Estimating the designated use attainment decision error rates of US Environmental Protection Agency's proposed numeric total phosphorus criteria for Florida, USA, colored lakes
✍ Scribed by Douglas B. McLaughlin
- Publisher
- Society of Environmental Toxicology and Chemistry
- Year
- 2011
- Tongue
- English
- Weight
- 285 KB
- Volume
- 8
- Category
- Article
- ISSN
- 1551-3777
- DOI
- 10.1002/ieam.223
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✦ Synopsis
Abstract
The utility of numeric nutrient criteria established for certain surface waters is likely to be affected by the uncertainty that exists in the presence of a causal link between nutrient stressor variables and designated use–related biological responses in those waters. This uncertainty can be difficult to characterize, interpret, and communicate to a broad audience of environmental stakeholders. The US Environmental Protection Agency (USEPA) has developed a systematic planning process to support a variety of environmental decisions, but this process is not generally applied to the development of national or state‐level numeric nutrient criteria. This article describes a method for implementing such an approach and uses it to evaluate the numeric total P criteria recently proposed by USEPA for colored lakes in Florida, USA. An empirical, log‐linear relationship between geometric mean concentrations of total P (a potential stressor variable) and chlorophyll a (a nutrient‐related response variable) in these lakes—that is assumed to be causal in nature—forms the basis for the analysis. The use of the geometric mean total P concentration of a lake to correctly indicate designated use status, defined in terms of a 20 µg/L geometric mean chlorophyll a threshold, is evaluated. Rates of decision errors analogous to the Type I and Type II error rates familiar in hypothesis testing, and a 3rd error rate, E~ni~, referred to as the nutrient criterion–based impairment error rate, are estimated. The results show that USEPA's proposed “baseline” and “modified” nutrient criteria approach, in which data on both total P and chlorophyll a may be considered in establishing numeric nutrient criteria for a given lake within a specified range, provides a means for balancing and minimizing designated use attainment decision errors. Integr Environ Assess Manag 2012;8:167–174. © 2011 SETAC