From looking at all my graphs, you probably don't know whether having things like iron in your water is good or bad.
It isn't very good to have iron in your household water, because it gives water some taste and also makes the water stain things.
It isn't a good idea to have too much copper in your water as well, because this can cause stomach and intestinal sickness.
The proper amount of copper and iron is below:
The MCLG level (Maximum Contaminant Level Goal) for copper is 1.3ppm. Copper can enter the water when it is going through the kilometers of metal piping.
The MCLG level for iron is 0.3 to 1ppm. Iron also causes discoloured water and it also doesn't work very well in a filter.