Washington State Department of Ecology

Publication Summary

Title	Washington State Dissolved Oxygen Standard: A Review and Discussion of Freshwater Intragravel Criteria Development
Month-Year Published	September 2009
Online Availability	View this publication in Acrobat PDF format 2661 kilobytes, requires version 4.0 or later of Adobe Acrobat Reader Software get Acrobat Reader
Short Description	This document presents scientific and policy information about intragravel dissolved oxygen (IGDO) criteria development. In 2006, EPA issued a Clean Water Act approval of Washington′s 2006 revision to the surface water quality standards. The approval required an Endangered Species Act condition to review the freshwater dissolved oxygen (DO) criteria. This document partially fulfills that condition and contains information on (1) the relationship between DO concentration and saturation, (2) an analysis of the Department of Ecology′s ambient DO monitoring data, (3) the environmental factors that contribute to IGDO conditions, and (4) freshwater DO criteria developed by Pacific Northwest states and tribes. (Also see abstract below)
Publication Number	09-03-039
Author(s)	Brown, C. and D. Hallock
Print Availability	Request from the program.
Number of pages	40 + app (75 total)
Keywords	aquatic, clean water act, criteria, dissolved oxygen, Ecology, Endangered Species Act, Environmental Protection Agency, freshwater, gravel, IGDO, intergravel, inter-gravel, intragravel, intra-gravel, Pacific Northwest, recommendations, salmon spawning, standards, surface water, tribe, water quality, water quality standards
Abstract	Long Description
	In 2006, the U.S. Environmental Protection Agency issued a Clean Water Act (CWA) approval of Washington′s 2006 revision to the surface water quality standards. The approval required an Endangered Species Act condition. This condition was to review the freshwater dissolved oxygen (DO) criteria contained in the standards. This document partially fulfills that condition. In addition to the direct CWA approval-based requirement to review the DO criteria, the Washington State Department of Ecology (Ecology) received recommendations from state and tribal agencies to re-evaluate Washington State′s freshwater DO criteria. These recommendations contend that the current criteria are not protective of salmon spawning and rearing. Specifically, the intragravel DO requirements for salmon embryo and larval development are of foremost concern. This document provides Ecology′s Water Quality Program with a review of issues relating to freshwater DO criteria. The report was prepared by Ecology′s Environmental Assessment Program. This document provides scientific information about the characteristics of DO in Washington streams, including: A discussion of the relationship between the DO concentration and DO saturation. An analysis of Ecology′s ambient monitoring data in relation to criteria recommended by other Pacific Northwest agencies and tribes. A discussion of current scientific knowledge about environmental factors that contribute to intragravel DO conditions. Additionally, this document provides a review of freshwater DO criteria developed by other Pacific Northwest states and tribes for the protection of salmon spawning and rearing.

This page last updated October 26, 2009

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