Mandatory certification program for wastewater treatment plant operators in the State of Washington.
Contributors: Washington (State). Dept. of Ecology.
Series: DOE -- 77-20.; Publication (Washington (State). Dept. of Ecology) -- no.  77-20.
Publisher: State of Washington, Dept. of Ecology, [1977].
Published: 1977
Place of publication: [Olympia?]
Language: eng
Number of pages: 79
Subjects: Sewage disposal plants -- Washington (State) -- Standards.; Sewage disposal plants -- Washington (State) -- Directories.
Genres: Directories.
Notes: Includes directory of certified wastewater treatment operators in Washington State.

"June 1977."