This is a matter of some debate, as there are pros and cons for each. PVC plumbing is much cheaper than copper plumbing, particularly since copper pipes have been increasing in cost steadily in recent years. PVC pipes are also easier to install, being lighter and more versatile. The issues arise once the system has been installed. While both PVC and copper will leach materials into the water, we do not have a full understanding of the materials leached by PVC or their effects. Copper has been in use for thousands of years, and as such there is more confidence that copper leaching is not harmful at normal levels. Plastics like PVC are relatively new, and the effects of their leached materials haven’t been as thoroughly studied yet.