Found this. The associations of the author should bring smiles to face of the most ardent environmentalist.

Everything in life involves risk. Usually unknowingly, we all do a benefit/risk analysis when evaluating most things. Some water can be quite potable and safe to drink while containing substances that react with copper to produce unpleasant and dangerous byproducts.
From age 91 to her death at 100, my wife's mother drank water from PEX pipes exclusively. In her early life, the household water source was an open spring.

Here is a link that might be useful: LEED

Basically, it makes me look as if I plagiarized Polly Osborne, lol. I'll have to read over the studied linked in the post.

I do like the fact that someone brought up the EU has been using pex for 30 years. Europe seems to have must higher standards of health vs the US, as a whole. Obviously, it's not a solid argument either.

Another poster, ironically linked to a study being conducted by Purdue with an even more ironic update that occurred today:

http://www.southce.org/ajwhelton/?p=4717

and continued here:

https://greenbuildexpo.com/Attendee/Schedule/SessionDetails/13864

That lead me here:

http://www.southce.org/ajwhelton/?cat=6

Too much reading to even comment on. I'll have to update later as I haven't even broken ground yet.

I won't touch on the mother in law argument as it's simply not relevant.

I thought MTBE had been banned from gasoline. California had mandated its use until it showed up in the drinking water supply (from marine use in boats). Around here it was polluting ground water from leaking storage tanks. Apparently it does not break down and evaporate.

So the switch has been made to ethanol which causes its own set of problems.

So, Bus Driver, you are saying that drinking water from PEX killed your mother in law?!? And in just 9 short years! Damn, that's some crazy lethal stuff!

Yes, the EU has been using it for some time and they generally have more stringent environmental regulations.

I am all for making sure things are safe, but I also echo what Bus Driver is saying about risk: We tend to be very, very bad about weighing relative risk... the classic example is my co-worker who was complaining about the pesticide residue on apples but who also smoked cigarettes. Another one was saying how he would never own a smaller car because they are unsafe in an accident. He drives a big SUV and.... a motorcycle.

There are tons of chemicals, radiation, etc. that have the potential to cause cancer. Sure it makes sense to be prudent. That said, our lifespan is much longer now. Eat a balanced diet, exercise, don't smoke and avoid excessive alcohol (and heroin, evidently - who knew?) and you will be miles ahead as far as health and happiness.

A new county-owned water line is in the planning stages for a limited area near where I live. The engineers are planning to use a variety of materials depending on the soil conditions and land contours at various places. At the public hearing, one of the citizen attendees pointed out health risks attendant to one of the proposed materials. The presenter pointed out that the EPA considers that there is a health risk because it is projected that a person consuming 7 quarts of that water daily for 70 years would accumulate a harmful amount of that substance. I wish I could recall more of the specifics of his presentation.

Wow, almost 2 gal of water a day for 70 years before it shows up as being potentially harmful.

Of course the real risk is installing an infrastructure with something that's toxic in a way that we aren't aware of yet such as was the case with lead plumbing.

I think it's good to have people who raise those issues - it keeps people on their toes. Look at the environmental disasters that we are cleaning up - from lead based paint, MTBE in groundwater from buried tanks, asbestos insulation, etc. We don't need to make those kinds of mistakes anymore. At the same time, we do need to be careful about not being paralyzed by very, very small risks.