In addition, very low pH levels can cause severe damage to copper plumbing. One indicator of this problem is a blueish or turquoise discharge on shower tiles, toilet reservoirs, and elsewhere. This ultimately results in the deterioration of pipes. Without proper treatment, copper pipes will develop pinholes, causing leaks. While trace levels of copper in water are not harmful, highly acidic water may accumulate enough copper from eroding the pipes to pose health issues if ingested.