Page 71 - Yucaipa Valley Water District
P. 71
January 2016
THE MEASUREMENT OF WATER PURITY
One part per hundred is generally represented by the percent (%).
This is equivalent to about fifteen minutes out of one day.
One part per thousand denotes one part per 1000 parts.
This is equivalent to about one and a half minutes out of one day.
One part per million (ppm) denotes one part per 1,000,000 parts.
This is equivalent to about 32 seconds out of a year.
One part per billion (ppb) denotes one part per 1,000,000,000 parts.
This is equivalent to about three seconds out of a century.
One part per trillion (ppt) denotes one part per 1,000,000,000,000 parts.
This is equivalent to about three seconds out of every hundred thousand years.
One part per quadrillion (ppq) denotes one part per 1,000,000,000,000,000 parts.
This is equivalent to about two and a half minutes out of the age of the Earth (4.5
billion years).
Yucaipa Valley Water District - August 1, 2017 - Page 71 of 76
