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GEOGRAPHIC-SPECIFIC WATER QUALITY CRITERIA DEVELOPMENT WITH MONITORING DATA USING CONDITIONAL PROBABILITIES - A PROPOSED APPROACH
Citation:
Paul, J F. AND M E. McDonald. GEOGRAPHIC-SPECIFIC WATER QUALITY CRITERIA DEVELOPMENT WITH MONITORING DATA USING CONDITIONAL PROBABILITIES - A PROPOSED APPROACH. October, JOURNAL OF AMERICAN WATER RESOURCES ASSOCIATION. American Water Resources Association, Middleburg, VA, 41(5):1211-1223, (2005).
Impact/Purpose:
To develop geographic-specific water quality criteria for the protection of aquatic life using a conditional probability approach
Description:
A conditional probability approach using monitoring data to develop geographic-specific water quality criteria for protection of aquatic life is presented. Typical methods to develop criteria using existing monitoring data are limited by two issues: (1) how to extrapolate to an entire geographic area and (2) possible bias in site selection. A conditional probability approach using survey data overcomes these issues. With this approach aquatic biological thresholds of impairment are expressed as the likelihood of exceeding a given value of a pollution metric. In the example presented, benthic community index values (EPT taxa) were used to identify impaired stream communities, and three different analytical procedures were used for identifying thresholds. Although final development of water quality standards is a management decision, scientifically defensible approaches for establishing criteria based on significant deviations from expected community condition across a wide range of geographic conditions could be a useful first step.