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Education & TrainingTraining ProgramsWater Quality Standards AcademyDeriving the CMC: Step 2—Rank the Genus Mean Acute Values
Education & TrainingTraining ProgramsWater Quality Standards AcademyDeriving the CMC: Step 2—Rank the Genus Mean Acute ValuesDeriving the CMC: Step 2—Rank the Genus Mean Acute Values
Course Navigation
- Listing Impaired Waters and Developing TMDLs
- Monitoring & Assessment
- NPDES Permit Program
- Human Health Ambient Water Quality Criteria
- Aquatic Life Criteria
- EPA's Role
- Two Concentration-Related Criteria
- Steps in Deriving the Criteria
- Prioritizing Chemicals
- Collecting Effects Data
- Assessing Acute Effects Data
- Calculate the GMAVs
- Rank the GMAVs
- Calculate the FAV
- From FAV to CMC
- Factoring in Water Characteristics
- CCC Approach Based on Available Data
- Assessing Chronic Effects Data
- CCC Calculation of the FCV
- FCV to CCC
- Criteria Review Process
- Site-Specific Criteria
- Summary
- Quiz
Basic Course: Supplemental Topics
Steps in the
FAV Calculation
- Calculate the GMAVs.
- Rank the GMAVs.
- Calculate the FAV.
The GMAVs from the minimum eight families of aquatic organisms are then ranked based on sensitivity, from high (most resistant to the chemical) to low (most sensitive to the chemical). From this ranking, the lowest four GMAVs are used in deriving the CMC, as described in the next step.
A sample ranking of the lowest four GMAVs is presented below.
| Rank | GMAV | SMAV | |
|---|---|---|---|
| µg/L | Species | µg/L | |
| 4 | 100 | Rainbow Trout, Oncorhynchus mykiss | 100 |
| 3 | 36 | Cladoceran, Daphnia ambigua | 42 |
| Cladoceran, Daphnia pulex | 38 | ||
| Cladoceran, Daphnia magna | 29 | ||
| 2 | 25 | Amphipod, Gammarus pseudolimnaeus | 25 |
| 1 | 19 | Amphipod, Hyalella azteca | 19 |
