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.)
For students in Canada: Due to the ongoing Canada Post strike, please use UPS or FedEx to return your scantrons for grading. You may take your exams online even if you received paper exams.
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 C
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
chlorine demand
The difference between the amount of chlorine added to water or wastewater and the amount of residual chlorine remaining after a given contact time. Chlorine demand may change with dosage, time, temperature, pH, and nature and amount of the impurities in the water.
Chlorine Demand = Chlorine Applied – Chlorine Residual