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 S

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

substrate

(1) The base on which an organism lives. The soil is the substrate of most seed plants; rocks, soil, water, or other plants or animals are substrates for other organisms. (2) Chemical used by an organism to support growth. The organic matter in wastewater is a substrate for the organisms in activated sludge.