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 M

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

manhole grade ring

A precast concrete ring 4 to 12 inches (10 to 30 centimeters) high that is placed on top of a manhole cone to raise the manhole cover frame flush with the surface grade. Sometimes called a spacer. Also called a grade ring.