Right. There are pages or whole chapters of other posts on this subject, on this and other threads. I was continuing those threads (and linking them together) more than I was responding to your particular post.
I added something that I hadn't said as clearly as I wanted to last time I saw this tip.
Your post brought it back into view (thank you), so I added the comment I had been saving for a while.
I could have said "By the way, pennies newer than 1982 are mostly zinc, which is much more toxic then copper, and if the zinc started to dissolve ... yack yack yack."
>> Also, it would take a heck of a long time for the copper, any copper, to sit in water for it to do anything otherwise we would all be replacing our copper plumbing every two months.
I was talking about
tiny amounts dissolving that would either bother birds, or concern bird lovers. We didn't find very definite numbers about what the totally safe levels of copper exposure would be for birds.
(Even with zinc and humans, where it's a more serious issue, I recall numbers like 10 mg recommended, , 40 mg probably not harmful, 75 mg maybe harmful or 150 mg probably some chronic effects. That's for big, fat human beings, so the numbers for birds might be much much lower.)
As to city water causing copper pipes to corrode so fast they would need to be replaced: yes, you're very right. Many towns neutralize acid water and pump it around slightly alkaline exactly so that it doesn't corrode pipes as fast and put copper, iron or whatever bad-tasting ions into drinking water.
Even with water from acid rain: you're right about it not eating copper so fast that pipes need replacement frequently. To corrode copper tubing enough to cause a leak and need replacement, acid water would have to eat away something like 30-50 thousandths of an inch. Call it almost a whole millimeter! I think it would taste very funky if it was being eaten away by one millimeter per decade.
http://www.gizmology.net/pipe....
BTW: the issue with toxicity in copper pipes with acid water is more the lead in the solder, if the pipes were soldered. Lead is so much more toxic than copper that a little solder is a bigger problem than long pipes! And yet, Rome city water was delivered in lead pipes and they didn't drop dead in droves.
Maybe they hadn't invented acid rain yet.
Maybe (I'm speculating) the copper metal in our modern pipes
encourages lead solder to dissolve because the lead is a little more electronegative than copper. The Romans only had lead in their system, no copper, so there was no "battery" between two dissimilar metals. "Galvanic corrosion" - that's the phrase I was looking for.
