OWP will be closed from 4:00 pm on Friday, December 20, 2024, until 8:00 am on Thursday, January 2, 2025, for Winter Break.
(All times are PST.)
| If exams are submitted: |
Course certificates will be mailed: |
| By December 13th |
By December 20th |
| After December 20th |
Early January |
Please note: Postmark dates will not be honored.
Water and Wastewater Terms Beginning P
A B C D E F G H I J K L M N O P Q R S T U V W Y Z
parts per million (ppm)
A measurement of concentration on a weight or volume basis. Parts per million by mass is equivalent to milligrams per liter. Parts per million by volume is a common way to measure concentrations of gases.
