The standard for drinking water is 1300 mg/l and the first area has a value of 837 µg

I am trying to figure out the hazard quotient of copper compared to the standard. The standard for drinking water is 1300 mg/l and the first area has a value of 837 µg. How do I convert this? 


I use the formula hq (hazard quotient) = contaminant (c) divided by standard (s). 
or $$HQ= \frac{C}{S}$$ I am having problems with the conversion.




I don't know what this standard or the "first area" are, but the hazard quotient is simply the ratio of potential exposure to the maximum exposure without adverse effects. You can't take the ratio of the two values you have because 1300 mg/L is a concentration and 837 µg is an absolute quantity. You need to first decide how much water your potential exposure will involve and multiply that by 1300 mg/L.


Incidentally, 1300 mg/L of copper shouldn't be any kind of standard level in drinking water. That's more like a standard solution for AAS or ICP, is definitely bright blue, and probably contains several percent of nitric acid.


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