Water: Water Quality Standards Academy
Deriving the CMC: Step 2—Rank the Genus Mean Acute Values
- 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
Basic Course: Supplemental Topics
Steps in the
- 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.
|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|