other countreris may be worse. Deeply underlying this is the question whether a government, even if elected by public vote, really represents the voice and will of its general citizens, or merely represents the interest of a small handful of  people.

Well, TTIP and other "agreements" will soon put an end to any specific country's internal standards for food, water, medicine and more still. 

It is a wonder to me how anyone can BELIEVE "their" government. The greatest myth ever told was democracy. 

Polution may affect water, and in that case the responsibles for the water quality may take appropriate measures.

How can anyone believe that the lead pipes did not contaminate the water before the so-called incident? That chemistry is irrespective of the testing... What is more likely the truth: the lead contamination was always there, as it is in every major, antiquated city infrastructure, and the truth only became apparent when the citizens took the water for testing by an independent researcher. Obviously, the lead was always there, but only became known when someone outside the local charade-system tested the water. 

The kids, the parents, etc, were being poisoned all along...

We can believe so because it is according to the known water chemistry and documented by previous analysis.

Lead remain in the pipe material if the water has a sufficient high alkalinity. Once the supplied water is changed to river water with lower alkalinity lead begin to dissolve into the water.

@Henrik,

The deal is that the local regulators and watchdogs blessed the water for decades, including during the period of the supposed crisis. The only reason the "truth" came forward and was undeniable was that a third party, an outsider, tested the water and confirmed high levels of lead, otherwise, we wouldn't even be talking about this "event". 

This goes for other known problems like GMOs, where testing has shown certain "issues" or "problems", yet we are told "all is fine." 

Sound familiar? 

My point is that humans tend to lull themselves into a false sense of belief, accepting the apparent "Goodness" of their world. They only realize the pernicious nature of everything around them during certain events, like this Flint thing.

I have read that the results of analysis over the decades are in the archives. The high lead concentrations only occurred after the change. I understand this was picked up in the routine analysis but there was a failure to react on the high concentrations until a university analysed the water and published the results. Obviously we would label it criminal neglect in my part of the world. 

I'll let the attached article do the talking...

Quoth: "Another mystery that must be examined very carefully in the days and weeks ahead: How is it possible, that Flint “passed” the official EPA Lead and Copper Rule sampling overseen by MDEQ?"

If it passed in the incidence of a supposed "major contamination", then it surely must be true that all earlier test results are true and show a clean bill of health.

I am sure this practice is widespread and covers all major continents, governments, both local and national, and I am also sure that each reported test result is trustworthy. This includes food, medicine, soil, pesticide use, recycling, disposal of toxic electronic equipment...

http://flintwaterstudy.org/information-for-flint-residents/results-for-citizen-testing-for-lead-300-kits/

It still seems that you are unable to understand that the previous water source has a higher alkalinity which will prevent lead from going into solution.

Lead has many oxidative states and they all exhibit differing solubility in water, moreover, solubility is rather numb to PH. Once again, people tend to psychologically believe the words told to them, regardless of the evidence or past history of counterfeit. 

If they tested the supposed "bad" water, which absorbed massive amounts of lead, and these tests passed with flying colors, then it is logical to question all previous tests.

You see, it's in the interests of YOUR government to avoid any undue snafus, hence, they always maintain a picture of "Nothing to see here, move along..." 

God bless this world...

The diagram shows that lead controlled by solubility to be below 15 ppb as long as pH is between about 7 and 10. This is not redox dependant.

Diagram shows solubility of all species of lead, throughout PH of 0 to 14. The scale is in volts, a measure of solubility. In other words, all such species do dissolve, except for elemental lead. Lead pipes are made of elemental lead, but they corrode from reactive species dissolved in water. The upshot is that all water flowing through lead pipes contains dissolves species of lead.

Now, once again, if--as implied by the authorities--all is under control, then how is that all the residents in Flint have high levels of lead in their system. This is certainly not the accumulation of a mere few months of exposure. The fact is that these residents have been exposed all their lives. 

On the aside, I think the major problem for people in Denmark is the ongoing nightmare of Chernobyl. Contamination from this disaster site continues to pollute all Europe down to Turkey. I won't even mention Fukushima; but, once again, it must be all OK, since we do not hear anything about it. Don't forget, a lot of your food in Denmark comes from Ukraine and similar areas.

http://www.ncbi.nlm.nih.gov/pubmed/20002056

One other thing, this magical 15 ppb is touted to be a safe level, if below. Well, the article, attached, reports that the 90th percentile of their tests for lead in Flint water is a whopping 22 ppb. Now, it seems to me little difference if the concentration is 15 ppb or 25 ppb, but wait, there's more, 60% of the households had conc. below 5 ppb. This all adds up to either "much to do about nothing" or a case of "a distinction, without a difference". In other words, if 60% of residents are being exposed to lead levels below 5 ppb, then how is it a crisis, also, how can it be that all the residents in Flint have been contaminated by lead exposure in their drinking water. Something's amiss...

http://flintwaterstudy.org/information-for-flint-residents/results-for-citizen-testing-for-lead-300-kits/

Your statement "The scale is in volts, a measure of solubility" proves that you do not understand the diagram. Would you amuse me by stating the conversion of 1 volt to mg/L of lead?

Conductometry.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3747999/

I don't think the paper shows your point. Can I have the conversion factor for the concentration of lead? 1 volt = x mg/L.

