To convert a value measured in milligrams per liter (mg/L) to micrograms per liter (μg/L), move the decimal point to the right three times. Examples of this are:
0.001 mg/L is equal to 1 ug/L
0.01 mg/L is equal to 10 ug/L.
The contaminant values given to you might also be written in parts per million (ppm) and/or parts per billion (ppb). ppm numerically mirrors mg/L while ppb reflects ug/L:
0.001 mg/L is equal to 0.001 ppm
1 ug/L is equal to 1 ppb.