Copper

[Snaz]

My water guy posted his latest trace metal results and copper jumped out at me with at 0.021ppm Which is 10 times the detectable limit of the test that the independent lab used. So there was differently some copper in the water if the results are accurate albeit only 21 parts per billion.

My question is 21 ppb cause for concern?

The total conductivity of the water was 2 and I think conductivity is the same as TDS. I will have to google to confirm.

[Snaz]

So I guess TDS and Total Conductivity share similarities but they are certainly not the same.

TDS and electrical conductivity

The term TDS describes all solids (usually mineral salts) that are dissolved in water. The TDS and the electrical conductivity are in a close connection. The more salts are dissolved in the water, the higher is the value of the electric conductivity. The majority of solids, which remain in the water after a sand filter, are dissolved ions. Sodium chloride for example is found in water as Na+ and Cl-. High purity water that contains in the ideal case only H2O without salts or minerals has a very low electrical conductivity. The water temperature affects the electric conductivity so that its value increases from 2 up to 3 % per 1 degree Celsius.

http://www.lenntech.com/tds-ec_engels.htm