Here's one source...

http://www.ehow.com/how_6925703_convert-conductivity-concentration.html

Yet, another...

http://www.uni-ulm.de/physchem-praktikum/media/literatur/2011_conductivity_Ka_ed100132m.pdf

Again not related. It doesn't even contain the word "volt".

1 volt = x mg/L?

OK, let's get off the volt thing... Let's get back to the point of the question: isn't it obvious that the lead contamination was ongoing in Flint, MI, including before the supposed crisis, furthermore, isn't obvious that the ensuing kerfuffle is nothing more than a charade to bamboozle the public back to sleep on the issue of pollution, powerlessness regardin safety and the incompetence of government?

Agreed. Volt is not related to concentration but to redox level.

The answer to your question remains that it is not so as there are plenty of evidence that the water chemistry has changed in 2014. Before pH and stabiliser was inhibiting dissolution of lead, after the change there is no stabiliser and pH is too low.

http://cen.acs.org/articles/94/i7/Lead-Ended-Flints-Tap-Water.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+cen_latestnews+%28Chemical+%26+Engineering+News%3A+Latest+News%29

Conductivity has everything to do with solutes. The resistance goes down with an increase in dissolved charged species. You can measure your own tap and conclude to what degree contaminates pollute your tap water. You will not know what species are there, not without further detailed analysis; but, you can definitely measure the partial molar increase in contaminates. 

Now, before I spend too much time on it: take a look at the attached picture, which depicts the difference in water quality for Flint versus that of Detroit. OK, I can easily see a color difference, but the supposed "clean" Detroit water still looks like ass. 

Obviously, the contaminates are there--I can see it! 

So, once again, the contamination was always there and this "crisis" is really a matter of things getting way out of control and the authorities being forced to reconcile with the fact that they pump poison to their citizens. 

http://mashable.com/2016/01/24/flint-water-crisis/#oZS709jfEkqt

http://1.mshcdn.com/wp-content/uploads/2016/01/2016-01-24-flint-header.jpg

http://i0.wp.com/flintwaterstudy.org/wp-content/uploads/2015/08/figure-3-edwards.png?resize=540%2C1024

This article goes through the sad fact that most cities in the US have serious problems with lead poisoning...

They don't report lead contamination in places like Nigeria, Brazil, etc, cause they don't care...

http://www.motherjones.com/environment/2016/02/lead-contamination-flint-your-county-cdc

Here's another diddly for ya: it turns out the phosphate used to make water "safe" is itself a contaminate, toxin, etc... 

Once again, why accept what the authorities tell you as the Gospel truth?

http://www.foodnavigator.com/Science/Phosphate-in-food-is-health-risk-that-should-be-labelled-claim-researchers

http://www.crotonblog.com/archives/2007/11/27/letters/fyi_zinc_orthophosphate_works_by_coating_water_pipes_with_lead_phosphate_and_copper_phosphate/

Voltammetry test method for lead in water, the word VOLT is in the name of the testing method. enjoy...

http://www.asdlib.org/onlineArticles/elabware/kuwanaEC_lab/PDF-23-Experiment5.pdf

http://www.ncbi.nlm.nih.gov/pubmed/10976686

http://www.voltammetry.net/_media/pine/pine/drl10008_anodic_stripping_analysis_of_lead_in_water_laboratory_.pdf

Conductivity does not have the unit “volt”. If you measure conductivity you get a rough estimate of sum of the concentration of dissolved ions. You cannot detect lead with this method as leads concentration is controlled by solubility to a concentration much lower than major ions such as sodium, chloride, carbonate etc.

You can measure the lead concentration by voltametry but the concentration is given by the current (amps) and the volts are fixed in the  analysis to ensure that one measure the electrochemical reaction of lead only. 

Mowing on to your comments about the visual appearance of the Flint water: You cannot tell from the visual appearance if the water is corrosive. Read the explanation of the water chemistry involved in changing water source.

http://cen.acs.org/articles/94/i7/Lead-Ended-Flints-Tap-Water.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+cen_latestnews+%28Chemical+%26+Engineering+News%3A+Latest+News%29

Strange, the visual appearance of the water in Flint, after switching the source, caused concern among the residents and prompted them to go and seek third party tests. The human eye is a great detector. 

Often, someone will harp on some particular point they are adamant makes a difference in the debate, yet precious time is wasted upon what is ostensibly an irrelevant issue. I see no difference in current versus voltage, for they are related through resistance...what whatever.

Once again, the real issue or point of concern, for me at least, is that what is officially presented to the public is often wrong, especially, if it is an issue with financial ramifications. Lead contamination is a major problem across many communities, not just Flint, MI; furthermore, most governments have a financial incentive to avoid admitting the true state of their water, for it would necessitate major investment in the infrastructure. 

In the case of Flint, MI, I still contend that the "problem" of lead contamination was a problem before the "event" occurred after switching the water source. The media claims a major crisis in Flint, MI, even though 90% of the homes are believed to be around 25 ppb lead, at most. In other words, I strongly doubt the lead levels were much lower before the water source switch. The alarmingly high lead levels measured in the children and residents of Flint did not accumulate over a span of a couple of months. 

The attached article/study does a great job of reporting that blood lead levels were high before the Flint water source debacle, also, that it exhibited a seasonal change, which is due to lead contaminated soil. Once again, the problem of Flint--or your city or town, for that matter--is the fact that pollution is so pervasive in our modern society that it would be scant possible to avoid it.