Many of the indoor water fountains and the cat fountains and pet fountains I make have a copper component to them and occasionally I am asked if this is safe for drinking water. The short answer is that copper is absolutely safe as a material for delivering potable water, and in fact, is beneficial. Now here’s the long answer.
As you may or not know the building trades are heavily regulated by quite a number of government agencies which are designed to look out for the consumer. Copper pipe is an accepted plumbing material for all building codes (and there are a lot of them.) It is safe for both hot and cold water, in your home and in your cat fountain.
Apart from the fact that copper is a necessary part of our diet which we consume by breathing, eating and drinking, copper in water delivery systems stabilizes. It does not absorb contaminants, it does not easily corrode unless exposed to very high or very low pH values. Water has neutral pH and has no corrosive effect on copper. Copper is biostatic, meaning that it does not promote bacteria growth.
In fact, quite the contrary. Not only is copper not at all harmful, it has been fairly recently discovered that there are healthful benefits of drinking water supplied through copper tubing, and this includes the copper in your little cat fountain’s plumbing too.
The antimicrobial effects of copper helps copper plumbing tube to preserve the purity of drinking water. Copper plumbing tube has been found to inhibit water-borne microorganisms, such as bacteria, viruses, algae, and infectious parasites, in the drinking water supply that resides in the plumbing tube.
Since copper plumbing tube is non-porous, it can prevent petrochemicals, insecticides, and organic contaminants from absorbing into the tube and polluting the water supply, and copper plumbing lasts for decades and is 100% recyclable. Therefore, copper tubing does not contribute to the earth’s solid waste problem.
Now I ask you. Can any of this be said to be true of the plastic drinking fountains, such as the Drinkwell, the Catit and the Petmate fountains which are nearly 100% plastic? The short answer is NO.
A handmade cat fountain with a copper 'waterflower' and a drinkwell cat fountain
cat-fountains.com 
Is there any reason one could not use a copper bowl then as the basin component of a cats drinking fountain?
None that I know of if it is the right copper, apart from the fact that cleaning might be a bit of a bother. A little spout or cat tap is one thing, an entire bowl another. Also, how would you work with the pump and pump cord? I first began making fountains from copper for home decor and had major issues getting the cord through the basin rather than over top, which to me is unacceptable.
K
Wow, this article is fastidious, my younger sister is
analyzing these things, so I am going to inform her.