What does a ppm and a ppb stand for in terms of measuring water quality?

Answer 1

ppm stands for parts per million and ppb stands for parts per billion. These units are used to measure the concentration of substances in water, with 1 ppm being equivalent to 1 milligram of substance per liter of water, and 1 ppb being equivalent to 0.001 milligrams of substance per liter of water.