Water test shows copper finding of 171 ug/l with detection limit for reporting of 50 but maximum contaminant level of 1300 for action level. why the disparity? what does this finding mean for the consumer? should the consumer do something?

It probably means...: Water's trace minerals are not a topic primary care doctors are involved in unless it's a lead poisoning issue or something similar. The numbers probably mean that the lab test can reliably detect the copper as low as 50, and the Public Health department must have set the "worry" level at 1300. A better website might be the county water district website, to see if there are local water concerns.